The breast is one of two prominences located on the upper
ventral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...
region of a
primate
Primates are a diverse order of mammals. They are divided into the strepsirrhines, which include the lemurs, galagos, and lorisids, and the haplorhines, which include the tarsiers and the simians ( monkeys and apes, the latter including ...
's
torso
The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a huma ...
. Both females and males develop breasts from the same
embryological
Embryology (from Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logia'') is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and ...
tissues.
In females, it serves as the
mammary gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in pri ...
, which produces and secretes milk to feed
infants.
Subcutaneous fat
The subcutaneous tissue (), also called the hypodermis, hypoderm (), subcutis, superficial fascia, is the lowermost layer of the integumentary system in vertebrates. The types of cells found in the layer are fibroblasts, adipose cells, and macro ...
covers and envelops a network of
ducts that converge on the
nipple
The nipple is a raised region of tissue on the surface of the breast from which, in females, milk leaves the breast through the lactiferous ducts to feed an infant. The milk can flow through the nipple passively or it can be ejected by smooth m ...
, and these
tissues give the breast its size and shape. At the ends of the ducts are
lobules
In anatomy, a lobe is a clear anatomical division or extension of an organ (as seen for example in the brain, lung, liver, or kidney) that can be determined without the use of a microscope at the gross anatomy level. This is in contrast to the m ...
, or clusters of
alveoli, where milk is produced and stored in response to
hormonal signals.
[
] During pregnancy, the breast responds to a complex interaction of hormones, including
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
s,
progesterone, and
prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...
, that mediate the completion of its development, namely
lobuloalveolar maturation, in preparation of
lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...
and
breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...
.
Humans are the only animals with permanent breasts. At
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a bo ...
,
estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
s, in conjunction with
growth hormone
Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in h ...
, cause permanent
breast growth in female humans. This happens only to a much lesser extent in other primates—breast development in other primates generally only occurs with
pregnancy
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
. Along with their major function in providing nutrition for infants, female breasts have social and sexual characteristics. Breasts have been featured in ancient and modern sculpture, art, and photography. They can figure prominently in the perception of a woman's body and
sexual attractiveness. A number of
culture
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups ...
s associate breasts with
sexuality and tend to regard bare breasts in public as immodest or indecent. Breasts, especially the nipples, are an
erogenous zone
An erogenous zone (from Greek , ''érōs'' "love"; and English ''-genous'' "producing", from Greek , ''-genḗs'' "born") is an area of the human body that has heightened sensitivity, the stimulation of which may generate a sexual response, s ...
.
Etymology and terminology
The English word ''breast'' derives from the
Old English
Old English (, ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the early Middle Ages. It was brought to Great Britain by Anglo-Saxon settlers in the mid-5th c ...
word ('breast, bosom') from
Proto-Germanic
Proto-Germanic (abbreviated PGmc; also called Common Germanic) is the reconstructed proto-language of the Germanic branch of the Indo-European languages.
Proto-Germanic eventually developed from pre-Proto-Germanic into three Germanic bran ...
(breast), from the
Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. Its proposed features have been derived by linguistic reconstruction from documented Indo-European languages. No direct record of Proto-Indo- ...
base ' (to swell, to sprout). The ''breast'' spelling conforms to the Scottish and North English dialectal pronunciations. The ''Merriam-Webster Dictionary'' states that "
Middle English
Middle English (abbreviated to ME) is a form of the English language that was spoken after the Norman conquest of 1066, until the late 15th century. The English language underwent distinct variations and developments following the Old English ...
,
omes
The branches of science known informally as omics are various disciplines in biology whose names end in the suffix ''-omics'', such as genomics, proteomics, metabolomics, metagenomics, phenomics and transcriptomics. Omics aims at the collective ...
from Old English ; akin to
Old High German
Old High German (OHG; german: Althochdeutsch (Ahd.)) is the earliest stage of the German language, conventionally covering the period from around 750 to 1050.
There is no standardised or supra-regional form of German at this period, and Old High ...
...,
Old Irish
Old Irish, also called Old Gaelic ( sga, Goídelc, Ogham script: ᚌᚑᚔᚇᚓᚂᚉ; ga, Sean-Ghaeilge; gd, Seann-Ghàidhlig; gv, Shenn Yernish or ), is the oldest form of the Goidelic/Gaelic language for which there are extensive writt ...
elly ndRussian
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
"; the first known usage of the term was before the 12th century.
A large number of colloquial terms for breasts are used in English, ranging from fairly polite terms to vulgar or slang. Some vulgar slang expressions may be considered to be derogatory or sexist to women.
Evolutionary development
Humans are the only mammals whose breasts become permanently enlarged after
sexual maturity
Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definit ...
(known in humans as
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a bo ...
). The reason for this evolutionary change was unknown.
Several hypotheses have been put forward:
A link has been proposed to processes for synthesizing the
endogenous steroid hormone
A steroid hormone is a steroid that acts as a hormone. Steroid hormones can be grouped into two classes: corticosteroids (typically made in the adrenal cortex, hence ''cortico-'') and sex steroids (typically made in the gonads or placenta). Withi ...
precursor
dehydroepiandrosterone
Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans. DHEA is produced in the adrenal glands, the gonads, and the brain. It fun ...
which takes place in fat rich regions of the body like the buttocks and breasts. These contributed to human brain development and played a part in increasing brain size. Breast enlargement may for this purpose may have occurred as early as ''
Homo ergaster
''Homo ergaster'' is an extinct species or subspecies of archaic humans who lived in Africa in the Early Pleistocene. Whether ''H. ergaster'' constitutes a species of its own or should be subsumed into '' H. erectus'' is an ongoing and unresol ...
'' (1.7–1.4
MYA).
Other breast formation hypotheses may have then taken over as principal drivers.
It has been suggested by zoologists Avishag and
Amotz Zahavi
Amotz Zahavi ( he, אמוץ זהבי) (August 14, 1928 – May 12, 2017) was an Israeli evolutionary biologist, a Professor in the Department of Zoology at Tel Aviv University, and one of the founders of the Society for the Protection of Nature in ...
that the size of the human breasts can be explained by the
handicap theory
The handicap principle is a hypothesis proposed by the biologist Amotz Zahavi to explain how evolution may lead to "honest" or reliable signalling between animals which have an obvious motivation to bluff or deceive each other. It suggests that c ...
of
sexual dimorphism
Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...
. This would see the explanation for larger breasts as them being an
honest display of the women's health and ability to grow and carry them in her life. Prospective mates can then evaluate the genes of a potential mate for their ability to sustain her health even with the additional energy demanding burden she is carrying.
The zoologist
Desmond Morris
Desmond John Morris FLS ''hon. caus.'' (born 24 January 1928) is an English zoologist, ethologist and surrealist painter, as well as a popular author in human sociobiology. He is known for his 1967 book '' The Naked Ape'', and for his televis ...
describes a sociobiological approach in his popular science book ''
The Naked Ape
''The Naked Ape: A Zoologist's Study of the Human Animal'' is a 1967 book by English Zoology, zoologist and ethology, ethologist Desmond Morris that looks at humans as a species and compares them to other animals. ''The Human Zoo (book), The Hu ...
''. He suggests, by making comparisons with the other primates, that breasts evolved to replace swelling buttocks as a sex signal, of ovulation. He notes how humans have, relatively speaking, large penises as well as large breasts. Furthermore, early humans adopted bipedalism and face-to-face coitus. He therefore suggested enlarged sexual signals helped maintain the bond between a mated male and female even though they performed different duties and therefore were separated for lengths of time.
The study ''The Evolution of the Human Breast'' (2001) proposed that the rounded shape of a woman's breast evolved to prevent the sucking infant offspring from suffocating while feeding at the teat; that is, because of the human infant's small jaw, which did not project from the face to reach the nipple, he or she might block the
nostrils
A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbi ...
against the mother's breast if it were of a flatter form (cf.
common chimpanzee). Theoretically, as the human jaw receded into the face, the woman's body compensated with round breasts.
Ashley Montagu
Montague Francis Ashley-Montagu (June 28, 1905November 26, 1999) — born Israel Ehrenberg — was a British-American anthropologist who popularized the study of topics such as race and gender and their relation to politics and development. He ...
e (1965) proposed that breasts came about as an adaptation for infant feeding for a different reason as early human ancestors adopted bipedalism and the loss of body hair. Human upright stance meant infants must be carried at the hip or shoulder instead of on the back as in the apes. This gives the infant less opportunity to find the nipple or the purchase to cling on to the mother's body hair. The mobility of the nipple on a large breast in most human females gives the infant more ability to find grasp it and feed.
Other suggestions include simply that permanent breasts attracted mates, that "pendulous" breasts gave infants something to cling to, or that permanent breasts shared the function of a
camel's hump
Camel's Hump (alternatively Camels Hump) is a mountain in the Green Mountains in the U.S. state of Vermont. The north slope of the mountain borders the Winooski River, which has carved through the Green Mountains over eons. At , it is tied (with ...
, to store fat as an energy reserve.
Anatomy
![Breast anatomy normal scheme](https://upload.wikimedia.org/wikipedia/commons/0/0f/Breast_anatomy_normal_scheme.png)
In women, the breasts overlie the
pectoralis major muscle
The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor, ...
s and extend on average from the level of the second rib to the level of the sixth rib in the front of the
rib cage
The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels.
The sternum, together known as the thoracic cage, is a sem ...
; thus, the breasts cover much of the chest area and the chest walls. At the front of the chest, the breast tissue can extend from the
clavicle
The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the r ...
(collarbone) to the middle of the
sternum
The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sha ...
(breastbone). At the sides of the chest, the breast tissue can extend into the
axilla
The axilla (also, armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm and the thoracic cage, bounded superior ...
(armpit), and can reach as far to the back as the
latissimus dorsi muscle
The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...
, extending from the lower back to the
humerus bone (the bone of the upper arm). As a
mammary gland
A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in pri ...
, the breast is composed of differing layers of
tissue, predominantly two types:
adipose tissue
Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular ...
; and
glandular tissue, which affects the lactation functions of the breasts.
Morphologically the breast is tear-shaped.
The superficial tissue layer (
superficial fascia) is separated from the skin by 0.5–2.5 cm of subcutaneous fat (adipose tissue). The
suspensory Cooper's ligaments are fibrous-tissue prolongations that radiate from the superficial fascia to the skin envelope. The female adult breast contains 14–18 irregular lactiferous lobes that converge at the nipple. The 2.0–4.5 mm milk ducts are immediately surrounded with dense connective tissue that support the glands. Milk exits the breast through the nipple, which is surrounded by a pigmented area of skin called the areola. The size of the areola can vary widely among women. The areola contains modified
sweat glands
Sweat glands, also known as sudoriferous or sudoriparous glands, , are small tubular structures of the skin that produce sweat. Sweat glands are a type of exocrine gland, which are glands that produce and secrete substances onto an epithelial sur ...
known as
Montgomery's glands
Areolar glands, Glands of Montgomery, Glandulae areolares, Montgomery glands, Tubercula Montgomery, or Tubercula areolae are 10-15 elevations of the areola, usually arranged in a circle around the nipple, which are often particularly visible when ...
. These glands secrete oily fluid that lubricate and protect the nipple during breastfeeding.
Volatile compounds in these secretions may also serve as an olfactory stimulus for the newborn's appetite.
The dimensions and weight of the breast vary widely among women. A small-to-medium-sized breast weighs 500 grams (1.1 pounds) or less, and a large breast can weigh approximately 750 to 1,000 grams (1.7 to 2.2 pounds) or more. The tissue composition ratios of the breast also vary among women. Some women's breasts have a higher proportion of glandular tissue than of adipose or
connective tissues. The fat-to-connective-tissue ratio determines the density or firmness of the breast. During a woman's life, her breasts change size, shape, and weight due to hormonal changes during
puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a bo ...
, the
menstrual cycle, pregnancy, breastfeeding, and
menopause
Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often ...
.
Glandular structure
The breast is an
apocrine
Apocrine () glands are a type of exocrine gland, which are themselves a type of gland, i.e. a group of cells specialized for the release of secretions. Exocrine glands secrete by one of three means: holocrine, merocrine and apocrine. In apocri ...
gland that produces the
milk
Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digest solid food. Immune factors and immune-modula ...
used to feed an infant. The
nipple
The nipple is a raised region of tissue on the surface of the breast from which, in females, milk leaves the breast through the lactiferous ducts to feed an infant. The milk can flow through the nipple passively or it can be ejected by smooth m ...
of the breast is surrounded by the
areola
The human areola (''areola mammae'', or ) is the pigmented area on the breast around the nipple. Areola, more generally, is a small circular area on the Human body, body with a different histology from the surrounding Tissue (biology), tissu ...
(nipple-areola complex). The areola has many sebaceous glands, and the skin color varies from pink to dark brown. The basic units of the breast are the terminal duct lobular units (TDLUs), which produce the fatty breast milk. They give the breast its offspring-feeding functions as a mammary gland. They are distributed throughout the body of the breast. Approximately two-thirds of the lactiferous tissue is within 30 mm of the base of the nipple. The terminal lactiferous ducts drain the milk from TDLUs into 4–18 lactiferous ducts, which drain to the nipple. The milk-glands-to-fat ratio is 2:1 in a lactating woman, and 1:1 in a non-lactating woman. In addition to the milk glands, the breast is also composed of connective tissues (
collagen,
elastin), white fat, and the suspensory Cooper's ligaments. Sensation in the breast is provided by the
peripheral nervous system
The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of nerves and ganglia, which lie outside the brain ...
innervation by means of the front (anterior) and side (lateral) cutaneous branches of the fourth-, fifth-, and sixth
intercostal nerves. The T-4 nerve (
), which innervates the
dermatomic area
A dermatome is an area of skin that is mainly supplied by afferent nerve fibres from the dorsal root of any given spinal nerve.
There are 8 cervical nerves (C1 being an exception with no dermatome),
12 thoracic nerves,
5 lumbar nerves and 5 s ...
, supplies sensation to the nipple-areola complex.
Lymphatic drainage
Approximately 75% of the
lymph
Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues ...
from the breast travels to the axillary
lymph nodes on the same side of the body, whilst 25% of the lymph travels to the parasternal nodes (beside the sternum bone).
A small amount of remaining lymph travels to the other breast and to the abdominal lymph nodes. The subareolar region has a lymphatic plexus known as the "subareolar plexus of Sappey".
The
axillary lymph node
The axillary lymph nodes or armpit lymph nodes are lymph nodes in the human armpit. Between 20 and 49 in number, they drain lymph vessels from the lateral quadrants of the breast, the superficial lymph vessels from thin walls of the chest and th ...
s include the pectoral (chest), subscapular (under the scapula), and humeral (humerus-bone area) lymph-node groups, which drain to the central
axillary lymph nodes
The axillary lymph nodes or armpit lymph nodes are lymph nodes in the human armpit. Between 20 and 49 in number, they drain lymph vessels from the lateral quadrants of the breast, the superficial lymph vessels from thin walls of the chest and th ...
and to the apical axillary lymph nodes. The lymphatic drainage of the breasts is especially relevant to
oncology
Oncology is a branch of medicine that deals with the study, treatment, diagnosis and prevention of cancer. A medical professional who practices oncology is an ''oncologist''. The name's etymological origin is the Greek word ὄγκος ('' ...
because breast cancer is common to the mammary gland, and cancer cells can
metastasize
Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, then, ...
(break away) from a
tumour
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
and be dispersed to other parts of the body by means of the lymphatic system.
Shape, texture, and support
The morphologic variations in the size, shape, volume, tissue density, pectoral locale, and spacing of the breasts determine their natural shape, appearance, and position on a woman's chest. Breast size and other characteristics do not predict the fat-to-milk-gland ratio or the potential for the woman to nurse an infant. The size and the shape of the breasts are influenced by normal-life hormonal changes (thelarche, menstruation, pregnancy, menopause) and medical conditions (e.g.
virginal breast hypertrophy).
The shape of the breasts is naturally determined by the support of the suspensory Cooper's ligaments, the underlying muscle and bone structures of the chest, and by the skin envelope. The suspensory ligaments sustain the breast from the clavicle (collarbone) and the clavico-pectoral fascia (collarbone and chest) by traversing and encompassing the fat and milk-gland tissues. The breast is positioned, affixed to, and supported upon the chest wall, while its shape is established and maintained by the skin envelope. In most women, one breast is slightly larger than the other.
[ More obvious and persistent asymmetry in breast size occurs in up to 25% of women.]
While it is a common belief that breastfeeding causes breasts to sag, researchers have found that a woman's breasts sag due to four key factors: cigarette smoking, number of pregnancies, gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
, and weight loss or gain.[
*]
The base of each breast is attached to the chest by the deep fascia over the pectoralis major muscles. The space between the breast and the pectoralis major muscle, called retromammary space Retromammary space is a loose areolar tissue that separates the breast from the pectoralis major
The pectoralis major () is a thick, fan-shaped or triangular convergent muscle, situated at the chest of the human body. It makes up the bulk of the ...
, gives mobility to the breast.
The chest (thoracic cavity
The thoracic cavity (or chest cavity) is the chamber of the body of vertebrates that is protected by the thoracic wall (rib cage and associated skin, muscle, and fascia). The central compartment of the thoracic cavity is the mediastinum. There ...
) progressively slopes outwards from the thoracic inlet (atop the breastbone) and above to the lowest ribs that support the breasts. The inframammary fold, where the lower portion of the breast meets the chest, is an anatomic feature created by the adherence of the breast skin and the underlying connective tissues of the chest; the IMF is the lower-most extent of the anatomic breast. Normal breast tissue typically has a texture that feels nodular or granular, to an extent that varies considerably from woman to woman.[
]
Development
The breasts are principally composed of adipose, glandular
In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
Structure
De ...
, and connective tissues.[
] Because these tissues have hormone receptors, their sizes and volumes fluctuate according to the hormonal changes particular to thelarche (sprouting of breasts), menstruation (egg production), pregnancy (reproduction), lactation (feeding of offspring), and menopause (end of menstruation).
Puberty
The morphological structure of the human breast is identical in males and females until puberty
Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a bo ...
. For pubescent girls in thelarche (the breast-development stage), the female sex hormone
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effect ...
s (principally estrogens) in conjunction with growth hormone
Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in h ...
promote the sprouting, growth, and development of the breasts. During this time, the mammary glands grow in size and volume and begin resting on the chest. These development stages of secondary sex characteristic
Secondary sex characteristics are features that appear during puberty in humans, and at sexual maturity in other animals. These characteristics are particularly evident in the sexually dimorphic phenotypic traits that distinguish the sexes of a s ...
s (breasts, pubic hair, etc.) are illustrated in the five-stage Tanner Scale
The Tanner scale (also known as the Tanner stages or Sexual Maturity Rating (SMR)) is a scale of physical development in children, adolescents and adults. The scale defines physical measurements of development based on external primary and se ...
.
During thelarche
Thelarche, also known as breast budding, is the onset of secondary breast development, often representing the beginning of pubertal development. It is the stage at which male and female breasts differentiate due to variance in hormone levels; howe ...
the developing breasts are sometimes of unequal size, and usually the left breast is slightly larger. This condition of asymmetry is transitory and statistically normal in female physical and sexual development. Medical conditions can cause overdevelopment (e.g., virginal breast hypertrophy, macromastia
Breast hypertrophy is a rare medical condition of the breast connective tissues in which the breasts become excessively large. The condition is often divided based on the severity into two types, macromastia and gigantomastia. Hypertrophy of the ...
) or underdevelopment (e.g., tuberous breast deformity
Tuberous breasts (or tubular breasts) are a result of a congenital abnormality of the breasts which can occur in both men and women (also see Hypoplasia), one breast or both. During puberty breast development is stymied and the breasts fail to dev ...
, micromastia
Micromastia (also called hypomastia, breast aplasia, breast hypoplasia, or mammary hypoplasia) is a medical term describing the postpubertal underdevelopment of a woman's breast tissue. Just as it is impossible to define 'normal' breast size, th ...
) in girls and women.
Approximately two years after the onset of puberty (a girl's first menstrual cycle), estrogen and growth hormone stimulate the development and growth of the glandular fat and suspensory tissues that compose the breast. This continues for approximately four years until the final shape of the breast (size, volume, density) is established at about the age of 21. Mammoplasia
Mammoplasia is the normal or spontaneous enlargement of human breasts. Mammoplasia occurs normally during puberty and pregnancy in women, as well as during certain periods of the menstrual cycle. When it occurs in males, it is called gynecomastia ...
(breast enlargement) in girls begins at puberty, unlike all other primates in which breasts enlarge only during lactation.
Changes during the menstrual cycle
During the menstrual cycle, the breasts are enlarged by premenstrual water retention and temporary growth.[
]
Pregnancy and breastfeeding
The breasts reach full maturity only when a woman's first pregnancy occurs. Changes to the breasts are among the first signs of pregnancy. The breasts become larger, the nipple-areola complex becomes larger and darker, the Montgomery's glands
Areolar glands, Glands of Montgomery, Glandulae areolares, Montgomery glands, Tubercula Montgomery, or Tubercula areolae are 10-15 elevations of the areola, usually arranged in a circle around the nipple, which are often particularly visible when ...
enlarge, and veins sometimes become more visible. Breast tenderness during pregnancy is common, especially during the first trimester. By mid-pregnancy, the breast is physiologically capable of lactation and some women can express colostrum
Colostrum, also known as beestings or first milk, is the first form of milk produced by the mammary glands of mammals (including humans) immediately following delivery of the newborn. Colostrum powder is rich in high protein and low in sugar and ...
, a form of breast milk.
Pregnancy causes elevated levels of the hormone prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...
, which has a key role in the production of milk. However, milk production is blocked by the hormones progesterone and estrogen
Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...
until after delivery, when progesterone and estrogen levels plummet.
Menopause
At menopause, breast atrophy occurs. The breasts can decrease in size when the levels of circulating estrogen decline. The adipose tissue and milk glands also begin to wither. The breasts can also become enlarged from adverse side effects of combined oral contraceptive pill
The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: proges ...
s. The size of the breasts can also increase and decrease in response to weight
In science and engineering, the weight of an object is the force acting on the object due to gravity.
Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as a scalar qua ...
fluctuations. Physical changes to the breasts are often recorded in the stretch marks
Stretch marks, also known as striae () or striae distensae, are a form of scarring on the skin with an off-color hue. Over time they may diminish, but will not disappear completely. Striae are caused by tearing of the dermis during periods of r ...
of the skin envelope; they can serve as historical indicators of the increments and the decrements of the size and volume of a woman's breasts throughout the course of her life.
Breastfeeding
The primary function of the breasts, as mammary glands, is the nourishing of an infant with breast milk. Milk is produced in milk-secreting cells in the alveoli. When the breasts are stimulated by the suckling of her baby, the mother's brain secretes oxytocin. High levels of oxytocin trigger the contraction of muscle cells surrounding the alveoli, causing milk to flow along the ducts that connect the alveoli to the nipple.[
]
Full-term newborns have an instinct and a need to suck on a nipple, and breastfed babies nurse for both nutrition and for comfort. Breast milk provides all necessary nutrients for the first six months of life, and then remains an important source of nutrition, alongside solid foods, until at least one or two years of age.
Clinical significance
The breast is susceptible to numerous benign and malignant conditions. The most frequent benign conditions are puerperal mastitis, fibrocystic breast changes
Fibrocystic breast changes is a condition of the breasts where there may be pain, breast cysts, and breast masses. The breasts may be described as "lumpy" or "doughy". Symptoms may worsen during certain parts of the menstrual cycle due to hormonal ...
and mastalgia
Breast pain is the symptom of discomfort in either one or both breasts. Pain in both breasts is often described as ''breast tenderness'', is usually associated with the menstrual period and is not serious. Pain that involves only one part of a b ...
.
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...
unrelated to pregnancy is known as galactorrhea
Galactorrhea ( also spelled galactorrhoea) ( galacto- + -rrhea) or lactorrhea ( lacto- + -rrhea) is the spontaneous flow of milk from the breast, unassociated with childbirth or nursing.
Galactorrhea is reported to occur in 5–32% of women. M ...
. It can be caused by certain drugs (such as antipsychotic
Antipsychotics, also known as neuroleptics, are a class of psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but also in a range of ...
medications), extreme physical stress, or endocrine disorders. Lactation in newborns is caused by hormones from the mother that crossed into the baby's bloodstream during pregnancy.
Breast cancer
Breast cancer is the most common cause of cancer death among women and it is one of the leading causes of death among women. Factors that appear to be implicated in decreasing the risk of breast cancer are regular breast examinations by health care professionals, regular mammograms, self-examination of breasts, healthy diet, exercise to decrease excess body fat, and breastfeeding
Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...
.
Male breasts
Both females and males develop breasts from the same embryological
Embryology (from Greek ἔμβρυον, ''embryon'', "the unborn, embryo"; and -λογία, ''-logia'') is the branch of animal biology that studies the prenatal development of gametes (sex cells), fertilization, and development of embryos and ...
tissues. Normally, males produce lower levels of estrogens and higher levels of androgen
An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...
s, namely testosterone
Testosterone is the primary sex hormone and anabolic steroid in males. In humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristi ...
, which suppress the effects of estrogens in developing excessive breast tissue.
In boys and men, abnormal breast development is manifested as gynecomastia
Gynecomastia (also spelled gynaecomastia) is the abnormal non-cancerous enlargement of one or both breasts in males due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse ( ...
, the consequence of a biochemical imbalance between the normal levels of estrogen and testosterone in the male body. Around 70% of boys temporarily develop breast tissue during adolescence.[
The condition usually resolves by itself within two years.][ When ]male lactation
Production of milk (lactation) from a male mammal's mammary glands is well-documented in the Dayak fruit bat and the Bismarck masked flying fox. The term "male lactation" is not used in human medicine. It has been used in popular literature, suc ...
occurs, it is considered a symptom of a disorder of the pituitary gland
In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...
.
Plastic surgery
Plastic surgery can be performed to augment
Augment or augmentation may refer to:
Language
*Augment (Indo-European), a syllable added to the beginning of the word in certain Indo-European languages
* Augment (Bantu languages), a morpheme that is prefixed to the noun class prefix of nouns ...
or reduce the size of breasts, or reconstruct the breast in cases of deformative disease, such as breast cancer. Breast augmentation and breast lift (mastopexy
Mastopexy (Greek μαστός ''mastos'' "breast" + -pēxiā "affix") is the plastic surgery mammoplasty procedure for raising sagging breasts upon the chest of the woman, by changing and modifying the size, contour, and elevation of the breasts. ...
) procedures are done only for cosmetic reasons, whereas breast reduction is sometimes medically indicated.[
In cases where a woman's breasts are severely asymmetrical, surgery can be performed to either enlarge the smaller breast, reduce the size of the larger breast, or both.][
Breast augmentation surgery generally does not interfere with future ability to breastfeed. Breast reduction surgery more frequently leads to decreased sensation in the nipple-areola complex, and to low milk supply in women who choose to breastfeed. Implants can interfere with mammography (breast x-rays images).
]
Society and culture
General
In Christian iconography
Iconography, as a branch of art history, studies the identification, description and interpretation of the content of images: the subjects depicted, the particular compositions and details used to do so, and other elements that are distinct fro ...
, some works of art depict women with their breasts in their hands or on a platter, signifying that they died as a martyr by having their breasts severed; one example of this is Saint Agatha of Sicily
Agatha of Sicily () is a Christian saint. Her Calendar of saints, feast is on 5 February. Agatha was born in Catania, part of the Sicilia (Roman province), Roman Province of Sicily, and was martyred . She is one of several virgin martyrs who are ...
.
Femen is a feminist activist group which uses topless protests as part of their campaigns against sex tourism[Femen wants to move from public exposure to political power]
, ''Kyiv Post
The ''Kyiv Post'' is the oldest English-language newspaper in Ukraine, founded in October 1995 by Jed Sunden.
History
American Jed Sunden founded the ''Kyiv Post'' weekly newspaper on Oct. 18, 1995 and later created KP Media for his holdings. ...
'' (28 April 2010) religious institutions,[Ukraine's Femen:Topless protests 'help feminist cause']
, BBC News
BBC News is an operational business division of the British Broadcasting Corporation (BBC) responsible for the gathering and broadcasting of news and current affairs in the UK and around the world. The department is the world's largest broad ...
(23 October 2012) sexism
Sexism is prejudice or discrimination based on one's sex or gender. Sexism can affect anyone, but it primarily affects women and girls.There is a clear and broad consensus among academic scholars in multiple fields that sexism refers pri ...
, and homophobia. Femen activists have been regularly detained by police in response to their protests.[Femen activists jailed in Tunisia for topless protest]
, BBC News
BBC News is an operational business division of the British Broadcasting Corporation (BBC) responsible for the gathering and broadcasting of news and current affairs in the UK and around the world. The department is the world's largest broad ...
(12 June 2013)
There is a long history of female breasts being used by comedians as a subject for comedy fodder (e.g., British comic Benny Hill's burlesque/slapstick routines).
Art history
In European pre-historic societies, sculptures of female figures with pronounced or highly exaggerated breasts were common. A typical example is the so-called Venus of Willendorf
The Venus of Willendorf is an Venus figurine estimated to have been made around 25,000-30,000 years ago. It was found on August 7, 1908, by a workman named Johann Veran or Josef Veram during excavations conducted by archaeologists Josef Szombat ...
, one of many Paleolithic Venus figurines
A Venus figurine is any Upper Palaeolithic statuette portraying a woman, usually carved in the round.Fagan, Brian M., Beck, Charlotte, "Venus Figurines", ''The Oxford Companion to Archaeology'', 1996, Oxford University Press, pp. 740–741 Most ...
with ample hips and bosom. Artifacts such as bowls, rock carvings and sacred statues with breasts have been recorded from 15,000 BC up to late antiquity all across Europe, North Africa and the Middle East.
Many female deities representing love and fertility were associated with breasts and breast milk. Figures of the Phoenician goddess Astarte
Astarte (; , ) is the Hellenized form of the Ancient Near Eastern goddess Ashtart or Athtart ( Northwest Semitic), a deity closely related to Ishtar ( East Semitic), who was worshipped from the Bronze Age through classical antiquity. The name ...
were represented as pillars studded with breasts. Isis
Isis (; ''Ēse''; ; Meroitic: ''Wos'' 'a''or ''Wusa''; Phoenician: 𐤀𐤎, romanized: ʾs) was a major goddess in ancient Egyptian religion whose worship spread throughout the Greco-Roman world. Isis was first mentioned in the Old Kin ...
, an Egyptian goddess who represented, among many other things, ideal motherhood, was often portrayed as suckling pharaohs
Pharaoh (, ; Egyptian: '' pr ꜥꜣ''; cop, , Pǝrro; Biblical Hebrew: ''Parʿō'') is the vernacular term often used by modern authors for the kings of ancient Egypt who ruled as monarchs from the First Dynasty (c. 3150 BC) until the ...
, thereby confirming their divine status as rulers. Even certain male deities representing regeneration and fertility were occasionally depicted with breast-like appendices, such as the river god Hapy
Hapi ( Ancient Egyptian: ''ḥʿpy'') was the god of the annual flooding of the Nile in ancient Egyptian religion. The flood deposited rich silt (fertile soil) on the river's banks, allowing the Egyptians to grow crops.Wilkinson, p.106 Hapi was gre ...
who was considered to be responsible for the annual overflowing of the Nile
The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest ...
.
Female breasts were also prominent in Minoan art
Minoan art is the art produced by the Bronze Age Aegean Minoan civilization from about 3000 to 1100 BC, though the most extensive and finest survivals come from approximately 2300 to 1400 BC. It forms part of the wider grouping of Aegean art ...
in the form of the famous Snake Goddess A snake goddess is a goddess associated with a snake theme.
Examples include:
* Meretseger ("She Who Loves Silence"), Egyptian snake goddess
* Minoan snake goddess figurines, a type of figurine in Minoan archaeology
*Renenutet, Egyptian snake godde ...
statuettes, and a few other pieces, though most female breasts are covered. In Ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean Sea, Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of Classical Antiquity, classical antiquity ( AD 600), th ...
there were several cults worshipping the "Kourotrophos", the suckling mother, represented by goddesses such as Gaia, Hera and Artemis
In ancient Greek mythology and religion, Artemis (; grc-gre, Ἄρτεμις) is the goddess of the hunt, the wilderness, wild animals, nature, vegetation, childbirth, care of children, and chastity. She was heavily identified wit ...
. The worship of deities symbolized by the female breast in Greece became less common during the first millennium. The popular adoration of female goddesses decreased significantly during the rise of the Greek city states, a legacy which was passed on to the later Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post- Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediter ...
.
During the middle of the first millennium BC, Greek culture experienced a gradual change in the perception of female breasts. Women in art were covered in clothing from the neck down, including female goddesses like Athena
Athena or Athene, often given the epithet Pallas, is an ancient Greek religion, ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretism, syncretized with the Roman goddess Minerva. Athena was regarded ...
, the patron of Athens who represented heroic endeavor. There were exceptions: Aphrodite
Aphrodite ( ; grc-gre, Ἀφροδίτη, Aphrodítē; , , ) is an ancient Greek goddess associated with love, lust, beauty, pleasure, passion, and procreation. She was syncretized with the Roman goddess . Aphrodite's major symbols inclu ...
, the goddess of love, was more frequently portrayed fully nude, though in postures that were intended to portray shyness or modesty, a portrayal that has been compared to modern pin ups
''Pin Ups'' (also referred to as ''Pinups'' and ''Pin-Ups'') is the seventh studio album by English musician David Bowie, released on 19October 1973 through RCA Records. Devised as a "stop-gap" album to appease his record label, it is a cove ...
by historian Marilyn Yalom
Marilyn Yalom (March 10, 1932 – November 20, 2019) was a feminist author and historian. She was a senior scholar at the Clayman Institute for Gender Research at Stanford University, and a professor of French. She served as the institute's dire ...
. Although nude men were depicted standing upright, most depictions of female nudity in Greek art occurred "usually with drapery near at hand and with a forward-bending, self-protecting posture". A popular legend at the time was of the Amazons, a tribe of fierce female warriors who socialized with men only for procreation and even removed one breast to become better warriors (the idea being that the right breast would interfere with the operation of a bow and arrow). The legend was a popular motif in art during Greek and Roman antiquity and served as an antithetical cautionary tale.
File:Θεά των Όφεων 6393 (cropped).JPG, A Cretan snake goddess from the Minoan civilization, BC
File:Robert Dampier's oil on canvas painting 'Tetuppa, a Native Female of the Sandwich Islands', 1825.jpg, 1825 oil painting entitled ''Tetuppa, a Native Female of the Sandwich Islands'', by Robert Dampier
Body image
Many women regard their breasts as important to their sexual attractiveness, as a sign of femininity
Femininity (also called womanliness) is a set of attributes, behaviors, and roles generally associated with women and girls. Femininity can be understood as socially constructed, and there is also some evidence that some behaviors considered f ...
that is important to their sense of self
In the psychology of self, one's self-concept (also called self-construction, self-identity, self-perspective or self-structure) is a collection of beliefs about oneself. Generally, self-concept embodies the answer to the question ''"Who am I? ...
. A woman with smaller breasts may regard her breasts as less attractive.
Clothing
Because breasts are mostly fatty tissue, their shape can—within limits—be molded by clothing, such as foundation garment
image:Kim_Kardashian_at_Madame_Tussauds.jpg, Kim Kardashian in Shapewear-dress
A foundation garment (also known as shapewear or shaping underwear) is an undergarment designed to impermanently alter the wearer's female body shape, body shape, t ...
s. Bras
A broadband remote access server (BRAS, B-RAS or BBRAS) routes traffic to and from broadband remote access devices such as digital subscriber line access multiplexers (DSLAM) on an Internet service provider's (ISP) network. BRAS can also be refe ...
are commonly worn by about 90% of Western women, and are often worn for support. The social norm in most Western culture
Leonardo da Vinci's ''Vitruvian Man''. Based on the correlations of ideal Body proportions">human proportions with geometry described by the ancient Roman architect Vitruvius in Book III of his treatise ''De architectura''.
image:Plato Pio-Cle ...
s is to cover breasts in public, though the extent of coverage varies depending on the social context. Some religions ascribe a special status to the female breast, either in formal teachings or through symbolism. Islam forbids free women from exposing their breasts in public.
Many cultures, including Western cultures in North America, associate breasts with sexuality and tend to regard bare breasts as immodest or indecent. In some cultures, like the Himba in northern Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
, bare-breasted women are normal. In some African cultures, for example, the thigh
In human anatomy, the thigh is the area between the hip ( pelvis) and the knee. Anatomically, it is part of the lower limb.
The single bone in the thigh is called the femur. This bone is very thick and strong (due to the high proportion of ...
is regarded as highly sexualised and never exposed in public, but breast exposure is not taboo. In a few Western countries
The Western world, also known as the West, primarily refers to the various nations and states in the regions of Europe, North America, and Oceania. and regions female toplessness
Toplessness refers to the state in which a woman's breasts, including her areolas and nipples, are exposed, especially in a public place or in a visual medium. The male equivalent is barechestedness, also commonly called shirtlessness.
Expose ...
at a beach is acceptable, although it may not be acceptable in the town center.
Social attitudes and laws regarding breastfeeding in public vary widely. In many countries, breastfeeding in public is common, legally protected, and generally not regarded as an issue. However, even though the practice may be legal or socially accepted, some mothers may nevertheless be reluctant to expose a breast in public to breastfeed due to actual or potential objections by other people, negative comments, or harassment. It is estimated that around 63% of mothers across the world have publicly breast-fed. Bare-breasted women are legal and culturally acceptable at public beaches in Australia and much of Europe. Filmmaker Lina Esco made a film entitled ''Free the Nipple
Free the Nipple is a topfreedom campaign created in 2012 during pre-production of a 2014 film of the same name. The campaign highlights the general convention of allowing men to appear topless in public while considering it sexual or indecent f ...
'', which is about "...laws against female toplessness or restrictions on images of female, but not male, nipples", which Esco states is an example of sexism
Sexism is prejudice or discrimination based on one's sex or gender. Sexism can affect anyone, but it primarily affects women and girls.There is a clear and broad consensus among academic scholars in multiple fields that sexism refers pri ...
in society.[
]
Sexual characteristic
In some cultures, breasts play a role in human sexual activity
Human sexual activity, human sexual practice or human sexual behaviour is the manner in which humans experience and express their sexuality. People engage in a variety of sexual acts, ranging from activities done alone (e.g., masturbation) t ...
. In Western culture, breasts have a "...hallowed sexual status, arguably more fetishized than either sex's genitalia". Breasts and especially the nipples are among the various human erogenous zone
An erogenous zone (from Greek , ''érōs'' "love"; and English ''-genous'' "producing", from Greek , ''-genḗs'' "born") is an area of the human body that has heightened sensitivity, the stimulation of which may generate a sexual response, s ...
s. They are sensitive to the touch as they have many nerve endings; and it is common to press or massage
Massage is the manipulation of the body's soft tissues. Massage techniques are commonly applied with hands, fingers, elbows, knees, forearms, feet or a device. The purpose of massage is generally for the treatment of body stress or pain. In E ...
them with hands or orally before or during sexual activity. During sexual arousal, breast size increases, venous
Veins are blood vessels in humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated ...
patterns across the breasts become more visible, and nipples harden. Compared to other primates, human breasts are proportionately large throughout adult females' lives. Some writers have suggested that they may have evolved as a visual signal of sexual maturity and fertility.
Many people regard bare female breasts to be aesthetically pleasing or erotic, and they can elicit heightened sexual desire
Sexual desire is an emotion and motivational state characterized by an interest in sexual objects or activities, or by a drive to seek out sexual objects or to engage in sexual activities. It is an aspect of sexuality, which varies significantly f ...
s in men in many cultures. In the ancient Indian work the ''Kama Sutra
The ''Kama Sutra'' (; sa, कामसूत्र, , ; ) is an ancient Indian Sanskrit text on sexuality, eroticism and emotional fulfillment in life. Attributed to Vātsyāyana, the ''Kama Sutra'' is neither exclusively nor predominantly ...
'', light scratching of the breasts with nails and biting with teeth are considered erotic. Some people show a sexual interest
Sexual attraction is attraction on the basis of sexual desire or the quality of arousing such interest. Sexual attractiveness or sex appeal is an individual's ability to attract other people sexually, and is a factor in sexual selection or mat ...
in female breasts distinct from that of the person, which may be regarded as a breast fetish. A number of Western fashions include clothing which accentuate the breasts, such as the use of push-up bra
There are a great many brassiere designs that are suitable for a wide variety of business and social settings and suitable to wear with a variety of outer clothing. The bra's shape, coverage, functionality, fit, fashion, fabric, and colour can ...
s and decollete (plunging neckline) gowns and blouses which show cleavage. While U.S. culture prefers breasts that are youthful and upright, some cultures venerate women with drooping breasts, indicating mothering and the wisdom of experience.
Research conducted at the Victoria University of Wellington
Victoria University of Wellington ( mi, Te Herenga Waka) is a university in Wellington, New Zealand. It was established in 1897 by Act of Parliament, and was a constituent college of the University of New Zealand.
The university is well kno ...
showed that breasts are often the first thing men look at, and for a longer time than other body parts. The writers of the study had initially speculated that the reason for this is due to endocrinology
Endocrinology (from '' endocrine'' + '' -ology'') is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental event ...
with larger breasts indicating higher levels of estrogen and a sign of greater fertility, but the researchers said that "Men may be looking more often at the breasts because they are simply aesthetically pleasing, regardless of the size."
Some women report achieving an orgasm
Orgasm (from Greek , ; "excitement, swelling") or sexual climax is the sudden discharge of accumulated sexual excitement during the sexual response cycle, resulting in rhythmic, involuntary muscular contractions in the pelvic region chara ...
from nipple stimulation, but this is rare. Research suggests that the orgasms are genital orgasms, and may also be directly linked to "the genital area of the brain". In these cases, it seems that sensation from the nipples travels to the same part of the brain as sensations from the vagina, clitoris and cervix. Nipple stimulation may trigger uterine contractions, which then produce a sensation in the genital area of the brain.[
*]
Anthropomorphic geography
There are many mountains named after the breast because they resemble it in appearance and so are objects of religious and ancestral veneration as a fertility symbol and of well-being. In Asia, there was "Breast Mountain", which had a cave where the Buddhist monk Bodhidharma (Da Mo) spent much time in meditation
Meditation is a practice in which an individual uses a technique – such as mindfulness, or focusing the mind on a particular object, thought, or activity – to train attention and awareness, and achieve a mentally clear and emotionally calm ...
. Other such breast mountains are Mount Elgon on the Uganda
}), is a landlocked country in East Africa. The country is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the south by Tanzania. The sou ...
–Kenya
)
, national_anthem = " Ee Mungu Nguvu Yetu"()
, image_map =
, map_caption =
, image_map2 =
, capital = Nairobi
, coordinates =
, largest_city = Nairobi
...
border; and the Maiden Paps in Scotland; the ('Maiden's breast mountains') in Talim Island
Talim Island is the largest lake island in Laguna de Bay, the largest lake in the Philippines. The hilly island is within the boundaries of the Province of Rizal, under the jurisdiction of two municipalities. The western side is part of the mu ...
, Philippines, the twin hills known as the Paps of Anu
The Paps of Anu ( ga, Dá Chích Anann, "the breasts of Anu") are a pair of breast-shaped mountains near Killarney in County Kerry, Ireland. The eastern summit, The Paps East, is high and the western top, The Paps West is high.
The mountain ...
( or 'the breasts of Anu'), near Killarney
Killarney ( ; ga, Cill Airne , meaning 'church of sloes') is a town in County Kerry, southwestern Ireland. The town is on the northeastern shore of Lough Leane, part of Killarney National Park, and is home to St Mary's Cathedral, Ross Cast ...
in Ireland; the 2,086 m high or in the , Spain; in Thailand, in Puerto Rico
Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
; and the Breasts of Aphrodite in Mykonos
Mykonos (, ; el, Μύκονος ) is a Greek island, part of the Cyclades, lying between Tinos, Syros, Paros and Naxos. The island has an area of and rises to an elevation of at its highest point. There are 10,134 inhabitants according to th ...
, among many others. In the United States, the Teton Range
The Teton Range is a mountain range of the Rocky Mountains in North America. It extends for approximately in a north–south direction through the U.S. state of Wyoming, east of the Idaho state line. It is south of Yellowstone National Park and ...
is named after the French word for 'nipple'.
See also
*
*
* Udder
An udder is an organ formed of two or four mammary glands on the females of dairy animals and ruminants such as cattle, goats, and sheep. An udder is equivalent to the breast in primates and elephantine pachyderms. The udder is a single mass han ...
References
Bibliography
*
* Morris, Desmond
Desmond John Morris FLS ''hon. caus.'' (born 24 January 1928) is an English zoologist, ethologist and surrealist painter, as well as a popular author in human sociobiology. He is known for his 1967 book ''The Naked Ape'', and for his televisi ...
''The Naked Ape: a zoologist's study of the human animal'' Bantam Books, Canada. 1967
*
*
*
External links
*
{{Authority control
Breastfeeding
Human sexuality