![1511 The Limbic Lobe](https://upload.wikimedia.org/wikipedia/commons/7/7a/1511_The_Limbic_Lobe.jpg)
In
vertebrate
Vertebrates () comprise all animal taxa within the subphylum Vertebrata () (chordates with backbones), including all mammals, birds, reptiles, amphibians, and fish. Vertebrates represent the overwhelming majority of the phylum Chordata, with c ...
anatomy
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having it ...
, the pituitary gland, or hypophysis, is an
endocrine gland
Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, ...
, about the size of a
chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
at the base of the
brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...
. The hypophysis rests upon the
hypophyseal fossa
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric ...
of the
sphenoid bone in the center of the
middle cranial fossa
The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest.
It is bounded in front by the pos ...
and is surrounded by a small bony cavity (
sella turcica
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalome ...
) covered by a
dural
Dural is a suburb of Sydney, in the state of New South Wales, Australia 36 kilometres north-west of the Sydney central business district in the local government areas of Hornsby Shire and The Hills Shire. Dural is part of the Hills District ...
fold (
diaphragma sellae
The diaphragma sellae or sellar diaphragm is a flat piece of dura mater with a circular hole allowing the vertical passage of the pituitary stalk. It retains the pituitary gland beneath it in the fossa hypophyseos as it almost completely roofs th ...
).
The
anterior pituitary (or adenohypophysis) is a lobe of the gland that regulates several physiological processes including stress, growth, reproduction, and
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 ...
. The
intermediate lobe
Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary. It contains colloid-filled cysts and two types of cells - basophils and chromophobes. The cysts are the remainder of Rathke’s pouch.
In human fetal
...
synthesizes and secretes
melanocyte-stimulating hormone
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating ...
. The
posterior pituitary
The posterior pituitary (or neurohypophysis) is the posterior lobe of the pituitary gland which is part of the endocrine system. The posterior pituitary is not glandular as is the anterior pituitary. Instead, it is largely a collection of axonal ...
(or neurohypophysis) is a lobe of the gland that is functionally connected to the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
by the
median eminence
The median eminence, part of the inferior boundary of the hypothalamus in the brain, is attached to the infundibulum. The median eminence is a small swelling on the tuber cinereum, posterior to and atop the pituitary stalk; it lies in the area rou ...
via a small tube called the
pituitary stalk
The pituitary stalk (also known as the infundibular stalk, Fenderson's funnel, or simply the infundibulum) is the connection between the hypothalamus and the posterior pituitary. The floor of the third ventricle is prolonged downward as a funnel- ...
(also called the infundibular stalk or the infundibulum).
Hormone
A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are require ...
s secreted from the pituitary gland help to control
growth,
blood pressure, energy management, all functions of the
sex organ
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
s,
thyroid glands and
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
as well as some aspects of
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 ...
,
childbirth
Childbirth, also known as labour and delivery, is the ending of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million births glob ...
,
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 ...
,
water/salt concentration at the
kidneys
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...
, temperature regulation and pain relief.
Structure
The pituitary gland, in humans, is oval in shape and is a pea-sized gland that sits in a protective bony enclosure called the
sella turcica
The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalome ...
. It is composed of two lobes:
anterior and
posterior, with the
intermediate lobe that joins the two regions. In many animals, these three lobes are distinct. The
intermediate is
avascular and almost absent in human beings. The intermediate lobe is present in many animal species, in particular in rodents, mice and rats, that have been used extensively to study pituitary development and function.
In all animals, the fleshy, glandular
anterior pituitary is distinct from the neural composition of the
posterior pituitary
The posterior pituitary (or neurohypophysis) is the posterior lobe of the pituitary gland which is part of the endocrine system. The posterior pituitary is not glandular as is the anterior pituitary. Instead, it is largely a collection of axonal ...
, which is an extension of the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
.
![Pituitary gland histology 2014](https://upload.wikimedia.org/wikipedia/commons/1/1a/Pituitary_gland_histology_2014.jpg)
The height of the pituitary gland ranges from 5.3 to 7.0 mm. The volume of the pituitary gland ranges from 200 to 440 mm
3.
Anterior
The anterior pituitary arises from an
invagination
Invagination is the process of a surface folding in on itself to form a cavity, pouch or tube. In developmental biology, invagination is a mechanism that takes place during gastrulation. This mechanism or cell movement happens mostly in the vegeta ...
of the oral
ectoderm (
Rathke's pouch
In embryogenesis, Rathke's pouch is an evagination at the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis), a part of the endocrine system.
Development
Rathke's pou ...
). This contrasts with the
posterior pituitary
The posterior pituitary (or neurohypophysis) is the posterior lobe of the pituitary gland which is part of the endocrine system. The posterior pituitary is not glandular as is the anterior pituitary. Instead, it is largely a collection of axonal ...
, which originates from
neuroectoderm
Neuroectoderm (or neural ectoderm or neural tube epithelium) consists of cells derived from ectoderm. Formation of the neuroectoderm is first step in the development of the nervous system. The neuroectoderm receives bone morphogenetic protein-inhi ...
.
Endocrine cells of the anterior pituitary are controlled by regulatory hormones released by
parvocellular neurosecretory cell
Parvocellular neurosecretory cells are small neurons within paraventricular nucleus (PVN) of the hypothalamus. The axons of the parvocellular neurosecretory cells of the PVN project to the median eminence, at the base of the brain, where their ne ...
s in the hypothalamic capillaries leading to infundibular blood vessels, which in turn lead to a second capillary bed in the anterior pituitary. This vascular relationship constitutes the
hypothalamo-hypophyseal portal system. Diffusing out of the second capillary bed, the hypothalamic
releasing hormone
Releasing hormones and inhibiting hormones are hormones whose main purpose is to control the release of other hormones, either by stimulating or inhibiting their release. They are also called liberins () and statins () (respectively), or releasing ...
s then bind to anterior pituitary endocrine cells, upregulating or downregulating their release of hormones.
The anterior lobe of the pituitary can be divided into the
pars tuberalis (pars infundibularis) and
pars distalis (pars glandularis) that constitutes ~80% of the gland. The
pars intermedia (the intermediate lobe) lies between the pars distalis and the pars tuberalis, and is rudimentary in the human, although in other species it is more developed.
It develops from a depression in the dorsal wall of the
pharynx
The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st ...
(stomal part) known as
Rathke's pouch
In embryogenesis, Rathke's pouch is an evagination at the roof of the developing mouth in front of the buccopharyngeal membrane. It gives rise to the anterior pituitary (adenohypophysis), a part of the endocrine system.
Development
Rathke's pou ...
.
The
anterior pituitary contains several different types of cells that synthesize and secrete hormones. Usually there is one type of cell for each major hormone formed in
anterior pituitary. With special stains attached to high-affinity antibodies that bind with distinctive hormone, at least 5 types of cells can be differentiated.
Posterior
The posterior lobe develops as an extension of the hypothalamus, from the floor of the
third ventricle
The third ventricle is one of the four connected ventricles of the ventricular system within the mammalian brain. It is a slit-like cavity formed in the diencephalon between the two thalami, in the midline between the right and left lateral ...
. The posterior pituitary hormones are synthesized by cell bodies in the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
. The
magnocellular neurosecretory cell
Magnocellular neurosecretory cells are large neuroendocrine cells within the supraoptic nucleus and paraventricular nucleus of the hypothalamus. They are also found in smaller numbers in accessory cell groups between these two nuclei, the larges ...
s, of the supraoptic and paraventricular nuclei located in the hypothalamus, project axons down the infundibulum to terminals in the posterior pituitary. This simple arrangement differs sharply from that of the adjacent anterior pituitary, which does not develop from the hypothalamus.
The release of pituitary hormones by both the anterior and posterior lobes is under the control of the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
, albeit in different ways.
Functions
![Pituiary gland - regulatory hormones](https://upload.wikimedia.org/wikipedia/commons/9/95/Pituiary_gland_-_regulatory_hormones.png)
Anterior
The anterior pituitary synthesizes and secretes hormones. All releasing hormones (-RH) referred to, can also be referred to as releasing factors (-RF).
Somatotropes:
*
Human growth hormone (HGH), also referred to as 'growth hormone' (GH), and also as somatotropin, is released under the influence of hypothalamic
growth hormone-releasing hormone (GHRH), and is
inhibited by hypothalamic
somatostatin.
Corticotropes:
* Cleaved from the precursor
proopiomelanocortin
Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. POMC is synthesized in corticotrophs of the anterior pituitary from the 267-amino-acid-long polypeptide precursor pre-pro-opiomelanocortin (pre-POMC), by the ...
protein, and include
adrenocorticotropic hormone
Adrenocorticotropic hormone (ACTH; also adrenocorticotropin, corticotropin) is a polypeptide tropic hormone produced by and secreted by the anterior pituitary gland. It is also used as a medication and diagnostic agent. ACTH is an important c ...
(ACTH), and
beta-endorphin
''beta''-Endorphin (β-endorphin) is an endogenous opioid neuropeptide and peptide hormone that is produced in certain neurons within the central nervous system and peripheral nervous system. It is one of three endorphins that are produced in ...
, and
melanocyte-stimulating hormone
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating ...
are released under the influence of hypothalamic corticotropin-releasing hormone (CRH).
Thyrotropes:
*
Thyroid-stimulating hormone
Thyroid-stimulating hormone (also known as thyrotropin, thyrotropic hormone, or abbreviated TSH) is a pituitary hormone that stimulates the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3) which stimulates the metabolism ...
(TSH), is released under the influence of
hypothalamic thyrotropin-releasing hormone
Thyrotropin-releasing hormone (TRH) is a hypophysiotropic hormone produced by neurons in the hypothalamus that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary.
TRH has been used clinicall ...
(TRH) and is inhibited by somatostatin.
Gonadotropes:
*
Luteinizing hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) ...
(LH).
*
Follicle-stimulating hormone (FSH), both released under influence of Gonadotropin-releasing Hormone (GnRH)
Lactotropes:
*
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 ...
(PRL), whose release is inconsistently stimulated by hypothalamic TRH, oxytocin, vasopressin, vasoactive intestinal peptide, angiotensin II, neuropeptide Y, galanin, substance P, bombesin-like peptides (gastrin-releasing peptide, neuromedin B and C), and neurotensin, and inhibited by hypothalamic dopamine.
These hormones are released from the anterior pituitary under the influence of the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
. Hypothalamic hormones are secreted to the anterior lobe by way of a special
capillary
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the bod ...
system, called the
hypothalamic-hypophysial portal system.
There is also a non-endocrine cell population called
folliculostellate cells.
Intermediate
The intermediate lobe synthesizes and secretes the following important endocrine hormone:
*
Melanocyte–stimulating hormone (MSH). This is also produced in the anterior lobe. When produced in the intermediate lobe, MSHs are sometimes called "intermedins".
Posterior
The posterior pituitary stores and secretes (but does not synthesize) the following important endocrine hormones:
Magnocellular neurons:
*
Antidiuretic hormone (ADH, also known as
vasopressin
Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then trave ...
and arginine vasopressin AVP), the majority of which is released from the
supraoptic nucleus
The supraoptic nucleus (SON) is a nucleus of magnocellular neurosecretory cells in the hypothalamus of the mammalian brain. The nucleus is situated at the base of the brain, adjacent to the optic chiasm. In humans, the SON contains about 3,000 n ...
in the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
.
*
Oxytocin, most of which is released from the
paraventricular nucleus
The paraventricular nucleus (PVN, PVA, or PVH) is a nucleus in the hypothalamus. Anatomically, it is adjacent to the third ventricle and many of its neurons project to the posterior pituitary. These projecting neurons secrete oxytocin and a smaller ...
in the
hypothalamus
The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
. Oxytocin is one of the few hormones to create a
positive feedback
Positive feedback (exacerbating feedback, self-reinforcing feedback) is a process that occurs in a feedback loop which exacerbates the effects of a small disturbance. That is, the effects of a perturbation on a system include an increase in th ...
loop. For example, uterine contractions stimulate the release of oxytocin from the posterior pituitary, which, in turn, increases uterine contractions. This positive feedback loop continues throughout labour.
Hormones
Hormones secreted from the pituitary gland help control the following body processes:
*
Growth (GH)
*
Blood pressure
* Some aspects of
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 ...
and
childbirth
Childbirth, also known as labour and delivery, is the ending of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million births glob ...
including stimulation of
uterine contractions
Uterine contractions are muscle contractions of the uterine smooth muscle that occur during the menstrual cycle and labour. Uterine contractions occur throughout the menstrual cycle in the non-pregnant state and throughout gestation.
Throughout ...
*
Breast milk production
*
Sex organ
A sex organ (or reproductive organ) is any part of an animal or plant that is involved in sexual reproduction. The reproductive organs together constitute the reproductive system. In animals, the testis in the male, and the ovary in the female, a ...
functions in both
sex
Sex is the trait that determines whether a sexually reproducing animal or plant produces male or female gametes. Male plants and animals produce smaller mobile gametes (spermatozoa, sperm, pollen), while females produce larger ones ( ova, of ...
es
*
Thyroid gland function
*
Metabolic conversion of food into
energy
In physics, energy (from Ancient Greek: ἐνέργεια, ''enérgeia'', “activity”) is the quantitative property that is transferred to a body or to a physical system, recognizable in the performance of work and in the form of hea ...
*
Water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
and
osmolarity
Osmotic concentration, formerly known as osmolarity, is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per litre (L) of solution (osmol/L or Osm/L). The osmolarity of a solution is usually expressed as Osm/L ...
regulation in the body
* Water balance via the control of reabsorption of
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
by the
kidneys
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...
* Temperature regulation
*
Pain relief
Clinical significance
![Acromegaly hands](https://upload.wikimedia.org/wikipedia/commons/4/47/Acromegaly_hands.JPEG)
Some of the diseases involving the pituitary gland are:
*
Central diabetes insipidus
Central diabetes insipidus, also called neurogenic diabetes insipidus, is a type of diabetes insipidus due to a lack of vasopressin (ADH) production in the brain. Vasopressin acts to increase the volume of blood (intravascularly), and decrease ...
caused by a deficiency of
vasopressin
Human vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the AVP gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It then trave ...
*
Gigantism and
acromegaly caused by an excess of growth hormone in childhood and adult, respectively
*
Hypothyroidism caused by a deficiency of
thyroid-stimulating hormone
Thyroid-stimulating hormone (also known as thyrotropin, thyrotropic hormone, or abbreviated TSH) is a pituitary hormone that stimulates the thyroid gland to produce thyroxine (T4), and then triiodothyronine (T3) which stimulates the metabolism ...
*
Hyperpituitarism, the increased (hyper) secretion of one or more of the hormones normally produced by the pituitary gland
*
Hypopituitarism
Hypopituitarism is the decreased (''hypo'') secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the brain. If there is decreased secretion of one specific pituitary hormone, the condition is know ...
, the decreased (hypo) secretion of one or more of the hormones normally produced by the pituitary gland
*
Panhypopituitarism a decreased secretion of most of the pituitary hormones
*
Pituitary tumour
Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.[Pituitary adenoma
Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.][tumor
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 ...]
s that occur in the pituitary gland
All of the functions of the pituitary gland can be adversely affected by an over- or under-production of associated hormones.
The pituitary gland is important for mediating the stress response, via the
hypothalamic–pituitary–adrenal axis
The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a ...
(HPA axis) Critically, pituitary gland growth during adolescence can be altered by early life stress such as childhood maltreatment or maternal dysphoric behavior.
It has been demonstrated that, after controlling for age, sex, and BMI, larger quantities of
DHEA
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 functio ...
and
DHEA-S
Dehydroepiandrosterone sulfate, abbreviated as DHEA sulfate or DHEA-S, also known as androstenolone sulfate, is an endogenous androstane steroid that is produced by the adrenal cortex. It is the 3β-sulfate ester and a metabolite of dehydroep ...
tended to be linked to larger pituitary volume.
Additionally, a correlation between pituitary gland volume and Social Anxiety subscale scores was identified which provided a basis for exploring mediation. Again controlling for age, sex, and BMI,
DHEA
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 functio ...
and
DHEA-S
Dehydroepiandrosterone sulfate, abbreviated as DHEA sulfate or DHEA-S, also known as androstenolone sulfate, is an endogenous androstane steroid that is produced by the adrenal cortex. It is the 3β-sulfate ester and a metabolite of dehydroep ...
have been found to be predictive of larger pituitary gland volume, which was also associated with increased ratings of social anxiety.
This research provides evidence that pituitary gland volume mediates the link between higher DHEA(S) levels (associated with relatively early adrenarche) and traits associated with social anxiety.
Children who experience early adrenarcheal development tend to have larger pituitary gland volume compared to children with later adrenarcheal development.
History
Etymology
Pituitary gland
The Greek
physician
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
Galen
Aelius Galenus or Claudius Galenus ( el, Κλαύδιος Γαληνός; September 129 – c. AD 216), often Anglicized as Galen () or Galen of Pergamon, was a Greek physician, surgeon and philosopher in the Roman Empire. Considered to be one ...
referred to the pituitary gland by only using the (
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
) name ἀδήν,
[Hyrtl, J. (1880). ''Onomatologia Anatomica. Geschichte und Kritik der anatomischen Sprache der Gegenwart.'' Wien: Wilhelm Braumüller. K.K. Hof- und Universitätsbuchhändler.] ''gland''.
[Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press.] He described the pituitary gland as part of a series of secretory organs for the excretion of
nasal mucus
The nasal mucosa lines the nasal cavity. It is part of the respiratory mucosa, the mucous membrane lining the respiratory tract. The nasal mucosa is intimately adherent to the periosteum or perichondrium of the nasal conchae. It is continuous wit ...
.
Anatomist
Andreas Vesalius
Andreas Vesalius (Latinized from Andries van Wezel) () was a 16th-century anatomist, physician, and author of one of the most influential books on human anatomy, ''De Humani Corporis Fabrica Libri Septem'' (''On the fabric of the human body'' ' ...
translated ἀδήν with ''glans, in quam pituita destillat'', "gland in which slime (''pituita''
[Lewis, C.T. & Short, C. (1879). ''A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary.'' Oxford: Clarendon Press.]) drips".
[Schreger, C.H.Th.(1805). ''Synonymia anatomica. Synonymik der anatomischen Nomenclatur.'' Fürth: im Bureau für Literatur.] Besides this 'descriptive' name, Vesalius used ''glandula pituitaria'', from which the English name ''pituitary gland''
[Anderson, D.M. (2000). ''Dorland’s illustrated medical dictionary'' (29th edition). Philadelphia/London/Toronto/Montreal/Sydney/Tokyo: W.B. Saunders Company.] is ultimately derived.
The expression ''glandula pituitaria'' is still used as official synonym beside ''hypophysis'' in the official Latin nomenclature ''
Terminologia Anatomica
''Terminologia Anatomica'' is the international standard for human anatomical terminology. It is developed by the Federative International Programme on Anatomical Terminology, a program of the International Federation of Associations of Anatomi ...
''.
[Federative Committee on Anatomical Terminology (FCAT) (1998). ''Terminologia Anatomica''. Stuttgart: Thieme] In the seventeenth century the supposed function of the pituitary gland to produce nasal mucus was debunked.
The expression ''glandula pituitaria'' and its English equivalent ''pituitary gland'' can only be justified from a historical point of view.
[Triepel, H. (1927). ''Die anatomischen Namen. Ihre Ableitung und Aussprache. Anhang: Biographische Notizen.''(Elfte Auflage). München: Verlag J.F. Bergmann.] The inclusion of this synonym is merely justified by noting that the main term ''hypophysis'' is a much less popular term.
[International Anatomical Nomenclature Committee (1966). ''Nomina Anatomica''. Amsterdam: Excerpta Medica Foundation, p. 62]
Hypophysis
Note: ''hypophysial'' (or ''hypophyseal'') means "related to the hypophysis (pituitary gland)".
The anatomist
Samuel Thomas von Sömmerring
Samuel Thomas von Sömmerring (28 January 1755 – 2 March 1830) was a German physician, anatomist, anthropologist, paleontologist and inventor. Sömmerring discovered the macula in the retina of the human eye. His investigations on the brain ...
coined the name ''hypophysis''.
This name consists
of ὑπό ('under')
and φύειν ('to grow').
In later Greek ὑπόφυσις is used differently by Greek physicians as ''outgrowth''.
Sömmering also used the equivalent expression ''appendix cerebri'',
with ''appendix'' as ''appendage''.
In various languages, ''Hirnanhang''
in
German
German(s) may refer to:
* Germany (of or related to)
** Germania (historical use)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizens of Germany, see also German nationality law
**Ge ...
and ''hersenaanhangsel''
[Pinkhof, H. (1923). ''Vertalend en verklarend woordenboek van uitheemsche geneeskundige termen.'' Haarlem: De Erven F. Bohn.] in
Dutch
Dutch commonly refers to:
* Something of, from, or related to the Netherlands
* Dutch people ()
* Dutch language ()
Dutch may also refer to:
Places
* Dutch, West Virginia, a community in the United States
* Pennsylvania Dutch Country
People E ...
, the terms are derived from ''appendix cerebri''.
Other animals
The pituitary gland is found in all vertebrates, but its structure varies among different groups.
The division of the pituitary described above is typical of
mammals, and is also true, to varying degrees, of all
tetrapod
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant and extinct amphibians, sauropsids ( reptiles, including dinosaurs and therefore birds) and synapsids ( pelycosaurs, extinct t ...
s. However, only in mammals does the posterior pituitary have a compact shape. In
lungfish
Lungfish are freshwater vertebrates belonging to the order Dipnoi. Lungfish are best known for retaining ancestral characteristics within the Osteichthyes, including the ability to breathe air, and ancestral structures within Sarcopterygii, i ...
, it is a relatively flat sheet of tissue lying above the anterior pituitary, but in
amphibians,
reptiles, and
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s, it becomes increasingly well developed. The intermediate lobe is, in general, not well developed in any species and is entirely absent in birds.
The structure of the pituitary in fish, apart from the lungfish, is generally different from that in other animals. In general, the intermediate lobe tends to be well developed, and may equal the remainder of the anterior pituitary in size. The posterior lobe typically forms a sheet of tissue at the base of the pituitary stalk, and in most cases sends irregular finger-like projection into the tissue of the anterior pituitary, which lies directly beneath it. The anterior pituitary is typically divided into two regions, a more anterior ''rostral'' portion and a posterior ''proximal'' portion, but the boundary between the two is often not clearly marked. In
elasmobranch
Elasmobranchii () is a subclass of Chondrichthyes or cartilaginous fish, including sharks (superorder Selachii), rays, skates, and sawfish (superorder Batoidea). Members of this subclass are characterised by having five to seven pairs of g ...
s there is an additional, ''ventral lobe'' beneath the anterior pituitary proper.
The arrangement in
lamprey
Lampreys (sometimes inaccurately called lamprey eels) are an ancient extant lineage of jawless fish of the order Petromyzontiformes , placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like s ...
s, which are among the most primitive of all fish, may indicate how the pituitary originally evolved in ancestral vertebrates. Here, the posterior pituitary is a simple flat sheet of tissue at the base of the brain, and there is no pituitary stalk. Rathke's pouch remains open to the outside, close to the nasal openings. Closely associated with the pouch are three distinct clusters of glandular tissue, corresponding to the intermediate lobe, and the rostral and proximal portions of the anterior pituitary. These various parts are separated by
meningial membranes, suggesting that the pituitary of other vertebrates may have formed from the fusion of a pair of separate, but associated, glands.
Most
armadillos also possess a neural secretory gland very similar in form to the posterior pituitary, but located in the tail and associated with the
spinal cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the sp ...
. This may have a function in
osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration o ...
.
There is a structure
analogous
Analogy (from Greek ''analogia'', "proportion", from ''ana-'' "upon, according to" lso "against", "anew"+ ''logos'' "ratio" lso "word, speech, reckoning" is a cognitive process of transferring information or meaning from a particular subject ...
to the pituitary in the
octopus brain.
Intermediate lobe
Although rudimentary in humans (and often considered part of the
anterior pituitary), the
intermediate lobe
Pars intermedia is the boundary between the anterior and posterior lobes of the pituitary. It contains colloid-filled cysts and two types of cells - basophils and chromophobes. The cysts are the remainder of Rathke’s pouch.
In human fetal
...
located between the anterior and posterior pituitary is important to many animals. For instance, in fish, it is believed to control physiological color change. In adult humans, it is just a thin layer of cells between the anterior and posterior pituitary. The intermediate lobe produces
melanocyte-stimulating hormone
The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating ...
(MSH), although this function is often (imprecisely) attributed to the anterior pituitary.
The intermediate lobe is, in general, not well developed in tetrapods, and is entirely absent in birds.
File:Pituitary gland.png, Location of the pituitary gland in the human brain
File:Illu pituitary pineal glands.jpg, Pituitary and pineal glands
File:Gray516.png, The arteries of the base of the brain.
File:Gray715.png, Mesal aspect of a brain sectioned in the median sagittal plane.
File:Hypophyse.png, Pituitary
File:Hypophyseal gland.jpg, Pituitary gland
File:Slide4MIR.JPG, Cerebrum.Inferior view.Deep dissection.
See also
*
Head and neck anatomy
This article describes the anatomy of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat.
Structure Bones
The head rests on the top part of the vertebra ...
*
Melanotroph A melanotroph (or melanotrope) is a cell in the pituitary gland that generates melanocyte-stimulating hormone (α‐MSH) from its precursor pro-opiomelanocortin
Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. ...
References
External links
*
*
The Pituitary Gland, from the UMM Endocrinology Health Guide
The Pituitary FoundationThe Pituitary Network Association -- pituitary.org
{{Authority control
Endocrine system
Human head and neck
Neuroendocrinology
Human female endocrine system
Articles containing video clips