The intermammary cleft or intermammary sulcus or sulcus intermammarius is a surface feature of

male Male (symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or ovum, in the process of fertilization. A male organism cannot reproduce sexually without access to ...

s and

female Female ( symbol: ♀) is the sex of an organism that produces the large non-motile ova (egg cells), the type of gamete (sex cell) that fuses with the male gamete during sexual reproduction. A female has larger gametes than a male. Females ...

s that marks the division of the two

breast The breast is one of two prominences located on the upper ventral region of a primate's torso. Both females and males develop breasts from the same embryological tissues. In females, it serves as the mammary gland, which produces and sec ...

s with 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) in the middle.Dr. Ted Eisenberg and Joyce K. Eisenberg, ''The Scoop on Breasts: A Plastic Surgeon Busts the Myths'', Incompra Press, 2012, The

International Federation of Associations of Anatomists The International Federation of Associations of Anatomists (IFAA) is an umbrella scientific organization of national and multinational Anatomy Associations, dedicated to anatomy and biomorphological sciences. Origins and objectives In 1903, Prof. N ...

(IFAA) uses the terms "sulcus intermammarius" or "intermammary cleft" when referring to the area between the breasts.Muhammad Adil Abbas Khan, Ammar Asrar Javed and Nigel Mercer
Cleavage classification: categorizing a vital feminine aesthetic landmark
Plastic and Aesthetic Research (PAR), 016-01-15

Etymology

"Intermammary" ("

inter Inter may refer to: Association football clubs * Inter Milan, an Italian club * SC Internacional, a Brazilian club * Inter Miami CF, an American club * FC Inter Sibiu, a Romanian club * FC Inter Turku, a Finnish club * FK Inter Bratislava, a form ...

", between + " mamma", breasts + " ry", place) means something that is located or performed between the breasts (example: intermammary intercourse). "Sulcus" is a Latin word that means a furrow or groove, commonly used to mean a fold, fissure or furrow of the brain (example:

lateral sulcus In neuroanatomy, the lateral sulcus (also called Sylvian fissure, after Franciscus Sylvius, or lateral fissure) is one of the most prominent features of the human brain. The lateral sulcus is a deep fissure in each hemisphere that separates the ...

). In popular usage the area is commonly referred to as a cleavage of breasts. In surgical parlance, the cleavage or intermammary cleft is also known as the "medial definition" or "medial fold" of breasts. An imaginary line between the nipples that crosses the intermammary cleft, serving as a landmark for some

CPR Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore sponta ...

procedures, is known as the "intermammary line".

Anatomy

Skin

At the midline of the breast—the intermammary cleft—a deep layer of superficial fascia (lowermost layer of the skin) is firmly attached to the

pectoral fascia The pectoral fascia is a thin lamina, covering the surface of the pectoralis major, and sending numerous prolongations between its fasciculi: it is attached, in the middle line, to the front of the sternum; above, to the clavicle; laterally and bel ...

(outer side of chest muscles) and the periosteum (bone membrane) of the sternum. It forms a shelving edge that supports the breasts.

Muscles

The

Sternalis muscle The sternalis muscle is an anatomical variation that lies in front of the sternal end of the pectoralis major parallel to the margin of the sternum. The sternalis muscle may be a variation of the pectoralis major or of the rectus abdominis. Struc ...

is an

anatomical variation An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categ ...

that lies in front of the sternal end of the pectoralis major runs along the anterior aspect of the body of the sternum. The sternalis muscle often originates from the upper part of the sternum and can display varying insertions such as the

, lower ribs,

costal cartilage The costal cartilages are bars of hyaline cartilage that serve to prolong the ribs forward and contribute to the elasticity of the walls of the thorax. Costal cartilage is only found at the anterior ends of the ribs, providing medial extension. ...

rectus sheath The rectus sheath, also called the rectus fascia,. is formed by the aponeuroses of the transverse abdominal and the internal and external oblique muscles. It contains the rectus abdominis and pyramidalis muscles. Structure The rectus sheat ...

, aponeurosis of the abdominal external oblique muscle. There is still a great deal of disagreement about its

innervation A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system. A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...

and its embryonic origin. The sternal side (towards the breastbone) of the pectoralis major is distinct from the

clavicular 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 rig ...

side (towards the collarbone), and the two are separated by a fascial interval. The sternal side is usually more robust and has a fiber orientation that best emulates the downward pull of the

subscapularis muscle The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint. Structure It arises from its medial two-thirds and So ...

(armpit muscle).

Ligaments

A dense structure of

Cooper's ligaments Cooper's ligaments (also known as the suspensory ligaments of Cooper and the fibrocollagenous septa) are connective tissue in the breast that help maintain structural integrity. They are named for Astley Cooper, who first described them in 1840. ...

is medially inserted into the skin overlying the sternum, determining the shape of the breasts and intermammary sulcus. These ligaments helpful in supporting the breasts in an youthful disposition; loss of elasticity or attenuation of these ligaments results in ptosis (sagging) of breasts. Intermammary sulcus anatomy

Arteries

Major blood supply in the area happens through the intermammary artery (also known as the internal thoracic artery) in the

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 ...

.Ruth A. Lawrence MD and Robert M. Lawrence, MD, ''Breastfeeding: A Guide for the Medical Profession'' page 47, Elsevier Health Sciences, 2015, Among women, this artery is larger.Rebecca F. Black, ''The Science of Breastfeeding'' (Volume 3), page 13, Jones & Bartlett Learning, 1998, From which anterior perforating branches carry blood into the circummammary arterial plexus, a vascular network formed by branches between minute arteries around the breasts, with lateral mammary branches curving around the lateral border of the pectoralis major.

Lymphs

Lymph vessels originating at the base of the nipples can

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 ...

ly extend as far as the intermammary cleft and to the opposite breast. The intermammary lymphatics begin as a bunch of small channels consisting of a single layer of epithelium that is supported by stroma tissues. Each mesh of this network surrounds one or more of the ultimate lobules of the glands and receives its

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 interacinous spaces between the

acini An acinus (; plural, acini; adjective, acinar or acinous) refers to any cluster of cells that resembles a many-lobed " berry," such as a raspberry ('' acinus'' is Latin for "berry"). The berry-shaped termination of an exocrine gland, where t ...

of glands.

Nerves

The first intercostal nerve, a tiny branch ('' ramus'') of the anterior division of the first

thoracic nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into th ...

, runs along the first

intercostal space The intercostal space (ICS) is the anatomic space between two ribs (Lat. costa). Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it. Structures in intercostal space * several kind ...

(the lower margin of the first rib), travels towards the sternum to innervate the skin near the midline, and, as the first anterior cutaneous (skin) branch of the

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

, ends on the front of the chest. The nerve supply to sternalis muscles comes from the right third intercostal nerve through its anterior cutaneous branch.

Clinical conditions

Poikiloderma of Civatte

Poikiloderma of Civatte Poikiloderma of Civatte is a cutaneous condition and refers to reticulated red to red-brown skin patches with telangiectasias. It is identifiable as a reddish-brown discoloration on the side of the neck, usually on both sides. It is more common in ...

, a condition of dilated blood vessels and red to red-brown spots, is common to upper part of the cleavage, especially for those who wear

sports bra A sports bra is a bra that provides support to the breasts during physical exercise. Sturdier than typical bras, they minimize breast movement and alleviate discomfort. Many women wear sports bras to reduce pain and physical discomfort caused ...

s or

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 for prolonged periods, and commonly affects fair skinned middle-aged to elderly women.Daphne Merkin,
The Great Divide
, ''New York Times'', August 28, 2005 It is characterized by

hypopigmentation Hypopigmentation is characterized specifically as an area of skin becoming lighter than the baseline skin color, but not completely devoid of pigment. This is not to be confused with depigmentation, which is characterized as the absence of all pi ...

hyperpigmentation Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin. Causes Hyperpigmentation can be caused by sun damage, inflammation, or other skin injuries, including those related to acne vulgaris.James, William; Ber ...

telangiectasias Telangiectasias, also known as spider veins, are small dilated blood vessels that can occur near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. These dilated blood vessels can develop anywhere on ...

and superficial skin atrophy (occasional itching is reported), is another condition caused by long exposure to sunlight.

Poikiloderma Poikiloderma is a skin condition that consists of areas of hypopigmentation, hyperpigmentation, telangiectasias and atrophy. Poikiloderma of Civatte is most frequently seen on the chest or the neck, characterized by red colored pigment on the skin ...

and Dermatoheliosis are treated by

desquamation Desquamation occurs when the outermost layer of a tissue, such as the skin, is shed. The term is . Physiologic desquamation Keratinocytes are the predominant cells of the epidermis, the outermost layer of the skin. Living keratinocytes reside in ...

(skin peeling).

Hidradenitis suppurativa

Hidradenitis suppurativa Hidradenitis suppurativa (HS), sometimes known as acne inversa or Verneuil's disease, is a long-term dermatological condition characterized by the occurrence of inflamed and swollen lumps. These are typically painful and break open, releasing ...

(HS) is a non-contagious chronic

skin disease A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...

affects

intertriginous In medicine, an intertriginous area is where two skin areas may touch or rub together. Examples of intertriginous areas are the axilla of the arm, the anogenital region, skin folds of the breasts and between digits. Intertriginous areas are known ...

skin of apocrine sweat gland bearing areas like

inframammary fold In human anatomy, the inframammary fold (IMF), inframammary crease or inframammary line is the natural lower boundary of the breast, the place where the breast and the chest meet. The choice of the term depends on the prominence of the feature. It ...

, and intermammary sulcus. It is characterized by clusters of abscesses,

epidermoid cysts An epidermoid cyst or epidermal inclusion cyst is a benign cyst usually found on the skin. The cyst develops out of ectodermal tissue. Histologically, it is made of a thin layer of squamous epithelium. Signs and symptoms The epidermoid cyst may ...

, sebaceous cysts,

pilonidal cyst Pilonidal disease is a type of skin infection which typically occurs as a cyst Intergluteal cleft, between the cheeks of the buttocks and often at the upper end. Symptoms may include pain, swelling, and redness. There may also be drainage of flui ...

s.Faye Lyons,
Dermatology for the Advanced Practice Nurse
', pages 118–121, Springer Publishing Company, 2014, There is no single effective treatment for HS. The recommended treatments include antibiotics,

antiandrogen Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the ...

s, corticosteroids,

ciclosporin Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease ...

s, and

TNF inhibitor A TNF inhibitor is a pharmaceutical drug that suppresses the physiologic response to tumor necrosis factor (TNF), which is part of the inflammatory response. TNF is involved in autoimmune and immune-mediated disorders such as rheumatoid arthritis, ...

Tinea versicolor

Tinea versicolor Tinea versicolor (also pityriasis versicolor) is a condition characterized by a skin eruption on the trunk and proximal extremities. The majority of tinea versicolor is caused by the fungus '' Malassezia globosa'', although '' Malassezia furfur'' ...

is a condition characterized by pinhead to coin sized eruptions on the body trunk and proximal extremities, often affecting the breast cleavage as a narrow band of lesions. The majority of tinea versicolor is caused by the fungus '' Malassezia globosa'', although '' Malassezia furfur'' is responsible for a small number of cases.

Topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...

antifungal medications An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryp ...

containing

selenium sulfide Selenium sulfide can refer to either of the following: * Selenium disulfide, SeS2 * Selenium hexasulfide, Se2S6 {{Short pages monitor