Mammary glands and vulva

 Mammary glands.

(1) Mammary glands are accessory organs of female reproductive system. These glands are essential for lactation after parturition 

(2) They are modified sweat glands present in the subcutaneous tissue of the anterior thorax. They are in the pectoral region in the location between 2nd to 6th rib. 

 (3) Each mammary gland consists of fatty connective tissue and many lactiferous ducts. 

 (4) Each breast has glandular tissue which is divided into 15-20 irregularly shaped mammary lobes. Each lobe has an alveolar glands and lactiferous duct. 

(5) Milk is secreted by alveolar glands and it is stored in the lumen of alveoli. The alveoli open into mammary tubules and these in turn forms a mammary duct. 

 (6) All the lactiferous ducts converge towards the nipple. 

 (7) The nipple is surrounded by a dark brown colored and circular area of ​​the skin called heqing tabori areola.

Structure of mammary gland

Mammary Glands

Each breast is a hemispheric projection of variable size anterior

to the pectoralis major and serratus anterior muscles and attached to them by a layer of fascia composed of dense irregular connective tissue.

 Each breast has one pigmented projection, the nipple, that

has a series of closely spaced openings of ducts called lactiferous ducts (lak-TIF-e-rus), where milk emerges. The circular pigmented area of skin surrounding the nipple is called the

areola (a-RE¯-oˉ-la -small space); it appears rough because it contains modified sebaceous (oil) glands. Strands of connective tissue called the suspensory ligaments of the breast 

(Cooper’s ligaments) run between the skin and fascia and support the breast. These ligaments become looser with age or with the excessive strain that can occur in long-term jogging

or high-impact aerobics. Wearing a supportive bra can slow

this process and help maintain the strength of the suspensory ligaments.

 Within each breast is a mammary gland, a modified sudoriferous (sweat) gland that produces milk . A mammary gland consists of 15 to 20 lobes, or compartments, separated

by a variable amount of adipose tissue. In each lobe are several

smaller compartments called lobules, composed of grapelike clus-

ters of milk-secreting glands termed alveoli (al-VE¯-o-lı¯ -small

cavities) embedded in connective tissue. Contraction of myoepithelial cells (mı¯-oˉ-ep-i-THE¯-le¯-al) surrounding the alveoli helps propel milk toward the nipples. When milk is being produced, it

passes from the alveoli into a series of secondary tubules and then into the mammary ducts. Near the nipple, the mammary ducts expand slightly to form sinuses called lactiferous sinuses

(lact- milk), where some milk may be stored before draining

into a lactiferous duct. Each lactiferous duct typically carries

milk from one of the lobes to the exterior.

The functions of the mammary glands are the synthesis,secretion, and ejection of milk; these functions, called lacta-

tion (lak-TAˉ-shun), are associated with pregnancy and childbirth. Milk production is stimulated largely by the hormone prolactin from the anterior pituitary, with contributions from

progesterone and estrogens. The ejection of milk is stimulated by oxytocin, which is released from the posterior pituitary in response to the sucking of an infant on the mother’s nipple (suckling).

What is vulva and how its function in human female?

Vulva

The term vulva (VUL-va to wrap around), or pudendum (puˉ-DEN-dum), refers to the external genitals of the female. The following components make up the vulva:

• Anterior to the vaginal and urethral openings is the mons pu-

bis (MONZ PU¯-bis; mons mountain), an elevation of adipose tissue covered by skin and coarse pubic hair that cushions

the pubic symphysis.

• From the mons pubis, two longitudinal folds of skin, the labia

majora (LAˉ-be¯-a ma-JO¯-ra; labia -

 lips; majora -larger), extend inferiorly and posteriorly. The singular term is labium majus.

The labia majora are covered by pubic hair and contain an abun-

dance of adipose tissue, sebaceous (oil) glands, and apocrine sudoriferous (sweat) glands. They are homologous to the scrotum.

• Medial to the labia majora are two smaller folds of skin called

the labia minora (min-OR-a -smaller). The singular term is

labium minus. Unlike the labia majora, the labia minora are

devoid of pubic hair and fat and have few sudoriferous glands,

but they do contain many sebaceous glands. The labia minora

are homologous to the spongy (penile) urethra.

• The clitoris (KLI-to-ris) is a small cylindrical mass composed

of two small erectile bodies, the corpora cavernosa, and numerous nerves and blood vessels. The clitoris is located at the

anterior junction of the labia minora. A layer of skin called the

prepuce of the clitoris (PRE¯-poos) is formed at the point

where the labia minora unite and covers the body of the clito-

ris. The exposed portion of the clitoris is the glans clitoris. The clitoris is homologous to the glans penis in males. Like the

male structure, the clitoris is capable of enlargement on tactile

stimulation and has a role in sexual excitement in the female.

• The region between the labia minora is the vestibule. Within the

vestibule are the hymen (if still present), the vaginal orifice, the

external urethral orifice, and the openings of the ducts of several

glands. The vestibule is homologous to the intermediate urethra

of males. The vaginal orifice, the opening of the vagina to the

exterior, occupies the greater portion of the vestibule and is bordered by the hymen. Anterior to the vaginal orifice and posterior to the clitoris is the external urethral orifice, the opening of the urethra to the exterior.

These mucussecreting glands are embedded in the wall of the urethra. The

paraurethral glands are homologous to the prostate. On either

side of the vaginal orifice itself are the greater vestibular glands

or Bartholin’s glands (BAR-to-linz), which open by ducts into a groove between the hymen and labia minora. They produce a small quantity of mucus during sexual

arousal and intercourse that adds to cervical mucus and provides lubrication. The greater vestibular glands are homologous

to the bulbourethral glands in males. Several lesser vestibular

glands also open into the vestibule.

• The bulb of the vestibule consists of two elongated masses of erectile tissue just deep to the labia on either side of the vaginal orifice. The bulb of the vestibule becomes engorged with blood during sexual arousal, narrowing the vaginal orifice and placing pressure on the penis during intercourse. The bulb of the vestibule is homologous to the corpus spongiosum and bulb of the penis in males.