Anatomy and physiology of the adrenal glands

Anatomy and physiology of the adrenal glands

2 adrenal glands are part of the endocrine system. They are located just above eachkidney, buried deep in the upper part of the abdomen.

Structure

The adrenal glands are made of three layers of tissue:

adrenal cortex (cortex)

outer layer of the adrenal gland

made of glandular tissue (gland)

composed of 3 layers (internal, external, intermediate)

adrenal Medulla (Medullary)

internal layer of the adrenal gland

made of nervous tissue (nerve)

capsule

external coating of the adrenal gland

made of dense fibrous tissue

Function

As part of the endocrine system, the adrenal glands produce hormones.

Adrenal cortex

The adrenal cortex produces several hormones. The most important are aldosterone(Mineralocorticoid), cortisol (glucocorticoid) and androgen and estrogen (sexhormones). These hormones regulate metabolism and body characteristics, such ashair growth and hair and the shape of the body.

Aldosterone

It helps the kidneys regulate the amount of salt in the blood and tissues of the body.

Cortisol (called hydrocortisone)

It helps the body to balance and use the carbohydrates, proteins and fats.

It causes changes in metabolism to help the body deal with stress.

It weakens the immune system.

Androgen (male sex hormone) and estrogen (female sex hormone)

Excessive androgen production is more common than the excessive production of estrogen.

The adrenal cortex is composed of an inner layer, a middle layer and an outer layer.Aldosterone is produced in the outer layer. Cortisol, androgen and estrogen areproduced in the inner layer (active area) and stored in the intermediate layer (storagearea). In times of stress, the storage area shrinks and the active area thickens tosecrete hormones.

Adrenal Medulla

The hormones produced by the adrenal Medulla are called catecholamines. They actnot only as hormones but also as neurotransmitters, or chemical messengers of thenervous system. They are responsible for the reaction of the body to stress. 2 the mostimportant catecholamines are as follows:

Adrenaline (epinephrine)

It is released during short periods of stress (fear or shock suddenly for example).

It increases heart rate, blood pressure and blood sugar levels.

noradrenaline (norepinephrine)

It constricts blood vessels.

Just like the adrenaline, it increases heart rate, blood pressure and blood sugar levels.

The adrenal Medulla is also produces a protein called Chromogranin A, whichinformation is stored and secreted with the adrenaline and noradrenaline.

Capsule

The capsule encloses and protects the adrenal gland.

The female genital tract

The reproductive system of women plays in reproduction, a much more complex role than that of man. In the latter image, it must produce gametes, but also must be prepared to support a developing embryo for a period of 9 months.

Ovaries:
It is paired organs, which, as the testes, are made from fibrous tunica albuginea, covered with a layer of epithelial cells, the germinal epithelium, which continuity is made with the peritoneal epithelium but also a cortex and a régionmédullaire. The ovary is maintained in its anatomical relationships by ligamentutéro ovarian, fixing it in the womb, but also by the suspensory ligament, attaching it to the pool wall, and finally by the mesovarium, suspending it from the pool wall and uterus. Their irrigation speak ovarian arteries pass through the branches of the abdominal aorta and a branch of the uterine arteries.
In the connective tissue of the ovarian cortex, are small structures in the form of sac, ovarian follicles, formed of an immature egg, oocyte, wrapped in layers of follicle cells and granular. Its structure changes as and when it matures: a primordial follicle, it becomes primary and secondary, and finally takes the follicle name De Graaf. It is then mated to the surface of the ovary, and is ejected, monthly, by a phenomenon similar to exocytosis is ovulation. The rest of the remaining follicle then called the corpus luteum, and eventually degenerate.

Fallopian tubes:
Also called fallopian tubes, they capture the oocyte at ovulation. Unlike sperm ducts whose stoma is made directly to the seminiferous tract, there is little or no contact between the tubes and ovaries. Indeed, the oocyte is ejected directly into the peritoneal cavity. This is the distal part of the tubes, called fringes, which "capture" the oocyte: indeed, their ciliated area created during ovulation, currents in the peritoneal fluid in order to capture the oocyte. However, many are definitely lost in the maze of the peritoneal cavity.
The inner wall of the fallopian tubes consists of a muscular coat and hair cells. This particular structure allows parpéristaltisme, and rhythmic beats of the hair cells, promotion of the oocyte. The distal part of the tubes, expanded, is called the bulb of the tube. It's usually at this point that takes place fertilization.


The uterus:
Thick-walled hollow organ, the uterus is located in the basin, its direct anatomical relationship being the rectum and bladder, its size is approximately that of a small fist, among nulliparous.
Its most important part is the body. The lower part, the cervix is the orifice of the uterus. The cavity of the cervix is the endocervical canal. The uterus is flexed forward, they say in anteversion. The paroiutérine comprises three tissue layers:




The périmétrium is a serous tunic portion of the peritoneum;

Myometrium is a thick layer of smooth muscle;


The endometrium is a solid epithelial tunic with a thick lamina propria of connective tissue in which the embryo implants.


Laterally, the uterus is maintained by the mesometrium the transverse ligament (or paracervix) and uterosacral ligaments
the vagina

Fibromuscular tube located between the bladder and rectum, uterine Ducol extending to the vulva, it is the organ of copulation, ensuring the collection of semen. Its wall is composed of the weed, external elastic layer fibro, the formed muscular smooth muscle and mucosal stratified squamous epithelium can withstand friction. Its pH is acid, thus protecting it from infection.
At the level of the vaginal opening, incomplete partition, the hymen, highly vascularized, usually breaks the first report, causing dessaignements. However, sometimes it breaks during a workout.


The external genitalia:
The mons pubis is a rounded adipose region covering the pubic symphysis. Two folds of skin fat lie back, large slèvres, surrounding two thin folds of skin, labia minora, limiting a region called vestibule containing etorifice vaginal urethral meatus. Found on both sides to the Bartholin gland, secreting mucus and moistening lubricant during intercourse.
The clitoris, a small protruding structure located just in front of the hall is richly innervated by sensory endings. He then started an erection and then contributes to sexual arousal in women.
Mammary glands finally, are exocrine glands, localized in a breast, rounded structure in front of the pectoral muscles, which include the center circle of a skin, pigmented areola surrounding a central protrusion, the nipple. Breasts have a food based postpartum, and also contribute to sexual pleasure. Their anatomophysiology will be explained in detail in the physiology part of the female reproductive system.