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Anatomy and physiology of the male and female reproductive
system
Ruth V. Tianco , RN
Structure of Male Reproductive Tract
External Structures
• Testes
• Scrotum
• Penis
Internal Structure
• Epididymis
• Vas deferens
• Seminal Vesicles
• Ejaculatory ducts
• Prostate gland
• Bulbourethral glands
• Urethra
TESTES/TESTICLES
(male gonads)
- Testes are two ovoid glands, 2 to 3 cm wide, that lie in the scrotum.
- Each testes is encased by a protective white fibrous capsule and is composed of a number of lobule containing interstitial cells (Leydig’s cells) and seminiferous tubule.
- Leydig’s cells are responsible for production of the male hormone testosterone.
Cont.. TESTES/TESTICLESFunctions:
• Like the ovaries (to which they are homologous), testes are components of both the reproductive system (being gonads) and the endocrine system (being endocrine glands). The respective functions of the testes are:
• producing sperm (spermatozoa)
• producing male sex hormones of which testosterone is the best-known
Cont.. TESTES/TESTICLES
Both functions of the testicle, sperm-forming and endocrine, are under control of gonadotropic hormones produced by the anterior pituitary:
• luteinizing hormone (LH)
• follicle-stimulating hormone (FSH)
Scrotum• scrotum is a rugated skin-
covered and muscle containing the testicles. It is an extension of the abdomen, and is located between the penis and anus.
• Its function is to support the testes and help to regulate the temperature of sperm.
Penis• Is composed of three
cylindrical masses of erectile tissue in the penis shaft.
• Penis serves as the outlet for both the urine and the reproductive tracts in men.
Epididymis• The seminiferous tubule of each
testis leads to a tightly coiled tube, the epididymis.
• Approximately 20 ft.• Responsible for conducting sperm
from the testis to the vas deferens.• It is narrow along its entire length,
infection of the epididymis can easily lead to scarring of the lumen that prohibits passage of sperm beyond the scarred point.
Vas Deferens• Is an additional hollow tube surrounded by
arteries and veins and the protected by a thick fibrous coating.
• It carries sperm from epididymis through the inguinal canal into the abdominal cavity where it ends at the seminal vesicles and the ejaculation ducts.
• Mature sperm pass to the vas deferens.
Seminal Vesicles• Two convoluted pouches
that lie along the lower portion of the posterior surface of the bladder and empty into the urethra by way of the ejaculatory ducts.
• These glands secrete s viscous portion of semen.
Ejaculatory ducts• Two ejaculatory
ducts pass through the prostate gland and join the seminal vesicles to the urethra.
Bulbourethral glands• Also know as Cowper’s
glands lie beside the prostate gland.
• Like prostate gland and seminal vesicles, they secrete an alkaline fluid that helps the counteract the acid secretion of urethra and ensure the safe passage of spermatozoa.
Urethra• Is a hollow tube leading
from the bladder, which after passing through the prostate gland, continues to the outside through the shaft and glans of the penis.
• Approximately 8 inch (18 to 20 cm) in long
External Female Genitalia
Internal Female Reproductive Structures
Mons Veneris / Pubis• Is a pad of adipose tissue located over the
symphsis pubis, the pubic bone joint.
• It is covered by a triangle of coarse, curly hairs.
• The purpose of the mons veneris is to protect the junction of the pubic bone from trauma.
Labia minora• The labia minora are
two soft folds of skin between the labia majora and to either side of the opening of the vagina.
• Normally the folds of the labia minor are pink.
• The area is abundant with sebaceous glands.
Labia Majora• The labia majora are lip-
like structures comprised mostly of skin and adipose tissue covered by loose connective tissue and epithelium.
• After puberty, it is typically covered with pubic hair.
• Protection for the external genitalia and the distal urethra and vagina.
Clitoris• Is approximately 1- 2 cm.• Rounded organ of erectile
tissue at the forward junction of the labia minora.
• Sensitive to touch and temperature and is the center of sexual arousal and orgasm in the female.
Bartholin's glands• Called Bartholin glands or
greater vestibular glands) are two glands located slightly below and to the left and right of the opening of the vagina in women.
• Secretions from both of these glands help to lubricate the external genitalia.
• The alkaline ph of their secretion helps to improve sperm survival in the vagina.
Fourchette• Is the ridge of tissue
formed by the posterior joining of the two labia minora and labia majora.
• This is the structure that is sometimes cut (episiotomy) during child birth to enlarge the vaginal opening.
Hymen• Is a tough but
elastic semicircle of tissue that covers the opening of the vagina during childhood.
• It is often torn with the first sexual intercourse.
Ovaries• Ovaries are oval shaped
• measure approximately 4cm long by 2 cm in diameter.
• The ovary is located close to and on both sides of the uterus in the lower abdomen.
Ovaries Functions:
1.Produce, mature and discharge of egg/ova
2.Ovulation
3.Hormone production- progesterone and estrogen
4.Initiate and regulate menstrual cycles
5.Development of follicles (Oogenesis- O for ova)- Oogenesis- is a process by which a
primitive egg is developed to a matured ovum
Fallopian tube• There are two Fallopian tubes attached to either
side of the cornual end of the uterus.
• Each terminates at or near one ovary forming a structure called the fimbria.
• The Fallopian tubes are not directly attached to the ovaries, but open into the peritoneal cavity (essentially the inside of the abdomen); they thus form a direct communication between the peritoneal cavity and the outside via the vagina.
• the Fallopian tubes are about 10 cm long in mature woman.
Cont.. Fallopian tube• The Fallopian tubes or oviducts are two very fine
tubes leading from the ovaries of females into the uterus.
• On maturity of an ovum, the follicle and the ovary's wall rupture, allowing the ovum to escape and enter the Fallopian tube. This trip takes hours or days.
There are four regions of the fallopian tube from the ovary to the uterus:• Infundibulum - contains fimbria
• Ampulla - usual site of fertilization
• Isthmus -
• Interstitial tube - inside wall of uterus
Uterus• Approximately 5 to 7 cm long, 5 cm wide, 2.5 cm deep, wt.
60 g. in non pregnant state.• After pregnancy approximately 9 cm long, 6 cm wide, 3 cm
thick and 80 g. in wt.• The uterus or womb is the major female reproductive organ
of humans. One end, the cervix, opens into the vagina; the other is connected on both sides to the fallopian tubes.
• The uterus is a pear-shaped muscular organ. Its major function is to accept a fertilized ovum which becomes implanted into the endometrium, and derives nourishment from blood vessels which develop exclusively for this purpose.
Cont…Uterus• The fertilized ovum becomes an embryo, develops into a fetus and
gestates until childbirth. If the egg does not embed in the wall of the uterus, a woman gets her period and the egg is flushed away.
• Three divisions:
1. Corpus
2. Isthmus- between the body and cervix, portion most commonly cut during CS.
3. Cervix- opening canal• Fundus is the portion that can be palpated abdominally to determine
the amount of uterine growth occurring during pregnancy.
The layers, from innermost to outermost, are as follows:
• Endometrium- inner lining of the uterine cavity. endometrium builds a lining periodically which is shed or reabsorbed if no pregnancy occurs. Shedding of the functional endometrial lining in humans is responsible for menstrual bleeding. Myometrium- The uterus mostly consists of smooth muscle, middle layer. The innermost layer of myometrium is known as the junctional zone, which becomes thickened in adenomyosis. Perimetrium- The loose surrounding tissue, outer of connective tissue.
Vagina
• The vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female.
• The vagina is the place where semen from the male is deposited into the female's body at the climax of sexual intercourse, commonly known as ejaculation.
• Around the vagina, pubic hair protects the vagina from infection and is a sign of puberty.
Cervix
• The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina.
• It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall.
• Approximately half its length is visible; the remainder lies above the vagina beyond view.