Embryology: Anatomy of Genital Organs PDF

EMBRYOLOGY ANATOMY OF GENITAL ORGANS The male sex organs The male sex organs are divided into: 1) Primary sex organs; the testis. 2) Secondary sex organs; the epididymis, the vas deferens, the seminal vesicles, the ejaculatory ducts an...

EMBRYOLOGY ANATOMY OF GENITAL ORGANS The male sex organs The male sex organs are divided into: 1) Primary sex organs; the testis. 2) Secondary sex organs; the epididymis, the vas deferens, the seminal vesicles, the ejaculatory ducts and the urethra. 3) The external genital organs. 77  I. Primary sex organs (the testis): 1) Number: two 2) Function: a. Produces the sperms. b. Secrets the male sex hormones. 3) Position: in the scrotum. Histological structure of the testis a. Tunica albuginea. b. Seminifrous tubules. c. Rete testis. d. Stroma. 78 A. Tunica albuginea: □ It is the fibrous capsule that surround the testis from which fibrous septa extend to divide the testis into 200-300 lobules, each containing 1-2 seminiferous tubules. B. Seminiferous tubules: □ They are convoluted tubules, become straight near the mediastinum testis to open into small anastomosing ducts, known as the rete testis. □ The seminiferous tubule contains two types of cells: 1) The supporting sertoli cells; gives nutrition to sperms. 2) The germinal cells that produce the spermatozoa. C. Rete testis: □ The vasa efferentia connect the rete testis with the head of epididymis. □ They join together to form the duct of the epididymis. D. Stroma: □ It contains secretory cells, known as the interstitial cells of leydig that secret testosterone. II. Secondary sex organs: A. Male genital ducts: 1) The epididymis: o Position: Situated along the posterior aspect of the testis. o Shape: Highly convoluted tubules and consists of head, body and tail. o Function: The epididymis acts as: 1) A store for the sperms. 2) A passage for sperms. 3) Helps their maturation. 79  2) The vas deferens: is the continuation of the tail of the epididymis. o Position and course: it lies along the posterior border of the testis. It joins the duct of seminal vesicle to form the ejaculatory duct. 3) The ejaculatory duct: is formed by the union of vas deference with the duct of seminal vesicle. It pierces the base of the prostate and open into the prostatic urethra. B. The accessory gland (for nutrition of the sperms): a) Seminal vesicle. b) Prostate: Fibro-musculo-glandular structure, situated below the neck of the urinary bladder. c) Bulbo-urethral gland: Present in the deep perineal pouch and open in the urethra below the prostate. III. The external genital organs: The penis: acts as a copulatory organ. It is the male external genital organ, which carry the ejaculate to the posterior fornix of the vagina. 80  The female sex organs The female sex organs are divided into: 1. Primary sex organs; the ovaries. 2. Secondary sex organs; the uterine tubes, uterus, vagina and associated glands. 3. External genital organs. I. Primary sex organs (the ovaries): 1) Number: two. 2) Function: 1. Produces the ovum. 2. Secretes female sex hormones. 3) Position: In the true pelvis, one on each side of the lateral wall of the pelvis. 81 II.Secondary sex organs: 1) The uterine tube: o Length: 10 to 12 cm long. o Position: Extend laterally from the uterus until the ovary. o Parts: it consists of: 1) The infundibulum, which lies close to the ovary. 2) The ampulla: its lateral dilated part (the site for fertilization). 3) Isthmus part: narrowest part near the uterus. 4) Intramural part: passes within the wall of the uterus between the fundus and the body. o Function: a) The uterine tube carries the oocytes from the ovaries. b) The uterine tube carries sperms from the uterus to reach the fertilization site in the ampulla of the uterine tube. c) After fertilization, the uterine tube conveys the dividing zygote to the uterine cavity. 82 2) The uterus: o Position: in the true pelvis hanging over the urinary bladder. o Shape: pear-shaped muscular organ. o Parts: It is divided into three parts. 1) The fundus: The rounded part superior to the orifices of the uterine tube. 2) The body: The expanded, superior two-thirds. It's lower part narrow and known as the isthmus. 3) The cervix: The cylindrical inferior third of the uterus. The lumen of the cervix (the cervical canal) communicates with the cavity of the body of the uterus through the internal os and communicates with the vagina through the external os. o Structure: The wall of the body of the uterus consists of three layers: a. Perimetrium: The external layer. b. Myometrium: The thick smooth muscle layer. c. Endometrium: The thin internal layer; formed of glandular epithelium. 3) The vagina: o Definition: It is the copulatory (intercourse) canal and also acts as birth canal. o Position: □ The upper part of the vagina surrounds the lower part of the cervix but is separated from it by an interval known as fornix. The posterior fornix receives the ejaculated semen during sexual intercourse. 83