Embryology Lecture 1 PDF

# Embryology ## Done by: Dr.Haneen Arafat * **Genital System:** This system is concerned with the production of germ cells, the sperm in males, and the ovum in females. ### Male genital system | Primary Sex organs | Secondary sex organs | External genital organs | |---|---|---| | (2 testis) -...

# Embryology ## Done by: Dr.Haneen Arafat * **Genital System:** This system is concerned with the production of germ cells, the sperm in males, and the ovum in females. ### Male genital system | Primary Sex organs | Secondary sex organs | External genital organs | |---|---|---| | (2 testis) - Produce the germ cells and secrets the sex hormones | **Duct system** - Epididymis - Vas deferens - Lejaculatory ducts - Urethra | **Accessory glands** - Seminal vesicale - Prostate - Bulbourethral glands | ### Female genital system | Primary sex organs | Secondary sex organs | External genital organ | |---|---|---| | (2 ovaries) - Produce the germ cells and secrets the sex hormones | **Duct system** - Fallopian tube - Uterus - Vagina | | ## (Male) * **Testis** - **Function:** production of sperms and secretion of testosterone - **Shape:** oval - **Position:** Lie in the scortal sac outside the abdominal cavity. - It needs a lower temperature for production of sperm (34-35°C). - **Structure** - The testis is divided by septa into 200 lobules. - Each lobule contains 1-3 seminiferous tubules. - 1. Germinal cells: Produce sperms - 2. Sertoli cells: supporting cells for sperm nutrition - Between the tubules, testicular stroma contain interstitial cells of Leyding that secret testosterone. - The vasa efferentia small tubules connect the testis with epididymis - **Covered by:** - Inner tunica albuginea = strong fibrous Capsule - Outer tunica vaginalis = Serous sac * **Epididymis** - **Shape:** comma shaped mass, formed of highly coiled single duct of 6 meters long - **Parts:** - **Head:** connected with testis by vasa efferentia - **Body:** lies on the posterior surface of the testis - **Tail:** continued by vas deferens - **Function:** storage and maturation of the sperms * **Vas deferens** - **Begins:** at the tail of epididymis - **Ends:** by union with duct of Seminal vesicale forming ejaculatory duct - **Function:** a tube that conveys sperm from the epididymis to the ejaculatory duct. - Seminal vesicale + vas deferens = ejaculatory duct - **Termination:** open in the prostatic urethra * **Ejaculatory duct** - Termination: open in the prostatic urethra  * **The male urethra (ejaculatory dection)** - **Shape & length:** S shape and 20 cm in length - **Parts:** - **Prostatic urethra: **widest part - **Membranous urethra:** narrowest, shortest part - **Penile urethra:** longest part * **The accessory glands** 1. **Seminal vesical (2 in number)** - **Position:** on the urinary bladder base - **Function:** secretion of seminal fluid for the nutrition of sperms 2. **Prostate (1 in number)** - **Shape:** looks like an inverted pyramid - **Position:** Below the neck of bladder - **Function:** Secretion for seminal fluid for the nutrition of the sperms 3. **Bulbourethral (cowper's) gland (2 in number)** - **Shape:** two pin-head gland - **Position:** beside the membranous urethra, its duct opens in penile urtha  * **Ovary (2 in number) (Female)** - **Function:** production of ova and secretion of two female sex hormones (progesterone and 'oestrogen) - **Shape:** almond-shape gland - **Position:** in the pelvis lateral to the uterus * **Uterine (Fallopian) tubes** - **Site:** Between the ovary and the uterus. - **Length:** about 10 cm - **Parts:** - **Infundibulum:** lies close to the ovary, has fimbriae. - **Ampulla:** the widest part of the tube, the site of fertilization. - **Isthmus:** the narrowest part of the tub. - **Intra-mural part:** lies in the wall of the uterus. - **Functions:** - Carry the oocytes from the ovaries - Carry the sperms from the uterus - The site of fertilization - Carry the zygote to the uterine cavity  * **Uterus** - **Shape:** a pear shaped thick walled muscular organ - **Site:** in the pelvic cavity - **Parts:** - **Fundus:** it lies above the entrance of the uterine tubes. - **Body:** it's the part that lies below the entrance of the uterine tubes, it's main triangular part. - **Cervix:** lower cylindrical part. It forms lower 1/3 of uterus. - **Internal os:** with the body of uterus - **External os:** with the vagina - **Function:** site of implantation and growth of the embryo. * **Vagina** - **Site:** It extends from the cervix of uterus down to the Vestibule. - **Parts:** - It has anterior (7.5 cm) and posterior (10 cm) walls. - Upper end surrounds the lower part of the cervix which divides it into 4 fornices (anterior, posterior, 2 lateral). - It acts as female copulatory and birth canal.  * **The story:** Ovary produces ovum. Fimbriae captures the ovum and takes it to the fallopian tube. Fertilization happens in the ampulla of the fallopian tube. The zygote travels to the uterus and implants. The embryo develops in the uterus. The baby is born through the cervix and the vagina.