Physiology of Reproduction PDF

Physiology of reproduction Presented by Dr. Sherif Diaaeldin The female reproductive system 1- The ovaries Functions (a) production of ova (b) endocrine function e.g., estrogen, progesterone, and relaxin. 2- The accessory sex organs (a) The vagina (b) The uterus (c) The 2 uterine tubes (=fal...

Physiology of reproduction Presented by Dr. Sherif Diaaeldin The female reproductive system 1- The ovaries Functions (a) production of ova (b) endocrine function e.g., estrogen, progesterone, and relaxin. 2- The accessory sex organs (a) The vagina (b) The uterus (c) The 2 uterine tubes (=fallopian tubes) Structure of the ovaries It is made of cortex and medulla -The cortex contains about 300,000 ovarian follicles. -The medulla contains connective tissue, blood vessels, lymph vessels, and nerves. The ovarian functions start at puberty and stop at menopause. During the period between these 2 events only one ovum is discharged from the ovaries approximately every month. The sex cycles in females These are regular cyclic changes that occur in the adult female reproductive system. These changes start at puberty and continues till the menopause. The duration of each cycle varies between women, but it is about 28 days in average.  The ovarian cycle 1- The follicular phase: starts with the first day of menstruation and ends with ovulation. This duration is not constant. During this phase the follicles start to grow under the effect of the hormone follicle stimulating hormone (FSH). On about the 6th day of the cycle one follicle in one ovary starts to grow rapidly and becomes graafian follicle 2- The ovulation phase: it is the process of expulsion of the ovum from the graafian follicle. It occurs in the midcycle, usually on the 14th day. Rupture of the graafian follicle occurs as a result of a burst of luteinizing hormone (LH) 3- The luteal phase: after the release of the ovum the ruptured empty follicle is called corpus luteum. The duration of this phase is constant at 14 days. The corpus luteum under the effect of LH secretes hormones estrogen and progesterone for 10 days reaching full maturation on about the 24th day of the cycle. If pregnancy occurs, it continues and grow further. If pregnancy does not occur, it degenerates and forms corpus albicans  Structure and Function Ovary Path of an Path Eggof an Egg in the Ovarian Cycle Egg Ovaries release the eggs cyclically from the graafian Uterine tube follicle The fertilized egg is Uterus transported to the uterus where it develops into an embryo If not If fertilized fertilized At the end of gestation the infant is born through the vagina or surgically through Expulsion Implantation the abdomen in a Cesarean through menstruation delivery 8  The uterine cycle 1- The bleeding phase (menstrual phase) This phase lasts 3-5 days The corpus luteum of the preceding cycle starts to degenerate on the 24th day of the cycle so the level of both estrogen and progesterone start to decrease, and this leads to the shedding of the endometrium 9 2- The proliferative phase It starts after the end of the menstrual phase. The damaged endometrium is regenerated under the effect of estrogen secreted from the graffian follicle. 3- The secretory phase This starts after the ovulation Further thickening of the endometrium occurs so it is ready for the implantation of the fertilized ovum The endometrium becomes more vascularized The glands in the endometrium start to secret a clear fluid 10 11  The male reproductive system The male reproductive system includes a group of organs that make up a man’s reproductive and urinary system. These organs do the following jobs within your body: They produce, maintain and transport sperm (the male reproductive cells) and semen (the protective fluid around sperm). They discharge sperm into the female reproductive tract. They produce and secrete male sex hormones. 12  The male has reproductive organs, or genitals, that are both inside and outside the pelvis. The male genitals include: 1. the testicles the duct system, which is made up of the epididymis and the vas deferens 2. the accessory glands, which include the seminal vesicles and prostate gland 13 3. the penis How does the male reproductive system function? The primary hormones involved in the functioning of the male reproductive system are follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone. FSH and LH are produced by the pituitary gland. It’s located at the base of your brain and it’s responsible for many functions in your body. FSH is necessary for sperm production (spermatogenesis). LH stimulates the production of testosterone from leydig cells, which is necessary to continue the process of spermatogenesis. Testosterone is also important in the development of male characteristics, including muscle mass and strength, fat distribution, bone mass and sex drive. 14  Testicles (testes) The testes are oval organs that lie in the scrotum to keep it cool. Men have two testes. The testes are responsible for making testosterone, the primary male sex hormone, and for producing sperm. Within the testes are coiled masses of tubes called seminiferous tubules. These tubules are responsible for producing the sperm cells through a process called spermatogenesis. 15 The Sperm Pathway Seminal vesicles Testes Ejaculatory duct Sperm Prostate gland Epididymis Urethra Vas deferens Expulsion from the body