The Reproductive System
Male Reproductive System
Penis Delivers sperm into the female reproductive tract
Testes The MALE gonad that serves as both a reproductive and endocrine organ. Where sperm is produced. Where testosterone is produced.
Epididymis Comma-shaped, tightly coiled tube Functions to mature and store sperm cells (at least 20 days) Expels sperm with the contraction of muscles in the epididymis walls to the vas deferens
Testes Vas Deferens Carries sperm from the epididymis to the ejaculatory duct Moves sperm by peristalsis
Seminal Vesicles Located at the base of the bladder Produces a thick, yellowish secretion (60% of semen) Fructose (sugar) Vitamin C Prostaglandins (regulating molecules) Other substances that nourish and activate sperm
Prostate Gland Encircles the upper part of the urethra Secretes a milky fluid Helps to activate sperm Enters the urethra through several small ducts
Semen Mixture of sperm and other secretions Fructose provides energy for sperm cells Alkalinity of semen helps neutralize the acidic environment of vagina
Anatomy of a Mature Sperm Cell The only human flagellated cell DNA is found in the head
A vasectomy
Female Reproductive System
Define these words! 1. Oocyte – p Ovum 3. Ovulation 4. Follicle 5. Corpus luteum 6. Fertilization 7. Gestation 8. Blastocyst 9. Zygote 10. Embryo 11. Fetus
Ovaries The FEMALE gonad that serves as both a reproductive and endocrine organ. Where eggs are produced. Where hormones are produced. Composed of ovarian follicles (sac-like structures)
Uterine (Fallopian) Tubes Receive the ovulated oocyte Provide a site for fertilization Attaches to the uterus
Fallopian Tube Function Fimbriae – finger-like projections at the receive the egg Cilia inside the tube slowly move the egg towards the uterus (takes 3–4 days) Fertilization occurs inside the fallopian tube.
Uterus Located between the urinary bladder and rectum Hollow organ Functions of the uterus Receives a fertilized egg Retains the fertilized egg Nourishes the fertilized egg
Walls of the Uterus Endometrium Inner layer Allows for implantation of a fertilized egg Sloughs off if no pregnancy occurs (menses) Myometrium – middle layer of smooth muscle Serous layer – outer visceral peritoneum
Endometriosis is the condition in which the tissue that normally lines the uterus (endometrium) grows on other areas of the body causing pain and irregular bleeding.
Tubal Ligation
HORMONES
Hormones in the Menstrual Cycle
1.Gonadotropin Releasing Hormone (GnRH) stimulates the pituitary gland. 2.The pituitary gland releases FSH, which stimulates a follicle. 3.The follicle releases E. 4.E increases the endometrium and slows production of FSH, but stimulates the production of LH 5.LH causes ovulation. 6.P is produced which prepares the uterus and stops LH and FSH. 7.If fertilization doesn’t occur, the cycle starts over. GnRH
Male Hormone Testosterone ◦ Produced by the testes. ◦ Functions include: Secondary sexual characteristics (facial hair, extra muscles, deeper voice) Growth and activity of reproductive organs Spermatogenesis Sexual desire Enhances immune function Protection against osteoporosis
In Vitro Fertilization “in vitro” = “in glass” IVF= fertilizes egg outside the body The first “test-tube baby” was Louise Brown in Why do it?
Infertility Female ◦ Sperm death ◦ Uterus prevents implantation ◦ Blockage of duct ◦ Egg failure Male ◦ Impotence ◦ Abnormal sperm ◦ Short-lived sperm ◦ Low #’s ◦ blockage
Steps 1. Menstruation stopped 2. FSH injected for super-ovulation 3. Semen sample 4. Eggs removed from ovary 5. Mix 6. Incubate 7. Transfer- up to 3
Let’s discuss! In groups of 3-4, come up with 4 or 5 arguments FOR and AGAINST in vitro-fertilization.