Lecture 14: The Genital (Reproductive) System Flashcards
what is the reproductive system
-Does not function continuously like other organ systems
-Does not become active until puberty
-Male and female reproductive organs are quite different, but perform four functions in common
what are the 4 common functions of both male and female reproductive systems
gametogenesis, copulation, fertilization, and development of fetus
what is gametogenesis
formation of specialized cells (gametes) for sexual reproduction
-sperm: gametes in males
-ova (eggs): gametes in females
what is copulation (coitus)
brings male and female gametes together through sexual intercourse
what is fertilization
combine genetic information contained within gametes through fertilization
-zygote: formed when sperm and egg fuse
-first cell of new individual and all body cells arise from it
what is gestation and parturition
the reproductive system support the development of fetus (gestation) and birth of baby (parturition)
what are the two types of reproductive organs
gonads & accessory reproductive organs
describe the gonads
primary sex organs
-testes: males
-ovaries: females
-produce two products: gametes, and sex hormones
describe gametes produced by gonads
-sperm: male
-ova: female
gamete formed by cell division is called meiosis
describe the sex hormones produced by gonads
sex hormaones are steroid hormones
-testosterone= males
-estrogen & progesterone= females
-vital in development and function of reproductive organs and other organs/tissues, sexual behavior, sexual drives
describe accessory reproductive organs
ducts, glands, and external genitalia
what are the functions of the male reproductive system
- testes (gonads): produce sperm and testosterone
- ducts: transport, storage, and maturation of sperm
- accessory glands: secrete liquid protion of semen
- penis: urethra within, passageway for semen ejaculation
describe the scrotum
-A sac of skin and superficial fascia
-Hangs outside abdominopelvic cavity
-Anterior to anus; inferior to base of penis
-Contains paired testes
-2 – 3°C lower than core body temperature
-Lower temperature is necessary for
sperm production
what is the midline septum of the scrotum
divide scrotum into two compartments, one for each testiw
what is the raphe of scrotum
raised thickening in scrotal surface
how is the scrotum affected by temp changes
when cold, testes are pulled closer to warm body wall
what does the dartos muscle do
smooth muscle layer that wrinkles the skin
what do the cremaster muscles do
skeletal muscles that elevate testes
describe testes
paired, oval glands within the scrotum (scrotal cavity) surrounded by two tunics:
-Tunica vaginalis: outerlayer derived from peritoneum (releases fluid into cavity to allow movments of testes in scrotum)
-Tunica albuginea: inner layer forms fibrous capsule (support erection)
what are the two tunics of the testes
tunica vaginalis & tunica albuginea
explain the histology of the testes
-Septa divide testis into ~250 lobules, each containing 1-4 seminiferous tubules
-Site of sperm production (spermatogenesis); Each is about 80 cm long
-Connect to rete testis, a network of interconnected straight tubules
-Efferent ductules connect rete testis to epididymis
describe the histology of the testes, more specifically the seminiferous tubules
-surrounded by CT capsules
-Areolar tissue fills spaces b/w tubules
-Within those spaces, there are:
* Blood vessels
* Large interstitial endocrine cells
→ Leydig cells: Produce androgens, dominant male sex hormones. Testosterone is most important androgen
what are the effects of testosterone
-Stimulates spermatogenesis
-Maintains libido (sexual drive) and related behaviors
-Stimulates bone and muscle growth
-Establishes and maintains male secondary sex characteristics
-Maintains accessory glands and organs of male reproductive system
what is the role of sustentocytes (Nurse/ sustenticular cells) of seminiferous tubules
-Provide nutrients and signals to dividing cells
-Move spermatocytes and spermatids along to lumen
-Secrete testicular fluid (rich in androgens and
metabolic acid) into lumen for sperm transport
-Phagocytize faulty germ cells and excess cytoplasm
-Produce 2 mediators to regulate spermatogenesis:
1. Androgen-binding protein (ABP): keeps
testosterone levels high to stimulate spermatogenesis
2. Inhibin: inhibits spermatogenesis by inhibiting FSH
release by anterior pituitary