Exam 4: Male Reproductive System Flashcards
Gonads
testes in the male, ovaries in the female
-functions: produce gametes (sex cells): sperm or oocytes, produce sex hormones
Accessory Reproductive Organs
- include “ducts” that transport/store the gametes, glands that secrete substances for the gametes’ well-being, and the external genitalia
Reproductive System and Puberty
- not fully formed until then
- at puberty hypothalamus secretes hormones that tell anterior pituitary to release FSH (follicle stimulating hormone) and LH (luteinizing hormone), which act on ovaries and testes
- so you need FSH and LH to start gamete maturation and increased sex hormone production by the gonads
- hypothalums–>anterior pituitary–>FSH and LH–>gonads
Testis Function and External Anatomy
- functions: produce sperm and produce androgens (male sex hormones)
- suspended in scrotum
Scrotum
-function: keeps testes 3 degrees C cooler than internal body temperature so sperm can be produced (if too warm, sperm won’t develop)
Spermatic Cord
- runs from each testis to abdomen
- contains blood vessels and nerves and the ductus (vas) deferens
Testis Internal Anatomy
- each testis divided into a series of internal compartments called lobules
- each lobule contains up to 4 seminiferous tubules within the seminiferous tubules are: spermatogonia, developing sperm Sustentacular cells
- between seminiferous tubules is some connective tissue, with interstitial cells
Spermatogonia
- sperm stem cells or parent cells
- at base/edge of seminiferous tubules
Sustentacular Cells
- nurse cells/sertoli cells
- nourish and support developing sperm
Intersticial Cells
-function: produce androgens
Sperm Production
- sex cells (gametes) created by MEIOSIS
- end result of meiosis: 4 cells produced, each w/23 chromosomes only!
- Meiosis I: DNA replicated and homologous chromosomes split (haploid at end) Meiosis II: sister chromatids split forming 4 new haploid cells
Cell Division in Males
-spermatagonia divide by MITOSIS and make primary spermatocytes which divide by MEIOSIS making secondary spermatocytes, divide in MEIOSIS II making spermatids which develop into sperm
Spermatogonia
- 23 pairs of chromosomes (46 total)
- divide by mitosis
- diploid
Primary Spermatocytes
- 23 pairs of chromosome (46 total)
- diploid
- divide by meiosis I
Secondary Spermatocytes
- contain only 23 chromosomes
- haploid
- divide by meiosis II