Reproductive System; Male Flashcards
(47 cards)
Male and female reproductive system consist of
Gonads and Accessory Reproductive Organs
Gonads
(primary sex organs):testesin the male,ovariesin the female
Gonads Function
produce gametes (sex cells): sperm or oocytes 2) 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
Accessory Reproductive Organs (2)
– the reproductive system is not fully functional until puberty
– 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 needFSH and LHto start gamete maturation and increased sex hormone production by the gonads
Testis Functions
1) to produce sperm
2) to produce androgens (male sex hormones)
* of the androgens, testosterone is the principal sex hormone
Testes External Anatomy
testes suspended in scrotum
Scrotum Function
to keep testes in a cooler external environment (3 degrees C cooler than internal body temp), to allow for normal sperm production
Spermatic Cord
runs from each testis into the abdomen
* contains blood vessels, nerves,and theductus (vans) deferens
Testis Internal Anatomy
– each testis divided into a series of internal compartments calledlobules
– each lobule contains up to 4seminiferous tubules (a tightly coiled structure, wheresperm are produced)
Testis - Within Seminiferous Tubules (1)
Spermatogonia: “stem cells” that help produce sperm
* these are the most immature male sex cells (This are on the outside of the tubule)
Testis - Within Seminiferous Tubules (2)
developing sperm (These are located more interiorly of the tubule, sperm develop from the outside edge toward the middle)
Testis - Within Seminiferous Tubules (3)
Sustentacular cells:these cells support, protect and nourish the developing sperm
Between Seminiferous Tubules
is someconnective tissue andinterstitial cells
*functionof these cells:produce and secrete androgens (specifically, testosterone)
Sperm Production
sex cells (gametes) created by MEIOSIS
* review your meiosis notes from exam 1 material!
* end result of meiosis: 4 cells produced, each w/23 chromosomes only!
First Step; Spermatogonia
- each contains 23 pairs of chromosomes (total: 46 chromosomes - diploid)
–divide by Mitosis and produceprimary spermatocytes
Second Step; Primary Spermatocytes
still 23 pairs of chromosomes (46 chromosomes - diploid)
* these cells divide by MEIOSIS * when they finish the 1st Meiotic Division, they form secondary spermatocytes
Third Step; Secondary Spermatocytes
contain 23 chromosomes only (haploid)
* they finish the 2nd Meiotic Division to produce spermatids (This is the end of Meiosis II)
Fourth Step; Spermatids
immature sperm - contain 23 chromosomes only (haploid)
*spermatids develop into sperm (spermatozoa)
Fifth Step; Sperm (Spermatozoa)
sperm will “shed” the cytoplasm from the spermatid, and develop:
1)head: contains DNA
* on head is an acrosome cap (Enzymes)
2)Midpiece (mitochondria)
3)tail (Flagellum)
Six Step: Release
sperm are then released from the sustentacular cell cytoplasm, and enter the lumen of seminiferous tubule
Regulation of the testes (1)
FSH from anteritor pituitary to sertoli cells on testes? – (Androgen-binding protein) facilitates sperm production; it is up to them to support this developing sperm
Regulation of the testes (2)
LH from anterior pituitary to interstitial cells – testosterone; LH encourages interstitial cells to produce testosterone
Spermatic Duct System - Epididymis
comma-shaped organ, located posterior to and on top of testis
* receive sperm from testis
