27 - Man

Question 1

List the similarities between the female and male reproductive systems.

Answer 1

1. Both produce gametes from primary reproductive organs (F - one oocyte per month, puberty to menopause, M - 100mil sperm per day, puberty to death)
2. Both produce relatively large amounts of sex hormones
3. Both sexes have accessory reproductive or sex organs

Question 2

Name the hormones responsible for initiating puberty in females and males.

Answer 2

GnRH - hypothalamus, FSH/LH - ant pit,

sex hormones from gonads - Estrogens, progesterone, testosterone

Question 3

Compare male and female roles in reproduction

Answer 3

Male: Make sperm,
Deliver sperm

Female:  Make ova, 
Receive sperm, 
Transport perm and ova, 
Fetal development, 
Nourish infant

Question 4

Gross anatomy of scrotum

Answer 4

Dartos, cremaster, spermatic cord

Question 5

Cremaster muscle

Answer 5

Bands of skeletal muscle that arise from the internal oblique muscles of the trunk (suspender)

Question 6

Dartos muscle

Answer 6

Layer of smooth muscle in the superficial fascia that wrinkles the skin of the scrotum. Controls scrotal sac.

Question 7

Pampiniform plexus

Answer 7

countercurrent mechanism -

spermatic artery, carrying warm blood to testes is circled with veins leaving the testes.

The spermatic veinous plexus absorb heat radiating off of the artery carrying away from the testes.

Question 8

Function of scrotum

Answer 8

Adjust temperature of testes

Question 9

Two ways intrascrotal temperature is regulated?

Answer 9

pampiniform plexus, cremaster/dartos muscle

Question 10

Gross anatomy of the testes

Answer 10

Seminiferous tubules, epidiymis, tunica vaginalis and bunginea

Question 11

Micro anatomy of the testes

Answer 11

Sustentacular/sertoli cells,

blood-testis barrier,

dividing germ cells that continuously produce sperm,

interstitial/Leydig cells,

Question 12

Function of the testes

Answer 12

Create sperm, produce androgens (testosterone most dominant)

Question 13

Sustenacular/sertoli cells

Answer 13

Sperm maturation is controlled, promoted, nursed by sertoli cells. Protctive environment.

Tight junctions create blood-testes barrier.

Each sertoli controls about 150 sperm cells.

Release ABP and Inhibin

clean up defective sperm,

Extend from basal lamina to tubule lumen in seminiferous tubule.

Question 14

Interstitial/leydig’s cells

Answer 14

Produce androgens/testosterone

Triggered by LH

Question 15

Seminiferous tubules

Answer 15

800’, sperm factories, most mature sperm in middle, orchestrated by sertoli

Question 16

Epididymis

Answer 16

Final maturation, learn to swim, ejaculated from.

If not ejaculated after a couple months they will be absorbed and processed by a macrophage.

Question 17

FSH

Answer 17

• main stimulus for spermatogenesis, talks to sustenacular cells to release ABP which causes the spermatogenic cells to bind and concentrate testosterone needed for spermatogenesis.

Question 18

LH

Answer 18

Binds to interstitial cells causing them to secrete testosterone needed for spermatogenesis.

Question 19

Testosterone

Answer 19

Acts as paracrine and hormone. Secondary male characteristics (hormone) and spermatogenesis (paracrine).

Question 20

Sperm pathway

Answer 20

Seminiferous tubules –> Straight tubule –> Rete testis –> Epididymis –> Ductus (vas) deferens –> Ejaculatory duct –> urethra (Ductus vas def is first structure outside testis)

Question 21

3 major accessory glands

Answer 21

Seminal vesicles, prostate, bulbourethral glands

Question 22

Seminal vesicles

Answer 22

Viscous, whitish-yellow, alkaline fluid.

Fructose for nutrients, prostaglandins that stimulate motility/smooth muscle contraction.

60-70% of semen.

Lies on posterior bladder surface, size of a little finger.

Question 23

Prostate gland

Answer 23

Slightly milky, weakly acidic, citric acid (energy in krebs), seminalplasmin (antibiotic), mucin (lube), prostate-specific antigen/PSA (protein to liquefy mass after ejaculation)

Encircles urethra just inferior to the bladder, peach pit size.

Question 24

Bulbourethral glands

Answer 24

Clear, viscous, mucin.

Mucus like substances for lube.

Also neutralizes acidity of urine.

Last gland to secrete, first to exit - lubes urethra.

Pea sized, Lies inferior to the prostate.

Question 25

Semen

Answer 25

Seminal fluid from glands + sperm, 3-5ml which included 200-500mil sperm. Alkaline - 7.2-8

Question 26

erection/ejaculation

Answer 26

Erection = Parasympathetic stimulates release of NO locally.

Ejaculation = Sympathetic spinal reflex. (bladder sphincter constricts, glands empty contents to urethra, contractions)

Question 27

Fertilization happens where?

Answer 27

Ampulla

Question 28

Importance of Blood-testis barrier

Answer 28

Prevents the membrane antigens of sperm escaping into bloodstream and activating an immune response.

Question 29

Hypothalmic-pituitary-gonadal axis

Answer 29

1. Hypothalamus GnRH, hypophyseal portal system, FSH/LH
2. FSH stimulates spermatogenesis by stimulating the sertoli cells to release ABP/androgen-binding protein. ABP keeps concentration of testosterone high in vicinity of spermatogenic cells.
3. LH binds to the instestitial/Leydig cells stimulating them to secrete testosterone, rising testosterone is final trigger for spermatogenesis.
4. Testosterone in bloodstream triggers other effects: mturation of sex organs, develop/maintain sex characteristics and libido.
5. ↑ testosterone inhibit GnRH and LH/FSH.
6. Inhibin produced by sustenocytes/sertoli when sperm count is high, inhibit GnRH FSH.