Test 4: lecture 4: male

Question 1

function of testis

Answer 1

endocrine → testosterone

exocrine → sperm

Question 2

Synthesize and secrete testosterone in response to LH

Answer 2

leydig cells (interstitial cells)

outside the seminiferous tubule

similar to theca cells in female

Question 3

sertoli cells

Answer 3

sustentacular cell (nurse cells)

blood-testis barrier
• Convert testosterone to DHT and estrogen in response to FSH
• Secrete androgen-binding protein, inhibin, AMH

Question 4

___ connect sertoli cells and prevent things from passing into the lumen of the seminiferous tubule

Answer 4

tight junction

Question 5

three regions of the epididymis

Answer 5

caput (head)

corpus (body)

cauda (tail)

Question 6

roles of the epididymis

Answer 6

absorb fluid (principle cells)

movement

maturating of sperm

storage of sperm

Question 7

how does sperm maturation work in the epididymis

Answer 7

Plasma membrane undergoes changes

• Cytoplasmic droplet is removed (fall off the tail of the sperm)
• Sperm start swimming
• Maturation is completed inside the female

Question 8

functions of the accessory sex glands

Answer 8

seminal plasma → nutrient sperm, protect sperm, lubrication

prostaglandins cause smooth muscle contraction → will cause uterus to contract and move sperm into uterine tubes

Question 9

seminal plasma

Answer 9

Lubricate during copulation

• Neutralize acidic female tract
• Nourish and protect viable sperm, help target nonviable sperm for destruction
• Maintain membrane stabilization/delay capacitation
• Promote sperm transport in female tract
• Induce ovulation in some species → camalids (llama)
• Mediate sperm binding to uterine tube epithelial cells
• Contribute to copulatory plug

The amount of SP and semen concentration that enters the uterus
varies

Question 10

columns of the penis

Answer 10

corpus spongiosum → glands penis (area around the urethra

corpus cavernosum→ fill with blood → rigidity

Question 11

round spermatids morph into elongated spermatids

Answer 11

Spermiogenesis:

Question 12

creates haploid spermatocytes

Answer 12

meiosis

Question 13

the mitotic phase of spermatogenesis; produces spermatocytes from spermatogonia (diploid)

Answer 13

Spermatocytogenesis

Question 14

spermatogenesis

Answer 14

the production of spermatozoa
• Spermatocytogenesis: the mitotic phase of spermatogenesis;
produces spermatocytes from spermatogonia (diploid)

• Meiosis: creates haploid spermatocytes

• Spermiogenesis: round spermatids morph into elongated spermatids

Question 15

undifferentiated male germ cell

Answer 15

Spermatogonium(a)

• Males are born with a finite number of spermatogonia

Question 16

produced by mitosis of spermatogonia and will undergo meiosis

Answer 16

Spermatocyte

Question 17

the haploid result of meiosis

Answer 17

spermatids

Round: still have lots of cytoplasm and organelles

Elongated: have shed much of cytoplasm and organelles; have a tail.

Question 18

The release of elongated spermatids from the Sertoli cell into the lumen of the seminiferous tubule

Answer 18

spermiation

Question 19

the haploid product of spermatogenesis.

Answer 19

spermatozoa

spermatogonia→ spermatocytes→ haploid spermatocytes → spermatids → spermatozoa

Spermatogonia produce an infinite number of spermatozoa

Question 20

spermatogenesis

Answer 20

mitosis (connects to each other by bridge)

meiosis

Question 21

compare mitosis vs meiosis in male and female

Answer 21

Question 22

retinoic acid is important for

Answer 22

differentiation of spermatogonia(4N) to spermatocytes (2N)

(mitosis → type A→ type B cells)

mitosis → meiosis

Question 23

how does sperm move in seminiferous tubule

Answer 23

contraction of the tubule

spermatids have tails but they have not learned to swim yet

Question 24

___ cells convert testosterone to DHT

Answer 24

Sertoli

Question 25

\_\_\_ enhances concentrations of androgens in the testes

Answer 25

Androgen binding protein (ABP)

Question 26

\_\_\_ triggers production of testosterone in Leydig cells

Answer 26

LH

Question 27

LH enhances production of StAR which will

Answer 27

help move cholesterol into mitochondria

Question 28

\_\_\_ Promotes spermatogeneis, spermatocyte maturation, and spermiation; synthesis of ABP, inhibin, activin, estrogen

Answer 28

FSH

Question 29

negative feedback of spermatogenesis

Answer 29

Question 30

hormone in spermatogenesis

Answer 30

**LH** binds to leydig cells and cause the **release of testosterone** testosterone moves across the basement membrane into the sertoli cell **FSH** binds to sertoli cell and causes the release of **ABP and aromatase,** the ABP and testosterone move into the lumen of the seminiferous tubule **aromatase** converts **testosterone → estrogen (estradiol)** estrogen will travel back into leydig cell and increase testosterone release

Question 31

why are abusers of anabolic steroids frequently infertile?

Answer 31

negative feedback anabolic steroid reduce FSH and LH which leads to decrease of testosterone in the seminiferous tubules

Question 32

what happens to DNA in sperm

Answer 32

moves from histones to protamine allows for super coiling → inactivates

Question 33

pathway of ejaculation

Answer 33

Seminiferous tubules Rete testis Efferent ductules Epididymis Vas deferens

Question 34

phases of sexual response for males

Answer 34

**Erection**: parasympathetic response **Emission:** sympathetic response **Ejaculation:** sympathetic response

Question 35

Upon ovulation, sperm are released and undergo \_\_\_prior to fertilization

Answer 35

**hyperactivation and capacitation** increase Calcium into the sperm (fast swimming) increased fluidity → plasma membrane changes

Question 36

what causes the breakdown of the zona pellucida

Answer 36

binding of sperm acrosome reaction

Question 37

binding of sperm causes

Answer 37

acrosome reaction breakdown of the zona pellucida and release of cortical granules into the perivitelline space this causes ZP to harden and **prevent polyspermy** **meoisis II is resumed and completed**

Question 38

granules from the sperm are released into the ___ during the acrosome reaction

Answer 38

perivitelline space (slow block → calcium release causes hardening of the ZP that prevents other sperm from entering)

Question 39

fertilization causes the formation of ___ that fuse to form the zygote

Answer 39

pronucleus

Question 40

prepuberty

Answer 40

Hypothalamic pituitary gonadal axis is suppressed, and GnRH secretion is maintained at low levels

Question 41

gonadostat hypothesis

Answer 41

**during prepuberty sex organs work but they are very sensitive to negative feedback → kept turned off. At puberty something changes and they are less sensitive and now work** Puberty Hypothalamus becomes **less sensitive to negative feedbac**k, and a new set point is created • GnRH increases * FSH and LH increase * Steroid hormone levels rise **Secondary sex characteristics develop**

Question 42

steps of meiosis

Answer 42