male urogenital system

Question 1

male blood supply

Answer 1

testicular artery from aorta

venous drainage from IVC

Question 2

spermatozoa

Answer 2

smallest human cell
3 micron diameter
highly condensed DNA

Question 3

functions of testis

Answer 3

production of spermatazoa and male sex hormones

Question 4

divisions of tubules

Answer 4

seminiferous tubules -> rete testes -> into epididymus

Question 5

centre of seminiferous tubules

Answer 5

spermatozoa

production of cells occurs from maturation from the peripheral to central region of the tubule

Question 6

interstitium between tubules contains

Answer 6

leydig cells = hormone production (androgen)

blood, nerve and lymph vessels

Question 7

making sperm called

Answer 7

spermatogenesis

Question 8

stages of sperm cells in 3 phases of life

Answer 8

fetal = primordial germ cells populate the testes with spermatogonia 
childhood = cells quiescent 
puberty = spermatogenesis begins

Question 9

initial mitosis produces

Answer 9

spermatogonia (A) produces spermatogonia (B) and replenishes the stem cell pool
spermatogonia (B) undergo mitosis to produce primary spermatocytes

Question 10

primary spermatocytes undergo

Answer 10

meiosis 1

Question 11

secondary spermatocytes undergo

Answer 11

meiosis 2

Question 12

stages of mitosis into mature cells

Answer 12

primary spermatocytes -> secondary spermatocytes (meiosis 1)
secondary spermatocytes -> round spermatids (meiosis 2)
round spermatids -> differentiating spermatids -> residual bodies and spermatozoa

Question 13

cytoplasmic bridges between cells function

Answer 13

allows for synchronisation

can transfer mRNA and proteins between haploid cells

Question 14

how does differentiation occur in the tubule

Answer 14

from the peripheral to the lumen

Question 15

function of Sertoli cells

Answer 15

form the blood-testis barrier

support

Question 16

why is the blood testis barrier needed

Answer 16

spermatogenesis begins after immune system is developed so sperm are ‘foreign’
Sertoli cells control lumen environment, separate lumenal and basal comportments. support spermatogenesis, secrete nutrients, absorb waste and phagocytose defunct sperm

Question 17

unique feature of cell divisions

Answer 17

divisions are incomplete

cells remain linked together and have junctional contacts with sertoli cells

Question 18

features of sperm DNA

Answer 18

DNA is packed more tightly than somatic cells

sperm DNA packed on protamines, not histones

Question 19

length of spermatogenesis process

Answer 19

about 60 days
new cohorts begin about every 12 days
within the tubule, adjacent parts are at different stages

Question 20

spermiogenesis stages

Answer 20

Golgi phase -> cap phase -> acrosome phase -> maturation

Question 21

features of sperm maturation

Answer 21

• Golgi assembles on one side, will form acrosome
• opposite side to this is flagella development, mitochondria move closer to flagella
• much of cytoplasm lost
• on top of acrosome plasma membrane, get receptors for the zona pellucid and oocyte membrane

Question 22

features of mature sperm

Answer 22

• mobile
• receptors for zona pellucida and oocyte
• can penetrate the zona pellucida and activate oocyte

Question 23

endocrine control from puberty

Answer 23

hypothalamic kisspeptin neurons activated
GnRH released in pulses from hypothalamus
stimulates secretion of FSH and LH
feedback control of hormones to pituitary and hypothalamus

Question 24

action of FSH

Answer 24

initially stimulates Sertoli cell division, then secretion (specific protein)

Question 25

action of LH

Answer 25

acts on Leydig cells to produce testosterone and androgens

Question 26

epididymus structure

Answer 26

very long could tube, about 7m | 4-6 weeks for sperm to pass through

Question 27

function of epididymus

Answer 27

sperm maturation removes cytoplasmic droplet from spermatozoa adds a glycoprotein coat over sperm heat concentrates spermatozoa allow development of unidirectional motility

Question 28

function of vas deferens

Answer 28

transport spermatozoa and can store them in its ampulla contract mainly in relation to sympathetic stimulation seminal vesicles pass into vas deferens

Question 29

seminal vesicles function

Answer 29

produce the major fluid component of sperm produce fructose as energy contracts mainly in relation to sympathetic NS

Question 30

prostate function

Answer 30

androgen dependent produce some factors in seminal fluid, not well understood key organ in cancers

Question 31

constituents of sperm

Answer 31

20 million sperm/ml seminal vesicles (2/3 volume) = fructose, fibrinogen, prostaglandins prostate (1/3 volume) = bicarbonate buffers, enzyme, citric acid, exosomes a few drops from bulbourethral gland = buffers. mucus

Question 32

what occurs during arousal

Answer 32

erection and arteriolar vasodilation

Question 33

how does arousal occur

Answer 33

NO (parasym) and cGMP, veins compressed and blood pressure increases - elevation of scrotum - elevation and swelling of testes

Question 34

what occurs during plateau

Answer 34

distension of penis and testis, mucus bulbourethral gland secretion

Question 35

what occurs during orgasm

Answer 35

emission with contraction of tubules and relaxation of urethras sphincter (sympathetic), ejaculation with rhythmic contraction of perineal striated muscle and anal sphincter (somatic)

Question 36

what occurs during refractory resolution

Answer 36

return to non-aroused state

Question 37

phases of nervous control

Answer 37

parasympathetic sympathetic somatic

Question 38

position of testes

Answer 38

in scrotum

Question 39

function of the vasa efferent

Answer 39

connect the rete testes to the head of the epididymus

Question 40

route of vas deferens

Answer 40

passes through the inguinal canal and exits the deep inguinal ring down to each testis

Question 41

control of testis temperature

Answer 41

kept cool in counter current heat exchange cremaster and dartos muscles contract the scrotum and draw the testis into the abdominal cavity when cold

Question 42

effects of testosterone

Answer 42

``` secondary sexual characteristics growth of reproductive organs hair growth increased libido voice drops ```