PHYSIOLOGY REPRODUCTIVE

Question 1

Where does spermatozoid production take place?

Answer 1

Testicle

Question 2

What is the function of the duct system (male)?

Answer 2

Guide gametes to urethra

Question 3

What is the function of accessory glands?

Answer 3

Provide an adequate “vehicle” for spermatozoid action

Question 4

What is the testicular parenchyma composed of?

Answer 4

Seminal ducts

Interstitial cells of Leydig

Question 5

What are the 2 types of cells found in seminal ducts?

Answer 5

Germinal

Sertoli

Question 6

What are 2 functions of interstitial cells of Leydig?

Answer 6

Testosterone production (in presence of LH)
Secondary sexual characteristics

Question 7

What is the function unit of the seminal ducts?

Answer 7

Seminal vesicle

Question 8

What do the seminal vesicles secretes for proper functioning of gametes?

Answer 8

Fructose
Prostaglandins
Alkaline fluid
Clotting factors

Question 9

What forms the ejaculatory duct?

Answer 9

Seminal vesicles + vas deferens

Question 10

What are the most relevant accessory glands of the male reproductive system?S

Answer 10

Prostate gland

Bulbourethral glands

Question 11

What are the main testicular functions?

Answer 11

Spermatozoid production
Steroid hormones (androgens) production

Question 12

Where are Leydig cells located?

Answer 12

In interstitial part of testicles

Question 13

In what part of the Leydig cells is cholesterol converted to pregnenolone?

Answer 13

Mitochondria

Question 14

In what part of the Leydig cells is pregnenolone converted to testosterone?

Answer 14

Smooth endoplasmic reticulum

Question 15

In what part of the Leydig cells are DHT and E2 secreted?

Answer 15

Periphery

Question 16

What are the seminiferous tubules composed of (cellular)?

Answer 16

Sertoli cells

Germinal epithelium

Question 17

What anatomical structure do the sertoli cells form?

Answer 17

Blood-testis barrier

Question 18

What is the function of the blood-testis barrier?

Answer 18

Partition interstitial blood compartment (testis) from adluminal compartment (seminiferous tubules)

Question 19

What are the adrenal androgens (androgens produced in adrenal cortex)?

Answer 19

DHEA

Androstenedione

Question 20

Which hormone stimulates the production of pregnenolone in leydig cells?

Answer 20

LH

Question 21

What is the precursor of DHEA?

Answer 21

Pregnenolone

Question 22

What enzyme converts pregnenolone into DHEA?

Answer 22

17a-hydroxylase

Question 23

Under influence of which enzymes is DHEA converted into testosterone?

Answer 23

3B-HSD

17B-HSD

Question 24

Which enzyme catalyses the conversion of testosterone into dihydrotestosterone & where?

Answer 24

5a-reductase in target tissues

Question 25

What enzyme catalyses the formation of cholesterol esters?

Answer 25

Acyl CoA cholesterol acyltransferase

Question 26

What protein transfers cholesterol to inner mitochondrial membrane?

Answer 26

StAR

Question 27

How is testosterone transported?

Answer 27

Mostly weak bond to albumin Some strong bond to SHBG 2% free

Question 28

What does bioavailable testosterone refer to?

Answer 28

Free & weakly bound (to albumin) testosterone

Question 29

What is the function of aromatase?

Answer 29

Facilitate conversion of: - testosterone to estradiol - androstenedione to estrone

Question 30

What are the sites of aromatase expression in males?

Answer 30

Reproductive tract Bone Adipose tissue

Question 31

What is gynecomastia?

Answer 31

Overdelopment of breast tissue in men due to adipose tissue increase

Question 32

How is testosterone metabolised?

Answer 32

Via hepatic conjugation with glucuronic acid or sulfate

Question 33

What occurs when testosterone/DHT binds to its androgen receptor?

Answer 33

Dissociation of heat shock proteins bound to androgen receptor

Question 34

3 comparable characteristics of DHT with testosterone (in relation to its androgen receptor)

Answer 34

DHT: - greater binding affinity - greater stability - slower dissociation rate

Question 35

Effect of testosterone on libido

Answer 35

Men and women Increased sexual drive Decreased libido with age

Question 36

Effect of testosterone on bone formation (men vs women)

Answer 36

Increased bone thickness | Women: PERIPHERAL aromatisation to estrogen accounts for increased bone strength in men

Question 37

Effect of testosterone on erythropoiesis

Answer 37

Promotes red blood cell formation

Question 38

Effect of excess estrogens on males

Answer 38

Gynecomastia Palmar erythema (redness) Spider angiomas

Question 39

Effect of estrogen deficiency

Answer 39

Metabolic syndrome

Question 40

Effect of estrogens on bone loss

Answer 40

Decreased resorption of bone (prevents loss in bone density & osteoporosis)

Question 41

Vasoprotective function of estrogens

Answer 41

Decreased risk of atherogenesis

Question 42

What triggers the release of LH and FSH into circulation?

Answer 42

Pulsatile release of GnRH from hypothalamus

Question 43

What does testosterone exert negative feedback on?

Answer 43

Pituitary LH | Hypothalamic GnRH

Question 44

What stimulates the release of inhibin from sertoli cells?

Answer 44

FSH

Question 45

What does inhibin exert feedback on?

Answer 45

Anterior pituitary release of FSH

Question 46

What cell releases inhibin?

Answer 46

Sertoli cells