Endocrine Control of Sex and Reproduction

Question 1

What is endocrine signaling?

Answer 1

Long-distance signaling via bloodstream

Question 2

What is paracrine signaling?

Answer 2

Short-range signaling between neighboring cells

Question 3

What is autocrine signaling?

Answer 3

A call signals tp itself via its own receptors

Question 4

What does the HGP axis stand for?

Answer 4

Hypothalamus-Pituitary-Gonad axis

Question 5

Which hormones are involved in the HPG ax-s?

Answer 5

Hypothalamus: GnRH
Pituitary: LH and FSH
Gonads: Estrogens, Androgens, Progesterone, AMH, Inhibin, Activin

Question 6

How is hormone release regulated?

Answer 6

Through negative feedback loops

Question 7

When does sexual differentiation begin in embryos?

Answer 7

After 6 weeks gestation

Question 8

What is the ‘defult’ sexual development pathway?

Answer 8

Female

Question 9

What structure leads to male reproductive development?

Answer 9

Wolffian ducts –> epididymis and vas deferens

Question 10

What hormone casue Mullerian ducts to regress in males?

Answer 10

Anti-Mullerian Hormone (AMH)

Question 11

What is the role of the SRY gene?

Answer 11

Acts as the ‘master switch’ for testies development

Question 12

What transcription factor partners with SRY?

Answer 12

SF1 (Steroidogenic Factor 1)

Question 13

What happens wihtout SRY?

Answer 13

Development follows the ovarian pathway

Question 14

Where is testerion produced in males?

Answer 14

Leydig cells of the testis

Question 15

What is DHT?

Answer 15

A more active form of testosterone created by 5a-reductase

Question 16

What are the effects of testosterone?

Answer 16

Masculinisation
Increased muscle
Deep voice
Body hair etc.

Question 17

What is Freemartin Syndrome?

Answer 17

Female cattle virilised due to shared uterus with male twin

Question 18

What causes the reproductive changes in Freemertins?

Answer 18

AMH and testosterone from the male twin

Question 19

Which cells produce testosterone in males?

Answer 19

Leydig cells

Question 20

Which cells support spermatogensis?

Answer 20

Sertoli cells

Question 21

What doe sertoli cells secrete?

Answer 21

Inhibin
Activin
AMH
Androgen-binding protein (ABP)

Question 22

What hormone stimulates sertoli cells?

Answer 22

FSH

Question 23

What hormone stimulates Leydig cells?

Answer 23

LH

Question 24

What hormone provides feedback to reduce LH?

Answer 24

Testosterone

Question 25

What provides feeedback to reduce FSH?

Answer 25

Inhibin

Question 26

Where are spermatogonia located?

Answer 26

Near th ebasal membrane of seminiferous tubules

Question 27

How long does sperm production take?

Answer 27

64 days

Question 28

What rolse do tight junctions play?

Answer 28

They reorganise as sperm move thorugh developmental stages

Question 29

What are the primary cell types in the ovary?

Answer 29

Granulose Thecal cells

Question 30

Which hormone stimulates granulosa cells?

Answer 30

FSH

Question 31

Which hormone stimilates thecal cells?

Answer 31

LH

Question 32

What enzyme converts androgens to estrogens in granulosa cells?

Answer 32

Aromatase

Question 33

What are the ovarian cycle phases

Answer 33

Follicular phase Ovulation Luteal pahse

Question 34

What are the uterine cycle phases?

Answer 34

Menses Proliferative phase Secretory phase

Question 35

What causes endometrail thickening?

Answer 35

Estrogens from granulosa cells

Question 36

What feedback effect does estrogen have in early follicular phase?

Answer 36

Negative on FSH and LH

Question 37

What feedback effect does estrogen have in late follicular phase?

Answer 37

Positive - leads to LH surge

Question 38

What triggers ovulation?

Answer 38

The LH surge

Question 39

What enzzymes are released for ovulation?

Answer 39

Collagenase and other from the mature follicle

Question 40

What is released along with the egg?

Answer 40

Antral flluid and granulosa cells

Question 41

What structure forms post-ovulation?

Answer 41

Corpus luteum

Question 42

What hormones does teh corpus luteum produce?

Answer 42

Progesterone and estrogen

Question 43

What physiological effects deos progesterone have?

Answer 43

Thickens cervical mucus Raises basal body temperature Perpares edometrium