Reproductive System

Question 1

What are the male reproductive hormones?

Answer 1

FSH
LH
Testosterone

Question 2

What are the gonodrophic hormones?

Answer 2

FSH and LH
Consist of 2 polypeptide chains, alpha and beta

Question 3

Give the physiological actions of testosterone?

Answer 3

In foetus:
Development of male gonads,
development of wolfian duct into vas deferens, development of penis, descent of testes
Masculinisation of brain
At puberty:
male pattern of body hair legs, chest
growth factor effects lead to bone development and muscle formation (enhanced protein synthesis)
acne
In adulthood:
Spermatogenesis
Sex drive (interaction with hypothalamic cells)
Maintains Reproductive structure/function
Maintains anabolic effects on bone/muscle

Question 4

What is the main function of FSH in males?

Answer 4

Stimulate synthesis of products required for spermatogenesis

Question 5

Outline the process of spermatogenesis

Answer 5

At puberty spermatogonia divide (mitosis)
Spermatocytes then undergo Meiosis
Yields Spermatozoa (Haploid Stages of number of unduplicated Sperm chromosomes) maturation
Spermiogenesis – reduction of cytoplasm and tail piece differentiation
Transport and further maturation
Storage in cauda of epididymus and ampulla of vas deferens

Question 6

Give an overview of the formation of ejaculate

Answer 6

60% of semen volume produced at the seminal vesicles
10% of semen volume at the epididymus
30% of semen volume at the prostate

Question 7

Outline the process of erection and ejacualtion

Answer 7

Erection:
Engorgement of penis with blood for vaginal penetration
Cholinergic reflex
ACH also leads to enhanced release of NO which dilates penile arterioles
Alters calcium signalling
Ejaculation:
Emission
SNS contraction of prostatic, reproductive duct and vas deferens smooth muscle
Propels sperm into urethra

Question 8

List the female reproductive hormones

Answer 8

FSH
LH
Oestrogen
Progestin
Activism/ inhibits

Question 9

Give some potential, genetic and nutritional factors that could induce the menstrual cycle

Answer 9

Potential- Inc GnRH
Plasticity leads to LH surge, marks initiation 1st menstrual cycle
Genetic- similiar in mother and daughter
Nutrition- improved nutrition in developed countries leads to earlier menarche

Question 10

Give the different phase sf the menstrual cycle

Answer 10

Days 0-14: Oestrogen production predominates
Day 14= Ovulation
Days 14-28: Luteal phase- progesterone is elevated

Question 11

Describe the menstrual phase

Answer 11

Breakdown of corpus luteum decreased progesterone Endometrium shed (period) -4 days with 30 mls blood loss

Question 12

Describe the proliferate phase

Answer 12

Increased estrogen levels as follicle develops Proliferation of epithelial (secretory) and stromal (connective tissue)

Question 13

Describe the secretory phase

Answer 13

Corpus luteal cells increase progesterone production Maturation of endometrium and increased secretion for implantation

Question 14

What is the minimum function of FSH in females?

Answer 14

Stimulate synthesis of enzymes to produce estrogenns in both follicular and leutal phase

Question 15

What is aromatase?

Answer 15

Enzyme that converts testosterone to estradiol
Converts androstenedione to store then estradiol

Question 16

Give 5 physiological effects of oestrogens

Answer 16

1. Smooth muscle – uterine, enhances effects of oxytocin
2. Breast tissue – proliferation (excess linked to cancer)
3. Stimulated thickening of vaginal epithelium (secretions)
4. Regeneration and proliferation of endometrium 5.Increased oviduct ciliated cells - movement of ovum

Question 17

What changes does oestrogen induce during puberty?

Answer 17

Breast development
Female distribution of adipose tissue
Inc organ size
Rapid epihyseal fusion

Question 18

What are the physiological effects of progestins?

Answer 18

Fallopian tube – increased ciliary movement Endometrium – secretory activity
Cervix – decreased mucus and increased viscosity – sperm retention
Smooth muscle: decreases contractility (uterine) Decreases sodium reabsorption through actions at aldosterone receptor

Question 19

How s progesterone involved in ovulation?

Answer 19

Enhances LH surge and inhibits estrogen which causes:
Stimulates college age in the follicular wall, which forms a stigma
Prostaglandins to increase blood flow, which causes follicular swelling

Question 20

Outline the 4 stages of the female sex response

Answer 20

1. Excitement – psychological factors, sight, tactile stimuli
2. Plateau – culmination of vasocongestion throughout body
3. Orgasm (hopefully) – myotonic response (sympathetically mediated)
4. Resolution – feelings of satisfaction – no refractory phase (male)

Question 21

What are the physical effects of menopause?

Answer 21

Atrophy of vaginal epithelia – decreased secretion and pH changes
Vaginal dryness – Female sexual dysfunction Osteoporosis
Cardiovascular disease (loss of protection)
Hirsuitism (change in androgen/estrogen ration) Hotflush (GnRH, hypothalamic thermoregulation)

Question 22

Give the 4 cognitive effects of menopause

Answer 22

Moodswings
Short-term memory loss
Headaches
Loss of Libido

Question 23

Oultine the development of the placenta up to 8 weeks

Answer 23

Multinucleate mass forms the primary connections of maternal blood supply
HCG is secreted into the villus
Secretion of progesterone an estrogens is maintained from corpus luterum

Question 24

Outline the role of the placenta

Answer 24

Gaseous exchange
Act barrier to prevent transmission of harmful molecules from mother to foetus

Question 25

Give the roles of progesterone during pregnancy?

Answer 25

Maintains optimal conditions throughout pregnancy Primes breast for lactation
Mucus plug production-cervix-prevent infection to foetus via vagina

Question 26

What are the key roles of oestrogens during pregnancy?

Answer 26

Facilitates growth of breast, epithelial and duct cells Stimulates prolactin production
Inhibits milk production (divert maternal nutrients away from foetus)
Sensitizes the myometrium to the actions of oxytocin Stimulates uterine growth
Relaxes pelvic ligaments – preparation for parturition.

Question 27

How does foetal growth impact maternal cardiovascular function?

Answer 27

Inc RBC prod- Inc blood carrying capacity
Inc level of clotting factors - protects in case of haemorrhage during parturition
Inc cardiac output- ensures sufficient blood flow to foetus

Question 28

What is the role of Human Chronic Smatomammotropin?

Answer 28

Convert glucose to FA and ketones for foetus to use as fuel source
Promotes development of mammary glands
Structurally similiar to growth hormone

Question 29

How does the pancreas function change during pregnancy?

Answer 29

Increased Cortisol and hCS
Elevated levels of blood glucose
Hyperplasia pancreatic beta cells to produce elevated insulin
Maternal Hyperinsulinaemia
Insulin resistance
Increased Glucose for foetal use

Question 30

What’s re the functional changes of the thyroid gland during pregnancy?

Answer 30

Hyperplasia inc PTH
This inc Ca availability

Question 31

List the stages of labour

Answer 31

0- Uterus refractory to contraction
1- Initiation of parturition and cervical dilatation
2- Active labour- complete dilatation and delivery
3- Expulsion of the placenta

Question 32

What is parturition?

Answer 32

The process of giving birth

Question 33

List the properties of oxytocin

Answer 33

9 amino acid neuropeptide hormone
Synthesised by cell bodies of neurons in PVN and SON
Stored in vesicles until released into circulation via posterior pituatay by appropriate stimulus

Question 34

How is partition initiated?

Answer 34

Uterus placenta and foetal membranes synthesise and secrete prostaglandins
3 main effects:
1. Strong stimulus to contract uterine smooth muscle 2. Potentiates oxytocin induced contractions by increasing gap junction number
3. Softening, dilatation and thinning of cervix

Question 35

Give the biological properties of prolactin

Answer 35

Decreases GnRH secretion- inhibiting menstrual cycle
Inhibits follicular development
Enhances cellular proliferation in breast