W01: Male & Female Repro Phys

Question 1

Female Reproductive Organs

Answer 1

Ovaries: ovarian follicles which undergo oogenesis

Fallopian Tubes: Egg pickup

Uterus: Body - Implantation
Cervix - communicates with the vagina

Question 2

Structure and function of ovary

Answer 2

Surface: connective tissue, simple cuboidal epithelium

Cortex: peripheralconnective tissue containing FOLLICLES; one oocyte surrounded by single layer of. cells

Medulla: central, vascular

Functions:
1) OOCYTE PRODUCTION = one mature egg per menstrual cycle

2) STEROID HORMONE PRODUCTION =
* estrogen develops female 2º sexual characters,
* progesterone prepares. endometrium for implantation
* 50% testosterone production before menopause

Question 3

Process of oogenesis

Answer 3

1. Foetal life: mitotic cell divison of oogonia = primordial germ follicles, process arrests until puberty sets in.
2. Puberty: hormone secretion = meitoic process resumes = primordial follicle => primary and secondary follicle
3. Fertilisation: second meitoic division after fertilisation

Question 4

What is a primordial follicle

Answer 4

Primary oocyte arrested in first meitoic division surrounded by one layer of squamous pre granulosa cells

Question 5

What is a primary follicle

Answer 5

Oocyte surrounded by zona and cuboidal granulosa cells

Question 6

Secondary follicle

Answer 6

Increased oocyte diameter and multiple layer of granulosa cells, resumption of first meiotic division

Question 7

Tertiary/Graffian Follicle

Answer 7

Follicular fluid secreted between the cells to coalesce to form antrum, completion of first meiotic division to form secondary oocyte and start of second meiotic division.

*start of antral phase

Question 8

What follows the graffianfollicle

Answer 8

The preovulatory follice: the egg is surrounded by granulosa cells as well as antrum (pool of fluid)

Question 9

Endocrine control of ovarian cycle; peaks and resulting effects

Answer 9

Gonadotropins acting on ovarian cycle:
1) FSH + LH increased = follicle developmnt
2) LH surge dt ESTROGEN peak = ovulation
= fertilised egg OR corpus luteum

Ovarian hormones acting on ovarian cycle:
1) Estrogen peaks followed by Luteal phase
2) Progesterone peaks = corpus luteum
3) E + P drop = -ve feedback stops = gonadotrophins released again

*meanwhile endometrium synchronously prepared

Question 10

Endocrine control of menstrual cycle

Answer 10

• Endometrium thickens throughout the menstrual cycle dt ESTROGEN
• Mid-cycle: vascular changes in endometrium dt PROGESTERONE

Question 11

How are ovarian and menstrual cycles linked

Answer 11

LH + FSH = ovarian cycle = Estrogen and Progesterone = Resulting changes in endometrium during the menstrual cycle

Question 12

Endocrine Female Repro Axis

Answer 12

HYPOTH. => GnRH

ANT. PIT. => FSH + LH

OVARY => ESTROGEN + PROGESTERONE
* +VE feedback (day 12-14)
* -VE feedback (most of the cycle to prevent overproduction and ensure coordination)

=> UTERUS

Question 13

Ovarian Cycle

Answer 13

1) FOLLICULAR PHASE
* FSH = follicle maturation = estrogen prod.

2) OVULATION
* LH surge = follicle ruptures and secondary oocyte released

3) LUTEAL PHASE
* Ruptured follicle forms a corpus luteum and secretes progesterone

4) MENSTRUATION
* degen. of corpus luteum = corpus albicans = new ovarian cycle begins

Question 14

Describe the factors affecting oogenesis

Answer 14

a

Question 15

Amenorrhoea

Answer 15

1º = Menarch / Never had

2º = absence of three or more periods in a row by someone who has had periods in the past

Question 16

Causes of Amenorrhoea

Answer 16

1. Disrupted regulating hormones
2. Disrupted ovarian function
3. Disrupted uterus or outflow tract

Question 17

Disrupted regulating hormones = Amenorrhoea

Answer 17

1. Disrupted regulating hormones
   * low FSH, LH, high prolactin
   * wt loss/gain; exertion, stress (functional)
   * chronic conditions: DM, renal disease, TB
   * intracranial SOLesion: prolactinoma, tumour, cysts
   * Infection Trauma in brain
   * Drugs: glucocorticoids, anabolid steroids, opiates suppress pituitary
   * Kallmann’s syndrome

= hypogonadotropic hypogonadosm

Question 18

Disrupted ovarian function = Amenorrhoea

Answer 18

Dt
* Turner’s Syndrome (46X), Fragile X
* Ageing = steep decline past 35yo
* AuIm Diseases
* RT or ChemoT
* Infection: TB, mumps oophoritis

= hypergonadotropic hypogonadism

Question 19

Disrupted uterus or outflow tract = Amenorrhoea

Answer 19

Dt
* congenital = absent uterus, vagina, lack of mmullerian duct
- transverse vaginal septum
- androgen insens syndrome

• Iatrogenic
• Uterine adhesions or synechiae
• RT

Question 20

Mgmt of Amenorrhoea

Answer 20

Lifestyle: stress, weight
Optimise control of chronic illness
Drugs: switch or halt
Prolactinoma - med tx

Sx tx = intracranial SOL, vaginal anomalies

Uterine adhesions = sx division hysteroscopic

*fertility preservation before RT and ChemoT

Question 21

Describe the hormonal control of spermatogenesis

Answer 21

1. GnRH (hypothalamus)
2. FSH and LH (ant pit) = stimulate spermatogen. and testosterone secretion
   FSH = Sertoli
   LH = Leydig/Interstitial => Sertoli
   • Leydig neg. inhibits Testosterone = neg feedback
3. Testosterone (testicles)

Question 22

Describe the factors affecting spermatogenesis

Answer 22

1) MEDICAL
*PRETESTICULAR: hormonal
- functional: weight
- intracranial
- prolactinoma
- meds: opiates, ext. testosterone, steroids

• TESTICULAR: site of prod
• sx
• STI
• mumps orchitis
• trauma / torsion
• RT, chemoT
• Klinefelters

2) LIFESTYLE
- reversible: environmental exposures
- obesity

3) COMBINATION

Question 23

List the major actions of sex steroids in the male

Answer 23

LH = LEYDIG = TESTOSTERONE = SPERMATOGENESIS

FSH = SERTOLI = SPERMATOGENESIS

INHIBIN (SERTOLI) = NEG FEEDBACK

Question 24

Testes Structure and function

Answer 24

1) sperm prod (64 day cycle)
2) testosterone prod (controls spermatogenesis + sexual characs)

*Sperm created in the testis => remain and mature in epididymis => vas deferns => urethra
+ seminal fluid

• SEMINIFEROUS TUBULES (site of sperm prod) segmented by TUNICA ALBUGINEA
  => RETE TESTIS = site of merging of tubules => stored at head of epididymis => body and then tail
• Within the seminiferous tubules:
  GERM CELLS = PRODUCE SPERM
  SERTOLI CELLS = support producing-cells, produce inhibin
  INTERSTITIAL CELLS = produce testosterone

Question 25

What cells are responsible for testosterone production?

Answer 25

Leydig / Interstitial Cells produce testosterone under the influence of LH (ant pit.)

Question 26

Describe the process of sperm production

Answer 26

1) SPERMATOCYTOGENESIS
- Clonal expansion via mitosis; SPERMATOGONIUM to 1º SPERMATOCYTE

• Followed by Maturation via meiosis; first division 1º to 2º spermatocyte produces 2 haploid cells
• second meitoic division produces SPERMATID

2) SPERMIOGENESIS
- Differentiation into mature functional sperm cells

Question 27

Oligospermia

Answer 27

fewer than 15 million sperm per millilitre of semen.

Question 28

Azoospermia:

Answer 28

Lack of sperm cells in semen. About 2% of the total male population is affected by it. It may be due to either a lack of sperm cell production in the testicles or to an obstruction in the seminal conducts that prevents them from being ejaculated.

Question 29

Polizoospermia

Answer 29

It takes place when there are more than 200 million spermatozoids per cc. It may be a cause of infertility since such a high concentration can difficult their movement. Polizoospermia is usually associated to a decrease in the volume of ejaculated matter.