Intro to RDA

Question 1

Functions of male reproduction system

Answer 1

androgens and production of mature sperm

Question 2

The two important cells of the testis and roles

Answer 2

Sertoli cells: form the seminiferous tubule and produce sperm
Lyedig cells: Produce Testosterone and androgens and release into circulation

Question 3

Function of the epididmys

Answer 3

Store of mature sperm

Question 4

Route of sperm during ejaculation

Answer 4

Epidiymis, vas deferens, +semen, The fluid then leaves the ejaculatory duct, and passes into the urethra where it mixes with secretions from the prostate gland.

Question 5

Which glycoprotein is produced by sertoli cells

Answer 5

Androgen Binding Protien

Question 6

Explain which hormones lead to spermatogenesis

Answer 6

GnRH->FSH&LH. FSH acts on ABP. LH acts on Lyedig to produce testosterone, which also acts on ABP. Testostrone and Inhibin act on negative feedback

Question 7

Spermatogenesis steps

Answer 7

Germ Cell 44xy, primary spermatocyte 44xy, secondary spermtocyte 22x22y, spermatid 22x22y, spermatozoa 22x22y, released into lumen

Question 8

Functions of the ovaries

Answer 8

gametogenesis, oestrogen and progesterone production

Question 9

Revise the anatomy of the uterus and surrounding structures

Answer 9

including zones of the uterus, ligaments, parts of the fallopian tubes

Question 10

What are the gonadotrophin independent stages of follicle growth

Answer 10

primordial follicle -> primary follicle -> pre-antral follicle

Question 11

What are the gonadotrophin dependent stages of follicle development

Answer 11

Small antral follicle -> Large antral follicle -> Pre-ovulatory follicle

Question 12

Why do not all germ cells reach follicular stage

Answer 12

Atresia

Question 13

Which cells are responsible for oestrogen production

Answer 13

thecal cells

Question 14

Which cells are responsible for oestrogen production during the second half of the ovarian cycle

Answer 14

granulosa-luteal cells

Question 15

Describe expected variences from the 28 day cycle

Answer 15

Normal range of 21-25. When menses starts can be longer eg. 45 days. at menopause, more irregular and more frequent

Question 16

What are the endometrial cycle phases

Answer 16

Menstrual (days 1-5)
Repair and proliferative (9 days)
Secretory phase (13 days)

Question 17

What happens in each of the endometrial cycle phases

Answer 17

Menstrual: Shedding of previous endometrium
Repair and Proliferation: 17b-oestradiol causes proliferation of endometrial cells
Secretory phase: Production of nutrients and widening of endometrial glands, increased coiling of arteries (progesterone and oestrogen)

Question 18

What are the stages of ovarian cycle

Answer 18

follicular: 14 days -> Growth of the follicle, thecal and granulosa cells produce oestrogen, this switches from negative to positive feedback and so LH and FSH surge occurs and ovulation occurs. This is oestrogen mediated.
Luteal phase: 14 days -> follicle produces oestrogen and progesterone

Question 19

When does oestrogen have negative feedback effectds

Answer 19

early, mid follicular phase and luteal

Question 20

When does oestrogen have positive feedback effect

Answer 20

late follicular phase

Question 21

What happens to body temperature during the luteal phase

Answer 21

it increases

Question 22

When is the first meiotic division of folliculogenesis

Answer 22

first meiotic division is completed during the formation of the Secondary follicle, linked to the LH surge

Question 23

When is the second meiotic division

Answer 23

Meiosis II follows immediately after this, but pauses in metaphase II

Question 24

How long does folliculogenesis take

Answer 24

56 days, therefore roughly a month each ovary. Ovaries have follicles at all stages of development inside them occurring simultaneously

Question 25

What is the dominant follicles pathway

Answer 25

becomes a secondary graffian follicle

Question 26

How many primordial follicles are there at the time of birth

Answer 26

2 million

Question 27

How many follicles are released in a lifetime

Answer 27

roughly 400

Question 28

Describe the course of meiosis and the timing of the cell cycle in oogenesis

Answer 28

Meiosis I starts during embryonic development, but halts at the diplotene stage of prophase I (primary follicle); this persists until puberty when meiosis resumes as secondary follicles develop. Only a sub-population of follicles become secondary follicles, and these undergo another pause in meiosis at the metaphase stage of Meiosis II. Only fertilisation can cause the completion of meiosis in a human oocyte.

Question 29

what is sexual reproduction

Answer 29

Produces offspring that differ genetically from both parents.

Question 30

What is the purpose of sexual intercourse

Answer 30

Required for sexual reproduction Sexual activity Sexual pleasure Human bonding

Question 31

How is the brain involved in sexual reproduction

Answer 31

Mesolimbic pthway for reward and pleasure Nigrostriatal tract: movement HPaxis -> necessary hormones

Question 32

Describe how an erection occurs

Answer 32

Initiated by: increased parasympathetic activity to smooth muscle of pudendal artery Increases the activity of Nitric Oxide Synthase (NOS), and hence nitric oxide (NO) NO increases production of cyclic GMP which induces dilatation of arterial smooth muscle. counteracts sympathetic-maintained myogenic tone increases blood flow in corpus cavernosum which compresses the dorsal vein, restricting the outflow of blood The urethra is protected from increased pressure by surrounding corpus spongiosum (less turgid)

Question 33

Explain the link between viagra and cGMP

Answer 33

Cyclic GMP is normally de-activated by a phosphodiesterase enzyme, and this will reverse the changes leading to penile erection. Viagra inhibits the phosphodiesterase, thus potentiating the effects of cyclic GMP.

Question 34

Describe the events leading to fertilisation

Answer 34

Deposition of sperm within female system following sexual intercourse. Sperm are deposited near cervix Cervical mucus is normally hostile to sperm This forms a physical barrier to sperm Cervical mucus changes at mid-cycle This change permits sperm to enter uterus Passage of sperm through uterus Passage of sperm into Fallopian tube Swim from there to Fallopian tube ampulla ~30 µm/sec average speed; 2 mm/min; 12 cm/hour Survival of the fittest (a few days) Capacitation – takes time within uterus Capacitation is essential preparation before the sperm meet the oocyte Meeting of egg with sperm Fusion of egg and one sperm (within 24 hours post ovulation) Acrosome reaction: penetration of Zona Pellucida (& Coronal cells) Calcium flux Resumption of meiosis, release of 2nd polar body Alignment of maternal and paternal chromosomes to generate zygote. Change in Zona Pellucida to prevent additional sperm fusing with zygote. Initiation of mitotic (cleavage) divisions in embryo.

Question 35

Whats the name of the hardening of the zona pelucida

Answer 35

cortical reaction