Coitus And Fertilistion

Question 1

What are the phases of coitus?

Answer 1

Excitement phase
Plateau phase
Organismic phase
Resolution phase

Question 2

What are the features of the male sexual response in the excitement phase?

Answer 2

Sensroy stimulation to the limbic system, activation of the sacral parasympatheic neurons
Inhibition of thoracolumbar spinal reflexes, Ach causes increased NO production, anterior vasodilation of the corpus cavernosa and increased penile blood flow, penile filling and penile tumensence

Question 3

How does Ach lead to NO production?

Answer 3

M3 receptros on endotheial cells, increase in ca2+ and activation of eNOS and NO production

Question 4

What happpens in the plateau stage of the male sexual response?

Answer 4

Activation of the sacrospinous reflex, contraction of ischicavernous which causes venous engorgemnt, rise in intracavernous pressure which causes decreased artial inflow, and stimulation of secretion from the cowpers and litres accessory galnds

Question 5

Which two stages can be the male orgasm be split into?

Answer 5

Emission and ejactulaiton/ expulsion

Question 6

What happens in the emission stage of the male orgasm?

Answer 6

Stimulation of thoracolumbar symaptheic reflex, contractiion of smooth in the ductus deferns, internal and external urethral spincthers controcat, and semen is polled in the urethra bulb

Question 7

What happens to cause ejaculation in the male?

Answer 7

The spinal relexic using L! And L2 sympathiec nervous syste, contraction of the smooth mucle and ducts, and the internal urthral spincther contracts, the filling of he internal urethra stimulate puedenal nerve, and contractions of the gential orghans the ischiocavernous and bulbocavernous causes the expulsion of semen

Question 8

What causes resolution of the male sexual response?

Answer 8

Activation of theoracolumbar sympathiec pathway,
Contraction of the arteriolar smooth muscle in the corpora cavernosa, increased venous return and detumesence and flaccidity and refractory period

Question 9

What happens in the excitement stage in the female sexual response?

Answer 9

Same neuronal responses as male, vaginal lubrication begins due to vascongestion, clitoris engorges wiht blood and the uterus eleales, and there is a increase in muscle tone hear rate and blood pressure, the uteurs elevates into the pelvic cavity

Question 10

What is the plateau stage of the female sexual respone?

Answer 10

Further increase in muscle ton, heart rate and B, and labia minora deepened in colour and the clitoris withdraws under its hood, and the bartholi gland secretions lubicates the vestibule for the entry of penis

Question 11

What happens during the female orgasm?

Answer 11

Organsimic platform, (outer 1/3 of vagina) contracts ruthmically 3-15 times, uterus contracts and the anal spincther contracts, and the clitoris remains retracted under hood, and there is no refractory period and therefore multiple orgasms are possible

Question 12

What happens in the resolution stage of the female sexual response?

Answer 12

The clitoris descends and engrogment subsides, the labia return to the unaroused size and colour, the uterus descends to the unaroused position, vagina shortens and narrows back to the contracted stage

Question 13

What is the changes in the breast in the excitement stage?

Answer 13

The breast size increases, the nipples become erect, and the veins become more disticnt

Question 14

What happens to the breasts during the plateua and the orgams phase?

Answer 14

There is a greater size increase, the areloa increases in size and causes the nipple to become less erect, and the sex flush may appear on the breasts and the upper abdomien

Question 15

What happens to the breasts during the resolution phase

Answer 15

There is deturmensece of the areola, the niple appears more erect, there is return to unaroused state and the disappearance of the sex flush

Question 16

What is the G spot?

Answer 16

A area of erotic sensitvity located along the anterior wall of the vagina- and some women are able to exprience orgasm from that area

Question 17

What happens to the sexual response cycle in women with age?

Answer 17

Some women report reduced desrire, and there is a reduced vasocongestion response causing reduced lubricaiton, and there is a loss of elasticity in the vaginal and the urethal tissue, and the lenght and width of the vagina decreases, and the number of orgasmic contractions in reduced

Question 18

What is kulwer bucci syndrome?

Answer 18

Biateral temproal lobe lesions, causing hyperphagai, hypersexulaity, hyperorlaity and visual agnosia and docility

Question 19

What are some of the feature of sexual dysfunction in women?

Answer 19

A persistant or recurrent inability to attain or maintian and lubricating swelling response, there is a lack of lubricaiton, especially in menopause

Question 20

What are some of the features of male sexual dysfunction?

Answer 20

Pscyological descening inability of spinal reflexes, and tears in the firbours tissue of the corpus cavernose or vascular including arthersocleorisis and diabetes

Question 21

What are the actions of viagra?

Answer 21

Inhibitis cGMP breakdown in the corpus cavenous, there is an increased in No stimulated vasodilation and there is a increase in penile blood flow an erection

Question 22

What are some potential morpholgical defects in sperm?

Answer 22

Gaint, mirco sperm, double head, double body, long head, rought head and a abnromal middle piece

Question 23

How does cytoplasmic maturation take plae in the female?

Answer 23

Mitochrondria are dispered through the cytopalsm, and the endoplamic reulticulation acculmated in the oocyte corted, and theri in protein lipid syntheiss in the cortical granuls, and in mature oocyte the cortical granules are displaced throughout the cytoplasm.

Question 24

What layers of the oocyte does the sperm need to penetrate?

Answer 24

The corona radiata- follicular cells,

The zona pellucida (the glycoprotien membrane) and undergoes capcitationg

Question 25

What is capitation of sperm and what does it involve?

Answer 25

Sperm cell membrane changes to allow fusion with the oocyte cell surface, removal of the protein coat of sperm, and acrosomal enzymes are exposed

Question 26

What is the acrosome reaction?

Answer 26

When sperm contacts the cornora radiaita, it has a intact acrosome, and spemr pushes through the granulosa cells of the corona radiata, proteins on the sperm head bind to the ZP3 proteins of the zona pellucida, and the binding triggers the acrosome reaction, an key signalling mechanism involving intracellular calicium, and the acrosomal enzyme digest path through the ZP

Question 27

What are the two main regions that the oocyte plasma membrane is divided into?

Answer 27

The part of the membrane that directly overlies the metaphase chromosomes has a smooth surface that is devoid of mirocvili, and the remainder of the occyte is rich in micovillar protusions that is the region of the oocyte where sperm bind and fuse

Question 28

What is the proccess of the fast block of plyspermy?

Answer 28

The electrical chane in the oocyte membrane, and the sodium channels open and the wave of depolasristaiton starts at the site of entry for sperm and propogates across the cytoplasm

Question 29

What is the slow block to polyspermy?

Answer 29

Ca is realeased from the Er, induced local exocytosis of the corticla granules, and the granules realease enymes to stimulate the adajacent corticla granules ot undergo exocytsis, and the eve of exoctosis occurs aroung the oocyte in 3 dimensions from the site of the orignal sperm entry

Question 30

What is the proccess of syngamy?

Answer 30

Union of the male and female pronuclei to form a diploid zygote

Question 31

What proccess can result in plyploidy?

Answer 31

The entry of more than one sperm of the falure of strusion of a second ploar body