Coition

Question 1

What is the EPOR model for human sexual responses?

Answer 1

1. Excitement
2. Plateau
3. Orgasm
4. Resolution

Question 2

What is excitement?

Answer 2

In response to psychogenic or somatogenic stimuli

Increasing sexual arousal or tension

Question 3

What is plateau?

Answer 3

Arousal is maintained and intensified

Increased pelvic haemodynamics

Question 4

What is orgasm?

Answer 4

A few seconds of involuntary climax

Tension relieved by wave of intense pleasure

Question 5

What is resolution?

Answer 5

Arousal dissipated

Pelvic haemodynamics resolve

Question 6

What causes penile erection?

Answer 6

Changes in blood flow in erectile tissue

Increased pressure in corpora cavernosa

Pressure in corpus spongiosum remains low to prevent compression of urethra and allow ejaculation

Question 7

How is flaccidity maintained?

Answer 7

Arterial input to corpora cavernosa blocked by smooth muscle mounds

Keeps pressure in corpora lower than in artery

Question 8

What is tumescence?

Answer 8

Stimulation of pelvic nerve causes increased blood flow through penis

After 20-30 seconds, increased pressure in corpus cavernosum leading to engorgement

Question 9

How is erection maintained?

Answer 9

Relaxation of smooth muscle mounds at arterial input allows full arterial input and high pressure but reduced blood flow

Reduced venous drainage due to occlusion by flaps of smooth muscle keeps pressure high

Question 10

What is detumescence?

Answer 10

Contraction of smooth muscle causes arterial flow to decrease and increases venous outflow

Question 11

Which autonomic system regulates erection?

Answer 11

Parasympathetic

Pelvic nerve - S2, 3, 4

Question 12

Which autonomic system regulates detumescence?

Answer 12

Sympathetic

T12 - L3 via hypogastric nerves

Question 13

What causes smooth muscle relaxation?

Answer 13

Prostacyclin
VIP
NO

Question 14

How does viagra work?

Answer 14

PDE5 inhibitor

Maintains level of cGMP

Causes smooth muscle relaxation

Question 15

What is the bulbospongiosus reflex?

Answer 15

Ischiocavernosus muscle contracts and compresses proximal part of corpus cavernosum to increase penile rigidity

Triggered by pressing on glans penis

Mediated by pudendal nerve S2, 3, 4

Question 16

What are the organic causes of erectile dysfunction?

Answer 16

1. Neurogenic
2. Arteriogenic
3. Drugs
4. Endocrine

Question 17

What is the treatment for erectile dysfunction?

Answer 17

1. Sex therapy
2. Hormone replacement
3. Injection of smooth muscle relaxants
4. Viagra

Question 18

How does sperm travel through vasa efferentia?

Answer 18

Passively in bulk flow

Sperm are non-fertile and immotile

Question 19

How does sperm travel through vas deferens?

Answer 19

Muscular contractions move sperm along

90% fluid reabsorbed

Question 20

What are the vasa efferentia?

Answer 20

Connect seminiferous tubules to epididymis

Question 21

What occurs in the epididymis?

Answer 21

Sperm maturation

1. Nuclear condensation and acrosome remodelling complete
2. Loss of cytoplasmic droplet
3. Rise in cAMP in tail allows movement
4. Membrane lipid composition becomes more fluid
5. Surface coated with stabilising glycoproteins
6. Sialic acid levels rise

Question 22

What causes seminal emission?

Answer 22

Contraction of smooth muscle in prostate, vas deferens and seminal vesicle

Controlled by sympathetics from lumbar splanchnics via α-adrenergic fibres

Question 23

What provides nutrition in sperm?

Answer 23

Fructose

Question 24

What is the role of prostaglandins?

Answer 24

Muscle stimulants

Question 25

Which antioxidants are present in semen?

Answer 25

1. Ascorbic acid | 2. Hypotaurine

Question 26

What causes ejaculation?

Answer 26

Rhythmic contractions of urethra and bulbospongiosus and ischiocavernosus at orgasm Controlled by pudendal nerve

Question 27

What prevents retrograde ejaculation?

Answer 27

Urethral sphincter at neck of bladder

Question 28

Where do the ejaculate contributions come from?

Answer 28

Early - prostate - 30% Mid - vas deferens - 10% Late - seminal vesicle - 60%

Question 29

What are Cowper's glands?

Answer 29

Produce lubricant in ejaculate and pre-ejaculate

Question 30

What do corpora cavernosa do in the female?

Answer 30

Enlargement of clitoris

Question 31

What do corpora spongiosa do in the female?

Answer 31

Enlargement and eversion of labia

Question 32

What lubricates the vaginal orifice?

Answer 32

Greater vestibular glands Bartholin's duct Cervical secretions

Question 33

What is transudation?

Answer 33

Lubrication of vagina and vestibule through vascular engorgement of walls

Question 34

What is the tenting effect?

Answer 34

Dilatation of upper part of vagina caused by increased stimulation

Question 35

What is uterine elevation?

Answer 35

Uterine and vaginal contractions at orgasm

Question 36

What are the characteristics of the cervix during oestrogen dominance?

Answer 36

Watery secretion Os open Good for sperm

Question 37

What are the characteristics of the cervix during progesterone dominance?

Answer 37

Thick secretion Os closed

Question 38

What is spinnbarkeit?

Answer 38

Elasticity of cervical secretion

Question 39

How does the cervix act as a filter?

Answer 39

1. Prevents pathogens ascending female tract during non-receptive phase of cycle 2. Filters out abnormal sperm 3. Separates sperm from seminal fluid

Question 40

How many sperm are inseminated?

Answer 40

~350,000

Question 41

How quickly do first sperm arrive at oviduct?

Answer 41

5 mins

Question 42

What is sperm capacitation?

Answer 42

Acquisition of capacity to fertilise eggs 1. Loss of membrane cholesterol to albumin in uterine fluid 2. Loss of glycoproteins by glycosidase enzymes in uterine fluid 3. Increases fusogenicity with oocyte 4. Influx of calcium causes increase in cAMP and PKA

Question 43

Where does capacitation occur?

Answer 43

In uterus during passage to oviduct

Question 44

How can sperm capacitation be reversed?

Answer 44

By seminal fluid

Question 45

How is the oocyte transported?

Answer 45

1. Ovulated oocyte and cumulus cells picked up by fimbriae | 2. Cilia beat in direction from ovary to uterus

Question 46

What is Mittelschermz pain?

Answer 46

Bleeding into peritoneal cavity from ovulation

Question 47

Which hormone stimulates cilia to beat?

Answer 47

Oestrogen

Question 48

Where does fertilisation occur?

Answer 48

Ampulla of oviduct