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Flashcards in Coition Deck (48):
1

What is the EPOR model for human sexual responses?

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

2

What is excitement?

In response to psychogenic or somatogenic stimuli

Increasing sexual arousal or tension

3

What is plateau?

Arousal is maintained and intensified

Increased pelvic haemodynamics

4

What is orgasm?

A few seconds of involuntary climax

Tension relieved by wave of intense pleasure

5

What is resolution?

Arousal dissipated

Pelvic haemodynamics resolve

6

What causes penile erection?

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

7

How is flaccidity maintained?

Arterial input to corpora cavernosa blocked by smooth muscle mounds

Keeps pressure in corpora lower than in artery

8

What is tumescence?

Stimulation of pelvic nerve causes increased blood flow through penis

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

9

How is erection maintained?

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

10

What is detumescence?

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

11

Which autonomic system regulates erection?

Parasympathetic

Pelvic nerve - S2, 3, 4

12

Which autonomic system regulates detumescence?

Sympathetic

T12 - L3 via hypogastric nerves

13

What causes smooth muscle relaxation?

Prostacyclin
VIP
NO

14

How does viagra work?

PDE5 inhibitor

Maintains level of cGMP

Causes smooth muscle relaxation

15

What is the bulbospongiosus reflex?

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

16

What are the organic causes of erectile dysfunction?

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

17

What is the treatment for erectile dysfunction?

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

18

How does sperm travel through vasa efferentia?

Passively in bulk flow

Sperm are non-fertile and immotile

19

How does sperm travel through vas deferens?

Muscular contractions move sperm along

90% fluid reabsorbed

20

What are the vasa efferentia?

Connect seminiferous tubules to epididymis

21

What occurs in the epididymis?

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

22

What causes seminal emission?

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

Controlled by sympathetics from lumbar splanchnics via α-adrenergic fibres

23

What provides nutrition in sperm?

Fructose

24

What is the role of prostaglandins?

Muscle stimulants

25

Which antioxidants are present in semen?

1. Ascorbic acid
2. Hypotaurine

26

What causes ejaculation?

Rhythmic contractions of urethra and bulbospongiosus and ischiocavernosus at orgasm

Controlled by pudendal nerve

27

What prevents retrograde ejaculation?

Urethral sphincter at neck of bladder

28

Where do the ejaculate contributions come from?

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

29

What are Cowper's glands?

Produce lubricant in ejaculate and pre-ejaculate

30

What do corpora cavernosa do in the female?

Enlargement of clitoris

31

What do corpora spongiosa do in the female?

Enlargement and eversion of labia

32

What lubricates the vaginal orifice?

Greater vestibular glands

Bartholin's duct

Cervical secretions

33

What is transudation?

Lubrication of vagina and vestibule through vascular engorgement of walls

34

What is the tenting effect?

Dilatation of upper part of vagina caused by increased stimulation

35

What is uterine elevation?

Uterine and vaginal contractions at orgasm

36

What are the characteristics of the cervix during oestrogen dominance?

Watery secretion

Os open

Good for sperm

37

What are the characteristics of the cervix during progesterone dominance?

Thick secretion

Os closed

38

What is spinnbarkeit?

Elasticity of cervical secretion

39

How does the cervix act as a filter?

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

40

How many sperm are inseminated?

~350,000

41

How quickly do first sperm arrive at oviduct?

5 mins

42

What is sperm capacitation?

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

43

Where does capacitation occur?

In uterus during passage to oviduct

44

How can sperm capacitation be reversed?

By seminal fluid

45

How is the oocyte transported?

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

46

What is Mittelschermz pain?

Bleeding into peritoneal cavity from ovulation

47

Which hormone stimulates cilia to beat?

Oestrogen

48

Where does fertilisation occur?

Ampulla of oviduct