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ESA 4 - Reproductive System > Coitus > Flashcards

Flashcards in Coitus Deck (121):
1

What do spermatogonia mature into? 

Spermatozoa

2

Where do spermatogonia mature into spermatozoa? 

In the seminiferous tubules of the testis

3

How long does maturation of spermatogonia into spermatzoa take? 

Up to 74 days

4

How much of maturation of spermatogonia to spermatozoa occurs in the testis? 

Up to 74 days

5

How much does maturation of spermatongonia to spermatozoa take in the epididymis? 

12-24 days

6

From what stages in life does spermatogenesis occur? 

Starts at puberty, continues until death, there is no male menopause

7

How many sperm to the testes produce each day? 

200-300 million

8

How many of the sperm produced by the testes become viable? 

About half

9

What happens to the sperm produced with age? 

Slight decrease in quality and quantity

10

What is spermatogenesis controlled by?

Hormones

11

What produces LH? 

Anterior pituitary

12

What does LH act on in males? 

Leydig cells of the testis

13

What is the result of the action of LH on the Leydig cells of the testes? 

Stimulates them to produce testosterone, which is a direct stimulant of spermatogenesis

14

What does FSH act on in the male? 

Androgen binding protein in the Sertoli cell

15

What is formed when FSH acts on androgen binding protein in Sertoli cells? 

The blood-testis barrier

16

What is the result of the formation of the blood-testis barrier? 

Increases testosterone concentration, which is a further stimulant for spermatogenesis

17

What can spermatogenesis be initated with if the pituitary gland is removed? 

FSH and testosterone alone, bypass the need for LH 

18

What is the effect of oestrogen from Leydig cells? 

It can increase sperm viability 

19

How is hormonal control of spermatogenesis in itself controlled? 

By a negative feedback loop

20

How does the negative feedback loop controlling the hormonal control of spermatogenesis work? 

The release of inhibin from stimulated Sertoli cells decreased FSH, and so decreases spermatogenesis

21

What happens in spermiogenesis? 

The spermatid matures to spermatozoon 

22

What forms the head of the spermatozoon? 

The acrosome and nucleus 

23

What happens in the maturation to a spermatazoon? 

  • The head undergoes nuclear condensation
  • The acrosome forms

 

24

What happens in nuclear condensation? 

The nucleus becomes much smaller

25

What are the features of the acrosome? 

  • Golgi apparatus
  • Lysosome like, in that it has hydrolytic enzymes

 

26

What is the function of the acrosome? 

Enable sperm to penerate ovum 

27

What is the midpiece of the sperm made of? 

Mitochondria packed around contractile filaments

 

28

What is the tail of the sperm? 

It is a flagellum produced by microtubules growing from centriole to form axoneme

29

What happens to the spermatozoon? 

It matures to spermatozoa

30

What happens in the maturation to spermatozoa? 

Cytoplasm and organelles stripped under influence of testosterone

31

What is true of sperm once they have matured into spermatozoa? 

They are now mature, but lack motility, so are infertile

32

Where are spermatozoa released from? 

Sertoli cells

33

Where are spermatozoa released from Sertoli cells into? 

The lumen of seminiferous tubules

34

What is the process of releasing spermatozoa into the lumen of the seminiferous tubule called? 

Spermination

35

Where do spermatazoa go from the seminiferous tubules? 

The epididymis

36

How are spermatozoa transported to the epididymis? 

In testicular fluid, by peristaltic contraction

37

What produces testicular fluid? 

Sertoli cells 

38

What happens to spermatozoa in the epididymis? 

They gain motility and become fertile in the epididymis 

39

How long can sperm be stored in the epididymis with no loss of fertility? 

Several months 

40

What happens to the epididymis during sexual arousal? 

There is contraction of the epidiymal wall muscle

41

What does contraction of the epididymal wall do? 

Expels spermatozoa into ductus (vas) deferens, and then out through penis in ejaculation

42

What happens to the spermatozoa if they are not expelled? 

They are eventually phagocytosed by the epididymal epithelial cells 

43

What are the phases of coitus? 

  1. Excitement phase
  2. Plateau phase
  3. Orgasmic phase
  4. Resolution phase

 

44

What happens in the excitement phase of the male sexual response? 

Sensory and psychological stimulation needs to the activation of the sacral parasympathetic neurones, and inhibition of the thoracolumbar sympathetic neurones

45

What is the affect of activation of the sacral parasympathetic neurones? 

ACh acts on M3 receptors on endothelial cells, leading to an increase in intracytoplasmic Ca2+, leading to activation of eNOS, and thus increasing nitric oxide production 

46

What does nitric oxide production cause in the male sexual response?

Arteriolar vasodilation in the corposa cavernosa

47

What does arteriolar vasodilation in the corposa cavernosa cause? 

Increased penile blood flow, and then penile filling (latency) to penile tumesence (erection)

48

What is true of the erection at the excitement phase? 

It is reversible

49

What happens to the testes in the excitement phase? 

They begin to elevate and engorge

50

What happens to the scrotum in the excitement phase? 

Scrotal skin thickens and tenses

51

What happens in the plateau phase in the male sexual response? 

  • Activation of the sacrospinous reflex
  • Stimulation of secretion from accessory glands
  • Corona may become further engorged

 

52

What does activation of the sacrospinous reflex lead to in the plateau phaes of the male sexual reponse? 

Contraction of the ischiocavernosus 

53

What is the result of the contraction of the ischiocavernosus? 

Compresses the crus penis and impedes venous return, leading to venous engorgement

54

What happens to intracavernous pressure in the plateau phase of the male sexual response? 

It rises

55

What does the rise in intracavernous pressure lead to? 

Decreased arterial inflow 

56

What accessory glands are stimulated in the plateau phase of male sexual excitement? 

Cowpers and Littre's glands

57

What is the function of the stimulation of secretion from Cowpers and Littre's glands? 

  • It lubricates distal urethra
  • Neutralise acidic urine in urethra

 

58

What % of the ejaculate do the secretions from the Cowpers and Littres glands in the plateau phase constitute? 

5%

59

What happens to the testes in the plateau phase?

They become completely engorged and elevated

60

What happens to the scrotum in the plateau phase?

It maintains its thickened and tensed state

61

What is true of the erection in the plateau phase?

Loss is unlikely

62

What is the orgasm phase of the male sexual response split into? 

  • Emission
  • Ejaculation

 

63

What happens in the emission phase of the male sexual response? 

Stimulation of thoracolumbar sympathetic reflex

 

64

What does stimulation of the thoracolumbar sympathetic reflex cause? 

  • Contraction of smooth muscle in ductus deferens, ampulla, seminal vesicle, and prostate
  • Internal and external urethral sphincters contract

 

65

What is the result of the contraction of the smooth muscle in the ductus deferens, ampulla, seminal vesicle, and prostate? 

Semen is pooled in the urethral bulb

66

Why do the internal and external urethral sphincters contract in the emission stage of the male sexual response? 

So don't get retrograde ejaculation into the bladder

67

What happens in the ejaculation stage of the male sexual response? 

Spinal reflex (with corticol control) stimulates sympathetic nervous system (L1, 2)

68

What does L1 and 2 stimulation in the ejaculation phase of the male sexual response cause? 

  • Contraction of the glands and ducts
  • Internal urethral sphincter contracts

 

69

What does filling of the urethra stimulate in the ejaculation phase? 

Pudendal nerve, which stimulates the contraction of the genital organs, the ischiocavernosus, and the bulbocavernosus muscles

70

What does contraction of the genital organs, ischiocavernosus, and bulbocavernosus muscles lead to? 

Expulsion of semen

71

What happens to the anal sphincter during ejaculation? 

It contracts

72

What happens in the resolution phase of male sexual excitement? 

Activation of the thoracolumbar sympathetic pathway

73

What does the activation of the thoracolumbar sympathetic pathways lead to in resolution of the male sexual response? 

  • Contraction of arteriolar smooth muscle in the corporta cavernosa
  • Increased venous return
  • Detumescence and flaccidity

 

74

Is there a refractory period in the male sexual response? 

Yes

75

What happens to the testes in the resolution phase of the male sexual response? 

Testes descend and return to unstimulated size

76

What happens to the scrotum in the resolution phase?

Thins and resumes wrinkled appearance 

77

What happens in the excitement phase of the female sexual response? 

  • Same neuronal responses as male 
  • Vaginal lubrication begins
  • Clioris engorges with blood
  • Uterus elevates
  • Increase in muscle bone, heart rate, and BP 
  • Inner 2/3 of vagina lengthens and expands

 

78

What causes vaginal lubrication? 

Vasocongestion

79

What happens in the plateau phase of the female sexual response? 

  • Further increase in muscle tone, heart rate, and BP
  • Labia minora deepens in colour
  • Clitoris withdraws under its hood
  • Bartholin glands secretions lubricate vestible
  • Orgasmic platform forms in lower 1/3 of vagina
  • Inner 2/3 of vagina fully distended 
  • Uterus is fully elevated

 

80

What happens in the orgasmic phase of the female sexual response? 

  • Orgasmic platform (outer 1/3 of vagina) contracts rhythmically 3-15 times, inner 2/3 remains motionless
  • Uterus contractions beginning at top (fundus) and moving down towards cervix
  • Anal sphincter contracts
  • Clitoris remains retracted under hood

 

81

Is there a refractory period in the orgasmic phase of the female sexual response? 

No, multiple orgasms possible

82

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

  • Clitoris descends and engorgement subsides
  • Labia returns to unaroused size and colour
  • Uterus descends to unaroused position
  • Vagina shortens and narrows back to unaroused state

 

83

What happens to the breasts in the excitement phase of the female sexual response?

  • Breast size increases
  • Nipple becomes erect
  • Veins become more distinct

 

84

What happens to the brests in the plateau and orgasm phase of the female sexual response? 

  • Greater size increase
  • Areola increases in size, and causes nipple to appear less erect
  • Sex flush may appear on breasts and upper abdomen

 

85

What causes the sex flush in the female sexual response? 

Increase in arterial inflow

86

What happens to the breats in the resolution phase of the sexual response? 

  • Detumesence of areola
  • Disapperance of sex flush
  • Reutrn to unaroused size

 

87

What is the result of detumescene of the areola? 

Nipple appears more erect

88

What is the G-spot? 

An area of erotic sensitivity located along the anterior wall of the vagina

89

What is the sexual relevance of the G-spot? 

Some women are able to experience orgasm and possibly ejaculation from G-spot stimulation

90

What is G-spot tissue similar too? 

Similar to the male prostate

91

What is the result of the G-spot tissue being similar to the prostate? 

Therefore, fluid may be similar to prostatic component of semen

92

What evidence is there that the G-spot fluid is similar to the prostatic component of semen? 

Research has showed the presence of enzyme in female ejaculate is characteristic of prostate secretions

93

How does orgasm from G-spot stimulation differ from clitoral stimulation? 

It is the same, though intensity may vary depending on method of stimulation

94

What effect does age have on sexual response in females? 

  • Some women report reduced desire
  • Vaginal and urethral tissue loose elasticity
  • Length and width of vagina decrease
  • Number of orgasmic contractions is often reduced
  • More rapid resolution

 

95

Why does sexual desire decrease with age in women? 

  • Psychological factors, e.g. body changes 
  • Reduced vasocongestion response

 

96

What does the reduced vasocongestion response cause in females? 

Reduced vaginal lubrications

97

What is the result of the length and width of the vagina decreasing with age? 

Reduced expansile ability of inner vagina during arousal 

98

What % of married couples report in engaging in sexual intercourse a few times a year? 

10-20%

99

What % of married couples report having sexual intercourse of 2-3 times a week? 

30%

100

What is the most common sexual dysfunction? 

Problems with desire

101

What is happening to the incidence of sexual desire problems? 

It is increasing

102

What are the potential problems with sexual desire? 

  • Hypoactive
  • Aversion
  • Hyperactive
  • Nymphomaniac
  • Kluver Bucci syndrome

 

103

What is hypoactive sexual desire? 

Little or no interest in sex

104

What is sexual aversion? 

Revulsion or fear of one or all aspects of sex

105

What is sexual aversion often a result of? 

Abuse or assault

106

How common is sexual aversion? 

Rare

107

How is sexual aversion treated? 

Intensive psychological therapies

108

What causes Kluver Bucci syndrome? 

Bilateral medial temporal lobe lesions

109

What can cause bilateral medial temporal lobe lesions? 

  • Head injury
  • Multiple cerebral metastases 

 

110

What are the symptoms of Kluver Bucci syndrome? 

  • Hyperphagia
  • Hypersexuality
  • Hyperorality
  • Visual agnosia
  • Docility

 

 

111

What are arousal disorders defined as in females? 

Persistent, recurrent, inability to maintain lubrication-swelling response, leading to lack of lubrication

112

When are arousal disorders especially prevalent in females? 

In menopasue

113

What are arousal disorders called in males? 

Impotence

114

What is impotence caused by? 

  • Psychological 
  • Tears in fibrous tissue of corpora cavernosa
  • Vascular
  • Drugs

 

115

How do psychological factors cause impotence? 

Descending inhibition of spinal reflexes

116

What can cause a tear in the fibrous tissue of the corpora cavernosa? 

Trauma sustained with erection 

117

How is a tear in the fibrous tissue of the corpora cavernosa treated? 

  • Try to treat with surgical stitches
  • If this fails, penile implant

 

118

What vascular problems can cause impotence? 

  • Atherosclerosis
  • Diabetes

 

119

What drugs can cause impotence? 

  • Alcohol
  • Antihypertensives - ß-blockers, diuretics

 

120

How is impotence treated? 

Viagra

121

What is the mechanism of action of viagra?

Inhibits cGMP breakdown in corpus cavernosum, which increases nitric oxide-stimulated vasodilation and increases penile blood flow leading to erection