1: Physiology and pharmacology - Reproduction/Sex steroid axis Flashcards Preview

Endocrine Week 5 2017/18 > 1: Physiology and pharmacology - Reproduction/Sex steroid axis > Flashcards

Flashcards in 1: Physiology and pharmacology - Reproduction/Sex steroid axis Deck (83)
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61

Testosterone is secreted by which cell of the testes?

Leydig cells

62

What process does testosterone stimulate in the seminiferous tubules?

Spermatogenesis

63

Testosterone has what sort of effect on LH and GnRH secretion?

Negative feedback

64

Which hormone, along with testosterone, also stimulates spermatogenesis?

FSH

65

Which hormone reduces FSH secretion by the anterior pituitary and therefore reduces the rate of spermatogenesis?

Inhibin

66

Name a specific way in which Sertoli cells support Germ cells as they undergo spermatogenesis.

Secrete androgen-binding globulin (ABG) which mops up excess testosterone

Controlling the rate of spermatogenesis

67

What does dihydrotestosterone do?

Enlarges testes

Causes expression of male sexual characteristics

Anabolism

68

What is an acrosome?

Sac, found in the sperm cell head, which contains digestive enzymes

These enzymes break down the outer membrane of the oocyte to help with fertilisation

69

Sperm cells have large numbers of which organelle?

Mitochondria

70

Why are oocytes much larger than spermatozoa?

They contain:

Yolk proteins (food source)

Ribosomes

tRNA and mRNA

71

Where is the site of fertilisation?

Ampulla of Fallopian tubes

72

What happens to the cervical mucus when spermatozoa are detected in the uterus?

Cervical mucus thins

73

Which type of muscular movements bring the unfertilised oocyte to the ampulla of the Fallopian tubes?

Peristalsis

74

Where do spermatozoa mature?

In the female genital tract

75

Which process do spermatozoa undergo in the female genital tract before they are capable of fertilising an egg?

Capacitation

76

Following capacitation, which organelle do spermatozoa use to penetrate the egg?

Acrosome

77

Fertilisation occurs when which organelles of the oocyte and spermatozoa fuse?

Nuclei

78

What is the outer membrane of an oocyte called?

Zona pellucida

79

Once a spermatozoa has penetrated the zona pellucida using its acrosomal enzymes, what reaction occurs?

What does this reaction prevent?

Zona reaction - zona pellucida becomes impenetrable to any more sperm cells

Polyspermy

80

When a sperm cell penetrates the zona pellucida, the levels of certain ions changes to

a) prevent polyspermy

b) activate the egg.

Which ions?

Na+

Ca2+

81

Which process begins in an oocyte once it has been activated by sperm penetration?

Meiosis

82

Once an oocyte has been activated, its rate of protein synthesis (increases / decreases).

rate of protein synthesis & metabolism increases

83

The ___ sperm cell nucleus and ___ egg cell nucleus fuse to form a ___ zygote.

(haploid , diploid)

haploid sperm and egg

diploid zygote