Reproductive - Physiology Flashcards Preview

USMLE (S1) Reproductive > Reproductive - Physiology > Flashcards

Flashcards in Reproductive - Physiology Deck (96)
Loading flashcards...
1
Q

How long does it take for the development of a mature spermatid?

A

2 months

2
Q

Where does spermatogenesis occur in the testis?

A

In the seminiferous tubules

3
Q

Put the following in order of their development during spermatogenesis: spermatozoan, primary spermatocyte, secondary spermatocyte, spermatid, and spermatogonium.

A

Spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid then spermatozoan

4
Q

In spermatogenesis, what is the immature form of sperm called? What is the mature form called?

A

Spermatogonium; spermatozoan

(remember: Gonium is going to be a sperm; Zoan is Zooming out of testis)

5
Q

A spermatogonium has _____ (number) _____ (single chromosomes/sister chromatids), is _____ (diploid/haploid), and is _____ (4N/2N/N).

A

46; single chromosomes; diploid; 2N

6
Q

A primary spermatocyte has _____ (number) _____ (single chromosomes/sister chromatids), is _____ (diploid/haploid), and is _____ (4N/2N/N).

A

46; sister chromatids; diploid; 4N

7
Q

A secondary spermatocyte has _____ (number) _____ (single chromosomes/sister chromatids), is _____ (diploid/haploid), and is _____ (4N/2N/N).

A

23; sister chromatids; haploid; 2N

8
Q

A spermatid has _____ (number) _____ (single chromosomes/sister chromatids), is _____ (diploid/haploid), and is _____ (4N/2N/N).

A

23; single chromosomes; haploid; N

9
Q

What events define the process known as spermiogenesis?

A

The spermatid becomes a spermatozoan by losing cytoplasmic contents and gaining an acrosomal cap

10
Q

During spermatogenesis, _____ undergoes meiosis I to form _____, whereas _____ undergoes meiosis II to form _____.

A

Primary spermatocyte; secondary spermatocyte; sperm

11
Q

In males, follicle-stimulating hormone stimulates which cells? What is the resulting secretion?

A

Follicle-stimulating hormone stimulates Sertoli cells to produce androgen-binding protein and inhibin

12
Q

In males, luteinizing hormone stimulates which cells? What is the resulting secretion?

A

Luteinizing hormone stimulates Leydig cells to produce testosterone

13
Q

In male spermatogenesis, what is the effect of inhibin released by Sertoli cells?

A

Inhibin provides negative feedback of follicle-stimulating hormone release by the anterior pituitary

14
Q

How does testosterone affect the hypothalamus-pituitary axis in the regulation of spermatogenesis?

A

Testosterone is necessary for sperm production in the testes but provides negative feedback on gonadotropin-releasing hormone and luteinizing hormone secretion in the hypothalamus and pituitary

15
Q

Gonadotropin-releasing hormone from the hypothalamus stimulates the release of what two hormones from the anterior pituitary?

A

Luteinizing hormone and follicle-stimulating hormone

16
Q

What are the functions of luteinizing hormone and follicle-stimulating hormone?

A

Follicle-stimulating hormone causes Sertoli cells to aid in Sperm production, whereas LH causes Leydig cells to release testosterone (also aiding sperm production)

17
Q

Rank the following three androgens in order of potency: androstenedione, dihydrotestosterone, and testosterone.

A

Dihydrotestosterone > testosterone > androstenedione

18
Q

What is the major source of dihydrotestosterone and testosterone in men?

A

The testis

19
Q

What is the major source of androstenedione in men?

A

The adrenals

20
Q

What enzyme converts testosterone to dihydrotestosterone?

A

5α-Reductase

21
Q

What medication inhibits 5α-reductase?

A

Finasteride

22
Q

What enzyme converts testosterone and dihydrotestosterone to estrogen in men? Where is this enzyme found?

A

Aromatase, which is found in adipose tissue and Sertoli cells

23
Q

What effects does testosterone have during puberty?

A

Testosterone is responsible for the growth spurt (affecting the penis, seminal vesicles, sperm, muscle, and red blood cell development), deepening of the voice, increased libido, and closure of epiphyseal plates (ending linear growth)

24
Q

Name three structures in which differentiation depends on testosterone during embryogenesis.

A

The epididymis, the vas deferens, and the seminal vesicles

25
Q

How does testosterone cause epiphyseal plate closure in men?

A

Testosterone is converted to estrogen, which closes epiphyseal plates

26
Q

What are the effects of dihydrotestosterone during male embryogenesis?

A

Differentiation of the penis, scrotum, and prostate

27
Q

What are the effects of dihydrotestosterone on adult males?

A

Balding, prostate growth, and sebaceous gland activity

28
Q

A bodybuilder comes to your office for infertility, and on exam you note small testicles; what is a likely cause of his infertility?

A

Azoospermia, caused by exogenous testosterone use resulting in hypothalamic-pituitary-gonadal axis inhibition and low intratesticular testosterone

29
Q

Name four places in female body where estrogen is produced.

A

The ovaries (17β-estradiol), the placenta (estriol), the blood (aromatization), and the adipose tissue

30
Q

Rank the following three forms of estrogen in order of potency: estradiol, estriol, and estrone.

A

Estradiol > estrone > estriol

31
Q

What major hormone is produced by the granulosa cells?

A

Estrogen via conversion of androstenedione by aromatase

32
Q

What major hormone is produced by the theca cells?

A

Androstenedione

33
Q

What is the effect of follicle-stimulating hormone in granulosa cells?

A

Follicle-stimulating hormone promotes the conversion of androstenedione to estrogen via the aromatase enzyme

34
Q

What is the effect of luteinizing hormone in theca cells?

A

Luteinizing hormone promotes the conversion of cholesterol to androstenedione via the enzyme desmolase

35
Q

What effects does estrogen have on the uterus and ovaries?

A

Estrogen stimulates follicle growth and endometrial proliferation and increases myometrial excitability

36
Q

What is the role of estrogen on physical development during puberty?

A

Genital and breast development and creation of female fat distribution

37
Q

What is the effect of estrogen on the liver?

A

Increased synthesis of binding globulins and transport proteins

38
Q

What is the effect of estrogen on the plasma lipid profile?

A

Increased high-density lipoprotein, decreased low-density lipoprotein

39
Q

How does estrogen affect follicle-stimulating hormone and luteinizing hormone levels?

A

It provides negative feedback on follicle-stimulating hormone and luteinizing hormone secretion except near ovulation, when estrogen provides positive feedback for the luteinizing hormone surge

40
Q

During pregnancy, what happens to the levels of endogenous estrogens?

A

There is a 50-fold increase in estradiol and estrone, and a 1000-fold increase in estriol

41
Q

Which is an indicator of fetal well being during pregnancy, an increase in estradiol or estriol?

A

Estriol

42
Q

What is the effect of estrogen on prolactin levels and function?

A

Estrogen increases prolactin secretion but blocks the action of prolactin at the breast

43
Q

Name four places in the human body where progesterone is produced.

A

Corpus luteum, placenta, adrenal cortex, and testes

44
Q

Progesterone causes what changes in the endometrium?

A

Spiral artery development and increased glandular secretions

45
Q

What effect does progesterone have on pregnancy?

A

Progesterone maintains the pregnancy (remember: PROGESTerone is PRO-GESTation)

46
Q

Progesterone _____ (increases/decreases) myometrial contractility whereas estrogen _____ (increases/decreases) myometrial contractility.

A

Decreases, increases

47
Q

What is the effect of progesterone on cervical mucus?

A

Progesterone thickens cervical mucus to prevent sperm entry

48
Q

Progesterone causes what effect on body temperature?

A

Increases body temperature; basal body temperature can be used to predict ovulation

49
Q

What is the effect of progesterone on uterine smooth muscle?

A

It causes decreased myometrial contractility and smooth muscle relaxation

50
Q

Progesterone levels are monitored daily during a woman's menstrual cycle; what conclusion can you make upon noting an elevation in the progesterone level?

A

Progesterone elevation indicates that ovulation has occurred

51
Q

What hormone stimulates endometrial proliferation during the menstrual cycle?

A

Estrogen

52
Q

What hormone maintains endometrium to support implantation?

A

Progesterone; fertility is decreased without progesterone

53
Q

When do luteinizing hormone levels peak during the menstrual cycle?

A

Luteinizing hormone levels peak just before ovulation

54
Q

How long does the luteal phase of the menstrual cycle typically last?

A

14 days

therefore, ovulation day + 14 days = menstruation

55
Q

How long does the follicular phase of the menstrual cycle typically last?

A

The follicular phase can vary in length, and this variation is what alters the length of the menstrual cycle

56
Q

Estrogen levels peak _____ (after/before) ovulation, whereas progesterone levels peak _____ (after/before) ovulation.

A

Before; after

57
Q

Does the graafian follicle mature during the follicular or luteal phase?

A

Follicular phase

58
Q

Is the corpus luteum present during the follicular or luteal phase?

A

Luteal phase

the corpus luteum is formed from the ruptured follicle

59
Q

Regression of the corpus luteum leads to what event?

A

Menstruation

when progesterone levels decrease the endometrial lining sloughs off

60
Q

Put these events of the menstrual cycle in order: progesterone release from the corpus luteum, increase in luteinizing hormone secretion, menstruation, ovulation and increase in estrogen secretion.

A

Increase in estrogen secretion, increase in luteinizing hormone secretion, ovulation, progesterone release from the corpus luteum and menstruation

61
Q

Oligomenorrhea is defined as a cycle lasting more than _____ days, whereas polymenorrhea is defined as a cycle lasting fewer than _____days.

A

35 days; 21 days

62
Q

What is the difference between metrorrhagia and menometrorrhagia?

A

Metrorrhagia is frequent and irregular menstruation (often called spotting), whereas menometrorrhagia is irregular, heavy menstruation

63
Q

A woman presents with pain in her right lower quadrant on the fourteenth day of her menstrual cycle, which is normally 28 days. After ruling out appendicitis, you determine this is caused by blood from a ruptured ovarian follicle at ovulation, also known as what?

A

Mittelschmerz

the blood from the ruptured follicle may cause peritoneal irritation that can mimic appendicitis

64
Q

What happens following the luteinizing hormone surge in the normal menstrual cycle?

A

Luteinizing hormone surge stimulates the rupture of the follicle and ovulation

65
Q

When does a primary oocyte undergo and complete meiosis I?

A

Meiosis I begins during fetal life and is completed just before ovulation

66
Q

In what stage of meiosis I is an oocyte arrested in between fetal life and ovulation?

A

Prophase (remember that meiosis I is in prOphase until Ovulation)

67
Q

In what stage of meiosis II is a secondary oocyte arrested in between ovulation and fertilization?

A

METaphase (remember that an egg MET a sperm)

68
Q

An oogonium is _____ (diploid/haploid) , _____ (2N/4N) and contains _____ (23/46) _____ (single chromosomes/sister chromatids/single chromatids).

A

Diploid; 2N; 46; single chromosomes

69
Q

A primary oocyte is _____ (diploid/haploid), _____ (2N/4N) and contains _____ (23/46) _____ (single chromosomes/sister chromatids/single chromatids).

A

Diploid; 4N; 46; sister chromatids

70
Q

A secondary oocyte is _____ (diploid/haploid), _____ (2N/4N) and contains _____ (23/46) _____ (single chromosomes/sister chromatids/single chromatids).

A

Haploid; 2N; 23; sister chromatids

71
Q

An ovum is _____ (diploid/haploid), _____ (N/2N) and contains _____ (23/46) _____ (single chromosomes/sister chromatids/single chromatids).

A

Haploid; N; 23; single chromatids

72
Q

What stage of oogenesis begins with an oogonium and ends with a primary oocyte?

A

Replication (interphase)

73
Q

What stage of oogenesis begins with a primary oocyte and ends with a secondary oocyte and a polar body?

A

Meiosis I

74
Q

What stage of oogenesis begins with a secondary oocyte and ends with an ovum and a polar body?

A

Meiosis II

75
Q

Where does fertilization most commonly occur?

A

In the upper end of the oviduct (the ampulla)

76
Q

When does fertilization occur in relation to ovulation?

A

Fertilization commonly occurs within one day of ovulation

77
Q

When does implantation occur in relation to fertilization?

A

Implantation occurs 6 days after fertilization

78
Q

When is β-human chorionic gonadotropin first detectable in the blood after conception? In the urine?

A

β-Human chorionic gonadotropin can first be detected in the blood 1 week after conception, and in the urine 2 weeks after conception

79
Q

What is the source of β-human chorionic gonadotropin shortly following conception?

A

β-Human chorionic gonadotropin is secreted by trophoblasts

80
Q

In which trimester does the β-human chorionic gonadotropin level peak?

A

In the first trimester; after the first trimester, the placenta becomes the source of progesterone so high β-human chorionic gonadotropin levels are not needed to maintain the corpus luteum

81
Q

In pregnancy when do progesterone, estriol, and prolactin levels peak?

A

The levels increase throughout pregnancy

82
Q

What process induces lactation? When does this occur?

A

The decrease in maternal hormones (estrogen) induces lactation after labor (recall that estrogen blocks the action of prolactin at the breasts)

83
Q

Why is suckling necessary to maintain milk production?

A

Suckling stimulates nerves that induce increased oxytocin and prolactin levels

84
Q

What are two roles of prolactin in the perinatal period?

A

Prolactin induces and maintains milk production and decreases reproductive function

85
Q

What are two functions of oxytocin in the perinatal period?

A

Oxytocin increases milk letdown and is involved with uterine contractions

86
Q

A woman has abnormally elevated human chorionic gonadotropin levels for her gestational age and you suspect gestational trophoblastic disease; name three examples of this disease.

A

Hydatidiform moles, choriocarcinoma, and gestational trophoblastic tumors

87
Q

A woman presents to your office having missed her period 2 weeks ago; what noninvasive test can you perform to determine if she is pregnant?

A

A urinary human chorionic gonadotropin test can be used to detect early pregnancy

88
Q

What is the role of human chorionic gonadotropin in the first trimester of pregnancy?

A

By acting like luteinizing hormone, human chorionic gonadotropin maintains the corpus luteum, which is the source of progesterone

89
Q

During the second and third trimesters, where are human chorionic gonadotropin, estriol and progesterone produced?

A

The placenta

90
Q

What physiologic process occurs as the number of ovarian follicles decrease with age?

A

The cessation of estrogen production resulting in menopause

91
Q

What happens to levels of estrogen, luteinizing hormone, follicle-stimulating hormone, and gonadotropin-releasing hormone during menopause?

A

Estrogen decreases, whereas luteinizing hormone, follicle-stimulating hormone, and gonadotropin-releasing hormone increase

92
Q

After 4-5 years of abnormal menstrual cycles, a 50 year-old woman presents with amenorrhea, pain during intercourse, and feelings of heat in her chest; what test would confirm the most likely diagnosis?

A

This is likely menopause, with amenorrhea, vaginal atrophy causing dyspareunia, and hot flashes; a serum follicle-stimulating hormone level will be greatly elevated

93
Q

What is the average age for the onset of menopause in nonsmokers?

A

51 years; menopause occurs earlier in smokers

94
Q

What is the main source of estrogen following menopause?

A

The peripheral conversion of androgens into estrogen; increased androgens may cause hirsutism

95
Q

A 35-year-old woman presents with amenorrhea, hot flashes, and a low bone mineral density; what diagnosis is likely?

A

She has symptoms of early menopause, which may indicate premature ovarian failure

96
Q

What are the clinical and pathologic manifestations of menopause?

A

Hirsutism, Hot flashes, Atrophy of the Vagina, Osteoporosis, Coronary artery disease (remember: menopause causes HHAVOC)