Reproductive System Flashcards

1
Q

What are the 3 lipid soluble hormones?

A

Androgens
Oestrogens
Progestagens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 4 water soluble hormones and where are they secreted from?

A

Gonadotrophin releasing hormone (GnRH) - hypothalamus
Follicle stimulating hormone (FSH) - anterior pituitary
Luitinising hormone (LH) - anterior pituitary
Oxytocin - posterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe the neurosecretory neurons:

A

They connect the hypothalamus to the pituitary and they can conduct a nerve impulse but also synthesise and carry and release neurosecretory peptide hormones. They are aggregated into nuclei and have long axon tracts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe how oxytocin and ADH are released from the pituitary gland and what their functions are:

A

They are synthesised in the hypothalamus, travel bound to carrier proteins down the axon terminals and are then stored as secretory vesicles. Nerve impulses travel along the axon to trigger exocytosis of the secretory vesicles, releasing the hormones

  1. Oxytocin - a reproductive hormone that has major effects on smooth muscle contraction - milk ejection - contraction of uterus - secreted in response to nipple stimulation - used to induce labour
  2. Antidiuretic hormone (ADH) - works on kidneys to retain water
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe how gonadotrophs (LH and FSH) are released from the pituitary gland?

A

Neurosecretory neurons synthesise releasing and inhibiting hormones in their cell bodies into vesicles which travel to the axonal terminus in response to nerve impulses they are secreted into the hypophyseal portal vessels in the anterior pituitary.

  1. Gonadotrophs - produce FSH and LH
  2. Somatatrophs
  3. Lactotrophs
  4. Corticotrophs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Why are hypothalamic secretion released in a pulsatile release?

A

They are released in bursts separated by periods of time of no secretion. This prevents receptor desensitisation and down-regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does FSH and LH cause changes in the gonads?

A

By binding to receptors on the outside and promoting the synthesis of sex steroid hormones and gametogenesis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does FSH do in a female?

A

Promotes growth of ovarian follicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does FSH do in a male?

A

Promotes growth of spermatazoon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does LH do in a female?

A

Secretion of female sex hormones and stimulates ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does LH do in a male?

A

Stimulates production of testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe an antiflex uetrus:

A

The uterus is suspposed to be at 90 degrees facing the back, but some women have it facing the front which is called a retroflex uterus and this is usually corrected after the first baby

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the structure of the vagina:

A

An elastic muscular 7.5cm to 9cm tube extending from the cervix to the exterior of the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the structure of the uterus:

A

It is a small pear shaped organ that weighs 30-40g. The endometrium can be divided up into inner functional zone (stratum functionalis) that contains most of the uterine glands and the outer basal layer (stratum basalis) which attaches the endometrium to the myometrium.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the structure of the fallopian tubes:

A

The epithelium lining of the uterine tube has both ciliated and non-ciliated secretory columnar cells. The mucosa is surrounded by a concentric layers of smooth muscle. Transport along the tube requires both ciliary action and peristalsis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Describe the structure of the ovaries:

A

They are oval shaped and weigh about 5-10g. They are comprised of 3 distinct regions: the outer ovarian cortex containing the ovarian follicles, the central ovarian medulla consisting of ovarian stroma and steroid producing cells and the inner hilum which acts as a point of entry for nerves and blood vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the function of the uterine tubes:

A

Fertilization usually occurs at the ampulla. The tubes provide a rich nutritive environment containing lipids and glycogen for the spermatazoa, oocyte and developing embryo.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the function of the uterus:

A

It is the pathway for sperm transport. Provides mechanical protection, nutritional support and waste removal for the developing embryo ad foetus. Contractions in the muscular wall is important in ejecting the foetus. It is also the source of menstrual flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the function of the vagina:

A

It serves as a passageway for the elimination of menstrual fluids, receives penis during intercourse, holds the sperm before they pass into the uterus and forms the lower part of the birth canal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the order of follicular development?

A

Primoridal follicle, primary, secondary, mature, ovulation, corpus luteum, corpus albicans.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe this stage of follicular development: primordial follicle

A

The oocyte is surrounded by a layer of follicular (granulosa) cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe this stage of follicular development: primary follicle

A

The follicles grow and become more columnar and are now called primary. The oocyte secretes glycoproteins which form a translucent layer known as the zona pellucida. Condensation of ovarian stroma cells begin to form the thecal layer. In response to FSH some follicles may grow more layers of granulosa cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe this stage of follicular development: secondary

A

As the granulosa cells proliferate they produce a viscous follicular fluid that forms a cavity known as the antrum. The inner most cells of the granulosa layer becomes firly attached to the zona pellucida and is called the corona radiata. Mass of loosly associated granulosa cells is called the cumulus oophorus. The theca develops to become the inner glandular highly vascular theca interna and externa. The theca interna and granulosa cells work together to make oestrodiol.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe this stage of follicular development: mature follicle

A

As the follicular antrum grows, the the oocyte becomes suspended in fluid and is connected to the rim of the peripheral granlosa cells by a thin stalk of cells. It bulges out of the ovarian surface.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe this stage of follicular development: ovulation

A

The follicle ruptures, carrying with it the oocyte and the surrounding mass of cumulus cells. The oocyte is collected by cilia on the fimbriae which sweep it down the fallopian tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Describe this stage of follicular development: corpus luteum

A

The antrum breaks down and the basement membrane between the granulosa and thecal layers breaks down and blood vessels invade. The granulosa cells form large lutein cells. This transformation os called luitenisation and is associated with an increasing secretion of progestagens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe this stage of follicular development: corpus albican

A

The whitish scar tissue left is absorbed back into the stromal tissue of the ovary over weeks to months.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What happens to the corpus luteum if the oocyte is fertilised?

A

It persists past its normal 2 week life span and is rescued from degeneration from the presence of hCG which is a hormone produced by the chorion of the embryo about 8 days after fertilisation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When taking a pregnancy test at home, what is the hormone present?

A

hCG in the urine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What are the 2 phases in the ovarian cycle and what phases do they include?

A
  1. Follicular phase = primordial, primary and secondary

2. Luteal phase = secondary, mature, ovulation, corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 3 phases of the menstruation cycle?

A
  1. Menstruation
  2. Proliferative phase
  3. Secretory phase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Which of the ovarian phases is variable?

A

Follicular phase because luteal phase is always 14 days (2 weeks)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Describe the hormonal changes in the following days of menstruation: 24

A

Corpus luteum regresses there is increased FSH and oestrogen and progestagen levels are low.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Describe the hormonal changes in the following days of menstruation: 3

A

FSH stimulation leads to growth of follicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Describe the hormonal changes in the following days of menstruation: 7

A

At about day 7, there is selection of the dominant follicle and increased oestrogen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Describe the hormonal changes in the following days of menstruation: 9-10

A

Oestradiol suppresses FSH and LH production in the pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Describe the hormonal changes in the following days of menstruation: 12

A

Oestragen levels rise about day 12 and a threshold concentration of oestrodiol is exceeded. If this is maintained for about 36 hours, there is a temporary switch from negative to positive feedback.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Describe the hormonal changes in the following days of menstruation: 13

A

Oestrogen mediated positive feedback triggers a rise in GnRH leading to an LH surge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Describe the hormonal changes in the following days of menstruation: 14

A

LH surge leads to ovulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Describe the hormonal changes in the following days of menstruation: 17

A

Corpus luteum develops and there is increased progesterone.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Describe the hormonal changes in the following days of menstruation: 21

A

Elevated progesterone levels lead to the inhibition of GnRH which decreases LH and FSH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Describe the hormonal changes in the following days of menstruation: 26

A

Demise of the corpus luteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

How does oestrogen affect feedback?

A

High levels of oestrogen exert a positive feedback effect on the hypothalamus and anterior pituitary, increasing secretion of GnRH and LH

44
Q

What is sex determination?

A

Commitment of the indifferent gonad to testis or ovary. The SRY gene provides the pathway for testes to develop. In the absence of the SRY gene, the embryo is female.

45
Q

What is sex differentiation?

A

The phenotypic development of genital structures due to the action of hormones produced following gonadal development

46
Q

Describe the internal ducts that are present early in development:

A

Both the mullerian (female) and wollfian (male)

47
Q

Describe male differentiation:

A

Mullerian duct regression occurs under the control of anti-mullerian hormone (AMH) which is secreted by the sertoli cells. Testosterone is secreted by the leydig cells in the testes and it actively maintains the wolffian ducts which develop into the epididymus, vas deferens and seminal vesicles.

48
Q

When do the testes descend from their internal position in the abdomen to the scrotum?

A

About the 7th month

49
Q

Describe female differentiation:

A

It lags behind males because there are no hormones to actively drive it. The wollfian ducts spontaneously regress slowly from about 10 weeks. The mullerian ducts persist and develop to give the uterine tubes, uterus, cervix and upper vagina

50
Q

Describe the changes to the external genitalia when the embryo becomes a male:

A

There is fusion of the urethral folds enclosing the urethral tube forming the shaft of the penis. Labioscrotal swellings fuse in the midline to form the scrotum. The genital tubercle expand to form the glans penis.

51
Q

Describe the changes to the external genitalia when the embryo becomes a female:

A

The urethral folds and labioscrotal swellings remain seperate forming the labia majora and minora. The genital tubercle forms the clitorus.

52
Q

What is androgen resistance syndrome?

A

Genotypically XY and has internal testes but the genital ducts and external genatalia is female. It is caused by a mutation in the androgen receptor gene which prevents androgen receptor function.

53
Q

What is puberty

A

The reawakening of the reproductive endocrine system leading to full secondary sexual characteristic development. Plasma levels of gonadotrophins are low during childhood until the initiation of events leading to full puberty.

54
Q

What is the first endocrine sign of puberty?

A

An increase in plasma LH levels which is the result of an increase in GnRH (FSH and LH) release during the night during sleep.

55
Q

What is the first physical sign of secondary sexual characteristic development in females?

A

Breast development

56
Q

Female puberty: breast development

A

Age 10-11, starts with oestrogen secretion leading to the formation of a breast mound. Ovulation with subsequent progesterone secretion leads to full breast development.

57
Q

Female puberty: sexual hair development

A

Usually within 6 months of breastbud and age 10-12. Due to exposure of hair follicles to androgens. Armpit hair follows about 1 year later

58
Q

Female and Male puberty: growth spurt

A

Stimulated by the steroid hormones (oestrogen and androgen) with epiphyseal closure (bony ends) by oestrogen. 11-12 for girls and 13-15 for boys

59
Q

Female puberty: menarche

A

Around 12-13yrs. The first ovulation does not take place until 6-9 months after menarche because positive feedback mechanism of oestrogen hasn’t developed yet. Regular cycles begin around 1-2 years later

60
Q

Male puberty: testicular and penile enlargement

A

Leydig cells in the testes enlarge and secrete testosterone giving rise to increased size of testicles. Elongation and enlargement of penis begins within 1 year

61
Q

What is the first physical sign of male puberty?

A

Testicular englargement

62
Q

Male puberty: sexual hair growth

A

Pubic hair appears about 6 months later, armpits about 18 months and then facial hair

63
Q

Male puberty: spermarche

A

Motile sperm is seen in urine at around 13-14 years old and first ejaculation soon after

64
Q

What is precocious puberty?

A

The appearance of physical and hormonal signs of puberty before 7 yrs (girls) and 9 yrs (boys). Usually due to a GnRH dependent problem - could be a hypothalamic tumor

65
Q

What is delayed puberty?

A

The lack of physical and hormonal sign of puberty after 13 yrs (girls) and 14 yrs (boys). Occurs when the gonadotrophin signals from the pituitary are inadequate for sex steroid hormone secretion.

66
Q

What is menopause and when does it occur?

A

The consequence of the body running out of follicles occurs between 50-52

67
Q

What happens to women experiencing the early stages of menopause at ages 46-50?

A

They have irregular cycles.

68
Q

What is peri-menopause?

A

Ages 46-52 where women experience the symptoms of menopause

69
Q

Describe post-menopausal oestrogen production:

A

By about 1 year after menopause, the ovary has essentially stopped producing hormones (ovarian scenesence) oestrogen production reduces 10 fold. Oestrone arises mainly from production in the stromal cells of adipose tissue and is a weaker form of oestrogen

70
Q

What are the main perimenopausal symptoms?

A
Hot flushes
Night sweats
Atrophic changes
Vaginal dryness
Osteoporosis
Depression
Tension
Anxiety
Mental confusion
Loss of libido
71
Q

How can the symptoms of menopause be prevented or stopped?

A

By oestrogen treatments

72
Q

What is the main site of sperm production?

A

Seminiferous tubules

73
Q

Where are leydig cells found?

A

In the spaces between seminiferous tubules

74
Q

What are the 3 stages of spermatogenesis?

A
  1. Mitotic division
  2. Meiotic division
  3. Cytodifferentiation/spermeogenesis
75
Q

Describe the stage of spermatogenesis: mitotic division

A

At puberty the primary germ cells are reactivated and they are called spermatogonial stem cells which sit on the basement membrane of a seminiferous tubule. They begin to divide by mitosis. One of the daughter cells stays on the basement membrane to keep the stem cell population alive and the other one continues to divide by mitosis forming a spermatogonia. It still continues to divide by mitosis.

76
Q

Describe the stage of spermatogenesis: meiotic division

A

The spermatogonia move between adjacent sertoli cells to the adluminal compartment of seminiferous tubules. These are called primary spermatocytes and undergo meiosis I. During meiosis 1 the DNA content doubles so each of the spermatocytes will still have 46 chromosomes. Now they are called secondary spermatocytes and they undergo meiosis II to give 4 spermatids each with 23 chromosomes.

77
Q

Describe the stage of spermatogenesis: cytodifferentiation/spermeogenesis

A

Spermatids are round cells so they must differentiate their shape to become spermatozoa. The spermatids move into the lumen of the seminiferous tubule and form a tail a mid piece and a head. The mid piece is packed with mitochondria for energy and the head has all of the DNA and is covered by an acrosome compartment filled with many enzymes to penetrate the zona pellucida. The excess cytoplasm of the spermatid is lost into a structure called the residual body that is phagocytosed by the sertoli cells after the sperm leaves.

78
Q

What is the order of a spermatogonium becoming a spermatozoa?

A

Spermatogonium, primary spermatocyte, secondary spermatocyte, spermatid, sperm cell

79
Q

What is necessary with the leydig cells to produce sperm?

A

Testosterone

80
Q

Describe the hormonal control of LH on the male reproductive system:

A

It travels through the blood to the leydig cells to produce testosterone and can be regulated by negative feedback of testosterone

81
Q

What regulates FSH in males?

A

Inhibin

82
Q

What ABP - androgen binding protein?

A

It is produced by the sertoli cells in response to FSH and testosterone. It is also secreted into the testes to lock androgens in because ABH cant leave.

83
Q

What is kisspeptin?

A

These are neurons that trigger GnRH neurons at the start of puberty

84
Q

What is considered a reduced sperm count?

A

Less than 20million/mL

85
Q

What is oligospermia?

A

Reduced sperm count

86
Q

What is azoospermia?

A

No sperm

87
Q

What is immotile sperm?

A

Sperm that cant swim/move

88
Q

How many motile sperm does IVF require?

A

50000

89
Q

Describe ICSI - intracytoplasmic sperm injection:

A

It is where a single sperm is directly inserted into the oocyte using microfine pipettes. Sperm doesn’t need to be motile and can be harvested from a biopsy of the testes

90
Q

What is cryptorchidism?

A

If the testes do not descend down from the abdomen during pregnancy

91
Q

Describe the pathway that sperm take to get out of the testes and into the ejaculatory fluid:

A

They are produced in the testes then they move through the epididymus, up the vas deferens, loop over the bladder and down into the ejaculatory duct urethra, through the penis and out during ejaculation.

92
Q

Describe what happens to the sperm in the epididymus

A

Sperm move into the rete ducts and then the epididymus where they acquire the ability to be mobile and to fertilise. This may take 10-14 days. The epididymus also reabsorbs some of the liquid around the sperm making it more concentrated

93
Q

Describe what happens to the sperm in the vas deferens:

A

This is the main site of sperm storage and can be stored for many months. They are about 45cm long and run from the epididymus, up and around the bladder and then back down to join the ejaculatory duct

94
Q

Describe what happens to the sperm in the urethra:

A

Carries the sperm down with urine too. They are abut 20cm long and run from the bladder through the prostate and to the end of the penis

95
Q

What makes up the seminal vesicle fluid?

A

It is a mucoid sticky substance that:

  • is alkaline
  • contains fructose as an energy source for sperm
  • contains prostaglandins
  • contains clotting proteins
96
Q

Describe the seminal vesicle fluid:

A

The contents is emptied into the ejaculatory duct directly after sperm is ejected by the vas deferens and it washes the sperm down the ejaculatory duct. The prostaglandins may induce contractions in the female reproductive tract once the ejaculate gets into the female to push the sperm along to the oocyte

97
Q

When is the prostatic fluid secreted into the urethra?

A

Before the sperm

98
Q

What does the prostatic fluid consist of?

A
  • it is milky in colour
  • slightly acidic (pH 6.5)
  • contains citrate (for ATP)
  • contains phosphate and calcium
  • contains PSA - prostate specific antigen which breaks down the coagulant and other proteases.
99
Q

What is the pH of the semen?

A

Approx 7.5 because it is neutralised by the seminal vesicle fluid.

100
Q

What is semen made up of?

A

Prostatic fluid - 60%
Sperm - 10%
Seminal vesicle fluid - 30%

101
Q

What is benign prostatic hyperplasia?

A

Is it excess growth of the prostate so that it compresses the urethra. It causes difficulty in emptying the bladder, weakening of the bladder walls and eventually urinary infections and kidney problems.

102
Q

What are the treatments for benign prostatic hyperplasia?

A
  1. Selective 5 alpha reductase inhibitors (finasteride and outaseride) which stop the prostate enlarging or shrink it by inhibiting the enzyme that turns testoterone into digydrotestoseterone
  2. Surgery
103
Q

What are the treatments for prostate cancer?

A
  1. Surgery - prostatectomy
  2. Androgen depletion = 5 alpha reductase inhibitors, castration, inhibitors of androgen synthesis
  3. Inhibition of testosterone action - block the receptors
104
Q

Describe the 3 major structures of the penis:

A
  1. Copora cavernosa = the 2 main erectile tissues
  2. Corpus spongiosum = surround penile urethra and prevents occlusion during erection
  3. Penile urethra = conducts semen and urine
105
Q

Describe the process of getting an erection:

A

Occurs following sexual stimulation. Releases NO which is a vasodilator and prostaglandin E1 which causes the relaxation of the smooth muscle in the corpora cavernosa and copus spongiosum. Blood fills the cavernous spaces (8x normal). Of the copora cavernosa and the enlargement of the copora reduces the venous outflow, adding to the enlargement

106
Q

How does viagra work?

A

Relaxation of the smooth muscle in the corpor cavernosa requires guanosine monophosphate (cGMP) which is a second messenger that reduces cellular calcium. The enzyme phsophodiesterase breaks down cGMP. Viagra works by inhibiting phosphodiesterase (type 5) leading to increased GMP, relaxation of the arteries supplying the corpora cavernosa and erection