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Flashcards in Reproductive System Deck (162)
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1
Q

sperm production facts

A
  • 300 million per day
  • constant fertility post puberty, gradual decline with age
  • 1500 sperm/second
2
Q

oocyte production facts

A
  • 7 million follicles at birth
  • 400 ovulate
  • 0 follicles at menopause
3
Q

relative size of egg and sperm

A

sperm is the smallest cell in the body, whereas egg is the largest

4
Q

hierarchal arrangement of the neurons between the pituitary and the hypothalamus allows for…

A

signal amplification

5
Q

function of the gonads (ovaries, testes)

A
  1. produce gametes

2. produce reproductive hormones

6
Q

the hypothalamus sends ____________ neurons to the posterior pituitary, where it releases _________ which is made in the __________ and affects ________ organs.
___________ neurons within the hypothalamus release ______ into _______ vessels which lead into the anterior pituitary, stimulating the release of __________ (___ and __). These hormones stimulate ___________ in males and ___________ in females.

A

the hypothalamus sends neurosecretory neurons to the posterior pituitary, where it releases oxytocin which is made in the hypothalamus and affects target organs.
Neuroscretory neurons within the hypothalamus release GnRH into portal vessels which lead into the anterior pituitary, stimulating the release of gonadotrophins (LH and FSH). These hormones stimulate spermatogenesis in males and oogenesis in females.

7
Q

4 water soluble, peptide and protein, reproductive hormones and their sites of secretion

A
  1. GnRH - gonadotrophin releasing hormone, which is released from the hypothalamus
  2. FSH - follicle-stimulating hormone, which is released from the anterior pituitary
  3. LH - Luteinising hormone, which is released from the anterior pituitary
  4. Oxytocin, which is made in the hypothalamus but released at the posterior pituitary
8
Q

3 lipid soluble, steroid reproductive hormones and their sites of secretion

A
  1. androgens, which are released from the testes
  2. Oestrogens, which are released from the ovaries
  3. progestagens, which are released from the ovaries
9
Q

how are lipid soluble hormones transported?

A

transport proteins

10
Q

steroid hormones made from?

A

cholesterol

11
Q

2 androgens and their differences

A
  1. testosterone

2. 5α dihydrotestosterone (more active)

12
Q

3 oestrogens and their differences

A
  1. oestradiol
  2. oestrone (weaker)
  3. oestriol
13
Q

oestradiol is active during which stage of a girls life? (how does it compare to oestrone)

A

puberty through to menopause.

Oestradiol is a weaker oestrogen

14
Q

oestriol

A

produced by the placenta

softens the cervix to prepare for birth

15
Q

progestogens

A

PROGESTERONE (menstrual cycle and pregnancy)

16
Q

Neurosecretory cells of the posterior pituitary

A

NEUROHYPOPHYSIS

  1. hormones synthesised in the hypothalamus
  2. carried down the axon
  3. stored in secretory vesicles in the posterior pituitary
  4. nerve impulse leads to exocytosis
  5. OXYTOCIN or ADH released into the blood from the posterior pituitary
17
Q

effects of oxytocin

A
  • smooth muscle contraction
  • milk ejection
  • contraction of the uterus during childbirth (used to induce labour)
18
Q

ADH

A

water retention in the kidneys

19
Q

neurosecretory cells involved with the anterior pituitary

A

ADENOHYPOPHYSIS

  • Don’t leave the hypothalamus, release hormones (GnRH) into hypophyseal portal vessels
  • Hormones act on the gonadotrophs of the anterior pituitary to release FSH and LH
20
Q

somatotrophs, lactotrophs, thyrotrophs, and corticotrophs are all…

A

secretory cells

21
Q

why does the hypothalamus release GnRH into hypophyseal portal vessels?

A

if it was diluted in the blood stream it wouldn’t be effective

22
Q

neurosecretory neurons

A

can conduct a nerve impulse, synthesis and carry and release neurosecretory hormones

23
Q

true/false

“the reproductive system only has single positive hormone”

A

TRUE

= GnRH

24
Q

how do hypothalamic secretions release?

A

Pulsatile release.
secretions occur in discrete bursts, separated by periods of little or no secretion.
Prevents desensitisation and down-regulation

25
Q

LH effect on Males vs. females

A

Male: stimulates production of testosterone

Female: secretion of female sex hormones and stimulate ovulation

26
Q

FSH effect on Males vs. females

A

Male: growth of spermatozoan

Female: growth of ovarian follicles

27
Q

negative feedback effect of sex hormones

A

inhibit hypothalamus from releasing GnRH and inhibit Anterior pituitary from releasing FSH and LH

28
Q

true/false

females produce no androgens and Males produce no oestrogens

A

false. they produce some

29
Q

key properties of androgens in males

A
  • Male sex development
  • spermatogenesis
  • sexual behaviour
  • muscle development
30
Q

site of oestrogen production

A

granulosa cells of the growing follicle

31
Q

key properties of oestrogens

A
  • female sex development
  • growth of the endometrium
  • regulation of the menstrual cycle
  • bone growth
32
Q

True/false

Males make some progestagens

A

False. only females produce progestagens

33
Q

Progesterone released by the _______ ________ and the _________. Associated with preparations for _________ and its maintenance.

A

Progesterone released by the corpus luteum and the placenta. Associated with preparations for pregnancy and its maintenance.

34
Q

Vagina features

A
  • 7.5-9cm elastic muscular tube
  • receives the penis
  • holds spermtazoa
  • lower portion of the birth canal
  • passageway for the elimination of menstrual fluids
35
Q

uterus features

A
  • 30-40g
  • sperm transport pathway
  • mechanical protection, nutritional support and waste removal for the developing embryo/fetus
  • muscular wall (myometrium) for ejecting the fetus
36
Q

2 zones of the uterus endometrium

A
  1. inner functional zone (stratum functionalis) - contains uterine glands
  2. outer basilar zone (stratum basalis) - attaches the endometrium to the myometrium
37
Q

uterine (fallopian) tubes features

A
  • fertilisation in the ampulla
  • rich, nutritive environment (lipids and glycogen) for spermatozoa, oocyte and the developing embryo
  • ciliated and non-ciliated secretory columnar cells
38
Q

transport along the fallopian tube involves

A

both ciliary movement and peristaltic contractions

39
Q

3 distinct regions of the ovaries

A
  1. outer ovarian cortex - contains ovarian follicles
  2. central ovarian medulla - ovarian stroma and steroid producing cells
  3. inner hilum (hilus) - point of entry for nerves and blood vessels
40
Q

source of menstrual flow

A

endothelium

41
Q

ectopic pregnancy

A

fertilised embryo implants into tissue other than uterine wall. Most occur in the uterine tube. Risk factors include: smoking, age, and prior tube damage

42
Q

Basilar zone

A

where the endometrium meets the myometrium

43
Q

outside of the uterus

A

the fundus of the uterus

44
Q

primordial follicle

A

the oocyte, surrounded by a single layer of flat follicular cells

45
Q

flat follicular cells surrounding the oocyte develop into the…

A

granulosa cells

46
Q

primary follicle / pre-antral follicle

A

follicles grow.
immature primary follicles have just one layer of granulosa cells.
With FSH, some follicles get larger, producing many layers of granulosa cells.

47
Q

zona peillucida

A

translucent, acellular layer, surrounding and secreted by the oocyte

48
Q

Thecal cells

A

condensation of stromal cells

49
Q

secondary follicle / antral follicle

A

granulosa cells produce a viscous follicular fluid that coalesces to form a single follicular antrum.

50
Q

when a primary follicle develops into a secondary follicle, the theca develops into

A
  1. THECA INTERNA - inner glandular, highly vascular

2. THECA EXTERNA - fibrous capsule

51
Q

cumulus oophorus

A

mass of loosely associated granulosa cells

52
Q

Graafian follicle also known as…

A

mature follicle

53
Q

mature follicle / pre-ovulatory

A

Antrum grows and the oocyte becomes suspended in fluid, connected to the rim of the granulosa cells by a thin stalk of cells

54
Q

ovulation

A
  1. the follicle increases to the correct size and is in the correct position
  2. bulges out from the ovarian surface
  3. follicle ruptures, carrying the oocyte and the cumulus cells with it
  4. oocyte collected by the cilia on the fimbria
  5. cumulus mass swept down the uterine tubes
55
Q

what happens to the antrum and the basement membrane between the granulosa and thecal layers, after ovulation?

A

they breakdown and blood vessels invade

56
Q

lutenisation

A

after ovulation, granulosa cells form large lutein (yellow pigment) cells = CORPUS LUTEUM

57
Q

hormones released by the corpus luteum?

A

progestagens

58
Q

Corpus albicans

A

whitish scar tissue which remains after luteinisation and is absorbed back into the stromal tissue

59
Q

corpus luteum lifespan without fertilisation

A

2 weeks

60
Q

human chorionic gonadotrophin (hCG)

A
  • released by the chorion of the embryo (8 days after fertilisation)
  • rescues the corpus luteum from degeneration
  • presence in urine = pregnancy test
61
Q

two phases in the ovarian cycle (day 1 - ovulation)

A
  1. follicular phase (day 1 - menstruation) VARIABLE TIME

2. luteal phase ~14 days CONSTANT (ovulation - menstruation)

62
Q

three phases of the endometrial cycle

A
  1. menstrual
  2. proliferation
  3. secretory
63
Q

what happens when the there is a high level of oestrogen?

A

POSITIVE FEEDBACK EFFECT on the hypothalamus and anterior pituitary, thereby increasing secretion of GnRH and LH

64
Q

10 steps of the menstrual cycle

A
  1. corpus luteum regresses, oestrogen and progesterone levels are low, increased FSH
  2. FSH stimulation leads to increased follicular growth
  3. day 6-7 there is selection of dominant follicle with increased oestrogen levels
  4. Oestradiol suppresses FSH and LH production in the pituitary
  5. Oestrogen levels rise, by day 12, a threshold concentration of oestradiol is exceeded. If this is maintained for 36 hours, there is a temporary switch from a negative to positive feedback
  6. Oestrogen-mediated positive feedback triggers a rise in GnRH leading to an LH surge
  7. LH surge induces ovulation
  8. corpus luteum develops, see increased progesterone
  9. elevated progesterone levels inhibit GnRH, lead to decreased FSH and LH
  10. demise of the corpus luteum
65
Q

sex determining region is found on the ___ chromosome and provides a pathway for _____ to develop. Also known as the _____ gene. In the absence of the _____ gene the embryo develops into a ______ .

A

sex determining region is found on the Y chromosome and provides a pathway for testis to develop. Also known as the SRY gene. In the absence of the SRY gene the embryo develops into a female .

66
Q

development of male internal genitals

A
  1. Presence of SRY gene
  2. testis form from bipotential gonad
  3. leydig cells release testosterone
  4. Wolffian duct develops into internal male genitals
  5. sertoli cells in the testis release Anti-mullerian hormone
  6. AMH causes Mullerian duct regression
67
Q

development of female internal genitals

A
  1. absence of SRY gene
  2. Bipotential gonad becomes ovary
  3. oestrogens and progestagens released
  4. mullerian ducts develop into internal female genitals
  5. wolffian duct regresses (10 weeks)
68
Q

epididymis, vas deferens, and seminal vesicles develop from

A

wolffian ducts

69
Q

fallopian tubes, uterus, cervix and upper vagina develop from

A

mullerian ducts

70
Q

_________ must be imposed against an inherent trend towards _________

A

musculanity must be imposed against an inherent trend towards femaleness

71
Q

forming the shaft of the penis

A

fusion of the urethral tube

72
Q

forming the scrotum

A

SCROTALISATION

fusion of the labioscrotal swellings

73
Q

forming the glans penis

A

genital tubercle expands

74
Q

forming labia minora and majora

A

urethral folds remain separate to form the labia minora and the labioscrotal swellings remain separate to form the labia majora

75
Q

external genitalia formation without androgen? what can cause this?

A

external genitalia will appear female. Caused by a mutation in the androgen receptor gene.

76
Q

reproductive system during childhood (prepuberty)

A

asleep. plasma levels of gonadotrophs are very low during childhood

77
Q

two changes at puberty as a result of hormonal changes

A
  1. behavioural changes

2. physical changes

78
Q

endocrine changes during puberty

A
  1. GnRH increase during sleep
  2. leads to LH and FSH increase
  3. sex steroid levels rise
79
Q

endocrine changes in late puberty

A

daytime LH pulses increase

80
Q

Tanner stages (what it is? why it is?)

A

sequence in which events of puberty should occur. Allows abnormalities to be detected.

81
Q

GROWTH SPURT
stimulated by ______ hormones (________ and _______), with _______ closure (bony ends) by ________. In boys it occurs ___ years ______ girls but boys have a _______ peak.

A

GROWTH SPURT
stimulated by steroid hormones (androgen and oestrogen), with epiphyseal closure (bony ends) by oestrogen. In boys it occurs 2 years after girls but boys have a higher peak.

82
Q

female stages of puberty

A
  1. breast development begins
  2. pubic hair
  3. height spurt
  4. menarche
83
Q

male stages of puberty

A
  1. testicular enlargement
  2. pubic hair
  3. penile enlargement
  4. height spurt
84
Q

menarche

A
  • beginning of menstrual bleeds
  • critical weight ~47kg must be reached (withstand pregnancy)
  • first ovulation 6-9 months later
  • not regular for 1-2 years
85
Q

Puberty in boys aged __ and girls aged __ is too young and is alarming. Puberty is late if it has not begun by age __ in boys and __ in girls.

A

Puberty in boys aged 9 and girls aged 7 is too young and is alarming. Puberty is late if it has not begun by age 14 in boys and 13 in girls.

86
Q

reasons puberty onset may be late / non-existant

A

gonadotrophin signals are inadequate

87
Q

early puberty onset maybe because of…

A

GnRH dependant problem due to CNS lesion or injury

88
Q

menopause is a consequence of? occurs at what age?

A

consequence of ovaries running out of follicles, occurs between age 50-52

89
Q

regular menstruation - irregular menstruation period called…

A

pre-menopause

90
Q

irregular menstruation - last bleed period called…

A

menopausal transition

91
Q

last bleed called

A

menopause

92
Q

no activity in the ovaries called

A

ovarian senescene

93
Q

True/false

ovaries are inactive after menopause

A

false

94
Q

peri-menopause

A

starts when irregular menstruation begins and ends when activity in the ovaries stops

95
Q

activity in the ovaries stops

A

1-2 years after menopause

96
Q

in ovary senescene, what happens to oestrogen production?

A

reduced to 1/10.

stromal cells of the adipose tissue produce oestrone (weaker)

97
Q

vasomotor symptoms of perimenopause

A
  • hot sweats

- night sweats

98
Q

genitourinary symptoms of perimenopause

A
  • atrophic changes

- vaginal dryness

99
Q

bone metabolism symptoms of perimenopause

A
  • osteoporosis
100
Q

behavioural/psychological symptoms of perimenopause

A
  • depression, tension, anxiety, mental confusion

- loss of libido

101
Q

how are the symptoms of perimenopause combated?

A

oestrogen treatment

102
Q

what is the main reason for the symptoms most women experience during perimenopause?

A

oestrogen deprivation

103
Q

spermatogenesis begins

A

post puberty

104
Q

sperm production per gram testis per second

A

300-600

105
Q

5 phases of spermatogenesis (including chromosome numbers)

A
  1. spermatogonium stem cells (2n)

//mitosis//

[1 daughter cells remains as stem cell]

  1. primary spermatocyte (2n)

//meiosis I//

  1. 2x secondary spermatocyte (n)

//meiosis II//

  1. 4x spermatids (n)

//cyto-differentition//

  1. 4 x sperm cell (n)
106
Q

another name for sperm cell

A

spermatazoon

107
Q

excess cytoplasm from sperm cells forms the ______ ______ which is phagocytosed by ______ cells.

A

excess cytoplasm from sperm cells forms the residual body which is phagocytosed by sertoli cells.

108
Q

leydig cells

A

endocrinocyte - hormone release

109
Q

spermatogonia move between ______ cells from ________ _________ to the _______ ________, where they become _________ __________.

A

spermatogonia move between sertoli cells from basal compartment to the adluminal compartment, where they become primary speratocytes.

110
Q

true/false

spermatogonia don’t develop into sperm without testosterone

A

true

111
Q

sertoli cells secretes androgen binding protein because…

A

keeps testosterone levels high in the seminiferous tubules (otherwise it would diffuse away).

112
Q

DHT potency vs testosterone

A

dihydrotestosterone is twice as potent

113
Q

secondary sexual characteristics

A

DHT and testosterone

  • libedo
  • hair growth
  • baldness
  • agressiveness
114
Q

Leydig cells found?

A

outside seminiferous tubules

115
Q

testosterone production

A
  1. GnRH from hypothalamus to anterior pituitary
  2. anterior pituitary releases LH
  3. leydig cells bind LH
  4. Leydig cells stimulated to produce testosterone
116
Q

spermatogenetic cells can undergo spermatogenesis when…

A

testosterone and FSH present

117
Q

Acrosome of sperm

A

compartment filled with enzymes to penetrate the egg

118
Q

midpiece of sperm contains

A

mitochondria - energy production

119
Q

tail of sperm

A

flagellum, very long

120
Q

Intracytoplasmic sperm injection

ICSI

A
  • a single sperm is captured and injected into an oocyte using microfine pipettes
  • sperm doesn’t need to be motile
  • can use sperm collected by biopsy from the testes
121
Q

In vitro fertilisation

IVF

A
  • oocytes harvested and fertilised ex vito

- require 50,000 motile sperm

122
Q

reason for a suction pipette in ICSI

A

to hold the oocytes steady when injecting the single sperm

123
Q

oligospermia

A

reduced sperm count (less than 20 million per mL)

124
Q

azoospermia

A

no sperm

125
Q

3 things that might make a male infertile

A
  1. oligospermia
  2. azoospermia
  3. sperm may be immotile - can’t swim
126
Q

Inguinal canal

A

connects scrotum and pelvic cavity

127
Q

cremaster muscle

A

encases nerves, vessels, vas deferens, etc. to the testes

128
Q

RAPHE

A

external line down the middle of the scrotum

129
Q

scrotal septum

A

internal separation between each testis

130
Q

spermatic cord

A

encases the cremaster muscle

131
Q

cryptorchidism

A

testes are supposed to descend to the scrotum at ~7 months.

when they don’t descend = cryptorchidism

132
Q

fertility of cryptorchid individuals

A

infertile

133
Q

path taken by sperm, post production

A
  1. produced in the seminiferous tubules
  2. move to the rete testis
  3. move to the epididymis
  4. to the vas deferens
134
Q

function of vas deferens

A

major site of storage (several months)

135
Q

2 functions of the head of the epididymis

A
  1. stimulates sperm to move flagellum and become motile (10-14 days)
  2. absorption of fluid around sperm – concentrates sperm
136
Q

peritoneum of the testis

A

tunica vaginalis

137
Q

tunica albuginea

A

tough, white connective tissue which divides the testis into 200-300 lobules

138
Q

1 lobule contains __ seminiferous tubules

A

2-3

139
Q

what 4 things are present in the mucoid (sticky) substance that seminal vesicles secrete, and what do they do?

A
  1. alkaline (neutralise female acidity)
  2. fructose (energy source)
  3. prostaglandins (aid sperm motility and viabiltiy, may induce contractions of cervix)
  4. clotting proteins (sticky and viscous)
140
Q

vas deferens over or under the bladder?

A

over the bladder

141
Q

length of vas deferens and spongy urethra = total length travelled by sperms =

A

45cm vas deferens + 20cm urethra

= 65cm

142
Q

where does the ejaculatory duct start from and whee does it join the urethra

A

starts at the end of the vas deferens and joings urethra at the prostate

143
Q

swollen end of the vas deferens called

A

ampulla

144
Q

what ‘washes’ sperm down the urethra

A

seminal vesicle fluid

145
Q

prostatic fluid includes

A
  1. citrate (ATP)
  2. acidic (pH 6.5) - neutralized by alkaline seminal vesicle fluid
  3. milky colour (phosphates and calcium)
  4. PSA (prostate specific antigen) and other proteases to break down coagulum
146
Q

Bulbourethral gland AKA Cowper’s gland

A

neutralises acidic urine

147
Q

body of penis

A
  1. corpora cavernosa x2
    - the main erectile tissue
  2. corpus spongiosum penis
    - surrounds penile urethra and prevents occlusion
  3. spongy (penile) urethra
    - conducts semen and urine
148
Q

percentage composition of semen / ejaculated fluid

A

10% sperm
60% seminal vesicle fluid
30% prostatic fluid

149
Q

overall pH semen

A

7.5

150
Q

erection (following sexual stimulation ;) )

A
  • release of NO and Prostaglandin E1
  • smooth muscle of the corpora cavernosa relaxes
  • blood fills cavernous spaces of the corpora cavernosa
  • engorgement of the corpora cavernosa reduces venous outflow, adding to the engorgement
151
Q

erect penis has __x blood volume of a flaccid penis

A

8

152
Q

elevated levels of PSA is an indicator of

A

prostatic overgrowth

153
Q

prostatic cancer treatments

A
  1. androgen reduction
  2. inhibit testosterone action
  3. remove prostate (prostatectomy)
154
Q

relaxation of the ______ muscle of the corpora __________ requires ____________ _____________ (________) which is a secondary messenger that _______ intracellular calcium. The enzyme _____________ breaks down GMP, therefore preventing relaxation and preventing an _________.

A

relaxation of the smooth muscle of the corpora cavernosa requires guanosine monophoshate (cGMP) which is a secondary messenger that reduces intracellular calcium. The enzyme phosphodiesterase breaks down GMP, therefore preventing relaxation and preventing an erection.

155
Q

viagra (sidenafil)

A
  • inhibits phosphodiesterase
  • cGMP levels rise
  • relaxation of arteries supplying blood to the corpora cavernosa
  • erection
  • skux
156
Q

incidence of benign prostatic hyperplasia in men over 85

A

90%

157
Q

treatment for BPH

A
  • 5α-reductase inhibitors

- surgery

158
Q

2 5α-reductase inhibitors and what they do

A
  1. finasteride
  2. dutasteride
    - they stop the prostate enlarging/shrink it
159
Q

3 methods to reduce androgen

A
  1. 5α-reductase inhibitors - finasteride
  2. castration - remove testes
  3. inhibitors of androgen synthesis (testes)
160
Q

adenohypophysis

A

anterior pituitary

161
Q

neurohypophysis

A

posterior pituitary

162
Q

to what, does the sperm bind during fertilisation

A

zona pellucida