Reproductive System Flashcards
(162 cards)
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
- 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
- GnRH - gonadotrophin releasing hormone, which is released from the hypothalamus
- FSH - follicle-stimulating hormone, which is released from the anterior pituitary
- LH - Luteinising hormone, which is released from the anterior pituitary
- 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
- androgens, which are released from the testes
- Oestrogens, which are released from the ovaries
- 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
- testosterone
2. 5α dihydrotestosterone (more active)
12
Q
3 oestrogens and their differences
A
- oestradiol
- oestrone (weaker)
- 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
- hormones synthesised in the hypothalamus
- carried down the axon
- stored in secretory vesicles in the posterior pituitary
- nerve impulse leads to exocytosis
- 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
LH effect on Males vs. females
Male: stimulates production of testosterone
Female: secretion of female sex hormones and stimulate ovulation
26
FSH effect on Males vs. females
Male: growth of spermatozoan
Female: growth of ovarian follicles
27
negative feedback effect of sex hormones
inhibit hypothalamus from releasing GnRH and inhibit Anterior pituitary from releasing FSH and LH
28
true/false
| females produce no androgens and Males produce no oestrogens
false. they produce some
29
key properties of androgens in males
- Male sex development
- spermatogenesis
- sexual behaviour
- muscle development
30
site of oestrogen production
granulosa cells of the growing follicle
31
key properties of oestrogens
- female sex development
- growth of the endometrium
- regulation of the menstrual cycle
- bone growth
32
True/false
| Males make some progestagens
False. only females produce progestagens
33
Progesterone released by the _______ ________ and the _________. Associated with preparations for _________ and its maintenance.
Progesterone released by the _corpus_ _luteum_ and the _placenta_. Associated with preparations for _pregnancy_ and its maintenance.
34
Vagina features
- 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
uterus features
- 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
2 zones of the uterus endometrium
1. inner functional zone (stratum functionalis) - contains uterine glands
2. outer basilar zone (stratum basalis) - attaches the endometrium to the myometrium
37
uterine (fallopian) tubes features
- 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
transport along the fallopian tube involves
both ciliary movement and peristaltic contractions
39
3 distinct regions of the ovaries
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
source of menstrual flow
endothelium
41
ectopic pregnancy
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
Basilar zone
where the endometrium meets the myometrium
43
outside of the uterus
the fundus of the uterus
44
primordial follicle
the oocyte, surrounded by a single layer of flat follicular cells
45
flat follicular cells surrounding the oocyte develop into the...
granulosa cells
46
primary follicle / pre-antral follicle
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
zona peillucida
translucent, acellular layer, surrounding and secreted by the oocyte
48
Thecal cells
condensation of stromal cells
49
secondary follicle / antral follicle
granulosa cells produce a viscous follicular fluid that coalesces to form a single follicular antrum.
50
when a primary follicle develops into a secondary follicle, the theca develops into
1. THECA INTERNA - inner glandular, highly vascular
| 2. THECA EXTERNA - fibrous capsule
51
cumulus oophorus
mass of loosely associated granulosa cells
52
Graafian follicle also known as...
mature follicle
53
mature follicle / pre-ovulatory
Antrum grows and the oocyte becomes suspended in fluid, connected to the rim of the granulosa cells by a thin stalk of cells
54
ovulation
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
what happens to the antrum and the basement membrane between the granulosa and thecal layers, after ovulation?
they breakdown and blood vessels invade
56
lutenisation
after ovulation, granulosa cells form large lutein (yellow pigment) cells = CORPUS LUTEUM
57
hormones released by the corpus luteum?
progestagens
58
Corpus albicans
whitish scar tissue which remains after luteinisation and is absorbed back into the stromal tissue
59
corpus luteum lifespan without fertilisation
2 weeks
60
human chorionic gonadotrophin (hCG)
- released by the chorion of the embryo (8 days after fertilisation)
- rescues the corpus luteum from degeneration
- presence in urine = pregnancy test
61
two phases in the ovarian cycle (day 1 - ovulation)
1. follicular phase (day 1 - menstruation) VARIABLE TIME
| 2. luteal phase ~14 days CONSTANT (ovulation - menstruation)
62
three phases of the endometrial cycle
1. menstrual
2. proliferation
3. secretory
63
what happens when the there is a high level of oestrogen?
POSITIVE FEEDBACK EFFECT on the hypothalamus and anterior pituitary, thereby increasing secretion of GnRH and LH
64
10 steps of the menstrual cycle
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
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 ______ .
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
development of male internal genitals
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
development of female internal genitals
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
epididymis, vas deferens, and seminal vesicles develop from
wolffian ducts
69
fallopian tubes, uterus, cervix and upper vagina develop from
mullerian ducts
70
_________ must be imposed against an inherent trend towards _________
_musculanity_ must be imposed against an inherent trend towards _femaleness_
71
forming the shaft of the penis
fusion of the urethral tube
72
forming the scrotum
SCROTALISATION
| fusion of the labioscrotal swellings
73
forming the glans penis
genital tubercle expands
74
forming labia minora and majora
urethral folds remain separate to form the labia minora and the labioscrotal swellings remain separate to form the labia majora
75
external genitalia formation without androgen? what can cause this?
external genitalia will appear female. Caused by a mutation in the androgen receptor gene.
76
reproductive system during childhood (prepuberty)
asleep. plasma levels of gonadotrophs are very low during childhood
77
two changes at puberty as a result of hormonal changes
1. behavioural changes
| 2. physical changes
78
endocrine changes during puberty
1. GnRH increase during sleep
2. leads to LH and FSH increase
3. sex steroid levels rise
79
endocrine changes in late puberty
daytime LH pulses increase
80
Tanner stages (what it is? why it is?)
sequence in which events of puberty should occur. Allows abnormalities to be detected.
81
GROWTH SPURT
stimulated by ______ hormones (________ and _______), with _______ closure (bony ends) by ________. In boys it occurs ___ years ______ girls but boys have a _______ peak.
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
female stages of puberty
1. breast development begins
2. pubic hair
3. height spurt
4. menarche
83
male stages of puberty
1. testicular enlargement
2. pubic hair
3. penile enlargement
4. height spurt
84
menarche
- 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
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.
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
reasons puberty onset may be late / non-existant
gonadotrophin signals are inadequate
87
early puberty onset maybe because of...
GnRH dependant problem due to CNS lesion or injury
88
menopause is a consequence of? occurs at what age?
consequence of ovaries running out of follicles, occurs between age 50-52
89
regular menstruation - irregular menstruation period called...
pre-menopause
90
irregular menstruation - last bleed period called...
menopausal transition
91
last bleed called
menopause
92
no activity in the ovaries called
ovarian senescene
93
True/false
| ovaries are inactive after menopause
false
94
peri-menopause
starts when irregular menstruation begins and ends when activity in the ovaries stops
95
activity in the ovaries stops
1-2 years after menopause
96
in ovary senescene, what happens to oestrogen production?
reduced to 1/10.
| stromal cells of the adipose tissue produce oestrone (weaker)
97
vasomotor symptoms of perimenopause
- hot sweats
| - night sweats
98
genitourinary symptoms of perimenopause
- atrophic changes
| - vaginal dryness
99
bone metabolism symptoms of perimenopause
- osteoporosis
100
behavioural/psychological symptoms of perimenopause
- depression, tension, anxiety, mental confusion
| - loss of libido
101
how are the symptoms of perimenopause combated?
oestrogen treatment
102
what is the main reason for the symptoms most women experience during perimenopause?
oestrogen deprivation
103
spermatogenesis begins
post puberty
104
sperm production per gram testis per second
300-600
105
5 phases of spermatogenesis (including chromosome numbers)
1. spermatogonium stem cells (2n)
//mitosis//
[1 daughter cells remains as stem cell]
2. primary spermatocyte (2n)
//meiosis I//
3. 2x secondary spermatocyte (n)
//meiosis II//
4. 4x spermatids (n)
//cyto-differentition//
5. 4 x sperm cell (n)
106
another name for sperm cell
spermatazoon
107
excess cytoplasm from sperm cells forms the ______ ______ which is phagocytosed by ______ cells.
excess cytoplasm from sperm cells forms the _residual_ _body_ which is phagocytosed by _sertoli_ cells.
108
leydig cells
endocrinocyte - hormone release
109
spermatogonia move between ______ cells from ________ _________ to the _______ ________, where they become _________ __________.
spermatogonia move between _sertoli_ cells from _basal_ _compartment_ to the _adluminal_ _compartment_, where they become _primary_ _speratocytes_.
110
true/false
| spermatogonia don't develop into sperm without testosterone
true
111
sertoli cells secretes androgen binding protein because...
keeps testosterone levels high in the seminiferous tubules (otherwise it would diffuse away).
112
DHT potency vs testosterone
dihydrotestosterone is twice as potent
113
secondary sexual characteristics
DHT and testosterone
- libedo
- hair growth
- baldness
- agressiveness
114
Leydig cells found?
outside seminiferous tubules
115
testosterone production
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
spermatogenetic cells can undergo spermatogenesis when...
testosterone and FSH present
117
Acrosome of sperm
compartment filled with enzymes to penetrate the egg
118
midpiece of sperm contains
mitochondria - energy production
119
tail of sperm
flagellum, very long
120
Intracytoplasmic sperm injection
| ICSI
- 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
In vitro fertilisation
| IVF
- oocytes harvested and fertilised ex vito
| - require 50,000 motile sperm
122
reason for a suction pipette in ICSI
to hold the oocytes steady when injecting the single sperm
123
oligospermia
reduced sperm count (less than 20 million per mL)
124
azoospermia
no sperm
125
3 things that might make a male infertile
1. oligospermia
2. azoospermia
3. sperm may be immotile - can't swim
126
Inguinal canal
connects scrotum and pelvic cavity
127
cremaster muscle
encases nerves, vessels, vas deferens, etc. to the testes
128
RAPHE
external line down the middle of the scrotum
129
scrotal septum
internal separation between each testis
130
spermatic cord
encases the cremaster muscle
131
cryptorchidism
testes are supposed to descend to the scrotum at ~7 months.
| when they don't descend = cryptorchidism
132
fertility of cryptorchid individuals
infertile
133
path taken by sperm, post production
1. produced in the seminiferous tubules
2. move to the rete testis
3. move to the epididymis
4. to the vas deferens
134
function of vas deferens
major site of storage (several months)
135
2 functions of the head of the epididymis
1. stimulates sperm to move flagellum and become motile (10-14 days)
2. absorption of fluid around sperm -- concentrates sperm
136
peritoneum of the testis
tunica vaginalis
137
tunica albuginea
tough, white connective tissue which divides the testis into 200-300 lobules
138
1 lobule contains __ seminiferous tubules
2-3
139
what 4 things are present in the mucoid (sticky) substance that seminal vesicles secrete, and what do they do?
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
vas deferens over or under the bladder?
over the bladder
141
length of vas deferens and spongy urethra = total length travelled by sperms =
45cm vas deferens + 20cm urethra
| = 65cm
142
where does the ejaculatory duct start from and whee does it join the urethra
starts at the end of the vas deferens and joings urethra at the prostate
143
swollen end of the vas deferens called
ampulla
144
what 'washes' sperm down the urethra
seminal vesicle fluid
145
prostatic fluid includes
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
Bulbourethral gland AKA Cowper's gland
neutralises acidic urine
147
body of penis
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
percentage composition of semen / ejaculated fluid
10% sperm
60% seminal vesicle fluid
30% prostatic fluid
149
overall pH semen
7.5
150
erection (following sexual stimulation ;) )
- 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
erect penis has __x blood volume of a flaccid penis
8
152
elevated levels of PSA is an indicator of
prostatic overgrowth
153
prostatic cancer treatments
1. androgen reduction
2. inhibit testosterone action
3. remove prostate (prostatectomy)
154
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 _________.
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
viagra (sidenafil)
- inhibits phosphodiesterase
- cGMP levels rise
- relaxation of arteries supplying blood to the corpora cavernosa
- erection
- skux
156
incidence of benign prostatic hyperplasia in men over 85
90%
157
treatment for BPH
- 5α-reductase inhibitors
| - surgery
158
2 5α-reductase inhibitors and what they do
1. finasteride
2. dutasteride
- they stop the prostate enlarging/shrink it
159
3 methods to reduce androgen
1. 5α-reductase inhibitors - finasteride
2. castration - remove testes
3. inhibitors of androgen synthesis (testes)
160
adenohypophysis
anterior pituitary
161
neurohypophysis
posterior pituitary
162
to what, does the sperm bind during fertilisation
zona pellucida
