WH: Reproductive System + Physiology Flashcards
1
Q
At how many weeks does fetal heart beat start?
A
6 weeks
2
Q
What type of hormone is oestrogen? produced where? in response to what?
A
oestrogen is a steroid sex hormone produced by the ovaries in response to LH + FSH
3
Q
What is the most common form of oestrogen?
A
17-beta oestradiol
4
Q
What type of hormone is progesterone? produced where?
A
progesterone is steroid sex hormone produced by the corpus lute after ovulation
5
Q
What type of hormone is LH? produced from where? under the influence of what? and what does it stimulate production of?
A
(gonadotrophin hormone)
GnRH stimulates AP to release LH => which acts on theca cells in the ovaries to produce and release androgens
6
Q
What type of hormone is FSH? produced from where? under the influence of what?
A
(Gonadotrophin)
GnRH stimulates AP to release FSH => which acts on granulosa cells
7
Q
What happens when FSH binds to granulosa cells? (3)
A
- Follicle growth
- Permit conversion of androgens to oestrogen
- Stimulate Inhibin secretion
8
Q
Describe the negative feedback mechanisms in the HPG axis?
A
- Oestrogen negatively feedsback to AP and hypothalamus to decrease GnRH and gonatrophin release
- Inhibin negatively feedback to AP to reduce FSH
9
Q
In males: What cells does LH act on and what does it stimulate?
A
LH stimulates Leydig cells to produce testosterone
L-L
10
Q
What is testosterone?
A
main male sex steroid hormone
11
Q
What does testosterone stimulate in males? (8)
A
- Formation of sperm (spermatogenesis
- Maintenance of libido
- development of secondary sexual characteristics
- Growth of external genitalia
- deepening of voice
- Muscle growth
- Bone growth
- promotion of anabolic creation
12
Q
In males: What cells does FSH act on and what does it stimulate (2)?
A
FSH drives sperm production in the Sertoli cells (spermatogenesis)
(and drives synthesis of proteins)
S_S
13
Q
What in the menstrual cycle? generally
A
menstruation occurs on a monthly cycle throughout female reproductive yrs
14
Q
how long is an average menstural cycle (range)
A
21 - 35 day cycle
15
Q
what are the words for the start and end of mesntruation ?
A
menarche
menopause
16
Q
what is the average age for menarche ? (range)
A
10 - 16
17
Q
What is the average age for menopause ? (range)
A
45 - 55
18
Q
describe the HPG feedback response to:
Moderate oestrogen levels?
A
moderate oestrogen levels exert negative feedback on the HPG axis
19
Q
Describe the HPG feedback response to: High oestrogen levels (in the absence of progesterone) ?
A
High oestrogen levels (in the absence of progesterone) positively feedback on the HPG axis
20
Q
Describe the HPG feedback response to: Oestrogen in the presence of progesterone?
A
exerts negative feedback on the HPG axis
21
Q
Describe the HPG feedback response to: Inhibin ?
A
selectively inhibits FSH at the AP
22
Q
What are the general 2 phases of the menstrual cycle in terms of the ovarian cycle?
A
Follicular + luteal phases
23
Q
When does the follicular phase start? end? how long is it?
A
starts at beginning of menstruation till ovulation (about 14 days)
24
Q
What happens during follicular phase? generally
A
marks beginning of new cycle
- follicles begin to mature + prepare oocyte release
25
What it a follicle? structure
oocyte surrounded by stromal cells
26
describe the ovarian production levels at the beginning of the follicular phase? and the follicle action?
little ovarian oestrogen production (follicle begins development independate of gonadotrophines and ovarian hormones) => low steroid sex hormones
27
How does the lack of ovarian production at the beginning of the follicular phase affect the other hormones ?
low steroid + Inhibin levels => reduced negative feedback => rise in FSH + LH => stimulate follicle growth and oestrogen production
28
Describe the oestrogen levels by the end of the follicular phase? what does this cause ?
follicular oestrogen becomes high => positive feedback => increased GnRH => LH surge (ovulation)
29
Why does the high oestrogen levels lead to only an LH surge and not FSH surge?
gransulosa cells still secreted Inhibin which acts to reduce FSH levels
30
What hormone causes ovulation?
LH surge
31
what happens in the ovaries at ovulation?
LH surge => mature oocyte ruptures from follicle (smooth muscle in theca external contract) => assisted to fallopian tube by fimbrae
32
How long is the oocyte viable for after ovulation ?
24 hrs
33
What hormones does the corpus lute produce ?
- Progesterone
- Oestrogen
- Inhibin
34
What 3 phases of the mesntural cycle are there in terms of the uterine cycle? which do they run alongside compared to the ovaries)
- Proliferative (alongside follicular)
- Secretory (luteal)
- Menses
35
What happens to the uterus during the proliferate phase ? (4) which hormone initials this ?
Uterine cycle: proliferative phase (follicular)
- oestrogen initials fallpain tube formation
- Endometrial thickening
- increased myometrial growth and motility
- Production of thin alkaline cervical mucus
oestrogen initiates this
36
What happens do the uterus during the secretory phase? which hormone initiates this?
Uterine cycle: secretory phase (luteal)
- endometrial and myometrial thickening
- Decreased myometrial motility
- Thick acidic mucus
initated by progesterone
37
What is the purpose of the thick acidic cervical mucus? during which phase? which hormone causes this?
progesterone (during secretory/ luteal phase) => thick acidic cervical mucus => hostile environment to prevent polyspermy
38
How long does menses last? how much blood?
2 -7 days
10 -80 ml
39
Which levels of follicle development can happen independent of the stage of the menstrual cycle?
primordial follicles => primary follicles => secondary follicles
40
What hormone is required for further follicle development ? what kind of follicle would this be?
FSH => astral follicle development (from secondary follicles)
41
How does oestrogen affect cervical mucus? during which phase?
increase cervical permeability (sperm can pass) during the follicular phase
42
What is an ovum?
unfertilised egg
43
What happens to the follicle that released the oocyte after ovulation?
collapses and becomes the corpus luteum
44
If fertilisation occurs: what maintains the corpus luteum? which hormone?
the syncytiotrophoblast of the the embryo secretes hCG which maintains the corpus luteum
45
How does LH surge occur in mestrual cycle?
Oestrogen levels rise to v high, meaning that a +ve feedback is exerted on the HPG axis, rapidly increasing LH secretion bytnot FSH (Inhibin)
46
What is gametogenesis? overall
when haploid cells (n) are formed form a diploid cell (2n) through meiosis
47
what are the words for the male and female gametogenesis?
- Spermatogensis
- Oogenesis
48
What is spermatogenesis?
the process by which male gametes (sperm) are made
49
how long does spermatogenesis take?
70 days
50
where does spermatogenesis take place? which cells?
seminiferous tubules of the Sertoli cells
51
what is a spermatogonium? haploid or diploid?
diploid germ cells
(large amounts present at base of Sertoli cells in seminiferous tubules)
52
describe the steps from spermatogonium => spermatazoa
spermatogonium => (enter meiosis) => primary spermatocyte => secondary spermatocyte => spermatids => (spermiogenesis) => spermatozoa
53
Spermatogenesis: meiosis 1 is just completed. What stage of dev?
secondary spmatocyte
54
What are spermatids? diploid/haploid?
haploid cells not fully differentiated (correct no. chromosomes but not characteristic to survive)
55
Spermatogenesis: meiosis 2 is just completed. What stage of dev?
spermatids
56
What are the 3 components to a function spermatozoa (sperm) ? describe ?
- Nucleus (haploid genome)
- Acrosome (cap over most of nucleus)
- Flagellum ( whip like cellular appendage for locomotion)
57
What cell type are the seminiferous tubules lined by? function of these cells (2)?
lined with epithelial layer of sertolli cells
- Support + provide nutrients to various sperm precursors
- Protective: form blood-testes layer
58
What is sperm maturation ? what becomes what? where does it happen
the spermatids undergo spermiogenesis (remodelling and differentiation into spermatozoa) as they travel along the seminiferous tubules
59
What is sperm capacitation? which sperm stage goes through this? where does it happen? what does it allow for/why important ?
once sperm leave M + enter F body (in the uterus)
- removal of cholesterol + glycoproteins allows it to bind to soma pellucid of the egg)
60
Describe the structure of a primordial follicle?
oocyte surrounded by pregranulsoa cells
61
what is an oocyte
a germ cell which undergoes meiosis => mature ovum
62
What are the 3 layers to a primary oocyte?
(inner oocyte)
- Zona pellucida
- Cuboidal granuloma cells
- Theca cells
63
What forms the song pellucida ?
the graudlosa cells secrete material that becomes ZP
64
What does the theca do? 2 parts?
-Theca interna: secretes androgens
- Theca externa: made of connective tissue (smooth muscle + collagen)
65
Which part of the follicle is affected by the LH surge?
causes the tech external to squeeze => follicle burst
66
When does oocyte undergo meiosis 1? what is it now at this stage? at what stage does it stop?
at around time of ovulation, oocyte undergoes meiosis 1 up until metaphase 2
- it is now a secondary oocyte
67
when does meiosis II of ovum take place?
at fertilisation, creates final (3rd) polar body
68
What is coitus?
sexual intercourse that results in the deposition of sparm in the vagina at level of cervix
69
what are the 5 stages of coitus?
- Sexual arousal
- Excitement phase
- Plataue phase
- Orgasm
- Resolution phase
70
What happens during the Male plateau phase (4) ?
- Penile erection
- Increase size of testicles
- Increased HR
- Increased BP
71
What happens during the male orgasmic phase? (2)
- Emission
- Ejaculation
72
What happens during male emission (coitus)
orgasmic phase
- structures contract in order to mix the contents of ejaculate
73
what happens during male ejaculation (coitus)?
orgasmic phase
- semen is expelled form the prostate urthra due to muscle contractions
74
What happens during the female excitement phase of coitus?
- Increase the circumference of vagina
- Lubricate vagina
- Inner 2/3 vagina lengthen + expand
75
How long can sperm serve in the email reproductive tract for ?
120 hours
76
What is conception?
it is the union of the male sperm and the female oocyte to form a zygote
77
when the sperm approaches the egg, what stage of dev is the egg?
secondary oocyte
78
what are the 6 stages of conception?
1) sperm transport to site of fertilisation
2) Sperm capacitation
3) acrosomal reaction
4) Polyspermy block
5) Completion of meiosis II
6) Zygote formation
79
What helps promote sperm transport to site of fertilisation? (2)
- High female oestrogen at time of ovulation => decrease cervical mucus => allow sperm passage
- Prostaglandin in seminal fluid promote myometrial contractions to propel sperm => fallopian
80
What is sperm capacitation? triggered by what?
final maturation process of sperm
- Triggered by uterine secretions
81
What is the acrosomal reaction involved in conception?
hydrolytic + proteolytic enzymes digest ZP
82
On which day after fertilisation does the embryo become a blastocyst ?
Day 5
83
Where does conception most commonly occur? be specific?
in the ampulla of fallopian tubes
84
When does development of the placenta begin?
during implantation of the blastocyst
85
When cells for the placenta?
the outer trophoblast cells form the placenta
86
What happens day 6 after conception?
ZP disintegrates + blastocyst "hatches" so implantation can take place
87
Where does normal implantation occur?
on the anterior or posterior wall of the body of the uterus
88
What happens day 8 after conception ?
trophoblast differentiation into syncytiotrophblast
89
what is the syndcytiotrohpblast? and why is it important?
outer layer of trophoblast (of blastocyst) that is in contact in contact with the endometrium
- secrete hCG to maintain corpus luteum
90
what properties do the maternal blood arteries in the syncytiotrophoblast have?
low resistance, high blood flow condition to meet fetal demands
91
How long dies it typically take for placenta to be delivered?
30 min
92
Average weight of placenta at full term?
600g
93
at what point in pregnancy is the early utero placental circulation established?
by end of week 2
94
What structure in the placenta separates maternal blood from fetal tissue ?
syncytial layer
95
what vessel in umbilical cord? what blood? direction to/from heart?
- 2 umbilical arteries carrying deoxy blood away form heart
- 1 vein carrying oxy blood to the heart
96
What are the 3 layers of the fetal pole?
- endoderm (inner)
- mesoderm (middle)
- ectoderm (outer)
97
what does the endoderm become ?
(inner)
- Gi tract
- Lungs
- Liver
- Pancreas
- Thyroid
- Reproductive system
98
What does the mesoderm become?
(Middle)
- Heart
- Muscle
- Bone
- Connective tissue
- Blood
- Kidneys
99
What does the ectoderm become?
(outer)
- Skin
- Hair
- Nails
- Teeth
- CNS
100
how does maternal blood get to uterine veins?
maternal blood => uterine arteries => lucanae => uterine veins
101
What are the 5 main functions of the placenta?
- Respiration
- Nutrition
- Excretion
- Endocrine
- Immunity
102
what is the oxygen source for fetus
Placenta is the only oxygen source of the fetus
103
describe the fetus affinity for oxygen compared to maternal
fetal Hämoglobin has higher affinity for oxygen than adult haemoglobin
104
What substances are exchanged in the placenta (respiration)?
- Oxygen
- CO2
- H+
- Bicarb
- lactic acid
105
What can be transferred to the fetus from the placenta nutrition-wise
- mostly glucose
- harmful substances: meds, alcohol, caffeine, cigarette
106
What is expected from the placenta on behalf of the fetus?
acts as adult kidney (urea + kidney)
107
How to pregnancy levels of oestrogen and progesterone compare to normal?
Throughout pregnancy the levels of progesterone and oestrogen increase; the oestrogen being produced by the placenta and the progesterone being produced by the corpus luteum and later by the placenta.
108
how does oestrogen affect T3 and T4 levels? and TSH?
oestrogen increase thyroid-binding globulin => increased requirement => increased TSH => increased total T3 + T4 (but no change to free T3 + T4)
109
What fetal development is thyroid essential for
neural development
110
when does the fetal thyroid gland become functional
2nd trimester
111
why are pregnant women more prone to diabetes?
in pregnancy there is an increase in anti-insulin hormones (lactose, prolactin, cortisol) => ensure continuo supply of glucose to fetus
112
what cardiovascular changes are there in pregnancy? BP? CO? blood vol? SV? HR? PVR?
- Increased in progesterone => decrease systemic vascular resistance => decrease diastolic BP => increase CO (in response to this)
- Increase blood vol, SV, HR,
- Decrease PVR
113
What changes to circulating blood vol are there in pregnancy? what causes this?
increase in total blood col (due to increase sodium levels + water retention)
114
What respiratory changes are there in pregnancy ? TV? RR?
Increase in metabolic demand = increase oxy demand => increase TV + increase RR
115
what can pregnancy associated displacement of the stomach cause?
increased infra-gastric pressure => reflux (+ nausea + vomiting )
116
what blood gas change would be expected in pregnancy?
compensated respiratory alkalosis
Many women experience hyperventilation during pregnancy. This results in a respiratory alkalosis with a compensated increase in renal bicarbonate excretion
117
how does the GFR change in pregnancy ?
increase GFR because increased CO
118
What contributes to the increased risk of UTI in pregnancy?
progesterone => relaxation of smooth muscle (ureter)
119
What haematological changes are there in pregnancy?
- increased fibrinogen + increased clotting factors => thromboembolism risk
- increased RBC => increased folate, B12 + iron requirements
120
what is the weight of a normal and a pregnancy uterus
0.1 - 1.1 kg
121
What is menopause? how many months of symptoms ?
it is the end of female reproductive life
- amenorrhoea for 12 months (retrospective diagnosis)
122
when does perimenopause begin ?
around 45 yrs
123
what is classified as early menopause ?
40 - 45
124
Describe the oestrogen, progesterone, LH and FSH levels in menopause?
oestrogen + progesterone: LOW
FSH + LH: HIGH (in response to absence of -ve feedback from oestrogen)
125
what is the hormone responable for most of the symptoms (of menopause)
oestrogen (lack of)
126
what causes the low oestrogen levels in menopause?
low follicle numbers => reduced gonatorophin receptor sensitivity => low FSH + LH => low oestrogen
- negative feedback then drives LH and FSH up
- low follicle embers also cause low Inhibin => increased FSH
127
What are the main perimenopausal symptoms?
(progressing toward the menopause)
- Hot fluses
- urinary incontinence
- Increased UTIs
- Irregular vaginal bleeding
- Low mood
- PMS
- Decreased libido
128
Explain how dyspareunia is linked with menopause?
decrease circulating oestrogen => vaginal atrophy + myometrial thinking => vaginal wall thinning + dryness => pain during sex
129
What risks are associated with menopause? (5)
- Osteoporosis
- CVD
- Stroke
- POP
- Urinary incontinence
130
why is there an increased osteoporosis risk associated with the menopause? what cells involved?
oestrogen protect bone mass + density (by reducing osteoclast activity) => so less oestrogen => increased osteoclast action
131
When is it considered no longer possible for a woman to conscieve?
after 12 consecutive moths of no menstruation
132
What tests might you do in menopause? what might you find
FSH blood test (increase FSH)
(not worth relying oestrogen levels as they can fluctuate a lot anyway)
133
which mechanism stimulates the female secondary oocyte to complete meiosis II?
cortical reaction
134
What is congenital structural abnormalities caused by? due to?
by abnormal development of pelvic organs prior to birth
- Due to faulty genes of by chance
135
What is another name for the paramesonephric ducts?
mullerian ducts
136
what do the paramesonephric ducts develop into?
- upper vagina
- Cervix
- Uterus
- Fallopian tubes
137
What structure in fetus does congenital structural abnormality relate to?
mullerian ducts
138
why do males not develop a uterus?
Anti-mullerian hormone
- AMH supresses growth of paramesonephric ducts => causes them to disappear
139
give examples of congenital structural abnormalities ?
- Bicornuate uterus
- Imperforate hymen
140
What is androgen insensitivity syndrome?
it is a condition where cells are unable to respond to androgen hormones due to a lack of androgen receptors
- extra androgens are converted into oestrogen => female secondary characteristics
141
what type of inheritance is androgen insensitivity syndrome ?
x-linked recessive
142
describe the the genotype of phenotype of a patient with androgen insensitivity syndrome ?
- patients are genetically male (XY)
- Normal female external genitalia and breast tissue (patients have testes in abdo or inguinal canal)
143
describe the pathophysiology of androgen insensitivity syndrome?
patient XY (male) but the absent response to testosterone plus conversion of additional androgens to oestrogen
144
androgen insensitivity syndrome presentation infancy? puberty?
- Infancy: inguinal hernias
- Puberty: primary amenorrhoea
145
androgen insensitivity syndrome managment?
generally raised as female
- bilateral orchidectomy
- oestrogen therapy
- Vaginal dilators (to create adequate vaginal length)
146
in fertilisation: what prevents multiple sperm from fertilising egg?
cortical reaction
147
