Reproduction Flashcards
1
Q
what is gametogenesis
A
process by which gametes are produced in the reporductive organs
2
Q
what are the three parts of the fallopian tube?
In which part does fertilisation occur?
A
Ismus, Ampulla, Fimbriae.
Fertilisation occurs in ampulla usually
3
Q
Label the steps of Folliculogensis:
A
4
Q
When does the mitosis stage of Oogenesis begin?
A
During fetal life (before birth)
5
Q
When does meiosis I of Oogenesis begin?
A
after puberty
primary Oocyte
6
Q
At what stage does an Oocyte become fully matured?
A
Meiosis II of secondary oocyte during fertilization
7
Q
what is this a diagram of?
label the missing labels
A
this is a mature follicle (Graafian follicle) diagram
8
Q
what is the blue arrow pointing to?
A
polar body
9
Q
what is the zona pelucida?
A
the thick transparent membrane surrounding the ovum before implantation.
10
Q
In the Hypothalamus-Pituitary-Gonad Feedback Loop, what hormone does the hypothalamus release to the pituitary gland?
A
Gonadotropin-releasing hormone (GnRH)
11
Q
In the Hypothalamus-Pituitary-Gonad Feedback loop, what does the pituitary gland release?
A
Follicle-stimulating hormone (FSH) and
Luteinizing hormone (LH)
12
Q
In the Hypothalamus-pituitary-Gonad feedback loop, what is the role[s] of FSH?
A
FSH = Follicle-stiumlating hormone:
1. stimulate the maturation/growth of follicules
2. stimulate estrogen production = thickens endometrium
proliferating phase/follicular phase
13
Q
In the female Hypothalamus-pituitary-Gonad feedback loop, what is the role[s] of LH?
A
Luteinizing Hormone:
1. stimulates ovulation = oocyte release and corpus lutem formation
2. Stumulates progesterone production = stimulates endometrium to secrete things
secretory/luteal phase
14
Q
what are the negative feedback loops in the hypothalamus-pituitary-gonad feedback loop?
A
estrogen and progesterone inhibity pituitary
15
Q
what happens during days 1-7 of the menstural cycle?
A
Mensturation
16
Q
what happens during days 8-11 of the menstural cycle?
A
The lining of the womb thickens in preparation for the egg.
17
Q
what day of the menstural cycle does ovulation occur?
A
14
18
Q
what happens during days 18-25 of the menstural cycle?
A
If fertilisation has not taken place, the corpus luteum fades away
19
Q
what happens during day 26-28 of the menstural cycle?
A
the uterine lining detaches leading to mensturation
20
Q
where are spermatozoa produced?
A
testes
21
Q
What are the three glands related to the male reproductive system?
A
- Seminal vesicle
- Prostate Gland
- Bulbourethral gland
22
Q
how large are the testes?
A
4cm long, 2,5cm diameter
23
Q
What are Leydig cells?
A
clusters of cells between the seminferous tubules.
produce testosterone
24
Q
what are sertoli cells?
A
promote sperm development
25
seminiferous tubules drain into network called?
rete testis
26
In the testes, where would the most mature cells be found?
| (not the epididymis)
towards the centre
27
how does thermoregulation in the testes take place?
paminiform plexus allows countercurrent heat exchange with the testicular artery and maintains the thermoregulation
28
what are the four phases of spermatogenisis?
1. Spermatagoniu**m**
2. Spermato**c**yte
3. Sperma**t**id
4. Spermato**z**oa
| Men Cum Too Zoon
29
during mitosis, two types of spermatogonium are made.
which are permeable to the blood-testis-barrier and which are not?
Type A impermeable to blood testis barrier and produce more daughter cells until death.
Type B pass through the BTB and go on to differentiate into primary spermatocytes
30
what is spermiogenesis?
transformation of spermatids into spermatozoa
-sprouts tail and discards cytoplasm to become lighter
31
how much sperm is produced in the testis per second?
300-600 sperm per gram of testis per second
32
33
in the hypothalamo-pituitary-testicular axis, what is the role of FSH?
Acts on sertoli cells to surge spermatogenesis.
negative feedbakc to hypothalaums and pituitary.
34
in the hypothalamo-pituitary-testicular axis, what is the role of LH?
acts on Leydig cells (interstitial cells) which produce terstosterone = negative feedback to pituitary and hypothalamus
35
what is contained within the acrosome of sperm head?
enzymes that penetrate the egg
36
what are the two processes that a sperm is required to go through to mature?
To become fertilization-competent they must go through an epididymal maturation (motility) process in the male, and capacitation in the female tract (to fertalise).
37
where to sperm become motile?
in the epididymis
38
how much semen is expelled during ejaculation?
2-5ml
39
what is ejaculation composed of?
60% seminal vesicle fluid
30% prostatic flui
10% sperm
trace bulbourethral fluid
40
what is a normal sperm count range?
50-120 million/mL
< 25 associated with infertility
41
the following can also be found in semen:
* fructose
* fibrinogen + clotting enzymes
* fibrinolysin
* postaglandins
* sperimine
what are their functions?
* fructose = energy for sperm motility
* clotting enzymes convert fibrinogen to fibrin causing semen to clot
* fibrinolysin degrades fibrin - liquefies semen within 30 mins
* prostaglandins - stimulate female peristaltic contractions
* spermine = keeps sperm pH at 7.2-7.6
42
what determines the sex of a child?
the sperm
| opposite in birds lol
43
how many chromosones doe our cells have?
23 pairs:
22 autosomes, 1 sex
44
where does capacitation take place?
what is it?
capacitation is the spermatozoa gaining the ability to fertilizze oocyte.
takes place in female genital tract
45
what mediates the primary binding of the sperm to the ZP?
Zp3 Glycoprotein
46
what mediates the secondary binding of the sperm to the ZP?
Zp2 Glycoprotein
47
once a sperm has passed through the ZP, what happens to prevent polyspermy?
Cortical Granule Exocytosis
-blocks other sperm from enetring
48
Embryo development:
Day 1. ?
?
Day 2. ?
Day 3. ?
Day 4. ?
Day 5. ?
Day 5/6. ?
Day 6+
Day 1 - Fertilisation = pronucleus stage
Syngamy
Day 2 - Cleavage --> 2 cell --> 4 cell
Day 3 -Cleavage --> 8 cells
Day 4 - Compaction --> morula
Day 5 - Cavitation and Differentiation
Day 5/6 - Expansion
Day 6+ - Hatching
49
Oocyte acitivation activates the egg to release [?] which facilitates fertilistation?
| Day 1 Fertilisation
calcium
| Day 1 Fertilisation
## Footnote
by phospholipase c zeta. Oocyte activation is when the oocyte (immature egg cell) is stimulated to resume meiosis. Will end with a male and female pro nucleus
50
what occurs after fertilisation but before the first cleavage?
Syngamy - two become one
- male and female procnucleus migrate to centre
- DNA duplication for mitosis
- Pronuclear membrane breaks down
51
what are teh first three divisions of an embryo called?
The first three divisions of the embryo are called cleavage divisions; thus, one-to eight-cell embryos are defined as cleavage stages (day 2-3)
52
when does a blastomere first appear?
when does a blastocyst first appear?
after the first cleavage - day 2
after expansion - day 5
53
Cleavage stage embryos can be described as totpotent - what is meant by this?
the nuceli of each individual blastomere (up to 8) are each capaby of forming an entire fetus
54
when does developmental control of the embryo transition from maternal control to zygotic (both) control?
BETWEEN TWO CLEAVAGE DAYS (day 2-3)
Prior to the 4-8 cell stage the developmental control depends on maternal RNA.
At 4-8 stage celavage, transitions to zygotic control
55
what happens during day 4 of embryo development?
compaction -
cells flatten, tight junctions form, outer cells polarised.
the embryo is at this stage a morula = 16 indistinuishable cells
56
what stage of emryological development is this? What is happening?
label the gaps
Cavitation and Differentiation - Day 5
- Tight junctions occur between outer cells = trophectoderm
- Sodium pumped in, water out =. fluid filled cavity expands
- >80 cells at this stage - pluripotent.
-
57
what does the trophectoderm go onto become?
what does the inner cell mass go onto become?
trophectoderm => placenta
Inner cell mass => baby
58
When does expansion take place in embryological development.
what hapens?
day 5/6.
Cavity expands
Diameter increases.
ZP thins
59
When does hatching take place? what happens?
Day 6+
* expansion = enzyme cause embryo to hatch from ZP
* essential for implantation
* Trophectoderm = extraembyronic
* Inner Cell Mass = embryonic
60
when is metabollic activity high/low in embryological development?
Early Cleavage = low metabolic activity, low biosynthetic activity, simple sugars.
Blastocyst stage = high metabolic activity, high biosynthetic activity, complex sugars
61
what are the three ways a blastocyst gets exogenous nutrients in vivo
- cumulus cells
- fallopian tube excretions e.g. calcium
- uterine excretione e.ge iron, fat soluble vitamins, glucose
62
what increases cell numbers in blastocysts?
Insulin Like Growth Factor
63
when does histogenesis take place?
histogenesis = development of the three germ layers.
takes place after implantation
64
what three changes take place in the uterus for implantation?
* endometrial cell changes to help absorbtion of uterine fluid = brings the balsts nearer to the enodmetrium and immobilises it.
* Chnages in thickness of endometrium and its blood supply
* fomration of decidua
65
what is the decidua
The decidua has been known as maternal uterine tissue, which plays essential roles in protecting the embryo from being attacked by maternal **immune** cells and provides **nutritional** support for the developing embryo prior to placenta formation.
66
how long/when is the implantation window?
4 day long.
6-10 days postovulation
67
What are the 3 phases of embryo implantation?
1. Apposition (day 6/7)
2. Attachment (adhesion) (day 7/8)
3. Invasion (penetration) (day 8/9)
68
what happens during **1. Apposition ** of embryo implantation?
- an unstable adhesion of bastocyst to uterine lining
- Hatched blastocyst orientates via embryonic pole at the are above ICM
- synchronisation of embryo and endometrium (decidua)
- endometrium is receptive (day 19-22 window)
69
what happens during 2. Attachment (adhesion) of embryo implantation?
* stable/stronger adhesion via integrin molecules
* penetretive protrusions of trophoblasts microvilli
70
what happens during 3. Invasion (penetration) of embryo implantation?
* trophoblast portrusions continue to proliferate and penetrate the endometrium - erodes into endometrial stoma
* cells differentiate into syncytiotrophoblasts - come into contact with maternal blood flow and form chorionic villi
* blood filled lacunae form (spaces filled with maternal blood) exchange nutrients and waste
* enzyme mediated
71
what is the role of progesterone in embryonic development?
modifies oestrogen receptors
stimulates secretions
increases volume of blood vessels
? immunosuppresent
?growth factor
72
what prevents maternal recognition of the embryo as a foreign body during early stages of implantation?
* leukocytes in the endometrial stroma secrete interleukin-2
73
where is Human Chorionic Gonadotropin produced?
hCG-𝛃 = syncytiotrophoblast in the placenta
hCG-𝛂 = cytotrophoblast
74
why is hCG important?
essential to sustain early pregnancy -
ensure corpus luteum continues to produce progesterone throughout first trimester
immunosuppressive
75
what hCG pattern signifies a normal pregnancy?
hCG levels should double every 1.3 days in the first 10-12 days.
short hGC time isgnifieis helathy pregnancy, slow indicates earyl abortino/ectopic/inadequate trophoblast
76
name some factors affecting embryo growth in vitro
* exposure to light
* exposure to high O2 conc
* chnages in pH or osmolarity
* medium
* volatile organic compouns - no aftershave in the lab plz!
77
name some underlying causes of recurrent implantation failure
poor ovarian function
increased sperm DNA fragmentation
polyps/fibroids
78
maternal adaptation to pregnancy is driven by?
hormonal changes
79
[?] resistance and
[?] synthesis
occurs during pregnancy
insulin resistance
protein and lipid synthesis
80
which hormone is tested for in a pregnancy test?
what is its function?
human chorionic gonadotropin (hCG)
stimulates oestrogen and progesterone production by ovary
81
when does hCG diminish?
once the placenta is mature enought to take over oestrogen/progesterone production
peaks around 8-10/40
82
role of oestrogen throughout pregnancy?
regulates progesterone, helps the uterus grow, maintains uterine lining, and triggers the development of baby's organs
83
role of progesterone during pregnancy?
prevents miscarriage, builds up endometrium for support of placenta.
prevents uterine contractions
## Footnote
Throughout pregnancy, progesterone continues to be produced by the corpus luteum initially and later by the placenta, ensuring the continued support of the uterine environment and preventing menstruation.
84
role of prolactin during pregnancy?
produced in pituitary
increases cells that produce milk
After birth, levels of progesterone and oestrogen drop dramatically, allowing prolactin to stiumulate production of milk, also controlled by suckling.
prevents ovulation unreliably
85
what is the role of relaxin in preganancy?
high in early pregnancy - limits uterine activity, softens cervix = cervical ripening for delivery
86
role of oxytocin in pregnancy?
triggers "caring" reproductive behaviour
responsible for uterine contractions during pregnancy and labour
cause of contractions felt during breast feeding
drug used to induce labour
87
role of prostaglandins in pregnancy?
tissue hormone, role in initiation of labour
can also be used as drug to induce labour
88
how much weight gain is expected in pregnancy?
10-15kg
89
what cardiovascular chnages does a pregnant person go through?
* increased CO
* Reduced TPR
* ∴ drop in BP
* increased uterine blood flow
* increased blood volume and RBC mass
* increased alveolar ventilation
90
why do varicose veins occur during pregnancy?
increased blood volume = pressure on valves veins
uterus pressure on IVC = pressure on valves of veins
∴ relaxation of smooth muscle of veins and feet swelling
91
what are these skin pigmentations called?
linea nigra
striae gravidarum
92
what can happen to the mothers spine during pregnancy?
lumbar lordosis
93
how does uterine growth occur?
cell division and hypertrphy of individual myometrial cells
94
what is the myometrium of the urterus made from?
bundles of smooth muscle cells that contract and relax
95
the uterine cervix protects the fetus during development, what is it made from?
mainly collagen and ground substance with glyosaminoglycogens.
crosslinks in collagen which increase tensile strength
96
what is cervical ripening?
the growth and remodelling of the cervix prior to labour under the influence of relaxin and placental hormones
97
cerival ripening accelerates in the last 3 months because of which hormones?
progesterones, oestrogens and relaxin
| maybe also DHEA
98
effacement and dilation of the cervix is promoted by which hormones?
PGE from cervical muscosa
rleaxin and placental oestrogesn
main labout hormone = oxytocin (+ve feedback loop)
PGE increases sensitivity to oxytocin
99
where can prostaglandin be produced?
all uterine tissues
100
which type of prostaglandin is the most potent, and which is the main prostaglandin released in labour?
PGE2 10x more potent than PGF2a
PGF2a relased in labour
101
Summary of events of labour:
1. Enhanced [a] production
2. Initiation of labour
- maternal signs = [b]
- fetal signs = [c]
3. [d] enhanced the action of oxytocin
4. increased pressure on cervix increased the release of [e]
[a] prostaglandin
[b] oxytocin
[c] oxytocin vasopressin and cytokines
[d] PGF2a
[e] Prostaglandin from decidua and chorioamnion
102
the contractile protein in labour is?
is its formed how?
actomyosin
formed from actin and myosin only when phorphorylated by MLCK which is dependent on Ca++
103
when does labout normally occur?
37-42 weeks
104
how do you diagnose labour?
contractions with effacement (thinning) and dilation of the cervix
105
how long is labour on average?
8h nulliparous
5h multiparous
106
what are the two phases of the first Stage of labour?
Latent <4cm
Active 4-10cm
107
what rotations occur during the first stage of labour?
90° rotation from Occipito Transverse (OT)
to Occipito Anterior (OA) or Occipito Posterior (OP)
108
what happens to the amniotic membrane during the first stage of labour?
ruptures of is ruptured artificially.
109
What happens during the Second stage of labour?
Contractions continue
Head descends and felxes.
Rotation usually completed
Pushing starts when head reaches pelvic floor = active second stage
110
when does the babys head extend during labour?
during delivery as head goes over perioneum.
Head then rotatess back to transverse before the shoulders deliver
111
what is the Third Stage of Delivery?
Placenta delivered - 15mins
112
when does the placenta stary developing
after implantation of the blastocyst.
from the trophoblast
113
The placenta provides: ?
for the developing fetus?
1. nutrition
2. gas exchange
3. waste removal
4. endocrine and immune support
114
The fetal surface of the placenta is covered with [a] which is atchaed to [b]
umbilical vessel branch into [c[?
115
the maternal surface of the placenta has a cobbble stoned appearance due to?
it is covered by?
116
117
3 main functions of the placenta?
1. metabolism
2. transport
3. endocrine
118
what does the placenta synthesise?
* glycogen
* cholesterol
* fatty acids
119
what does the placenta transport?
120
what maternal anitbodies can/cannot cross the placenta?
IgG
not IgM
121
name 6 placental hormones
122
what is placenta accreta?
abdnormal adherence of placenta with absence of decisua basalis
123
what is placenta percreta?
villi penetrate myometrium
124
what is placenta praevia?
placenta overlies internal os of uterus
abnormal bleeding
125
