Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Medicine Unit 7 > Fertilisation and implantation > Flashcards

Fertilisation and implantation Flashcards

1
Q

maturation of spermatozoA

A

100 fold concentration of sperm, oestrogen dependent
completion of sperm modelling
changes in metabolism
acquisiton of forward motion
changes in membrane surface proteins, charge and fluidity
coating of sperm plasma membrane with glycoproteins
dpeends on adequate stimulation of epididymis by androgen

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

what is coitus mediated by

A

sympatheti
parasympathetic
somatic

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

coitus sympathetic

A

hypogastric nerve
vascular tone in penile and clitoral arteries
emission of semen in the urethra

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

coitus parasympathetic

A

pelvic nerve
promotes vasodilation and erection of penile and clitoral tissues, lubrication

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

coitus somatic

A

pudenal nerve
sensations following stimulation of glans penis/clitoris emisison in internal urethra
reflex rhythmical contractions of muscles during ejaculation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

where does fertilisation occur

A

in ampulla of fallopian tubes

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

issues sperm encounters in the vagina

A

physical loss of sperm form vagina
survival of sperm cells in the vagina

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

adaptations of sperm to prevent loss form vagina

A

semenogelin 1, 2 and fibronectin
aggregate to form coagulum
forced retention

broken down in 20 mins
via proteolytic cleavage of semenogelins by prostate specific antigen so sperm can regain motility and continue journey

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

vaginal environment

A

normal vaginal flora prevent colonisation of pathogenic bacteria as lactobacillus produce lactic acid from anaerobic digestion of glycogen
vagna secretes hydrogen perodixde and antimicrobial peptides to exhibit strong adhesion to vaginal epithelium
abundance of immune cells

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

how do the sperm neutralise and overwhelm vaginal defences

A

neutralisation of acidic vaginal environement by alkaline seminal fluid
attenuation of vaginal immune response by immunosuppressive compounds in the seminal fluid e.g. prostaglandins
large number of sperm ejaculated overwhelms innate immune
sperm deposited near cervical os allowing fast escape though cervix

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

penetrating the cervix

A

sperm migrate out of seminal plasma and into mucus immediately

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

characterisics of the cervical canal

A

cervical crypts

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

quality of the cervical mucus

A

mucins
glycoproteins: long and flexible
aligned by secretory flow in the mucosal grooves
muc5B and muc4: hydrophillic

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

penetrating cervix in follicular phase

A

oestrogen relxaes muscles of cervix
increases secretion and hydration of cervical mucus
facilitates sperm penetration into the uterus

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

penetrating cervic in the luteal phase

A

progesterone decreases cervical mucus secretion and hydration level
impermeable to sperm and pathogens
protecting potential fertilised embryo

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

travel through uterus

A

self propulsion
cilitated endothelial celsl of endometrium create fluid current
oestrogen driven contractions of myometrium towards fundus during follicular phase

17
Q

sperm capacitation

A

loss of glycoprotein coat
reveals binding sites and receptors, epididymal protease inhibitor which facilitates acrosome reaction and increases sperm receptivity to chemo-attractants
change in the surface membrane properties
loss of membrane cholesterol destabilises the plasma membrane
facilitates the acrosome reaction
increase in intracellular Ca2+
activation of protein kinase A needed for acrosome reaction

18
Q

how does the sperm enter the right fallopian tube

A

labelled microspheres show to be preferentially transported to fallopian tube in late follicular phase
dominant follicel secrete progesterone, disperses to ipsilateral fallopian tube, relaxation of musces at utero-tubual junction
ipsilateral to dominant follicle allows controlled sperm penetration

19
Q

how do sperm find the oocyte in the fallopian tube

A

specific receptors on capacitated sperm responding to chemo attractive substances: ANP or progesterone from follicualr fluid or cumulus oophorus or odorant recpetors similar to those in the olfactory epithelium

activation of adenylate kinase, cAMP mediated rise in intracellular Ca2+ for chemotaxis and chemokinesis

20
Q

ovulated oocyte pathway

A

moved from the surface of the ovary by fimbrated ostium
passes into the ampulla of fallopian tube adhering epithelium via cumulus cells
contractions of smooth muscle and oviductal cilia move cumulus oocyte to ampullary isthmic junction
intersittial celsl of Cajal

21
Q

fetilisation

A

Sperm hyaluronidases dissolve cumulus cell extracellular matrix
Sperm cell reaches the zona pellucida (ZP)
Short-lived binding of capacitated sperm to ZP3/ZP4 complex
Increased intracellular Ca2+ in sperm cell via activation GCPR
Exocytosis of acrosome enzymes (acrosome reaction)
“drill” into ZP
Acrosin
Hyaluronidases
Hexosaminidases

22
Q

use other flashcards

A

for fertilisatipn and cleavage

23
Q

what do the trophoblast outer rim form

A

trophectoderm
extra embryonic support tissue precursor

24
Q

what does the uterus consist of

A

An outer serous peritoneal layer
A thick layer of smooth muscles (myometrium) with spontaneous peristaltic activity
An internal endometrium consisting of a stromal matrix overlaid by a simple columnar epithelium containing ciliated and glandular cells

changes during hormone cycles

25
Q

maternal recognition of conceptus

A

trophoblasts secrete HCG
prevents luteal regresison by binding to LH receptors on luteal cells, stimulates estrogen and progesteron secretion
preventing endometrium shedding
prepares uterus
triggers deciduation of the endometrial lining
to make the endometrium receptive to implantation

26
Q

deciduation

A

differentiation from elongated fibroblast like endometrial stromal cells
into more rounded and high specialised secretory epithelioid cell type

27
Q

blastocyst in implantation

A

Oxygen and metabolic substrates from uterine secretions
Continued growth and survival
Trophoblast cells use specific transport mechanisms to accumulate ions and organic molecules
Oxygen and carbon dioxide exchange through diffusion

28
Q

zona pellcuida in implantation

A

Zona Pellucida
Prevents cells of pre-compaction conceptus from separating (monozygous twins)
Prevents genetically distinct conceptuses from forming a chimera
Prevents the blastocyst from implanting in an inappropriate location in the uterus

29
Q

mucins in implantation

A

Mucins (MUC-1) in the endometrial glycocalyx prevents binding of the conceptus and guides it to a receptive area

30
Q

phases of implantation

A

hatching
apposition
adhesion
invasion

31
Q

hatching phase

A

ZP breaks down by lytic enzymes in glandualar secretions
hatching of the conceptus by contraction/expansion of conceptus allowing rapid size increase

32
Q

apposition phase

A

paracrine signalling controlled unstable interaction between blastocyst and uterine epithelium
tropholbasts express L-selectin to allow blastocyst to roll across surface of uterus until it finds receptive area of uterine epithelium that express sulphated oligosaccharide ligand
leukaemia inhibitory factor: oestrogen induced cytokine that promotes luminal endothelial receptivity and stromal cell decidualisation

33
Q

adhesion

A

receptive areas of endometrium are the pinopodes
EGF receptors expressed by trophoblast
luminal cells express Hb-EGF which bnnds EGFR
signals from blastocyst upreg cell adesion such as integrins which mediate firm adhesion of blastocyst to endometrial linng

34
Q

invasion

A

adhesion triggers local singlaling events: proliferate and differentiate into cytotrophoblast and syncytiotrophoblast
St secrete TNFa which reduces intracellular adesion to allow ST invasion
produce lytic enzymes to invade stromal celsl
stromal reaction: oedema, increased sprouting and capillary growth, decidualisation
then secondary decidualisation reaction and endometrial component of the placenta is prepared
breakdown of decidual cells prodive nutrition
ST projections will degrade maternal vessels
casuing maternal blood to floow ST lacunae allowing direct uptake of nutrients
cytotrophoblastic cells form finger like projections in the syncytiotrophoblast
form foetal blood vessels
endometrial epithelium reforms behind

35
Q

implantation window

A

Days 1-7 luteal phase
Endometrium is prereceptive
Long apical microvilli
High surface charge
Thick glycocalyx
Days 7-10 receptive phase
Transition to receptivity
Pinopodes appear
Loss of surface negative charge
Shortening of microvilli
Thinning of mucin coat
If no implantation:
Refactory phase
Resist attachment

Medicine Unit 7 (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions