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Flashcards in Ovarian Function Deck (31):

What are the two phases of the mestrual cycle?

Which hormone is present in each?

Follicular/Proliferative phase: oestrogen

Luteal/Secretory phase: progesterone and oestrogen 


Which secondary sex characteristics are controlled by which hormones in females?

Oestrogen: breats development, distribution of body fat

Adrenal androgens: growth of pubic and axillary hair, sex drive


Describe the structure of the ovary?

Surface epithelium > theca > basal lamina > granulosa cells > antral fluid 



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Describe the structure of the uterus?

Endometrium > myometrium > outer connective tissue > uterine artery 

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Which parts of the ovary produce hormones?

Theca and granulosa cells 


Describe the timing of the phases of the menstrual cycle?

What is happening to the follicle in each stage?

Follicular/Proliferative: days 0-13 (variable)
Follicle growth in ovary

Ovulation at day 14 (variable)
Release of oocyte 

Luteal/Secretory phase: days 15-28 (constant)
Ruptured follicle transforms into corpus luteum

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Describe the changes that occur in the endometrial lining during the menstrual cycle?

Menses: endometrium shed with no pregnancy

Proliferative phase: new layer of endometrium in preparation for pregnancy

Secretory phase: conversion of endometrium into a secretory structure to promote implantation 

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Describe the menstrual and uterine cycles?

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What is the corpus albicans?

Regressed form of corpus luteum that appoears when pregnancy does not occur


Describe the hormonal control in the follicular phase of the menstrual cycle?

FSH > stimulates follicular development 
> granulosa cells produce oestrogen (positive feedback)

LH > stimulates thecal cells to produce androgens > converted to oestrogen in granulosa cells (under control of FSH)

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Describe the hormonal control of menstruation during ovulation?

High oestrogen > switch to positive feedback to GnRH > LH and FSH surge 

High inhibin > inhibits FSH

Low progesterone > positive feedback on GnRH and LH

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Why does inhibin inhibit FSH during ovulation?

Getting ready for conception > don't need a new follicle


Describe why oestrogen levels drop after ovulation?

No more follicle to produce it


Describe the cervical mucous that is present during ovulation?

Abundant, clear, non-viscous


Describe the hormonal control of the menstrual cycle during the early luteal phase?

Corpus luteum formed from granulosa cells, secretes:
High oestrogen
High progesterone
High inihibin 

Decreased GnRH, LH and FSH 

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Why are progesterone, oestrogen and inhibin high during the early luteal phase?

Oestrogen and progesterone: maintain endometrium

Inhibin: prevent new follicle formation 


Describe the cervical mucous produced during the early luteal phase?

Thick, sticky, viscous mucous 

Protect intrauterine environment (don't need any more sperm)


Describe the change in body temperature that occurs in the mestrual cycle?

Rises by 0.5 degrees during the early luteal phase 


Describe the hormonal control of the menstrual cycle during the late luteal phase?

Pregnancy: maintain high hormones

No pregnancy: CL dies > low oestrogen and progesterone, low inhibin > increased FSH 
Increased LH

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Describe the process of fertilisation?

Sperm capacitation occurs in vagina > sperm reach oocyte in Fallopian tube > acrosomal reaction, zona pellucida and cell junctions dissolve > membranes fuse and sperm nucleus enters > cotrical reaction > diploid cell = zygote 


What is the purpose of the cortical reaction?

Prevents more than one sperm from entering 


What are the lifespans on sperm and secondary oocytes?

Sperm: 48 hours

Secondary oocyte: 12-24 hours 


Describe the process of zygote development, from ovulation to implantation?

Ovulation >

Day 1: fertilisation
Days 2-4: cell division
Days 4-5: blastocyst reaches uterus 
Days 5-9: blastocyst implants

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Describe how the endometrium changes after implantation?

Trophoblastoic cells of blastocyst invade endometrium > blastocyst becomes completely buried > endometrium becomes decidus


Describe the three phases of pregnancy?

Early pregnancy: weeks 1-2

Embryonic period: weeks 3-8

Foetal period: weeks 9-term 


Describe the susceptibility during early pregnancy?

Not susceptible to teratogens

Susceptible to chromosomal abnormalities

Environmental disturbances may interfere with implantation


Describe the susceptibility during the embryonic period?

Most susceptible to teratogens


When are all organ systems present?

Embryonic period 


Describe the susceptibilityduring the foetal period?

Physiological defects

Minor morphological abnromalities

Functional disturbances


Describe the factors that influence normal foetal gorwth?

Genetic factors

Environmental factors:
- multiple pregnancies
- maternal malnutrition
- placental function
- smoking
- alcohol
- drugs
- infectious agents
- exercise
- environmental chemicals 


Describe the efficacy of various contraceptive methods?

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