From The Textbook Flashcards
How many oogonia by 20 weeks?
7 million
How many oocytes at birth and at puberty?
1 million at birth
0.4 million at puberty
What is the chromosome number in gametes?
23, half of that in other cells
What stage is the primary oocyte suspended in?
Prophase
When does the second meiotic division occur?
When the ovum enters the Fallopian tube.
What are thecal cells?
Stromal cells aggregated around the follicles
What forms the corona radiata?
The innermost layers of granulosa cells
When is the corpus luteum formed
After ovulation
What stimulates follicular growth
FSH
What stimulates LH receptor development
FSH
Where is oestrogen produced?
The follicles of the ovary
What does the corpus luteum produce?
Oestrogen and progesterone
What occurs during the menstrual phase of the endometrial cycle
The functional layer of the endometrium is shed
When is the repair phase?
Day 4-7
Describe the follicular phase
Maximum period of growth of endometrial glands (due to oestrogen)
Features of the luteal phase
Saw-toothed glands, pseudodecidual reaction in stroma.
How long does full maturation of sperm take?
64-70 days
What do mature sperm develop from?
Haploid spermatids
What is the head of a sperm covered by?
The acrosomal cap
What does the body of the sperm contain?
Helix of mitochondria
What dos the tail of the sperm consist of?
2 longitudinal fibres and nine pairs of fibres
Where does seminal plasma originate?
Prostate, seminal vesicles, bulbourethral glands
Why does the semen contain a high concentration of fructose?
To provide energy for sperm motility
Why does semen contain high concentration of prostaglandins?
Potent stimulatory effect on uterine musculature
Where does final sperm maturation occur?
In the oviduct
What initiates the acrosomal reaction?
Adherence of the sperm to the ovum
What is syngamy
The fusion of male and female chromosomes
When is the morula formed?
36hrs after after fertilisation
When does implantation occur?
6 days after fertilisation
What causes penile erection?
Compression of venous channels
How is ejaculation mediated?
Contraction of bulbocavernous and ischiocavernous muscles.
Where does vaginal lubrication come from?
Vaginal transudation and bartholins glands secretion
Changes to the cervix in pregnancy (5)
Increased vascularity Reduction in collagen Accumulation of glycosaminoglycans and water Hypertrophy of cervical glands Increased mucus secretions
Where do primordial germ cells develop from
Yolk sac
