Flashcards in Other Deck (16):
The umbilical artery arises from? (In the fetus)
The internal iliac artery
The umbilical vein goes into?
Through liver via the ductus venosus into the IVC
What is the function of the bulbourethral gland?
Lubricates male tract
Clears out left over urine
What are the 4 main methods of contraception?
Stop sperm production
What are the four main steps of fertilisation?
Survive the vagina
Penetrate the cervix
Swim to the Fallopian tubes
What part of ejaculate keeps the pH basic?
What helps the sperm swim through the cervix?
Oestrogen relaxes the muscles of the cervix and makes mucus more fluid
Progesterone makes mucus thicker making it harder for sperm to penetrate
Explain capacitation of the sperm
Proteins are stripped from the plasma membrane of the sperm
This expresses receptors for chemoattractants
Stripping of cholesterol from the plasma membrane allows influx of Ca
This triggers hyperactivation
Which chemical messengers attract sperm to the correct place?
Progesterone from corona radiata cells
Atrial natriuretic peptide from follicular fluid
Explain how sperm penetrates the oocyte
Sperm binds to ZP
influx of Ca in sperm triggers exocytosis of acrosome which contains hydrolytic enzymes
These enzymes dissolve ZP
Whip like action pushes sperm forwards
Membranes fuse and contents enters into oocyte
A rise in Ca in oocyte causes release of granules that make ZP harder
The rise in Ca causes second meiotic division
Male and female pronuclei fuse
Which hormones and how do they prepare the endometrium for implantation?
Oestrogen causes proliferation of endometrium
Progesterone maintains and thickens lining
What is involution? And what is it due to?
Dramatic shrinkage of the uterus
Due to the disappearance of oestrogen and progesterone
What are the two main theories for the onset of labour?
Which hormones inhibit milk production in pregnancy?
Progesterone and oestrogen
What are the anatomical changes of the breast in pregnancy?
First half of pregnancy, ducts branch and extend, the lobes and alveoli proliferate and expand
The third trimester, cells double in size, epithelial cells convert to lactocytes