Repro part 3 Pregnancy Flashcards
Where does fertilization occur?
in the fallopian tube (oviduct)
What must sperm go through before reaching the oocyte?
Pass through cervical mucus (thinned by estrogen).
What are the main parts of sperm?
Head
Midpiece
Tail (flagellum)
Acrosome
what do Acrosome contain and why?
contains enzymes to help penetrate the egg
How long are the egg and sperm viable?
Egg: 24 hours
Sperm: 4-6 days
How does fertilization occur?
- About 100 sperm reach the egg, guided by chemotaxis (progesterone).
- Acrosomal enzymes help sperm tunnel through the egg’s barriers.
- The first sperm to fuse with the egg fertilizes it.
What prevents menses after fertilization? (2)
The trophoblast secretes Human chorionic gonadotropin to maintain the corpus luteum.
Progesterone maintains the endometrium and prevents menses.
What endocrine gland is temporary in pregnancy?
The corpus luteum
What hormones trigger labor?
Increase in estrogen, oxytocin receptors, fetal cortisol, and prostaglandins.
what hormone does the corpus luteum secrete during pregnancy and for how long?
produces progesterone until the placenta takes over
what happens to the pelvis during labour?
Relaxin loosens pelvic ligaments and softens the cervix before birth.
What hormones are necessary for breast milk production before birth and what do they do?
Estrogen and progesterone develop mammary glands but inhibit milk production.
What hormones are necessary for breast milk production after birth and what do they do?
Prolactin stimulates milk production.
Oxytocin helps with milk ejection (let-down reflex).
how does the renal system adapt to pregnancy?
Increased blood volume due to vasopressin and RAS.
what helps the sperm transport to reach the egg?
Transported by uterine and oviduct contractions aided by estrogen and prostaglandins in semen.
