Embryology 1 Flashcards Preview

ESA 1 - Body Logistics > Embryology 1 > Flashcards

Flashcards in Embryology 1 Deck (14):

What is embryology?

Study of progression from a single cell to a baby in 9 months. Includes molecular, cellular and structural factors.


Why are zebrafish embryos used as models for embryology?

- Similar developmental process
- Translucent embryos develop outside mother
- Sequenced genome
- Cheap
- Can be genetically modified to resemble human genome


What is special about the uterine wall to aid pregnancy?

Very muscular (for pushing baby) and can reverse contractions to allow spermatocyte entry


What is the role of the cervix in pregnancy? Which condition is associated with deficiencies in this?

Prevents baby from falling out.
Cervical incompetence


How to differentiate between male and female (across animal kingdom)?

female gamete (ovum) always larger than male gamete (sperm)


Why are ova bigger than spermatozoa?

1. Females produce a few large gametes, males produce very many tiny gametes.
2. Ovum provides machinery and nutrients to nourish developing embryos as well as half the genetic material.
3. Large ratio of male to female gametes so numerous sperm must compete for access to rarer ova.


What is ovulation?

The release of an egg from one of the ovaries


When does ovulation occur?

Half way through menstrual cycle (exact timing may vary)


How uterus prepare for ovulation?

Endometrium (uterus lining) thickens


What stimulates the release of an egg?

Pituitary gland


How is the egg released from the ovary?

The wall of the ovarian follicle ruptures at the surface of the ovary and releases the egg.


What happens once the egg is released from the ovary?

Fimbriae sweep the egg into the neighbouring Fallopian tube. Travels along the tube, aided in part by contractions of the tube walls.


Where can the egg be fertilised by sperm?

Fallopian tube


What happens to an egg if it isn't fertilised?

It is reabsorbed by the body. 2 weeks later, lining of uterus sheds through vagina (menstruation).