embryology

Question 1

9 regional divisions

Answer 1

Question 2

peritoneal cavity

Answer 2

The largest body cavity

The peritoneum is a thin, translucent, serous membrane or sac that secretes peritoneal fluid for lubrication

It lines the walls of the peritoneal cavity from abdomen to pelvis and creates potential spaces where fluid can collect

Question 3

retroperitoneal cavity

Answer 3

Located behind & outside of the peritoneal cavity

Question 4

gender chromosomes

Answer 4

The normal number of human chromosomes is 46

23 pairs, for each pair one chromosome is maternal in origin & one chromosome is paternal in origin

Chromosomes #1-#22 are collectively called autosomes, 1 pair is called sex chromosomes

Question 5

sex chromosomes

Answer 5

Female gamete (ovum) are X

Male gamete (spermatozoon) & are either X or Y

At fertilization male gamete determines gender: X denotes a female, Y denotes a male

Question 6

when is the 1st morphologic indication of gender & what parts are formed?

Answer 6

7th week

Gonadal ridge forms:
Mesonephric / Wolffian duct (mostly male genital parts)
Also develops parts of urinary system
Paramesonephric / Műllerian duct (mostly female genital parts)

Question 7

What are the orange, grey, blue and yellow bits responsible for??

Answer 7

blue: Mesonephric duct / Wolffian duct, responsible for male development
orange: Paramesonephric duct /Műllerian duct, responsible for female development

Urogenital sinus is yellow

Gonads are grey & are responsible for either ovary or testicle development

Question 8

what does the paramesonphric/mullerian duct form in females?

Answer 8

1. Fallopian tubes
2. Uterus: ML septum fuses from inferior to superior & is gone by 3rd month, however it can fail to fuse
3. Upper vagina

Question 9

what does the urogenital sinus form in females?

Answer 9

1. Vestibule of vagina
2. Labia
3. Bladder –> Urethra

*yellow

Question 10

ducts on 12 week femal fetus

Answer 10

Question 11

newborn female

Answer 11

Question 12

At __ days primordial germ cells differentiate from caudal end yolk sac near allantois (outpouching, later becomes umbilical artery & vein)

Answer 12

21

Question 13

What part of the embryo becomes the ovaries?

Answer 13

primary sex cord

Question 14

What does teh primordial germ of teh embryo become?

Answer 14

oocytes

Question 15

When do the ovaries start to develop?

What 2 parts of the ovary are formed?

Answer 15

At approx. 16 weeks sex cords break into clusters that disappear & are replaced

Inside (ovarian medulla) from vascular stroma
Outside (ovarian cortex) from follicular epithelial cells

Question 16

What are the 4 remnants of embryology?

Answer 16

Gartner’s duct: Runs parallel to uterus & vagina inside of broad ligament
Part of mesonephros

Hymen: Covers external vagina
From urogenital sinus

Vaginal fornices: Wrap around external cervical os
From Műllerian duct

Hydatid (of Morgagni): Fallopian tube appendage
From paramesonephric duct

Question 17

In a female embryo the orange duct forms:

What do the grey structures become in a female?

Embryologically, wht are both names for the orange duct?

What is the yellow area named?

What does the yellow area form?

Answer 17

1 Fallopian tubes, #2 Uterus

Paramesonephric duct or Műllerian duct

Urogenital sinus

Vestibule of vagina, Labia, Bladder, Urethra

Question 18

When do oocytes develop?

What do oocytes become?

Answer 18

before birth. ~200,000 in each ovary at birth

Ova

Question 19

what is the primary follicle surrounded by?

Answer 19

a single layer of granulosa cells from the sex cord.