Comparative & Developmental Reproductive Anatomy

Question 1

What 3 sources are gonads derived from?

Answer 1

• Mesothelium: (mesodermal epithelium) lining posterior abdominal wall
• Underlying mesenchyme: (embryonic connective tissue)
• Primordial Germ Cells: (earliest undifferentiated sex cells)

Question 2

What is an indifferent gonad?

Answer 2

Primordial organ before differentiation into gonads

Question 3

At what week are initial stages of gonadal development?

Answer 3

5 wk

Question 4

What produces the gonadal ridge?

Answer 4

Proliferation of mesothelium and underlying mesenchymal cells

Question 5

What is the permanent kidney primordium?

Answer 5

Thickened area of mesothelium developing on medial side of mesonephros

Question 6

Indifferent gonad consists of

Answer 6

External cortex

Internal medulla

Question 7

Cortex differentiates into

Answer 7

Ovary, medulla regresses

Question 8

Indifferent gonad:

Medulla differentiates into

Answer 8

Testes, cortex regresses

Question 9

What do the Gonadal cords become in males at wk5?

Answer 9

Seminiferous cords (Primordia of the seminiferous tubules)

Question 10

What do the parts of the gonadal cords that enter the medulla become in wk 5?

Answer 10

Rete Testes

Question 11

What 2 kinds of cells are made during wk 5 male sexual differentiation in gonads?

Answer 11

Spermatogonia And Sertoli Cells

Question 12

What are spermatogonia derived from?

Answer 12

Primordial germ cells

Question 13

What are sertoli cells derived from?

Answer 13

Mesenchyme

Question 14

What are follicular cells derived from?

Answer 14

Surface epithelium of ovary

Question 15

Which duct is the paramesonephric duct?

Answer 15

Mullerian

Question 16

Which duct is the mesonephric duct?

Answer 16

Wolffian

Question 17

In male embryo, SRY turns on expression of…

Answer 17

Testis determining factor

Question 18

What cells make Anti-Mulerian Hormone?

Answer 18

Sertoli Cells

Question 19

Wolffian duct becomes the …

Answer 19

Conductive ducts: epididymis, vas deferens, seminal vesicles

Question 20

Where are PCGs initially located?

Answer 20

Amongst endodermal cells of yolk sac, near origin of allantois

Question 21

PCGs migrate along…

Answer 21

Dorsal mesentery of hindgut to gonadal ridges

Question 22

What is happenening to PGCs during 6th week of development?

Answer 22

PGCs enter underlying mesenchyme and incorporated into gonadal cords.

Question 23

The Homologous Genital tubercle differnetiates into:

Answer 23

Penis (male), Clitoris (female)

Question 24

The urethral folds develop into the:

Answer 24

Penile urethra (male), labia minora (female)

Question 25

The urethral groove deveops into the:

Answer 25

Disappears in males, Vestibule (Females)

Question 26

The labioscrotal swelling develops into the:

Answer 26

Scrotum (male), Labia majora (female)

Question 27

What directs direction of descent of ovaries and testes?

Answer 27

Gubernaculum

Question 28

Why does the testes descend into the scrotum?

Answer 28

Temperature regulation for sperm production

Question 29

What happens to the gubernaculum in males?

Answer 29

Shrinks into a small structure attached to the base of the scrotum

Question 30

What happens to the gubernaculum in women?

Answer 30

Gives rise to the ovarian and round ligaments, the latter is attached to the labia majora

Question 31

The male pelvic cavity shown no reprductive organs between the urinary bladder and the rectum except for the...

Answer 31

Seminal Vesicles

Question 32

Length of male urethra :

Answer 32

18-24cm

Question 33

Length of female urethra

Answer 33

3-5cm

Question 34

In females, the urethral sphincter...

Answer 34

Extendsright through the pelvic diaphragm to the neck of the bladder

Question 35

In males the urethral sphincter...

Answer 35

also extends through the pelvic diaphragm, but stops at the base of the prostate

Question 36

Where does the pudendal nerve arise from?

Answer 36

Sacral spinal nerve plexus

Question 37

What do the sensory nerve branches of the pudendal nerve supply?

Answer 37

Lower anus, perineum, and external genitalia

Question 38

What do the motor nerve branches of the pudendal nerve supply?

Answer 38

Anal sphincter, small perineal muscles including the urethral sphincter, the pelvic diaphragm.

Question 39

Where does the autonomic nervouse supply pass through to get to the genitalia?

Answer 39

Directly from the interior of the pelvis to the pelvic diaphragm

Question 40

Where does the sympathetic innervation to the genitalia arise from?

Answer 40

Lower thoracic / Upper lumbar

Question 41

Where does the parasympathetic innervation to the genitalia arise from?

Answer 41

Sacral S2-4

Question 42

Where do the testes and parts of the scrotum recieve their nerve supply from? Why?

Answer 42

Recieve nerve supplies directly from the lumbar levels and pelvic autonomic plexi via spermatic cord. Due to testes descending dragging diffrerent nerves w/ them. (Parts of labia majora supplied in similar way.)

Question 43

Describe the blood supply to the genitalia

Answer 43

Homologous in both sexes: Common Iliac branches into internal and external iliac. Femoral branches off external iliac and pudendal branches off internal iliac

Question 44

Compare the male pelvis to the female pelvis

Answer 44

- More heart shaped, - Greater anterior-posterior rather than lateral dimensions - Has more vertical iliac crests - More acute infrapubic angle - Inward directed ischial spines, sacrum and coccyx