Uanatomy of M + F Repro : Bendiak

Question 1

Where does meiosis take place during the development of spermatozoa from spermatogonia?

Answer 1

Seminiferous tubules

Question 2

Fxn of rete testes

Answer 2

region of anastomosing channels where the nonmotile spermatozoa enter and be moved to efferent ductules –> epididymus

• makes sense that it contains connective tissue with myoid cells: can contract and move sperm

Question 3

How do the efferent ductules move the still immotile sperm?

Answer 3

They are lined by a mixture of columnar ciliated cells
(and cuboidal absorptive cells)

Each ductulus also has a band of circularly arranged SM around it to facilitate spermatozoa propulsion into the epididymus

Question 4

Why are the ductuli (efferent ductules) and epididymus so structurally different?

Answer 4

Ductuli arise embryonically from primitive tubules that comprise the mesonephros

Epididymus arise from mesonephric (Wolffian) duct itself.

Question 5

When does the vas deferens become the ejaculatory duct?

Answer 5

when the vas deferens meets the seminal vesicle

Question 6

How do the seminiferous tubules help to propel the developing spermatozoa?

Answer 6

They have an outer basal lamina surrounded by myofibroblasts

- contract + propel spermatozoa

Question 7

Spermatogenesis initially occurs with _____.

• What is it?
• What does it become once committed?
• Where is it found?

Answer 7

mitotic division of type A spermatogonia (2N)

• true stem cells that divide to totipotent progenitors
• once committed to meiosis, become type B spermatogonia

*found in outer region of tubules

Question 8

How many chromosomes do primary spermatocytes have? (they form from type B spermatogonia)

Answer 8

4 C (chromosomes)
during cross over events during meiosis
- develop as primary spermatocyte at 3 weeks, then undergo meiosis II as secondary spermatocytes

Question 9

How long do primary, secondary spermatocytes develop for?

Answer 9

Primary: 3 weeks

Secondary: 2 hours
hardly ever observed
- quickly progress to spermatids

Question 10

What is special about the entire process of meiosis (in sperm development)?

Answer 10

during the entire process of meiosis, the cells derived from a given spermatogonium remain linked as a syncytium with a connected cytoplasmic bridge.
- Important for RNA exchange between developing haploid spermatids
(many recessive genes being exchanged)

Question 11

During spermatogenesis, the interconnected cells (during meiosis) that are underdeveloped are surrounded by ____.

Answer 11

sertoli cells

Question 12

blood testes barrier

Answer 12

Comprise of Sertoli cells via tight jxns.
- seal off spermatocytes

*spermatogonia at the base of the seminiferous epithelium are not contained in the barrier

Question 13

What secretes androgen binding protein? What is its fxn?

Answer 13

Sertoli cells
- ABP binds T and sequesters high levels of testosterone (200x as [ ] as the blood)

*sertoli cells also produce inhibin that feeds back to the hypothalamus to inhibit FSH

Question 14

When do spermatozoa gain motility?

Answer 14

En route along the epididymus

they are not motile when leaving the testes

Question 15

OOcytes are derived from a population of ____.

Answer 15

primordial follicles

primordial germ cells divide mitotically up to 5 months gestation –> stop in meiosis I

Question 16

What is the ovarian surface covered by?

Answer 16

Single layer of epithelial cells: germinal epithelium

Question 17

What surrounds oocytes in the ovary during development?

Answer 17

Primordial follicle

–> become cuboidal = primary follicles

–> acquire more than 1 layer = granulosa cells

• multiple layers of granulosa cells surround large primary/secondary follicle
• theca cells surround granulosa cells

Question 18

When are primary/secondary follicles stimulated to develop into large Graafian follicles (antral follicles) having fluid filled antrum?

Answer 18

After menarche
- granulosa cells proliferate and thecal cells enlarge –> graafian follicle

• remember the oocytes remain in prophase I around 6 mo after birth.
• also remember, the atretic follicles that form form primary follicles when Graafian (antral) follicles do not form

Question 19

Atretic follicles

Answer 19

the left over primary follicles that do not develop to antral (Graafian) follicles

Question 20

Thecal cells produce ____, which is converted to _____ by granulosa cells.

Answer 20

androstenedione

estradiol

Question 21

Corpus luteum

Answer 21

large endocrine group of cells that were remodeled from remaining granulosa and thecal cells after an OVULATORY FOLLICLE successfully releases an OOCYTE

*this occurs monthly and is driven by LH production

Question 22

What controls the release of the corpus luteum?

Answer 22

LH production around 12 days into the cycle and is referred to as luteinization

Question 23

Corpus albicans

Answer 23

corpus luteum degenerates into corpus albicans

• a residual body if implantation does not occur

Question 24

2 fates of the corpus luteum

Answer 24

1. No fertilization
   - -> degenerates into corpus albicans
2. Fertilization/implantation –> Corpus luteum enlarges under the influence of chorionic gonadotropin –> responsible for maintenance of pregnancy
   * placenta and CL are responsible for maintenance of pregnancy

Question 25

What 2 structures are responsible for maintenance of pregnancy?

Answer 25

1. COrpus luteum

2. Placenta

Question 26

Muscular make up of fallopian tube

Answer 26

inner circular
outer longitudinal

(IC, OL)

Inner has lots of folded mucosal surfaces that are secretory and ciliated with basal stem cells.
- estrogen stem cells

Question 27

Two zones of the endometrium?

Which one is hormonally responsive and cycles monthly?

Answer 27

Functionalis