Exam 4 (Lecture 53) - Avian Repro

Question 1

Describe the functions of the testes in the rooster.

Answer 1

1) Testosterone synthesis

2) Sperm production

Question 2

Describe the functions of the epididymis in the rooster.

Answer 2

Functions to maintain fertility
- fluid and calcium reabsorption
- sperm surface modifications

Question 3

Describe the functions of the vas deferens in the rooster.

Answer 3

Main storage area for sperm

Question 4

Describe the effect of light (short vs. long day) on the hypothalamic-pituitary-gonadal axis in the rooster.

Answer 4

In general:
- Increased light (long days) > hypothalamic photoreceptor > stimulates GnRH production
- GnRH > anterior pituitary > FSH and LH

Rooster:
- FSH and LH > Testes
- FSH > Spermatogenesis
- LH > Testosterone (androgen); testosterone is required for spermatogenesis

*So, during short days, there will be decreased testosterone and thus decreased spermatogenesis and increases in these during long days.

Question 5

Describe the effect of light (short vs. long day) on the hypothalamic-pituitary-gonadal axis in the hen.

Answer 5

Same “in general” information as the rooster.

Hen:
- FSH and LH > Ovary
- FSH > Follicular development (and small ovarian follicles)
- Estrogens and androgens (estrogen = hepatic vitellogenesis and yolk deposition)
- LH spike associated with ovulation
- LH > F1 preovulatory follicle > progesterone (progesterone = broodiness/sit on eggs)

*This is all decreased during short days and increased during long days.

Question 6

In the left ovary of the hen, as follicle size __________, oocyte size __________ due to accumulation of ___________.

Answer 6

Increases; increases; yolk lipoproteins

Question 7

Name the two types of yolk lipoproteins.

Answer 7

1) Vitellogenin

2) VLDLs (very low density lipoproteins)

Question 8

Where are lipoproteins produced? How do the lipoproteins reach the yolk?

Answer 8

Lipoproteins are produced from the hen’s liver
- Liver > Systemic Blood > Perivitelline Membrane > Yolk

Question 9

Describe how progesterone and estrogen concentrations change during follicular growth from F5 (smallest follicle) to F1 (largest follicle).

Answer 9

From F5 to F1, progesterone increases

From F5 to F1, estrogen decreases

Question 10

Describe the infundibulum.

Answer 10

1) Funnel and neck

2) Vascularized mucosa lined by pseudostratified columnar epithelium

3) Fertilization occurs in the neck region

Question 11

Describe the magnum (of the oviduct).

Answer 11

1) Longest part of the oviduct

2) Well-developed tubular glands produce albumen

3) Mucosal folds are more numerous and taller than those of the infundibulum

4) Tertiary folds are present

5) Muscularis is more developed than in the infundibulum

6) Pesudostratified epithelium is composed of ciliated columnar cells and secretory goblet cells

7) Deposits albumen egg white and is lined by ciliated and nonciliated columnar cells

Question 12

Describe the isthmus (of the oviduct).

Answer 12

1) Relatively short region with a diameter less than that of the magnum

2) Longitudinal primary mucosal folds possess numerous secondary folds

3) Muscularis is better developed than the magnum

4) Epithelium is ciliated, pseudo stratified columnar epithelium with secretory cells

5) Numerous tubular glands secrete the shell membranes

6) Formation of the inner and outer shell membranes and is similar in structure to the magnum

Question 13

Describe the uterus (shell gland).

Answer 13

1) Expanded portion of the oviduct

2) Walls are not as thick as those of the preceding segments

3) Muscularis is well developed, especially the longitudinal layer

4) Mucosa is longitudinal, leaf-shaped folds that are covered by ciliated pseudostratified columnar epithelium

5) Shell of the egg is produced from secretions of its tubular glands (formation takes 20-21 hrs)

6) Pigment deposition

Question 14

Describe the vagina.

Answer 14

1) Short and narrow duct

2) Tunica muscularis is well developed, especially the circular layer

3) Mucosa is in numerous tall, narrow folds bearing many small secondary folds

4) Surface is covered by a ciliated, pseudostratified columnar epithelium with mucous cells

5) Sperm storage occurs in the sperm-host glands

6) Tubular glands occur within the CT of the mucosa of the vagina near the junction btwn. uterus and vagina

Question 15

During aging, what happens with rooster, hen, and flock fertility?

Answer 15

Decreases as age increases

Rooster:
- Decrease in sperm quality
- Decrease in mating activity

Hen:
- Decline in fertility
- Not able to store sperm as long; so more frequent mating is required