Reproductive System Flashcards
What is the term used to describe the avian reproductive system?
Heterosexual.
What does the male contribute?
Sperm in semen.
What does the female contribute?
An ovum in the egg yolk.
What is the ovum referred to as?
Blastoderm, blastodisc, or germ disc.
Where does the yolk move to after it is released from the follicle?
Into the oviduct.
What happens to the yolk in the oviduct?
- Fertilization.
- Addition of albumen.
- Addition of the shell membrane.
- Addition of the shell.
What does the male reproductive system in fowl consist of?
- Two testes.
- Two deferent ducts.
What structure do male fowls lack that is found in other male animals?
A penis.
Where are the testes located?
Against the backbone, at the front of the kidneys.
What happens to the testes when the cock is mating?
They enlarge.
*The left is larger than the right.
What is the small, flattened area on each testis thought to correspond to?
The epididymis in mammals.
*Deferent ducts start here.
What is the function of the deferent duct?
To transport sperm from the testes to the cloaca.
What type of structure do the deferent ducts lead into in the cloaca?
A small pimple-like structure that is analogous to the penis in other animals.
What are the tubes inside the testes called?
Seminiferous tubules.
What two processes occur in the seminiferous tubules?
Meiosis and the early steps of spermatogenesis.
How many sperm are found in one cubic mm of semen?
3-5 million.
How is avian sperm described?
- Long pointed head.
- Long tail.
What type of hormones do the testes produce?
Androgens.
Why is the volume of the seminal fluid very low?
Due to lacking seminal vesicles and a prostate gland.
How much semen do chickens produce per ejaculate?
1 ml.
*Whitish
How much semen do turkeys produce per ejaculate?
0.5 ml, but 2x as concentrated as that of a chicken.
*Yellowish or brownish.
What does the female reproductive system consist of?
Ovary and oviduct.
*Have two sets, but only the left side is functional.
Where is the ovary located?
Just in front of the kidney, attached firmly to the peritoneum by the meso-ovarian ligament.
Why is the ovary well-vascularized?
To be able to transport nutrients to the developing yolk.
What does the ovary consist of?
A mass of yellowish, round follicles.
*Only a small number of follicles reach maturity.
What does each follicle contain?
An ovum/yolk.
What is the size of a normal egg yolk?
40 millimeters in diameter.
What is the first stage of follicular development?
Primary follicle.
*Not yet commenced growth.
What is the second stage of follicular development?
Growing follicle.
What is the third stage of follicular development?
Mature follicle.
*Ready or near ready for ovulation.
What is the fourth stage of follicular development?
Discharged follicle.
*Ovulation has occurred.
What is the fifth stage of follicular development?
Atretic follicle.
*Yolk was released some time ago.
How long does it take the yolk to develop?
10 days.
*Happens in the follicle.
What is the stigma?
An elongated, virtually blood vessel free area on the distal surface of a mature follicle that splits to release the yolk.
*If it splits elsewhere, blood spots appear in the yolk.
What is the function of the oviduct?
To produce albumen, the shell membrane, and the shell around the yolk.
*Why many glands are located within its walls.
How is the oviduct of a non-layer described?
- Short.
- Small in diameter.
How is the oviduct described when the hen is actively laying?
70-80 cm with variable diameter (depending on section function).
What are the 5 sections of the oviduct in order from innermost to outermost?
- Infundibulum/Funnel.
- Ampulla/Magnum.
- Isthmus.
- Uterus/Shell gland.
- Vagina.
How is the infundibulum described?
- Thin-walled.
- 6-9 cm long.
- Adjacent to the ovary w/ long segment enclosing the ovary.
What are the 2 functions of the infundibulum?
- Collects and directs the yolk into the oviduct.
- Site of fertilization.
What happens if the infundibulum is unable to collect a yolk?
It is absorbed within three days.
*If this occurs frequently enough, the hen’s abdomen will become distended as the yolks accumulate faster than they can be absorbed.
How long is the yolk in the infundibulum?
15 minutes.
How is the magnum described?
40 cm long.
What is the function of the magnum?
Secretes more than 40% of the albumen.
What are the 4 layers of albumen?
- Chalazae and chalaziferous layer.
- Liquid inner layer.
- Dense layer.
- Outer liquid layer.
What % of the albumen layer is the chalazae and chalaziferous layer?
2.7.
What % of the albumen layer is the liquid inner layer?
17.3.
What % of the albumen layer is the dense layer?
57.0.
What % of the albumen layer is the outer liquid layer?
23.0.
What are the chalazae?
Two twisted chords of albumen extending from opposite sides of the yolk into the remaining albumen.
What is the function of the chalazae?
To keep the yolk centrally located as it passes through the oviduct, to ensure embryo survival.
*Part of a special thin albumen envelope that surrounds the yolk to hold it in position.
How are the liquid inner and outer liquid layers formed?
Dense albumen produced by the bird is mixed with water, the egg is repeatedly rotated and the inner liquid and dense layers are formed, more water added in the uterus/shell gland causes the outer liquid layer to form.
What does the dense layer contain a significant amount of and what does this cause the texture of the dense layer to be?
Mucin, which causes it to be jelly-like.
What happens to the level of dense albumen as an egg stales?
It decreases and becomes more liquid.