Term
Describe the seasonality of the repro system in birds.
-any exceptions? |
|
Definition
-unlike other avian systems, the repro system is only active during part of the year in most species
-exception: domestics |
|
|
Term
| What changes occur to the avian repro tract during the off-season? Why? |
|
Definition
-ovaries, testes, and the associated ducts regress DRAMATICALLY
-this relates to the need to save weight during flight |
|
|
Term
| Why do we need to know that the avian repro tract changes size? |
|
Definition
-post mortems
-lots of people breed birds and need info
-very different from most mammals
-birds have something like dystocias |
|
|
Term
| There are 6 very different repro-related things that birds can do that other higher vertebrates usually don't. What are they? |
|
Definition
-birds can very rarely reproduce parthenogenitically
-can change gender from female to male, especially in domestic fowl
-can produce bilateral gynadromorphs
-old females become masculinized
-females are heterozygous while males are homozygous
-sex ratio is ALWAYS 50:50 |
|
|
Term
| In the bird, what hormone regulates follicle growth in females and spermatogenesis in the male? Where does it come from? |
|
Definition
|
|
Term
| In the bird, which hormone regulates testosterone and estrogen levels? Where does it come from? |
|
Definition
|
|
Term
| In the bird, which hormone regulates repro behavior and the development of secondary sex characteristics? Where do they come from? |
|
Definition
-testosterone: testes
-estrogen: ovaries |
|
|
Term
| How does the bird kidney differ from most mammals? |
|
Definition
| -trilbated, large, retroperitoneal, recessed in a special cavity of bone in the sacrum |
|
|
Term
| How do male birds produce viable sperm considering their very high body temp? |
|
Definition
| -go through spermatogenesis at night and store sperm in the cloaca |
|
|
Term
| Copulation and fertilization is a hit or miss strategy for birds. How do they compensate for this? What are the exceptions? |
|
Definition
-higher frequency of copulation
-waterfowl and ratities |
|
|
Term
| Why are the testes so large in male birds during breeding season? |
|
Definition
| -high sperm demand due to inc frequency of copulation |
|
|
Term
| True or FAlse: Delayed fertilization is common in birds. Why or why not? |
|
Definition
-TRUE
-sperm can remain viable for weeks
-gallinaeceous birds can produce fertile eggs for up to 72 days after copulation |
|
|
Term
| What do avian ovaries look like? |
|
Definition
|
|
Term
| Do most female birds have a right ovary, a left ovary, or both? Exceptions? |
|
Definition
-most only retain the left
-exceptions are raptors, gulls, and some passerines |
|
|
Term
| The avian ova increases in size about _____ times in volume from ovulation to laying. Why? |
|
Definition
-1000
-most of the volume is the yolk sac that acts as an energy source for the fetus |
|
|
Term
| What deposits the yolk in eggs? When is it added ot the egg? |
|
Definition
-cells lining the follicle
-yolk added just before ovulation (8-16 days before laying) |
|
|
Term
| Yolk is not produced in the follicles. Where does it come from? |
|
Definition
|
|
Term
| Describe the contents of yolk. How is it applied? |
|
Definition
-very high in proteins and lipids
-laid down in concentric spheres |
|
|
Term
| What are the two types of yolk? When are they deposited? |
|
Definition
-yellow: deposited during the day
-white: deposited during the night |
|
|
Term
| What portions of the female avian urogenital system are smooth muscle? Which are skeletal muscle? |
|
Definition
| -all smooth muscle except for the vagina |
|
|
Term
| What composes the oviduct in birds? |
|
Definition
|
|
Term
| How long does the passage of the ova take in the birds?- |
|
Definition
|
|
Term
| What is the function of the infundibulum? |
|
Definition
-fertilization takes place here
-lays down yolk membrane (separates albumen from yolk) |
|
|
Term
| What is the function of the magnum? |
|
Definition
-chalaza are formed
-albumin is secreted |
|
|
Term
|
Definition
| -supend the yolk within the albumin |
|
|
Term
| What are the two types of albumin? What are their purposes? |
|
Definition
-watery and dense
-absorb shock and keep temp stable |
|
|
Term
| What is the function of the isthmus? |
|
Definition
| -inner and outer shell membrane formed (outer membrane lines inside of shell) |
|
|
Term
| What is the function of the uterus? |
|
Definition
-large amounts of water are added
-hard shell is laid down |
|
|
Term
| What primarily composes an egg shell? |
|
Definition
|
|
Term
| What is the function of the vagina? |
|
Definition
| -voluntary expelling of egg |
|
|
Term
|
Definition
| -morning every one or two days |
|
|
Term
| When being laid, which end of the egg usually comes out first? |
|
Definition
| -large one except in chickens |
|
|
Term
| What are some of the causes of egg binding? |
|
Definition
-obstructions
-necrotic eggs
-senility
-infections
-obesity
-all seed low calcium diets |
|
|
Term
| Treat egg bound birds very carefully!! If the egg breaks in the oviduct they can cause _____. |
|
Definition
|
|
