Lecture 8 Flashcards
(21 cards)
Describe hyperosmolal and what happens
When blood osmolality is greater than that of the water so water flows into the body
Describe hyposmolal
When blood osmolality is less than the water. Water flows into the water
Describe what hyperosmolal and hyposmolal do in regards to conserving salts/water
hyperosmolal creatures need to conserve salts and excrete excess water whereas hyposmolal organisms need to conserve water and excrete excess salts
What is less toxic out of ammonia, urea or uric acid?
Urea
What are the advantages to converting ammonia to urea in the urea cycle?
Can be used to counter osmotic dehydration and can detoxify ammonia when there’s not enough water available
Why was ureotelism important for terrestrial vertebrates?
It allowed storage of detoxified nitrogen until water was available
What is poikilothermy?
The limited ability to maintain a difference between body and the environment
What is homeothermy?
“Same heat”
What is regional heterothermy?
Different temperatures in different parts of the body
Explain how fish manage heat
To use endothermal heat, they must prevent heat loss through gills. They use the counter-current from the rete mirabilia
Explain heat exchange in fishes gills
Cold arterial blood enters warm part of the body, flows through a rete and warmed by the heat of warm venous blood leaving the tissue. Some sharks and Scombroid fish.
How do billfishes release heat?
Calcium-cycling mechanism associated with muscle contraction
Hhow do marine tetrapods maintain whole-body endothermy?
They use lungs, insulation like fur/pelt/blubber to maintain metabolic heat
Where is the counter current heat exchange system in animals like seals?
In their flippers
Give an example of regional heterothermy
Blood enters the wings of a penguin through many arteries and returns through many veins. This establishes a counter current, an adaption to cold water
Give an analogy for heat exchange between an organism and its environment in regards to surface area
Peas have a higher surface area than potatoes therefore peas cool down faster than potatoes
What are the two major life zones in the sea?
The palagic and benthic zones
Explain the migration of mesopelagic fish
They migrate vertically to the surface and food at dusk and return to depths at dawn. They follow light levels and remain where its hard to see by predators
Describe the morphology of deep-sea fish in the bathypelagic zone
There’s a decrease in muscle and bone with limited locomotion
What are photophore organs?
They emmit blue light and communicate things like which sex the fish is
What is an adaption for food in deep sea fishes and why?
They have large mouths with distensible stomachs. Food is so rare they have to get it
