Homeostasis Flashcards
(19 cards)
What is positive feedback?
A change is detected and the body works to reinforce the change.
What is negative feedback?
A change is detected and the body works to reverse the change.
What is the main difference between Endotherms and Ectotherms?
Ectotherm’s body temperature is heavily dependent on their environment and surroundings. Endotherm’s body temperature is dependent on metabolic processes.
Name one Behavioural and one Physiological way Ectotherms cool down
Behavioural: Seek shade
Physiological: Altering heart rate
Name one Behavioural and one Physiological way Ectotherms warm up
Behavioural: Sun Basking
Physiological: Altering heart rate
In Endotherms, how is temperature change detected?
Peripheral detectors on the skin surface and temperature receptors in the hypothalamus measuring blood temperature
Name one Behavioural way Endotherms cool down and warm up
Cool down: Wallowing in mud and water
Warm up: Pressing against a warm surface
Name the 3 Physiological ways Endotherms cool down
Vasodilation, Increased Sweating, Hair and Feathers lying flat (Reducing insulating effect)
Name the 4 Physiological ways Endotherms warm up
Vasoconstriction, Decreased sweating, Erecting Hair and Feathers, Shivering
Name 3 forms of excretion in mammals.
Carbon Dioxide breathed out, Bile Pigments in faeces, and Nitrogenous waste in the urine as UREA
What are the two vessels supplying the liver with blood?
The Hepatic Artery and The Hepatic Portal Vein
What is the significance of the HPV?
It supplies the liver with 75% of its blood supply and is loaded with products of digestion straight from the intestine
What is the name of liver cells and how are they adapted to their purpose?
Hepatocytes: Large Nuclei, Prominent Golgi Apparatus, lots of Mitochondria (Indicating high metabolic activity)
Why is the blood for the HA and the HPV mixed?
To increase the oxygen content of the HPV blood, so the hepatocytes get as much oxygen as they need
How are foreign particles removed from Liver Blood?
Kuppffer cells in the Sinusoids act as local macrophages
What are the 3 main processes of the Liver?
Carbohydrate metabolism, Deamination of excess amino acids, and Detoxification
Define Transamination
The conversion of one amino acid to another
What is the significance of DeAmination?
The removal of an amine group from a molecule - it is significant as it allows excess proteins/amino acids to be converted into Ammonia, then Urea, and excreted by the kidneys, the remaining amino acid can be used for respiration or converted to lipids for storage
How does Ammonia become Urea?
The ornithine cycle
