2.8 - Homeostasis Flashcards
What is homeostasis?
The maintenance of constant internal environment to keep conditions at an optimum
What are responsible for homeostasis?
Nervous system and hormones
What are the differences between hormones and the nervous system?
1) its type of message is
2) carried by the…
3) speed of transmission is
1) chemical, electrical
2) blood, neurons
3) slow, fast
Where are hormones produced?
Endocrine glands
Which hormone is involved in the regulation of sugar (glucose) in the blood?
Insulin
What is glucose needed for?
respiration
When your body is low in glucose what are the effects on the pancreas, liver and blood glucose level?
Pancreas - Insulin not secreted (released) into blood
Liver - Doesn’t convert glucose into insoluble glycogen
Blood glucose level - increase
When your body is high in glucose what are the effects on the pancreas, liver and blood glucose level?
Pancreas - Insulin is secreted (released) into blood
Liver - Convert glucose into insoluble glycogen
Blood glucose level - decreases
What is a negative feedback mechanism?
mechanisms to lower raised levels of something, and to raise reduced levels of something
Explain what happens in your body regarding controlling the level of blood glucose after a meal?
1) Glucose is absorbed from the small intestine into the blood
2) The pancreas detects an increase in glucose in the blood
3) The pancreas releases insulin which travels in the blood to the liver
4) The liver converts excess glucose into insoluble glycogen for storage and the blood sugar falls
5) Pancreas stops producing Insulin
Explain what happens in your body regarding controlling the level of blood glucose following exercise?
1) During exercise glucose from the blood is quickly used up for respiration to keep the muscles moving
2) Pancreas detects decrease in glucose in blood
3) Pancreas releases glucagon which travels in the blood to the liver
4) Liver converts stored glycogen back into glucose and the blood sugar levels rise
5) Pancreas stops producing glucagon
Why does the skin help maintain the body temp at 37*C ?
Temp at which the body’s enzymes work best
What is in the skin?
blood capillaries hair erector muscle hair sweat sweat pore sweat duct sweat gland
When we are too warm what happens to the hairs on our skin?
1) hair erector muscle relaxes, lowering the hair
2) thin insulating layer of air is trapped above the skin
3) more heat is lost to the environment
When we are too cold what happens to the hairs on our skin?
1) hair erector muscles contract, raising the hair
2) hairs trap a thicker layer of air above the skin
3) air insulates skin against heat loss
What is vasoconstriction?
The response to being cold. Process involves the narrowing of blood vessels at the skin surface to reduce heat loss through the surface of the skin