Homeostasis Flashcards
(22 cards)
What is a receptor?
Receptors detect and react to the stimulus, a change in the environment. They send the input to the co-ordination centre.
What is a stimulus?
A stimulus is a change in the environment which triggers a response.
What is homeostasis?
The regulation of the body’s internal environment to ensure that enzymes are able to function correctly and efficiently.
What is an effector
Effectors are muscles and glands which produce a response.
What does the body do if internal temperature drops below 37 degrees?
- Vasoconstriction, the arterioles in the skin constrict to prevent blood from flowing too close to the skin and heat being lost to the environment.
-Shivering, the muscles quickly contract and relax to generate heat and stabilise the core temperature.
What happens to the body if it gets too hot?
Vasodilation, the arterioles in the skin dilate which allows a higher volume of blood to flow near the skin and allow heat to become lost.
Sweating, the sweat glands in the body open which allows sweat to be released, the sweat evaporates when temperatures are high which cools the body down.
Examples of positive feedback:
Blood clotting and childbirth
Which part of childbirth relates to positive feedback
What is positive feedback?
The end products of a reaction trigger the action to continue
What is negative feedback?
Negative feedback is the process of the body reversing a change in the body to maintain the internal environment.
How does the negative feedback system work?
What is the dynamic equilibrium?
The fluctuation of an internal environmental feature around the optimum
What does homeostasis control about the tissue fluid?
Water potential
PH
Temperature
What are enzymes?
globular proteins with complex, tertiary structures
tertiary structures are critical to the functionality of the active site
What happens if the pH fluctuates from the optimum?
The tertiary structure of the active site will become affected and change, this can stop the active site from binding to the substrate.
What else is effected except for enzymes?
Other proteins and ion channels.
What is an ectotherm?
An animal which is unable to regulate its own temperature, therefore relying solely on the environment.
(E.g snakes, bees, fish,
What is an endotherm?
A mammal which is able to regulate its internal temperature through processes such as shivering, using underfur, sweating, panting.
Humans, dogs, cats.
why is it so important for the blood glucose levels to be maintained?
1.Glucose concentration levels in the blood impact the water potential of the tissue fluid and blood. If blood glucose falls significantly it can increase water potential
- Glucose is used by cells for reactions to release energy eg. Respiration.
What happens if the water potential of the tissue fluid is high?
water can move into the cells causing them to burst
What is the standard response pathw
- stimulus
- receptor
- co-ordination centre
- effector
- response
