Homeostasis Flashcards
What is homeostasis?
The maintenance of a constant internal environment within the body.
Why is homeostasis important?
Homeostasis is important because it is essential for the survival of cells, to be independent of surroundings and for metabolism to work efficiently.
What are the 2 waste products that need to be removed and how they are produced and removed?
- CO2 - Produced by respiration, Removed via lungs.
- Urea - Produced by liver breaking down amino acids, Removed by kidneys + transferred to the bladder.
A cell’s delicately balanced chemical reactions work best within narrow limits of…?
- Temp
- pH
- Solute concentration
How is temperature Increased and decreased in the body?
- Increased by shivering
- Decreased by sweating
How is ion content Increased and decreased in the body?
- Increased by eating
- Decreased by sweating / urine
How is water content Increased and decreased in the body?
- Increased by drinking
- Decreased by sweating / urine
How is blood glucose Increased and decreased in the body?
It’s increased and decreased by hormones.
Most homeostatic mechanisms work by which type of feedback?
They work by negative feedback.
What is negative feedback?
If something changes from the optimum it is corrected back.
What do endotherms have?
They have a very constant body temperature.
What are two endotherms?
- Mammals
- Birds
What does this constant body temperature help with, in relation to their environment?
They can operate in low temperature environments, as they can keep their rate of enzyme activity high.
What are two ectotherms?
- Fish
- Amphibians
- Reptiles
How do ectotherms differ from endotherms?
Their temperature varies with the external temperature.
What should be the core body temperature?
37 degrees
What part of our body is mainly producing heat and from what?
The heat is mainly being produced from the liver during it’s metabolism.
How does our skin control body temperature rising and falling?
- If our temperature rises, more blood flows close to the surface of the skin and glands release sweat.
- If our temperature drops, blood flows under the adipose tissue, we stop sweating, our hairs stand up and we shiver.
Name three ways in which water is important to a living organism.
- *Metabolism
- *Medium for chemical reactions
- Movement of materials in and out of cells
- Transport system
- Lubricant
- Support
- *Temperature control
- Dispersal of reproductive cells and seeds
How is water lost through our lungs?
Some water gets evaporated as we exhale from our warm lungs.
How is water lost through our skin?
By evaporation from cells + through sweat.
How is water lost through our intestines?
Water is lost through faeces.
How is water lost through our kidneys?
n dissolving the poisons and wastes we wish to excrete from the body.
What organs are in charge of regulating water intake mainly?
The kidneys
