Coordination and response Flashcards
What is excretion?
The removal of toxic materials, waste products and excess materials in both plants and animals
What does homeostasis do?
Maintains a constant internal environment
What internal conditions have to be controlled?
Skin - Core body temperature
Kidney - Water and ion content
Lungs - CO2 content in the blood
Pancreas & Liver - Blood glucose level
What is normal body temperature?
37 degrees
Why must the body remain at around 37.5 degrees?
So that enzymes working in the body work at their optimum temperature and don’t denature
What happens if the body gets too cold?
- Blood vessels narrow
(vasoconstriction) - Less blood flows near skins
- Hairs stand to trap insulating air
- Shivering = rapid muscle
contractions which creates heat
What happens if the body gets too hot?
- Blood vessels widen (vasodilation)
- More blood flows near skins surface
- More heat is lost by radiation
- More sweat produced and released
What does the nervous system do?
Detects changes in the environment (stimuli) and co-ordinate a response
What coordinates a response so a stimulus in an animal?
They have receptors in their sense organs
What does a receptor do?
It’s a special type of cell that detects changes in the environment
What is a sense organ made up of?
lots of receptor cells
What is a stimulus?
change in the environment
What is a response?
A change in an organism triggered by a stimulus
Give 5 examples of sense organs and what they do.
- Mouth/tongue - detects food chemicals
- Eyes - detects light
- Ears - detects vibrations (sound)
- Nose - detects scent
- Skin- Detects pressure, heat + pain
What is the central nervous system made up of?
The brain and spinal cord which is protected by your skeleton
What do receptors do?
Sends an electrical impulse along nerve cells (neurones) to your central nervous system