Module 1- Communication & Homeostasis Flashcards
Define neurones
A differentiated cell that can pass impulses as action potentials
Define hormone
A molecule released into blood that acts as a chemical messenger
Define stimulus
A change in the environment of an organism that causes a response
Define response
The reaction to a stimulus
Define synaptic knob
The end of a neurone
Define target cell
Cell that have receptors in the plasma membrane that are complementary in shape to specific molecules
What are the features of a good communication system?
- Covers the whole body
- Allows cells to communicate
- Allows specific communication
- Allows rapid communication
- Allows short and long term response
What are the two main communication systems inside humans?
-Neronal system- quick and uses electrical impulses
Hormonal- Slow and uses chemical signals
Response of arctic fox during season change
Change fur colour, physiological response
Pupil response when lights are turned on
Will constrict, physiological change
Response of lions to increased temperature
Sleep in shade, behavioural response
Response of swallows to lower daylight and temperature
Migrate south to Africa, behavioural change
Response to drop in body temperature
Shivering, stop sweating, put on a jumper
Try to maintain 37 degrees centigrade
What conditions affect enzymes?
- Temperature
- pH
- Substrates in solution
- Toxins
