Unit 2: The Human Nervous System Flashcards
Why do living organisms respond to changes in their internal and external environment?
to increase their chance of surivival
What are the two control systems in humans?
The Nervous System and the Endocrine system
Describe the three main parts to a nervous system
- Detecting stimuli
- Coordination
- Effecting a response
List the sequences of events going from a stimulus to a response (5 points)
Stimulus, Receptor, coodinator, effectors, response
What is a stimulus?
a detectable alteration in the internal or external environment
Give example of a stimulus
light, pressure, blood sugar
What do receptor cells do?
Detect stimuli
Give an example of a receptor cell
Rod cells, cone cells, pacinian corpuscle.
What is a receptor?
a cell adapted to detect changes in the environment
What do receptor cells have on their cell surface membrane?
special receptor proteins
What are coordinators?
a network of interneurones
What do coordinators do?
Receives impulses from sensory neurones and transmits them to the motor system.
What are effectors?
cells that cause a response
What are the two types of effectors in humans?
muscles and glands
Give three different types of muscle cells
skeletal, cardiac, smooth muscles
What do muscles do?
contract to cause movement
What are the two types of glands?
endocrine and exocrine
What do endocrine glands do?
secrete hormones into the blood system
what do exocrine glands do?
secretes liquids outside of the body e.g. tears and sweat
Give examples of different responses that aid survival of an organism
- Movement
- Secretion from glands
- Different behaviours (stalking, reproducing)
