Nervous System - Homeostasis Flashcards
What is homeostasis?
- regulation of the internal conditions of a cell or organism to maintain optimum conditions for functions in response to internal and external changes
The automatic control is given by what 2 systems in the body.
-nervous
- endocrine systems
What are the 3 homeostatic control mechanisms?
- receptor cells
- coordinations centres
- Effectors
What is the function of receptor cells?
- detect stimuli (changes in environment)
What parts of the body are coordination centres and what is their function?
- Brain, Spinal Cord, Pancreas
- Receive and process information from receptors
The human nervous system is divided into 2:
- Central nervous system : Brain + spinal Cord
- Peripheral nervous system : all other nerves
What are nerves?
cells called neurones that carry electrical impulses around the body
What are receptor cells?
specialised cells that detect changes in the environment
What are effectors and what is their functions?
-muscles or glands
- bring about response to restore optimum levels
Reflex arc -
The nerve pathway involved in a reflex action (doesn’t involve the brain)
Reflex -
rapid + automatic response for body protection
Reflex action -
automatic + rapid response to a stimulus
Key characteristics of reflexes:
- automatic + rapid response
- Involuntary
- stimulus always leads to the same response
Describe the reflex arc pathway.
- Stimulus
- Change detected by receptor
- sensory neurone receives electrical impulse from receptor. Then sends to relay neurone across the synapse
-
relay neurone (central nervous system) receives electrical impulse and sends to motor neurone
5.motor neurone receives electrical impulse and sends it to effector -
effector produces a response:
- muscle contracts
- glands release hormones - Causes physical response / action
What is the acronym for the reflex arc?
Stimulus
Receptor
Sensory neurone
Relay neurone
Motor neurone
Effector
Response
