Homeostasis And Response (part 1) Flashcards
Homeostasis
Maintaining a stable internal environment
Automatic control systems such as nervous and hormonal
Receptors, coordination centres and effectors
Negative feedback
Automatic cycle
Receptor detects a level too high, coordination centre organises a response, effector counteracts
Level now too low, coordination centre organises a response, effector counteracts
Continues happening
CNS
Central nervous system, the brain and spinal cord in vertebrates
Sensory and motor neurones
Sensory receptor —> CNS
Motor CNS —> effector
Receptors and effectors
Receptors- the cells which detect stimuli, can form part of larger organs e.g. retina
Effectors respond to nervous impulses- muscles and glands
Synapses
The connection between two neurones
Chemicals diffuse across the gap
Set off a new electrical signal in the next neurone
Reflexes
- instant response
- don’t involve the conscious part of the brain
Reflex arc
- receptor detects a stimulus
- travels along the sensory neurone
- diffuses across a synapse
- relay neurone in the CNS
- diffuses across a synapse
- travel along a motor neurone
- effector brings about a response
Brain
Part of CNS
Billions of interconnected neurones
In charge of all complex behaviours
Cerebral cortex
Big, wrinkly big
Consciousness, intelligence, memory, language
Cerebellum
Back and base
Muscle coordination
Medulla
Above spinal cord
Controls unconscious activities
Studying patients with brain damage
The effect can tell you what part has been damaged if only a small part has been impacted
Electronically stimulating the brain
Pushing a tiny electrodes, a small zap of electricity. Stimulating different parts allow us to see what each does
MRI scans
Magnetic resonance imaging
Gives a detailed picture of the brain’s structures
Use it to see which parts are active when doing things e.g. listening to music or trying to recall a memory
