The Nervous System Flashcards
1
Q
Define stimulus
A
- a change in environment that triggers a reaction (response)
- organism responds in way that benefits itself
2
Q
Define Response
A
- organism reaction to stimulus
3
Q
Define sensitivity
A
- ability of organism to detect and respond to changes in environment
- survival dependent on appropriate response to stimuli
4
Q
Role of nervous system
A
- control activities of body and how it reacts to stimuli
- transmit info as nerve signals
- senses stimuli in surroundings, determines and directs responses to surroundings
- enable coordination of diff parts of body
- consist of well-developed brain, spinal cord, spianl nerves, highly specialised sense organs
5
Q
Define involuntary actions
A
- automatic activities
- not controlled consciously
6
Q
Define voluntary actions
A
- activities that are controlled consciously
7
Q
Voluntary actions (e.g. patting cat) Nervous pathway
A
- cat rubs against leg (stimuli)
- touch receptors at leg stimulated
- nerve impulses transmitted thru sensory neurones to spinal cord
- relay neurones conduct nerve impulses to brain
- brain evaluates info, decides response (pat cat)
- brain generate nerve impulses
- nerve impulses transmitted along relay neurones to motor neurones
- impulses transmitted to effector muscles (causes contraction of arm muscles, pat cat)
8
Q
Sense organs
A
- help body adjust quickly to stimuli
2. enable various parts of body to coordinate quickly
9
Q
Central Nervous System (CNS)
A
- brain
- spinal cord
- integrate and process impulses received frm PNS
10
Q
Peripheral Nervous System (PNS)
A
- cranial nerves
- spinal nerves
- provide comm link between CNS and other parts body
11
Q
How does nervous system process info? (nervous pathway)
A
- info gathered by receptors (sense organs)
- info converted to electrical signals (nerve impulses)
- nerve impulses transmitted by peripheral nerves to CNS
- brain process info based on pattern of impulses
- sends nerve impulses to effectors (muscle/glands)
- intended action carried out
12
Q
Nervous tissue (neurones)
A
- consist of 3 types of nerve cells (neurones)
- sensory, relay, motor neurones
13
Q
Basic structure of neurone
A
- cell body (nucleus, cytoplasm)
- axon
- dendron
- dendrites
14
Q
Cell body
A
- 1 nucleus and cytoplasm
- mitochondria and ribosomes present
- metabolic activities carried out
15
Q
Dendron
A
- receives info
- nerve fibres (conduct impulses towards cell body)
- small, break up into terminal branches (dendrites)