10 Flashcards
Central Nervous System componants
Brain and spinal cord
CNS role
Processes sensory information
Decides what to do and initiates a response
Peripheral Nervous System components and role
All other nerves
Carry info from receptors to CNS
Conscious Nervous Coordination
When you are aware of what you do - action is thought about
Unconscious Nervous Coordination
Uses spinal cord only - action is involuntary
Unconscious Nervous Coordination
Uses spinal cord only - action is involuntary
What neurones are used in a nerve response?
Motor
Intermediate
Sensory
Dendrite
Carries impulses toward cell body
Cell body
Contains neurone nucleus
Axon
Carries impulses away from cell body
Axon terminal
END
connects to dendrites of a new cell
Structure of myelin sheath
High fat content
Flat schwann cells
made from schwann cells
Why is speed of conduction faster in non myelinated neurones?
- lack of insulation
amplification causing less shielding
What is a synaptic cleft?
Gap between two neurones
Importance of mitochondria to neurones
Mitochondria produces ATP
Neurone dendrites and axons use ATP for the Na+/K+ pump to maintain/restore resting potential
Synapses use ATP for calcium induced exocytosis of Golgi vesicles containing neurotransmitter into synaptic clefts.
How does L-dopa affect synaptic transmission in a person with parkinsons?
L-dopa is precursor of dopamine
Increases amount of dopa in presynaptic neurone
normal levels of dopa stimulate the post synaptic neurone
How may serotonin imbalances affect a persons mood?
Lower levels of serotonin in brain may cause fewer receptors in brain to be stimulated meaning fewer brain impulses may lead to anxiety and or depression
Drug which mimics a neurotransmitter known as an
agonist
Drug which blocks neurotransmitter known as an
antagonist
Example of agonistic drug which impact on cholinergic synapses is
nicotine
Botulin prevents transmission
Ach not released from synaptic knob
So cannot diffuse across synaptic cleft
So cannot bind to receptors on post-synaptic membrane
So sodium gates cannot open
No depolarisation; no impulse
