CMB1004/L12 CNS & PNS Flashcards
What makes up for Central Nervous System (CNS)? (2)
Brain & spinal cord
What makes up the Peripheral Nervous System (PNS)? (3)
Cranial nerves
Nerve ganglia
Peripheral nerves
Name the 3 functional types of neurone.
Motor/efferent neurone
Interneurone of CNS
Sensory/afferent neurone
What is the difference between multipolar and bipolar neurones?
Multipolar neurones have multiple dendrites and a single axon
Bipolar neurones have an axon and one dendrite
Describe the structure of a unipolar neurone.
It has one axon and no dendrites
How do mature neuronal cells divide?
They don’t - they must function for a lifetime
Describe the metabolic rate of neuronal cells.
Very high - require abundant oxygen and glucose
What is a graded potential?
Variable-strength signals that travel over short distances and lose strength
What is an action potential?
A large, uniform depolarisation that travels very rapidly for long distances down the axon without losing strength
Where can graded potentials occur? (3)
Dendrites, cell bodies or axon terminals
What is the relationship between size/amplitude of graded potentials and stimulus?
Directly proportional
What is depolarising graded potential also known as?
Excitatory postsynaptic potential (EPSP)
What happens to Na+ as they diffuse through the cell body?
They become diluted/less concentrated
Depolarisation gets weaker
What is hyperpolarising graded potential also known as?
Inhibitory postsynaptic potential (IPSP)
How do IPSPs occur?
Cl- enter cell via ligand-gated Cl- channel
K+ leave cell
