HAP T1 W3 Nerves Cells & Impulses

T1 W3 Nerves Cells & Impulses

what are the 5 jobs of a neuron?

Receive , integrate, decide, transmit, communicate

what part of a neuron receives info?

dendrites

what part of a neuron integrates info ?

cell body

what is the role of a axol hillock?

decides whether to initiate an action potential.

what is the function of the axon?

transmits electrical signals.

what is the function of the axon terminal ?

communicates with the next cell

what is the CNS?

brain and spinal cord

what is the PNS ?

nerves, ganglia and receptors

define afferent

traveling towards CNS

Define efferent

traveling away from CNS

function of dendrites

receives info

neuron vs nerve

cell vs bundle of axons

typical RMP?

-70 mV

typical threshold

-55 mV

What is a graded potential?

local variable membrane potential change

what is depolarisation

membrane becomes less negative

what is hyperpolarisation

membrane becomes more negative

what iron enters during during depolarisation

Na+

what iron leaves during repolarisation

K+

define all or none

AP either occurs fully or not at all

what is the absolute refractory period? and why

no second AP possible - Na+ chanels inactivated

what determines stimulus strength

frequency and recruitment

what is myelin?

insulating sheath around axons

CNS myelin cell?

Oligodendrocyte

PNS myelin cell?

schwann cell

what are the nodes of ranvier

gaps in myelin

what is saltatory conduction?

AP jumps node to node

What opens at synaptic terminal ?

voltage gated Ca2+ channels

role of calcium

triggers neurotransmitter release

what is exocytosis

vesicle fusion with membrane

ionotropic receptor?

direct channel opening

metabotropic receptor?

indirect signalling cascade

ways to terminate a signal?

reuptake, diffusion, enzymatic breakdown

what is EPSP?

excitatory postsynaptic potential

what is IPSP

inhibitory postsynaptic potential

neurotransmitter at NMJ?

acetylcholine

enzyme that breaks down ACh?

Acetylcholinesterase

tetrodotoxin target

Na+ channels

Botulinum toxin effect

blocks transmitter release

multiple sclerosis effect

myelin loss slows conduction

what is neuroplasticity

ability of neural networks to change