Nerve Transmission Flashcards
(18 cards)
Definition of a neurotransmitter:
Chemicals released by parts of the nervous system to activate adjacent neurones or effectors
What is an axon?
Long fibre of a neurone that carries impulses away from the cell body
What direction are sodium and potassium ions transported during repolarisation?
Na+ in
K+ out
What are dendrites?
Finest extensions of a neurone that carry an impulse towards the cell body
What are the protein channels called that open/close depending on the voltage differences of a membrane?
Voltage-gated channels
What are the 2 co-ordination systems in mammals?
- Hormonal
2. Nervous
What direction are sodium and potassium ions transported during depolarisation?
Na+ out
K+ in
What function do Schwann cells have to remove cell debris?
Phagocytosis
What part of ion movement requires active transport?
Sodium-potassium pump
A synapse that utilises acetylcholine as the neurotransmitter is known as what type of synapse?
Cholinergic
What are the 2 types of summation?
- Temporal
2. Spatial
Which ion causers inhibition of a post-synaptic membrane due to hyperpolarisation?
Chloride ions
What are the organelles that store neurotransmitters in the pre-synaptic knob called?
Synaptic vesicles
What is temporal summation?
When repeat impulses along a single pre-synaptic neurone in a short period of time enable the threshold to be reached
What is a ligand-gated channel?
A type of sodium ion channel on the post-synaptic membrane that triggers initiation of an action potential
What are nodes of Ranvier?
Discrete areas of myelinated neurone where depolarisation occurs during an impulse
What does the dorsal root of the spinal cord do?
Carry sensory input from the stimulus to the central nervous system
What does the ventral root of the spinal cord do?
Carry motor input from the central nervous system to the effector
