Neuromuscular System Flashcards
(19 cards)
What is the CNS?
The Central Nervous System, the Brain (control centre) and the Spinal Cord (transmitter of messages from brain)
What is the PNS?
Peripheral Nervous System (Nerve Fibres that extend out from the spinal cord throughout the body- carries impulses to effector organs.)
What do Dendrites do?
Receives information from other neurons or the environment
What does a Nucleus do?
Holds biological instructions which are required to synthesize proteins in a neuron.
What does an Axon do?
Carries electrical impulses that are the means of communication within the brain and between the brain and the rest of the body
What does a Myelin Sheath do?
Allows electrical impulses to transmit quickly and efficiently along nerve cells- made up of protein and fatty substances
What does a Schwann Cell do?
Development, Maintenance, Function and Regeneration of peripheral nerves
What does a node of Ranvier do?
Gaps in the Myelin Sheath that allows for rapid nerve impulse transmission.
What is the order of events at the Neuromuscular Junction?
Acetylcholine (a transmitter substance) is released from pre-synaptic valves as the Nerve Impulse moves to Motor End Plate. Acetylcholine aids transmission over synaptic cleft. The Muscle fibre gets action potential if there is enough acetylcholine. Post Synaptic Receptors receive molecules of acetylcholine and responds in one of two ways: excitatory and inhibitory. When the Acetylcholine Threshold is reached, depolarisation across the muscle fibre membrane occurs, calcium released from sarcoplasmic reticulum, leads to contraction.
What does Excitatory mean?
Muscular Contraction
What does Inhibitory mean?
No Muscular Contraction
What is a Muscle Twitch?
A single, brief contraction caused by a single electrical stimulus
What is a Wave Summatic?
A Medium Intensity contraction that happen when the muscle contracts before it can fully relax
What is Tetanus?
No rest or recovery due to constant stimuli, maximal intensity- can lead to injury.
What is the All or None Law?
The Law that states that any level of molecules above the Acetylcholine Threshold results in a full contraction, with anything below resulting in no contraction at all.
What is the Cerebrum?
The Largest part of the brain which controls thought, speech and movement.
What is the Cerebellum?
A ‘little brain’ under the cerebellum that is responsible for maintaining balance and co-ordinating body movements
What is Action Potential?
The Ability to contract
What is a Motor Unit?
The Nerve + the number of fibres it stimulates.
