Neuromuscular junction (synapse) Flashcards
What happens when an action potential reaches the neuromuscular junction?
It releases a chemical (ACh) that makes the muscle contract.
This process is crucial for initiating muscle contraction.
What is acetylcholine (ACh)?
A chemical that tells the muscle to contract.
ACh is a neurotransmitter that plays a key role in muscle activation.
What is the all-or-none principle?
A motor unit contracts fully or not at all.
This principle explains how motor units function in muscle contractions.
What is motor unit recruitment?
Using more motor units to make muscles stronger.
This process allows for graded muscle contractions based on the demand.
Why does recruiting more motor units make stronger contractions?
More motor units = more force.
This is fundamental in increasing muscle strength during physical activities.
If a motor unit is partially stimulated, what happens?
It doesn’t contract at all.
This highlights the importance of the all-or-none principle in muscle physiology.
What is action potential?
cells cell membrane potential rapidly changes
What is Neuronmuscular junction?
a connection between a motor neuron and a muscle cell
What does tropomyosindo?
-Cover actins binding site for myosin
-blocks muscle contraction
What are the ends of the sarcomeres called
Z lines
What is the centre of the sarcomere called
M line
What protein does calcium bind with when initiating cross bridge cycling?
troponin C
During muscle contractions do filaments of acting and myosin shorten?
No
What happens during a power stroke?
myosin head pulls Actin toward the centre of the sarcomere
which area of the sarcomere does not shorten during muscle contraction?
A zone
