4.1.1 - 4.1.2 - Neuromuscular function Flashcards
What is the nucleus?
a membrane enclosed organelle that contains most of the cells’ genetic material
What is the axon?
long fiber of a nerve cell (neuron) that acts like a fiberoptic cable carrying outgoing (efferent) messages,
sends electoral impulses from its cell body through the axon to target cells,
each nerve cell has one axon,
can be up to 20 cm
What are dendrites?
brings information to the cell body
What is the motor end plate?
AKA neuromuscular junction is the synapse or junction of the axon terminal where a muscle cell (neuron) communicates with a target cell
What is a synapse?
the small junction across where a nerve impulse passes from one cell to another
What is the central nervous system (CNS)?
consists of the brain and spinal chord
What do sensory neurons do?
carry signals to CNS from receptors Body temp., BP, blood O2 and CO2 levels
What do motor neurons do?
carry signals from CNS to muscles contract and relax
What is a motor unit?
the motor neuron + muscle it innervates (supplies with nerves)
Why do the number of fibers change per motor neuron?
A large number of muscle fibers per motor neuron cause a muscle to generate large forces.
What is a neurotransmitter?
Neurotransmitters are chemicals that transmit signals across a synapse from one neuron (nerve cell) to another.
Where are neurotransmitters released from?
Neurotransmitters are released from synaptic vesicles in synapses into the synaptic cleft, where they are received by receptors on other synapses.
What are the two neurotransmitters used for motor neurons called?
Acetylcholine (ACH)
Cholinesterase
What is acetylcholine (ACH)?
Primary neurotransmitter for motor neurons that innervate skeletal muscle and for most parasympathetic neurons.
What is cholinesterase?
Enzyme that catalyses the neurotransmitter acetylcholine, through hydrolysis, into choline and acetic acid, a reaction necessary to allow a neuron to return to its resting state after activation.
