Lab 10: Muscular System Flashcards
Skeletal Muscle Review:
- muscle fiber is a long, thick, cylindrical cell.
- ends of the muscle fibers are blunt
- multiple, peripherally located nuclei.
- Striations
- voluntary (consciously controlled) and requires a stimulus to contract.
- Each individual muscle fiber is supplied with a nerve ending of a somatic motor neuron.
- A single motor neuron will control hundreds of muscle cells.
- All the muscle fibers controlled by a single motor neuron constitute a motor unit.
Origin
attachment of a muscle at stationary end of bone
Insertion
attachment site on the bone which moves
Agonist
The muscle whose contraction is primarily responsible for producing a particular action (aka the prime mover)
Antagonist
muscle that stretches and yields to the effects of the prime mover. muscle that opposes the action of an agonist
Fixator
stabilizing the origin of the prime mover so that the prime mover can act more efficiently
Synergist
contract at the same time as the prime mover. muscle whose contraction helps a prime mover in an action
Belly
middle, thicker region of the muscle
Action
when a muscle contracts, one bone is moved relative to another bone and a specific movement, or action is produced
Each muscle’s name provides information regarding the muscle. The name may include: 7
(i. ) Muscle location
(ii. ) Direction of the muscle fibers
(iii. ) Muscle shape
(iv. ) Relative size of the muscle
(v. ) Number of divisions in the origin of the muscle
(vi. ) Location of the muscle attachments
(vii. ) Basis of the muscle action
Synapse
site of communication between the neuron and muscle cell
synaptic end bulbs
The axon terminal divides into a cluster of structures.
synaptic vesicle
containing acetylcholine.
