Muscular System pt. 2

Question 1

Muscles have two things?

Answer 1

An origin and an insertion

Origin: fixed point of attachment
Insertion: Attached to the bone that moves with the muscle
* As the muscle shortens the insertion moves closer to the origin

Question 2

How do muscles work?

Answer 2

Muscles will pull but never push; one muscle will do a movement and another will undo that movement

Question 3

What is agonist and antagonist?

Answer 3

Agonist (prime mover) is a muscle with the main responsibility to produce a movement - muscle we intend to move
Antagonist is a muscle that will do the opposite of that prime mover muscle

Concentric is agonist and eccentric is antagonist
Reciprocal inhibition is the relaxation of antagonist muscles when the agonist muscle is contracting/pushing

Question 4

What are synergist and fixator?

Answer 4

Synergist are muscle(s) that assist the agonist
Fixator/stabilizers are the muscles that stabilize bone allowing agonist to do it’s job

Fixators are typically the bones that the agonist muscle originates from (i.e. the fixator for a bicep is the shoulder region)

Question 5

What are ways to name muscle?

Answer 5

• Location: intercostal (rib)
• Shape: teres (round); trapezius (trapezoid)
• Size: maximus and minimus of gluts
• Direction of muscle fibres: rectus (straight), oblique (diagonal)
• Number of origins: Bicep brachii (2 origins)
• Location of attachments: sternocleidomastoid (sternum, clavicle and mastoid process)
• Muscle action: adductor longus (elongating the adductor)