27 terms

Ch. 10 Muscular Gross Anatomy

Attach muscles to bones
A very broad tendon
Origin or head
Muscle end attached to more stationary of two bones
Muscle end attached to bone with greatest movement
Largest portion of the muscle between origin and insertion
Muscles that work together to cause a movement; prime mover, agonist, antagonist
Prime mover
Plays major role in accomplishing movement
Muscle causing an action when it contracts
A muscle working in opposition to agonist
Stabilize joint crossed by the prime mover
Unipennate muscle
all fasciculi on one side of the tendon
Bipennate muscle
meaning feather, fasciculi arranged like barbs of a feather on two sides of a common tendon
Circular muscle
(orbicular) orbicularis oris and oculi
Convergent muscle
fibers converge together (multipennate)
Multipennate muscle
fasciculi arranged at many places around the central tendon (triangular)
Parallel muscle
all fibers go in one direction (straight)
Named for Location
pectoralis (chest), gluteus (buttock), brachial (arm)
Named for Size
maximus (largest), minimus (smallest), longus (long), brevis (short)
Named for Shape
deltoid (triangular), quadratus(quadrate), teres (round), fuisform (like a pump handle), trapezium (like the trapezius), triangular
Named for Orientation
rectus (straight), oblique (oblique to longitudinal axis)
Named for Origin and insertion
sternocleidomastoid (originates on sternum and inserts on the mastoid process of temporal bone), brachioradialis (originates on the brachium, arm, and inserts onto the radius)
Named for Number of heads
biceps, triceps
Named for Function
abductor (moves away from midline), adductor (moves toward midline), masseter (chewer)
Muscle contractions
A pull or force by relative positions of lever (Rigid shaft or bone), Fulcrum (Pivot point or joint), and Weight (resistance)
Class I Lever
Fulcrum between force and weight. Seesaw or head movement
Class II Lever
Weight is between fulcrum and pull. Wheelbarrow, standing on toes
Class III Lever
Pull located between fulcrum and weight. Person using a shovel. Most common