MUSCULAR SYSTEM

What is the origin of a muscle?

Attachment to an immovable bone

What is the insertion of a muscle?

Attachment to a movable bone

What causes body movement?

A muscle moving an attached bone

What is flexion?

Decreases the angle of a joint and brings two bones closer together

Where does flexion typically occur?

Hinge joints like the knee and elbow

What is extension?

Increases the angle between two bones; opposite of flexion

What is rotation?

Movement of a bone around its longitudinal axis

Where is rotation common?

Ball-and-socket joints

Give an example of rotation.

Moving the atlas around the dens of the axis (shaking head “no”)

What is abduction?

Movement of a limb away from the midline

What is adduction?

Movement of a limb toward the midline

What is circumduction?

Combination of flexion

Where does circumduction commonly occur?

Ball-and-socket joints

What is dorsiflexion?

Lifting the foot so the superior surface approaches the shin

What is plantar flexion?

Depressing the foot (pointing the toes)

What is inversion?

Turning the sole of the foot medially

What is eversion?

Turning the sole of the foot laterally

What is supination?

Forearm rotates laterally so palm faces anteriorly

What is pronation?

Forearm rotates medially so palm faces posteriorly

What is opposition?

Moving the thumb to touch the tips of other fingers on the same hand

What is a prime mover?

Muscle with major responsibility for a certain movement

Give an example of a prime mover.

Biceps brachii

What is an antagonist?

Muscle that opposes or reverses a prime mover

Give an example of an antagonist.

Triceps brachii

What is a synergist?

Muscle that aids a prime mover and prevents unwanted movement

Give an example of a synergist.

Wrist muscles when making a fist

What is a fixator?

Muscle that stabilizes the origin of a prime mover

Give an example of a fixator.

Muscles anchoring to scapulae and thorax for posture

What are the methods of naming skeletal muscles?

By direction

What does 'rectus' indicate?

Straight direction of muscle fibers

What does 'maximus' indicate?

Largest muscle

What does 'temporalis' indicate?

Located on the temporal bone

What does 'triceps' indicate?

Three heads or origins

What does 'sternocleidomastoid' indicate?

Origin and insertion (sternum

What does 'deltoid' mean?

Triangular shape

What do 'flexor' and 'extensor' indicate?

Muscle action (flexes or extends a bone)

What are the fascicle arrangements?

Parallel

What are the muscles of facial expression?

Occipitofrontalis

What is the function of the frontalis?

Elevates eyebrows and wrinkles forehead

What is the function of the occipitalis?

Draws scalp backward

What is the function of orbicularis oculi?

Closes eyes

What is the function of orbicularis oris?

Closes mouth and protrudes lips

What is the function of buccinator?

Pulls cheeks against teeth when chewing

What is the function of zygomaticus major?

Elevates corners of the mouth

What is the function of depressor anguli oris?

Depresses corners of the mouth

What is the function of platysma?

Tenses skin of neck and depresses lower lip

What are the chewing muscles?

Masseter

What does the masseter do?

Closes jaw and elevates mandible

What does the temporalis do?

Closes jaw and assists the masseter

What do the pterygoid muscles do?

Elevate and move mandible laterally

What are the neck muscles?

Platysma and sternocleidomastoid

What does the sternocleidomastoid do?

Flexes the neck and rotates the head

What is torticollis (wryneck)?

Injury of a baby’s sternocleidomastoid causing spasms

What are the anterior neck muscles?

Suprahyoid (elevates hyoid) and infrahyoid (depresses hyoid)

What are the anterior trunk and shoulder muscles?

Pectoralis major

What is the function of the pectoralis major?

Adducts and flexes the humerus

What is the function of the pectoralis minor?

Pulls scapula downward and forward

What is the function of the serratus anterior?

Pulls scapula downward and forward

What is the function of the teres major?

Extends and adducts humerus

What are the intercostal muscles?

External intercostals and internal intercostals

What do the external intercostals do?

Elevate rib cage during inhalation

What do the internal intercostals do?

Depress rib cage during forced exhalation

What is the function of the diaphragm?

Contracts to pull central portion down

What are the abdominal muscles?

Rectus abdominis

What does the rectus abdominis do?

Flexes vertebral column and compresses abdominal contents

What do the obliques do?

Flex vertebral column

What does the transversus abdominis do?

Compresses abdominal contents

What are the posterior trunk and shoulder muscles?

Trapezius

What does the trapezius do?

Elevates

What does the latissimus dorsi do?

Extends and adducts humerus

What do the rhomboids do?

Elevate and retract scapula

What does the levator scapulae do?

Elevates scapula

What do rotator cuff muscles do?

Abduct and rotate humerus

What is the function of the erector spinae?

Extend the vertebral column

What is the function of the quadratus lumborum?

Extends and laterally flexes vertebral column

What does the deltoid do?

Abducts

What are the muscles of the upper limb?

Biceps brachii

What is the function of the biceps brachii?

Supinates forearm and flexes elbow

What is the function of the brachialis?

Flexes elbow

What is the function of the brachioradialis?

Weak elbow flexion

What is the function of the triceps brachii?

Extends elbow; antagonist to biceps brachii

What are the pronators of the forearm?

Pronator teres and pronator quadratus

What are the flexors of the forearm?

Flexor carpi radialis

What do the wrist flexors generally do?

Flex the wrist and fingers

What are the supinators of the forearm?

Supinator

What are the extensors of the forearm?

Extensor carpi radialis longus and brevis

What do the wrist extensors do?

Extend wrist and fingers

What are the gluteal muscles?

Gluteus maximus

What does the gluteus maximus do?

Extends thigh

What does the gluteus medius do?

Abducts thigh and steadies pelvis

What does the gluteus minimus do?

Abducts thigh

What is the iliopsoas responsible for?

Hip/thigh flexion and maintaining posture

What do the adductor muscles do?

Flex and adduct the thigh

What does the tensor fasciae latae do?

Connects to the iliotibial band

What does the gracilis do?

Flexes leg and adducts thigh

What does the pectineus do?

Flexes and adducts thigh

What are the hamstring muscles?

Biceps femoris

What do the hamstrings do?

Extend thigh and flex leg

What does the sartorius do?

Flexes the thigh

What is the quadriceps group?

Rectus femoris and vastus medialis