Ch 4 Muscular System Textbook

Muscle fibers

Long, slender cells that make up muscles. Each muscle consist of a group of fibers bound together by connective tissue.

Fascia

Band of connective tissue that envelops, separates, or binds together muscles or groups of muscles.

Myofascial

pertaining to muscle tissue and fascia.

Tendon

Narrow band of noneleastic, dense, fibrous connective tissue that attaches a muscle to a bone.

Patellar tendon

Attaches muscles to the bottom of the pettal (kneecap)

Achilles tendon

attaches the gastrocnemius muscle to the heel bone

Aponeurosis

sheet like fibrous connective tissue resembling a flattened tendon that connects muscles together or to a bone

Skeletal muscles

attached to the bones of the skeleton and make body motions possible

Which type of muscles are known as voluntary and striated muscles?

Skeletal muscles

Striated (dark and light bands in muscle fibers which creates a striped appearance) also means

striped

Smooth muscles

located in the walls of internal organs such as digestive tract, blood vessels, and ducts leading from glands

Function of smooth muscles

to move and control the flow of fluids through walls of digestive tract, blood vessels, and ducts

Smooth muscles are also known as

involuntary, unstriated, visceral

Visceral means

relating to internal organs

Myocardial muscles are also known as

myocardium or cardiac muscle

Myocardial muscles

form the muscular walls of the heart; the constant contraction and relaxation causes the heartbeat

How is myocardial muscle similar and different from smooth and striated muscle?

Similar in appearance to striated, similar to striated b/c it is involuntary

Muscle innervation

stimulation of a muscle by an impulse transmitted by a motor nerve

Neuromuscular

pertaining to relationship between nerve and muscle

What are all muscles arranged in?

Antagonistic pairs

Contraction

tightening of a muscle; as muscle contracts

What happens as muscle contracts?

Muscle becomes shorter and thicker causing belly of muscle to enlarge

Relaxation

occurs when a muscle returns to its original form

What happens when muscle relaxes?

Becomes longer and thinner and belly no longer enlarged

Abduction

movement of a limb away from the midline of the body

Adduction

movement of a limb towards midline of body

Abductor

muscle that moves a body part away from midline

Adductor

muscle that moves body part towards midline

Flexion

decreasing angle between two bones by bending a limb at a joint

Flexor muscle

bends a limb at a joint

Extension

Increasing the angle between two bones or straightening out a limb

Extensor muscle

straightens a limb at a joint

Hyperextension

extreme or overextension of a limb beyond normal limits

Elevation

act of raising or lifting a body part

Levator anguli oris

muscle of face that raises the corners of mouth into smile

Depression

act of lowering body part

Depressor anguli oris

muscle in face that lowers corner of mouth into a frown

Depressor

muscle that lowers a body part

Levator

muscle that raises a body part

Rotation

circular movement around an axis such as shoulder joint

Circumduction

circular movement at far end of a limb (e.g. swining motion of far end of arm)

Rotator muscle

turns a body part on its axis (e.g. head of humerus rotates within shoulder joint)

Rotator cuff

group of muscles and their tendons that hold the head of humerus securely in place as it rotates within shoulder joint

Supination

act of roating the arm or leg so that hand or foot is turned foward

Pronation

act of rotating arm or leg so that hand or foot is turned downward

Dorsiflexion

movement that bends foot upward at ankle (pointing toes up)

Plantar flexion

movement that bends foot downward at ankle (pointing toes down)

Superficial muscles

muscles located near surface under skin

Origin

where muscles begin, located nearest to midline of body, less movable attachment

Insertion

where muscles end, more movable attachment, farthest point from midline of body

Sternocleidomastoid

muscle that bends neck and rotates head

Stern/o

breastbone

Cleid/o

collar bone

Mastoid muscle

inserts at one point of insertion into the mastoid process (which is part of temporal bone located just behind ear)

Examples of muscles named for origin and insertion

Sternocleidomastoid muscle

Examples of muscles named for action

Flexor carpi muscles and extensor carpi muscles

Flexor carpi muscles and extensor carpi muscles

pairs of muscles that make flexion and extension of wrist

Examples of muscles named for their location

pectoralis major muscle, vastus lateralis, vastus medialis

Pectoralis major

thick fan shaped muscle situated on the anterior chest wall

Lateralis

toward the side

Medialis

toward the midline

Vastus

Huge

Vastus lateralis

large muscle toward outer side of leg

Vastus medialis

muscle toward midline of leg

Examples of muscled named for fiber direction

External and internal oblique, rectus abdominis, rectus femoris, transverse abdominis

Oblique

Slanted at an angle

Rectus

straight alignment with vertical axis of body

Sphincter

ring like muscle that constricts opening of a passageway

Transverse

crosswise direction (horizontal)

Examples of muscles named for number of origins of divisions

Biceps brachii and triceps brachii (flex and extend the upper arm)

Biceps brachii

formed from two divisions

Triceps brachii

formed from 3 divisions

Examples of muscles named for shape and size

gluteus maximus and deltoid muscle

Gluteus maximus

largest muscle of the buttock

Deltoid muscle

Located on the shoulder and is shaped like an inverted triangle, which is the Greek letter delta

Examples of muscles named for strange reasons

Hamstrings (muscles by which a butcher hangs a pig)

Hamstring group

located at the back of upper leg; consists of 3 separate muscles including biceps femoris, semitendinosus, and semimembranous muscles

Primary function of hamstrings

Knee flexion and hip extension

What are the muscles of the head?

Frontalis (occipitofrontalis), temporalis, masseter

Frontalis (occipitofrontalis)

muscle in forehead that raises and lowers eyebrows

Temporalis

muscle on side of head that moves lower jaw up and back to close mouth

Masseter

One of strongest muscles in body, attached to jawbone, moves lower jaw up to close mouth to help with chewing

What are muscles of the trunk?

Pectoralis major, external and internal oblique, rectus abdominis, transverse abdominis

Pectoralis major

makes up bulk of chest muscles in males; lies under breast in females

External oblique

flex and rotate vertebral column, flex torso and compress abdomen

Internal oblique

flex spine, support abdominal contents, help breathe, rotate the spine

Transverse abdominis

located on side of abdomen, engaged when a person laughts of coughs

Muscles of shoulders and arms

Deltoid, trapezius, biceps brachii, triceps brachii

Deltoid

forms muscular cap of shoulder

Trapezius

muscle that moves head and shoulder blade

Biceps brachii

located in anterior upper arm, flex the elbow

Triceps brachii

located in posterior upper arm, extends the elbow

Muscles of the legs

rectus femoris, quadriceps femoris, hamstring group, gastrocnemius

Rectus femoris

muscle running relatively straight along the front of the thigh that extends the knee (makes up the quadriceps)

Quadriceps femoris

group of four muscles located at the front of the thigh that primarily straighten the knee (includes vastus and medial lateralis)

Gastrocnemius

calf muscle that flexes knee and bends foot downwards (stomach of leg)

Medical specialities

Exercise physiologist, neurologist, occupational therapist, physiatrist, physical therapist, sports medicine physician

Exercise physiologist

A specialist who works under physician to studies how the body responds to exercise and develops exercise programs to improve health, fitness, and physical performance.

Neurologist

Physician who specializes in treating causes of paralysis and similar muscualr disorders involving loss of function

Occupational therapist

helps enable patients to participate in activities of daily living