Human Anatomy: Muscles

skeletal muscle

a muscle that is connected to the skeleton to form part of the mechanical system that moves the limbs and other parts of the body.

smooth muscle

Involuntary muscle found inside many internal organs of the body

cardiac muscle

Involuntary muscle tissue found only in the heart, striated

origin

attachment of a muscle's tendon to a stationary bone

Insertion

The attachment of a muscle tendon to a moveable bone or the end opposite the origin

belly

thicker, middle region of muscle between origin and insertion

Agonist

muscle that contracts to produce a movement

Antagonistic

muscle that relaxes to allow movement

Epimysium of muscle

a sheath of fibrous elastic tissue surrounding a muscle.

Perimysium

Connective tissue surrounding a fascicle

Endomysium

Connective tissue surrounding a muscle fiber

muscle fiber

muscle cell

Myofibrils

contractile organelles of skeletal muscle tissue

muscle fascicle

bundle of muscle fibers surrounded by perimysium

Fasicle Arrangement

parallel, fusiform, circular, triangular, unipennate, bipennate, multipennate

Occipitofrontalis

muscle that makes up the scalp with a frontal belly and an occipital belly

temporalis muscle

Muscle of the side of the head that moves the mandible upward and backward.

corrugator supercilii

the muscle that moves the eyebrow

obicularis oculi

Ring muscle of the eye socket; enables you to close your eyes.

Nasalis

Two-part muscle which covers the nose

Zygomatic major and minor

Muscles on both sides of the face that extend from the zygomatic bone to the angle of the mouth. These muscles elevate the lip, pull the mouth upward and backward, as when you are laughing or smiling.

Risourius

muscle that retracts the corner of the mouth

Platsyma

Muscle of the neck that moves the mandible down

Masseter

muscle of mastication

orbicularis oris

Muscle around the mouth that closes the lips

Sternocleidomastoid

muscle arising from the sternum and clavicle with its insertion in the mastoid process

Deltoid

muscle of the shoulder that raises the arm and moves the arm away from the body (abduction)

pectoralis major

chest muscle

serratus anterior

muscle of the chest - assists in breathing and in raising the arm

biceps brachii

Muscle of the anterior upper arm that bends the upper arm toward the shoulder (flexion) and bends the lower arm toward the upper arm (flexion). The origin of this muscle has two heads.

Brachialis

muscle that lies underneath the biceps and is the strongest flexor of the forearm

triceps brachii

The muscle of the posterior upper arm that extends the forearm. The origin of this muscle has three heads

Brachioradialis

a muscle of the forearm that flexes the forearm at the elbow

flexor carpi radialis

muscle that flexes and abducts the hand at the wrist

Pectineus

muscle that abducts and flexes the femur at the hip

adductor longus

muscle that adducts, medially rotates, and flexes the thigh

Sartorius

muscle on anterior side of thigh that abducts and flexes leg

gracilis muscle

A muscle that adducts the thigh and flexes the leg

vastus lateralis

the muscle at the lateral aspect of femur that is responsible for extending the leg and the knee

rectus femoris

The muscle of the anterior thigh that flexes the thigh and extends the leg; also called the quadricep

vastus medialis

a muscle toward the midline of the leg: extends the knee

tibialis anterior

muscle on front of lower leg that flexes and inverts the foot

Trapezius

Muscle that covers the back of the neck and upper and middle region of the back; rotates and controls swinging movements of the arm.

levator scapulae

muscle that elevates the scapula

Subscapularis

the muscles move the Humerus at Shoulder joint

Supraspinatus

Muscle that initiates abduction of arm

infraspinatus muscle

Rotator Cuff Muscle, originates on the infraspinous fossa of the scapula and inserts on the humerus

teres minor muscle

a muscle that adducts and laterally rotates the arm

teres major muscle

This muscle attaches from the scapula to the upper part of the humerus and is involved in movements of the upper arm.

latissimus dorsi

muscle that adducts the shoulder and causes extension of the shoulder joint

gluteus maximus

buttock muscle

Semitendinosus

The intermediate muscle of the posterior thigh that extends the thigh and flexes the leg at the knee.

biceps femoris

The lateral muscle of the posterior thigh that extends the thigh and flexes the leg and extends the thigh.

semimembranosus

The medial muscle of the posterior thigh that extends the thigh and flexes the leg at the knee and extends the thigh.

Gastrocnemius

the muscle in the posterior part of the leg that forms the greater part of the calf

soleus

muscle in the lower portion of the calf which flexes foot downward

rectus abdominis

flexes and rotates vertebral column: muscle of the abs

external oblique

part of the abdominal girdle; forms the external lateral walls of the abdomen

transversus abdominis

muscle that compresses abdominal contents

internal oblique

a muscle in the abdominal wall that lies below the external oblique and just above the transverse abdominal muscles.

linea alba

midline tendinous seam joining the abdominal muscles

inguinal ligament

ligament extending from pubic bone to anterior superior iliac spine, forming lower border of abdomen

internal intercostals

a muscle that depresses the ribs during forced expiration

external intercostal muscles

A muscle that raises the rib cage during inhalation

Diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing

ischiocavernosus

stabilizes erection and slows the return of blood to through the veins

Bulbospongiosus

Helps expel urine and assists with erection

superficial transverse perineal

stabilizes central tendon of perineum

external anal sphincter muscle

made of skeletal muscle, allows the person to control bowel movements

external urethral sphincter

muscular ring that can be consciously controlled to release or hold back urine

ischiococcygeus

muscle that assists the levator ani and pulls the coccyx anteriorly

Puborectalis

muscle that forms a sling around the rectum: the muscle which obstructs fecal flow while in a standing position

pubococcygeus

muscle that makes up the levator ani along with the iliococcygeus and puborectalis: maintains position of pelvic viscera

Iliococcygeus

muscle that makes up the levator ani along with the pubococcygeus and puborectalis: maintains position of pelvic viscera

superior oblique

muscle that wraps around eye diagonally on top; latched on to blue trochlea

inferior oblique muscle

muscle wraps around diagonally on bottom of eye; goes from inferior rectus to lateral rectus

superior rectus

a muscle attached on the top of the eye which elevates the eye and turns it medially

medial rectus

muscle located on the medial side of the eye; adducts eye

lateral rectus

muscle located on the lateral side of the eye; abducts eye; innervated by abducens nerve VI

inferior rectus

muscle located on the inferior part of the eye; adducts, depresses, and laterally rotates eye