Human Muscular System

Occipitofrontalis

forehead and scalp

Orbicularis oris

Circular muscle surrounding the mouth and lips.

Orbicularis oculi

Circular muscle surrounding the eyes.

Buccinator

Located in the cheek, deep to the masseter.

Masseter

Located on the lateral side of the jaw, covering the mandibular ramus.

Temporalis

Fan-shaped muscle located on the side of the skull above the ear, over the temporal bone.

Sternocleidomastoid

Located on the anterolateral neck, extending from the sternum and clavicle to the mastoid process.

Splenius capitis

Located on the posterior neck, the upper one.

Splenius cervicis

Located in the posterior neck, the lower one

Scalene muscles

Located deep on the lateral sides of the neck

Rectus abdominis

the six pack ab muscle

Tendinous intersections

Horizontal bands of connective tissue crossing the rectus abdominis, creating the segmented appearance of the six-pack.

Linea alba

vertical line in the middle of the abs that separates the left and right rectus abdominis muscles.

External oblique

Located superficially on the lateral abdominal wall; muscle fibers run downward and medially.

aponeurosis

Flat tendinous sheet covering the anterior abdominal wall, formed by the external oblique muscle.

Inguinal ligament

Thickened inferior border of the external oblique aponeurosis, extending from the anterior superior iliac spine to the pubic tubercle.

Internal oblique

Located deep to the external oblique on the lateral abdominal wall; muscle fibers run upward and medially.

Transversus abdominis

Deepest of the three flat abdominal muscles; located on the lateral abdominal wall with horizontally oriented fibers.

Diaphragm

Dome-shaped muscle separating the thoracic cavity from the abdominal cavity.

External intercostals

Located between the ribs, forming the superficial layer of intercostal muscles. sticking to ribs.

Serratus anterior

Located on the lateral thoracic wall, covering the upper ribs with saw-toothed projections.

Rhomboid major

Located deep to the trapezius between the vertebral column and medial border of the scapula, inferior to rhomboid minor.

Rhomboid minor

Located deep to the trapezius between the vertebral column and medial border of the scapula, superior to rhomboid major.

Latissimus dorsi

Large, broad superficial muscle covering the lower and lateral posterior trunk.

Quadratus lumborum

Located deep in the posterior abdominal wall, on either side of the lumbar vertebral column, between the iliac crest and 12th rib.

Trapezius

Large superficial triangular muscle covering the posterior neck and upper back, extending toward the shoulders.

Pectoralis minor

Located deep to pectoralis major on the anterior chest; extends from ribs 3-5 to the coracoid process of the scapula.

Pectoralis major

Large superficial fan-shaped muscle covering the anterior chest.

Levator scapulae

Located along the posterior and lateral neck, extending to the superior medial border of the scapula.

Deltoid

Located over the shoulder, forming the rounded contour of the shoulder.

Teres major

Located on the posterior scapula, inferior to teres minor; extends toward the humerus.

Subscapularis

Located on the anterior (costal) surface of the scapula, between the scapula and thoracic wall.

Supraspinatus

Located in the supraspinous fossa on the posterior surface of the scapula, above the scapular spine.

Infraspinatus

Located in the infraspinous fossa on the posterior surface of the scapula, below the scapular spine.

Teres minor

Located on the posterior scapula, inferior to infraspinatus and superior to teres major.

Biceps brachii

Located on the anterior upper arm, with two heads.

Brachialis

Located deep to the biceps brachii on the anterior distal upper arm.

Triceps brachii

Located on the posterior upper arm; has three heads.

Flexor carpi ulnaris

Located on the anterior and medial (ulnar) side of the forearm.

Extensor carpi ulnaris

Located on the posterior and medial (ulnar) side of the forearm.

Iliopsoas

Located deep in the anterior hip region; formed by the iliacus and psoas major.

Iliacus

Located in the iliac fossa on the internal surface of the ilium.

Psoas major

Located deep in the posterior abdominal wall, alongside the lumbar vertebral column, extending toward the femur.

Gluteus maximus

Large superficial muscle covering the posterior buttocks.

Gluteus medius

Located on the lateral surface of the ilium, partially covered by gluteus maximus.

Adductor longus

Located on the medial thigh, superficial to portions of the other adductor muscles.

Adductor magnus

Large muscle located deep in the medial thigh.

Gracilis

Long, thin, superficial muscle running vertically along the medial thigh.

Tensor fascia lata

Located on the anterolateral upper thigh, near the iliac crest; connects to the iliotibial tract.

Iliotibial tract

Thick band of fascia running along the lateral thigh from the iliac region to the lateral tibia.

Sartorius

Long, thin, strap-like muscle running diagonally across the anterior thigh from the lateral hip to the medial knee.

Quadriceps femoris

Group of four muscles located on the anterior thigh.

Rectus femoris

Centrally located on the anterior thigh; superficial and runs vertically.

Vastus lateralis

Largest quadriceps muscle, located on the lateral side of the anterior thigh.

Vastus intermedius

Located deep to rectus femoris on the anterior femur.

Vastus medialis

Located on the medial side of the anterior thigh, with a teardrop-shaped appearance near the knee.

Hamstrings

Group of three muscles located on the posterior thigh.