Anterior + Posterior Muscles Flashcards
FRONTALIS
(Frontal Belly of Epicranius Muscle)
Origin: At Galea Aponeurotica (tissue covering top of skull).
Insertion: Skin of the forehead above the eyebrows.
Function: Raises the eyebrows and wrinkles forehead.
ORBICULARIS OCULI
Origin: Orbital Margin (two borders: frontal bone, frontal process of maxilla).
Insertion: Skin around the eyelids.
Function: Closes the eyelids/keep debris out. Essential for blinking.
ZYGOMATICUS MAJOR
Origin: Zygomatic bone.
Insertion: Corners of the mouth (orbicularis Orbis).
Function: Elevate corners, smiling and laughing.
ORBICULARIS ORIS
Origin: From the maxilla and mandible bones.
Insertion: Tissue of the lips.
Function: Kissing muscle- Closes and puckers lips.
TEMPORALIS
Origin: Temporal Fossa
Insertion: Coronoid process of the mandible.
Action: Elevates and retracts the mandible.
MASSETER
Origin: Zygomatic Arch and Maxilla
Insertion: Angle and ramus of the mandible
Action: Elevates the mandible (closes jaw).
BUCCINATORS
Origin: Maxilla and mandible.
Insertion: Orbicularis Oris
Action: Compresses the cheek.
STERNOCLEIDOMASTOID
Origin: Manubrium of the sternum and clavicle.
Insertion: Mastoid process of the temporal bone.
Action: Flexes and rotates the neck.
DIAGASTRIC
Origin: (anterior & posterior belly)- Digastric fossa of mandible and Mastoid notch of temporal bone.
Insertion: Intermediate tendon to hyoid bone.
Function: Elevates the hyoid bone and aids in depressing the mandible (swallowing/speech).
STERNOHYOID
Origin: Manubrium of sternum and medial end of the clavicle.
Insertion: Hyoid bone
Function: Depresses the hyoid bone.
SERRATUS ANTERIOR
Origin: Ribs 1-8
Insertion: Anterior surface of the medial border of the scapula.
Function: Protracts scapula forward/upward (lifting arm), stabilizes (smooth shoulder movement).
EXTERNAL INTERCOSTALS
Origin: Inferior border of the above rib.
Insertion: Superior border of the rib below.
Function: Elevates the ribs during inhalation.
INTERNAL INTERCOSTALS
Origin: Superior border of the rib below.
Insertion: Inferior border of the rib above.
Function: Depresses the ribs during forced exhalation.
PECTORALIS MAJOR
Origin: Clavicle, sternum, costal cartilage of ribs up to 6.
Insertion: Bicipital groove of humerus.
Function: Adduction of the arm, rotates arm inward, assists in raising arm (pushing, lifting, hugging).
PECTORALIS MINOR
Origin: Ribs 3-5.
Insertion: Coracoid process of the scapula (scapula goes inward).
Function: Lowers the scapula, assists with inspiration, draws scapula forward/downward.
DELTOID
Origin: Clavicle, acromion, spine of scapula.
Insertion: Deltoid tuberosity of the humerus.
Function: Abducts the arm (away from body), raises arm forward and inward, moves arm backward and outward.
CORACOBRACHIALIS
Origin: Coronoid process of the scapula.
Insertion: Medial surface of the humerus shaft.
Function: Flexes (lifts at shoulder joint) and adducts the arm.
BICEPS BRACHII
Origin (short & long head): Coracoid process of the scapula, supraglenoid tubercle (beneath glenoid cavity). (Combine at end/gets more narrow)
Insertion: Radial tuberosity on radius.
Function: Bends arm at elbow, rotates forearm to turn palm upward, assists in raising arm at shoulder.
BRACHIALIS
Origin: Distal end of the humerus.
Insertion: Coronoid process and ulnar tuberosity of ulnar.
Function: Primarily responsible for bending the elbow. Elbow flexion.
BRACHIORADIALIS
Origin: Lateral supracondylar ridge of the humerus, coronoid process of the ulna.
Insertion: Midshaft of the radius.
Function: Assist in bending the elbow (thumbs up position), stabilizes elbow during rapid movement (handshake).
PRONATOR TERES
Origin: Medial epicondyle of humerus, coronoid process of the ulna.
Insertion: Lateral surface of the radius (midway along bone).
Function: Rotates the forearm to turn palm downward. Helps bend elbow.
FLEXOR CARPI RADIALIS
Origin: Medial epicondyle of humerus.
Insertion: Base of the second/third metacarpals.
Function: Bends the wrist forward, and away from midline (abduction) of the body (helps grip objects and stabilize wrist during activities).
FLEXOR CARPI ULNARIS
Origin: Medial epicondyle of humerus
Insertion: Pisiform (hook of hamate), base of fifth metacarpal.
Function: Flexing adducts the hand at the wrist.
PALMARIS LONGUS
Origin: Medial epicondyle of humerus.
Insertion: At palmar aponeurosis (tissue in palm).
Function: Assist in bending wrist forward, tenses aponeurosis (stabilizes skin of palm during gripping).
FLEXOR DIGITORUM SUPERFICIALIS
Origin: At medial epicondyle of humerus, coronoid process of ulna and radius head.
Insertion: Middle phalanges of fingers (2-5).
Function: Helps bend wrist forward. Bends fingers at proximal interphalangeal joints.
FLEXOR RETINACULUM
Thick band of connective tissue over wrist. Holds tendons of the flexor muscles in place.
RECTUS ABDOMINUS
(6 pack)
Origin: Pubic crest and symphysis.
Insertion: Xiphoid process and costal cartilages of ribs 5-7.
Function: Compresses abdominal contents, flexes and rotates vertebral column.
EXTERNAL OBLIQUE
Origin: Outer surface of 5-12 [lower] ribs.
Insertion: Iliac crest (top of pelvis), Linea alba (fibrous structure running down midline of abdomen), pubic tubercle (extrusion prominence near pubic bone).
Function: Twists torso, bends sideways, bending spine forward, aid in compressing contents.
INTERNAL OBLIQUE
Origin at iliac crest, inguinal ligament (ligament in groin area), lumbar vertebrae.
Insertion: Lower rib cartilage (last 3), Linea alba, pubic crest.
Function: Twisting torso, bending trunk sideways, supports core stability, compression of abdomen.
TRANSVERSE ABDOMINUS
Origin: Costal cartilages lower 7-12, Iliac crest, Inguinal ligament.
Insertion: Linea alba, pubic crest.
Function: Maintains posture (supporting spine/pelvis), shields internal organs, assists in respiration.
ILIACUS
Origin: Iliac fossa of ilium.
Insertion: Lesser trochanter of femur.
Function: Flexing hip (thigh towards body), posture support, pelvic stabilization (during movement) [Essential for activities like walking and running].
PSOAS MAJOR
Origin: Lumbar vertebrae.
Insertion: Lesser trochanter of Femur.
Function: Hip flexion, helps bend torso towards legs (when fixed), assists in rotating thigh outward, supports pelvic during movement.
ADDUCTOR LONGUS
Origin: At pubis
Insertion: Linea aspera of the femur
Function: Pulls thigh inward toward midline of body, assists in bending hip joint, helps rotate thigh toward center of body.
ADDUCTOR MAGNUS
Origin: At pubis and ischial tuberosity (bottom of pelvic).
Insertion: Linea Aspera (ridge on posterior side of femur), adductor tubercle (medial condyle of femur).
Function: Primarily responsible for moving thigh toward body midline, extending thigh (walking/climbing), inward rotation of thigh.
ADDUCTOR BREVIS
Origin: At pubis
Insertion: Linea aspera of femur
Function: Brings thigh closer to midline, assists in bending the hip, helps rotate thigh inwardly.
GRACILIS
Origin: Pubis
Insertion: Medial surface (condyle) of tibia.
Function: Thigh toward midline, bends knee joint, rotating lower leg inward when knee is bent.
TENSOR FASCIAE LATAE
Origin: Anterior iliac crest
Insertion: Iliotibial tract {that extends down to the Lateral tibial condyle}.
Function: Helps lift thigh upward, moves thigh away from midline, assists in rotating thigh inward, stabilization of pelvis during movement.
Iliotibial Tract (BAND)
Origin is Moreso a ‘continuation’ of the tensor fasciae Latae, and the gluteus maximus.
Insertion: Inserts to the lateral tibial condyle.
Functions: Pelvis stabilization (walking/running), lateral knee stability, force distribution across thigh during movement.
RECTUS FEMORIS
Origin at Anterior Inferior iliac spine.
Insertion: Base of patella
Function: Knee extension- Straightens the knee joint and assists in lifting the thigh toward abdomen.
VASTUS LATERALIS
Origin: Greater trochanter, intertrochanteric line, Linea aspera of femur.
Insertion: Tibial tuberosity
Function: Key muscle in straightening the knee. (Largest of the quadriceps muscles). [Squatting/Cycling].
VASTUS INTERMEDIUS
Origin at anterior/lateral surfaces of femur.
Insertion: At patella and tibial tuberosity.
Function: Primary role is to straighten the knee joint.
VASTUS MEDILAIS
Origin: Intertrochanteric line and Linea aspera of the femur.
Insertion: At patella and tibial tuberosity.
Function: Extending the leg at the knee.
SARTORIUS
Origin: at anterior superior iliac spine.
Insertion: Medial surface of the tibia.
Function: Lifts thigh toward abdomen, moves thigh away from midline, rotates thigh outward, bends knee joint. [Longest muscle in human body].
