Anatomy Practical 3

Temporalis

Origin: Temporal Bone

Insertion: angle & ramus of mandible

Masseter

Origin: Zygomatic arch

Insertion: angle & ramus of mandible

Action: Elevates & retracts mandible

Orbicularis Oculi

Action: Closes eyes (blink and wink)

Platysma

Action: Pulls lower lip inferiority, tenses skin of neck

Zygomaticus major

Origin: zygomatic bone

Insertion: skin of superior/lateral lip

Action: elevates corner of mouth

Zygomaticus minor

Origin: zygomatic bone

Insertion: skin of superior lip

Action: elevates corner of mouth

Digastric

Origin: mandible

Insertion: Hyoid bone

Action: Depresses mandible

Orbicularis oris

Action: Purses lips (kiss muscle)

Scalenes (anterior, middle, & posterior)

Origin: transverse processes of cervical ribs

Insertion: 1st and 2nd ribs

Action: flex neck if ribs are fixed, elevate ribs if neck is fixed

Sternocleidomastoid

Origin: Sternum & clavicle

Insertion: mastoid process

Action: Bilateral - neck flexion; Unilateral - contra lateral rotation, ipsilateral neck lateral flexion

Pectoralis Major

Origin: ribs, sternum, clavicle

Insertion: humerus

Action: flexes, abducts, and medically rotates arm at the shoulder

Pectoralis Minor

Origin: coracoid process of scapula

Insertion: ribs 3-5

Action: protracts, abducts, and depresses scapula

Deltoid

Origin: Clavicle, acromion, and spine

Insertion: deltoid tuberosity of humerus

Action: anterior fibers - flex and medically rotate arm and the shoulder; middle fibers - abduct the arm at the shoulder; posterior fibers - extend and laterally rotate arm at the shoulder

Infraspinatus

Origin: scapula

Insertion: humerus

Action: adducts and laterally rotates the arm at the shoulder

Supraspinatus

Origin: scapula

Insertion: humerus

Action: abducts the arm at the shoulder

Subscapularis

Origin: anterior surface of scapula

Insertion: humerus

Action: medially rotates arm at the shoulder

Teres minor

Origin: scapula

Insertion: Humerus

Action: Adducts and laterally rotates the arm at the shoulder

Teres major

Origin: inferior angle of the scapula

Insertion: humerus

Action: extends, adducts, and medially rotates arm at the shoulder

Rectus Abdominus

Origin: Sternum & Ribs 5-7

Insertion: Superior pubis near pubic symphysis

Action: Flexes spine and compresses abdominal wall

External oblique

Action: Bilateral - flexes spine and compresses abdominal wall; unilateral - ipsilateral lateral flexion and rotation of spine

Internal oblique

Action: bilateral - flexes spine and compresses abdominal wall; unilateral - ipsilateral lateral flexion and contralateral rotation of the spine

Transverse Abdominus

Action: bilateral - flexes spine and compress abdominal wall; unilateral - lateral flexion of spine

Trapezius

Origin: occipital bone, spinous process

Insertion: acromion and spine of scapular, lateral clavicle

Action: superior fibers - elevate scapula, rotate scapular superiorly; middle fibers - retract scapula; inferior fibers - depress scapula

Latissiumus dorsi

Origin: Spinous process T7-12

Insertion: humerus

Action: extends, adducts, and medially rotates arm at the shoulder

Rhomboid minor

Origin: Spinous process of C7-T1

Insertion: Medial border of scapula

Action: Extends, retracts, and rotates scapula inferiorly

Rhomboid major

Origin: spinous processes T2-T5

Insertion: medial border of scapula

Action: elevates, retracts, and rotates scapula inferiorly

Illiocostalis, longissimus, spinalis

Action: extends spine and maintains posture

Diaphragm

Action: increase thoracic volume, inhalation

Posas major

Origin: transverse processes

Insertion: lesser trochanter of femur (with iliacus)

Action: thigh flexion

Quadratics lumborum

Origin: 12th rib, transverse processes

Insertion: iliac crest

Action: Bilateral - extends spine; unilateral - ipsilateral lateral flexion of trunk

Serratus anterior

Origin: Lateral ribs 1-8

Insertion: medial border of scapula

Action: prevents winging of scapula; scapular stability; protraction of scapula

Levator scapula

Origin: transverse processes C1-C4

Insertion: superior medial border of scapula

Action: elevates scapula inferiorly

Biceps brachii

Origin: scapula

Insertion: radial tuberosity

Action: flexes arm at the shoulder and elbow, supination of forearm

Brachialis

Origin: humerus

Instertion: Coracoid process of ulna

Action: Flexes arm at the elbow

Triceps brachii

Origin: scapula, posterior humerus

Insertion: Olcrenon process of ulna

Action: Extends and adducts arm at boulder; extends arm at elbow

Brachioradialis

Origin: humerus

Insertion: styloid process of radius

Action: flexes arm at elbow

Pronator teres

Origin: medial epicondyle of humerus

Insertion: lateral surface of radius

Action: pronates forearm

Flexor carpi radialis

Origin: medial epicondyle of humerus

Insertion: base of metacarpals 2 & 3

Action: flexes wrist, abduction of hand

Palmaris longus

Origin: medial epicondyle of humerus

Action: flexes wrist

Flexor carpi ulnaris

Origin: medial epicondyle of humerus

Action: flexes wrist, adduction of hand

Flexor digitorum (superficial & profundus)

Action: flexes wrist and fingers

Flexor pollicis longus

Action: flexes thumb

Extensor carpi radialis (longus and brevis)

Action: extends wrist, abduction of hand

Extensor digitorium

Action: extends wrist and fingers

Extensor digiti minimi

Action: extends pinky finger

Extensor pollicis (longus and brevis)

Action: extends thumb

Gluteus Maximus

Origin: iliac crest, sacrum, coccyx

Insertion: Linea aspera of femur

Action: extends and laterally rotates thigh

Gluteus medius

Origin: posterior iliac crest

Insertion: greater trochanter of femur

Action: abducts and medially rotates thigh

Sartorius

Origin: ASIS

Insertion: Tibial tuberosity

Action: flexes and laterally rotates thigh, flexes and medially rotates leg

Adductor magnus

Origin: pubis & Ischial tuberosity

Instersion: linea aspera of femur

Action: adducts thigh

Adductor brevis

Origin: pubis

Insertion: linea aspera of femur

Action: Adducts thigh

Adductor longus

Origin: pubis

Insertion: Linea aspera of femur

Action: adducts thigh

Rectus Femoris

Origin: Anterior inferior iliac spine

Insertion: Patellar tendon to tibial tuberosity

Action: extends thigh

Vastus Lateralis

Origin: greater trochanter and linea of femur

Insertion: Patellar tendon to tibial tuberosity

Action: Extends leg

Vastus Medialis

Origin: intertrochanteric line and linea of femur

Insertion: Patellar tendon to tibial tuberosity

Action: extends leg

Vastus intermedius

Origin: Anterolateral surface of femur

Insertion: Patellar tendon to tibial tuberosity

Action: extends leg

Tensor fascia lata

Origin: iliac crest and ASIS

Insertion: Iliotibial band

Action: abducts and medially rotates thigh

Biceps Femoris

Origin: Ischial tuberosity, linea aspera

Insertion: head of fibula

Action: Extends thigh, flexes and laterally rotates leg

Semimembranosis

Origin: Ischial tuberosity

Insertion: medial condyle of tibia

Action: extends thigh, flexes and medially rotates leg

Semitendonosis

Origin: Ischial tuberosity

Insertion: medial surface of tibia

Action: extends thigh, flexes and medially rotates leg

Gastrocnemius

Origin: lateral and medial condyles of femur

Insertion: calcaneus

Action: flexes leg, plantar flexion of foot

Plantaris

Origin: lateral

Insertion: Calcaneus

Action: Plantar flexion of foot, weakly flexes leg

Soleus

Origin: Fibula and Tibia

Insertion: Calcaneus

Action: Plantar flexion of foot

Tibialis anterior

Action: dorsiflexes and inverts foot

Extensor hallucis longus

Action: dorsiflexes foot and extends big toe

Extensor digitorum longus

Action: dorsiflexes foot and extends toes 2-5

Peroneus (longus and brevis)

Action: everts foot, weak plantar flexion of foot

Piriformis

Origin: sacrum

Insertion: greater trochanter of femur

Action: laterally rotates thigh

Gracilis

Origin: pubis

Insertion: upper medial surface of tibia

Action: adducts and flexes thigh, flexes leg

Popliteus

Origin: lateral condyle of femur

Insertion: proximal posterior tibia

Action: flexes leg, medially rotates tibia to unlock knee

Iliacus

Origin: iliac fossa

Insertion: lesser trochanter of femur

Action: flexes thigh

Uniaxial

\- motion in a single plane

Ex: elbow - bend/straight

Biaxial

\- two axes at right angles to each other

Ex: condyloid

Multiaxial

\- several directions of movement

Ex: shoulder, hips

Articular cartilage

Hyaline cartilage that covers ends of bones in synovial joint

Synovial membrane

Membrane lining the capsule of a synovial join

Articular capsule

sleevelike structure around a synovial joint composed of a fibrous capsule and synovial membrane

Joint cavity

The space between two connecting bones filled with synovial fluid

Fibrous joint

location between bones that produces little to no movement

Cartilaginous joint

joint on either side of articulation that produces some movement

Synovial joint

most common joint type that is motile, encased in a capsule that allows for smooth movement

Synarthrosis

term for an immovable joint

Amphiarthrosis

Term for slightly moveable joint

Diarthrosis

term for freely motile joints

Fascicle

Bundle of muscle fibers

Tendon

Dense regular connective tissue that connects muscle to bone

Aponeurosis

Strong sheet of tissue that acts as a tendon to attach muscle to bone

Sarcomere

Repeating subunit of muscle fibers that contain myofilaments, contractile portion of muscle fiber

Pivot joint

Type of synovial joint that rotates around an axis

Ball and socket joint

Head of one bone and movies in the cavity of another

Saddle joint

Cuboidal bone moves in U shaped cavity of another, ie. thumb joint (metacarpal 1st phalangeal)

Plane joint

Produces a flat, gliding motion

Ex: intercarpals

Hinge joint

Joint between bones (as at the elbow or knee) that permits motion in only one plane

Knee joint

Modified hinge joint: includes the femur, tibia, and patella

Medial and lateral meniscus

Fibrous cushioning on either side of the knee joint

Anterior crucial ligament (ACL)

Attaches to anterior surface of the superior portion of tibia

Medial (tubular) collateral ligament (MCL)

Connect the femur to the proximal portion of the tibia

Posterior crucial ligament (PCL)

attaches to posterior surface of superior portion of tibia

Lateral (fibular) collateral ligament (LCL)

connects the femur to the proximal portion of the fibula

Flexion

decreases the angle of the joint