Lab 6 Muscular System (Appendicular Muscles)

biceps brachii

Flexes and supinates forearm (main function that assists in elbow flexion). (bicep curls- secondary function). Assists in shoulder flexion. Innervation is at the musculocutaneous nerve. (two heads of attachments). They converge into one tendon.

Achilles tendon

attaches the gastrocnemius muscle to the heel bone (back of the ankle) attaches onto the heel.

soleus

deep to gastrocnemius, extends underneath the gastrocnemius muscle. sole function - performs plantarflexion - only acts on the ankle joint because the muscle fiber does not cross over the knee joint. innervation - tibial nerve.

Pectineus

flexion and adduction of the hip. innervated by the femoral nerve.

gluteus minimus

hip abduction and internal rotation of the hip joint. innervation at the superior gluteal nerve.

semitendinosus

innervation - tibial nerve

Palmaris Longus

medial to flexor carpi radialis. anchors skin and fascia to the palmar region. very weakly developed and absent in a large part of the population - innervation- median nerve.

vastus medialis

medial to rectus femoris

flexor pollicis longus

performs flexion, pollicis - thumb (thumb flexion). Innervation - median nerve

Serratus anterior

protraction of the scapula. reaching forward or pushing motion. work with pectoralis minor to help draw scapula laterally and forward along the chest wall. Come down over top of external abdominal oblique (superior to that muscle). relatively deep.

Subscapularis

the one muscle of the rotator cuff that does not function in external or lateral rotation. functions in a medial or internal rotation of the shoulder. found on the anterior surface of the scapula in the subscapular fossa. Innervation comes from the lower subscapular nerve.

trapezius

Elevates, depresses shoulders. retracts, and rotates the scapula; rotates the arm. Stabilization role or movement role. Innervation comes from accessory nerve. Located alongside superior access of shoulder and neck.

extensor carpi radialis longus

Extends wrist and abducts hand. (extend, wrist, lateral carpi of forearm). performs or assists in radial deviation as the flexor carpi radialis did. Innervation comes from the radial nerve.

latissimus dorsi

Extends, adducts, and medially rotates the arm; draws the shoulder downward and backward. works with pectoralis major. Extension of shoulder as if you were pulling down on an object or pulling an oar like boating. Backward swing of the arm (like bowling and bringing the ball back). Attachment point comes up to the humerus which results in the movement of the humerus.

Flexor carpi ulnaris

Flexes and adducts wrist (ulnar deviation) tilting towards the floor. Innervation is at the ulnar nerve. Medial aspect of the forearm. Muscles that perform wrist flexion are all located on the anterior surface of the forearm.

Median Nerve

Nerve that is affected when people suffer from carpal tunnel. Nerves become inflamed. (thumb, first two fingers).

pectoralis minor

(moves the shoulder blade) works with the serratus anterior. Draws the scapula laterally and forward around the chest wall. One of the accessory muscles to breathing. Expands thoracic cavity to allow for more air to come into the lungs. Innervation is from the medial and lateral pectoral nerves.

Hamstrings

Knee Flexion/Hip Extension; Biceps Femoris, Semimembranosus, Semitendinosus

supraspinatus

abduction of shoulder or external or lateral rotation of the shoulder. resists downward slippage of humeral head, when the arm is relaxed or carrying an object. keeps the head of the humerus from sliding downward. Muscle sits right on the scapula above the spine. Innervation at the suprascapular (or subscapular nerve (c5 and C6) which arises from the superior trunk of the brachial plexus.

abductor pollicis longus

abducts and extends thumb. Innervation at the posterior interosseous nerve.

adductor magnus

adduct and medially rotate the hip. distal or inferior and medial to the adductor longus portion. innervated by the obturator nerve and tibial nerve.

adductor longus

adduction of the hip and medial rotation of the hip. aids in hip flexion. Innervated by the obturator nerve.

rectus femoris

anterior surface of the thigh. two functions - attaches above the hip joint and below the knee joint. Performs hip flexion and knee extension. kick foot up/stabilizing the knee as we walk, if not they would buckle and not support the body.

vastus intermedius

deep to rectus femoris. If you take away the rectus femoris, you can see this.

tibialis anterior

dorsiflexion and inversion of foot or ankle. muscle that resists backward tipping motion (standing in a bus and it comes to a full stop, the tibialis anterior muscle helps maintain balance). Innervation comes from the deep fibular or peroneal nerve (L4, L5) (lateral to the tibia.)

accessory nerve

each of the eleventh pair of cranial nerves that supply certain muscles in the neck and shoulder.

extensor carpi ulnaris

extends and adducts wrist; acts with Flexor carpi ulnaris to adduct wrist. ulnar deviation. innervation comes from the posterior interosseous nerve.

Extensor digitorum

extends fingers and the wrist. innervation comes from the posterior interosseous nerve.

extensor digiti minimi

extends little finger - assists in wrist flexion and extension of the fifth digit (metacarpal)/last phalange. innervation is at the posterior interosseous nerve. extends the wrist and located on the dorsal forearm.

extensor digitorum leg

extends the toes and dorsiflex the foot or the ankle. Tendons split and cover digits 2-5 to allow for extension of toes. Innervation is deep fibular or peroneal nerve for the extensor digitorum

Teres Major

extends, adducts, and medially rotates arm/shoulder extension or rotates shoulder in. Innervation is at the lower subscapular nerve. Inferior to deltoid and superior to latissimus dorsi.

Flexor carpi radialis

flexes wrist and abducts hand. (flex, wrist, side of the forearm, radius is the bone on the thumb side when in supine position (hands/palms out). Performs wrist flexion, radial deviation (deviate the wrist towards the thumb side). Innervation comes from the median nerve (C6, C7).

wrist flexion muscles

flexor carpi radialis, flexor carpi ulnaris, palmaris longus

triceps brachii

found on the posterior part of the upper arm or humerus. Main function is elbow extension (straightening arm) or shoulder extension. Also assists in adduction of the humerus. Three components include the medial, lateral, and long head. The innervation is at the radial nerve.

tensor fasciae latae

knee extension. lateral rotation of the tibia. Acts a lot on the knee and when traveling distally it attaches onto the iliotibial tract that attaches to the knee. assists in hip motions (abduction and medial rotation of the femur or hip joint). innervation - superior gluteal nerve.

Biceps Femoris

knee flexion and hip extension (first component of hamstrings).

gracilis

knee flexion and medial rotation. innervated by the obturator nerve which is a branch of the lumbar plexus that arises from the L2-L3 spinal nerves.

gluteus maximus

large muscle found on the posterior side of the hips that makes of up the buttocks. performs hip extension, hip abduction (sideways kick), picking up our upper body after we stoop over or bend over (elevates trunk after doing so). Innervation at the inferior gluteal nerve.

Deltoid

large muscle on top part of humerus (anterior, lateral, and posterior fibers). Anterior - flex and medially rotate shoulders (lift arm over head and internally rotate the arm) or forward flexion, lateral - abduct the arm, take the arm away from the body. extend and laterally rotate the shoulder (like walking), Posterior - rotates the joint laterally which moves the arm backward and outward. This moves the entire arm toward the spine which is where the head of the deltoid inserts (dressing, reaching backward, or throwing). Performs abduction of the upper limb at the glenohumeral joint and is innervated by the anterior terminal branch of the axillary nerve.

Infraspinatus

lateral or external rotation at shoulder. Provides stabilization too in which it prevents the humeral head from slipping upward when the shoulder is at rest. Innervation is also at the subscapular nerve.

Teres minor

lateral or external rotation of the shoulder. prevents upward slippage of the humeral head when it is sitting inside the glenoid cavity during abduction (lift arm out). Innervation is at the axillary nerve.

vastus lateralis

lateral to rectus femoris

Sartorius

longest muscle in the body. crosses over from the lateral side of the hip down to the knee (outer thigh to inner knee). abduction and lateral rotation of the hip. Performs hip flexion and knee flexion. innervation - femoral nerve.

Gastrocnemius

lower part of calf. performs plantarflexion of ankle (standing up on your toes or pointing toes). attaches above the knee joint, functions in knee flexion. innervation - tibial nerve

semimembranosus

medial to the biceps femoris.if you took of the semiteninosus you would see it in its entirety. innervation - tibial nerve.

Brachialis

prime muscle that performs elbow flexion. Located deep to the biceps brachii. Innervation at musculocutaneous nerve. Performs elbow flexion that starts above the elbow that crosses down into the middle of the forearm to the radial nerve. Originates above the elbow joint and inserts onto the forearm.

quadriceps femoris

rectus femoris, vastus lateralis, vastus medialis, vastus intermedius - performs knee extension - innervation: femoral nerve.

pectoralis major

the large, broad, superficial muscle in the chest that flexes and adducts the humerus and rotates the humerus medially. Pull the arm closer to the body in adduction. Innervation from the medial and lateral pectoral nerves.

gluteus medius

smaller and deeper to the gluteus maximus muscle. Fibers are deep and travel underneath the gluteus maximus. hip abduction and internal rotation of the hip joint. innervation at the superior gluteal nerve.

Rotator cuff

supraspinatus, infraspinatus, teres minor, subscapularis. Stabilizes the humerus head inside the glenoid cavity of the scapula. When we're moving our arm overhead, the four muscles will hug the head of the humerus, so that it stays in place.