PSK4U - Unit 3 Review

Appendicular Skeleton

Includes moveable limbs (arms, wrists, hands, fingers, legs, ankles, feet, & toes) and supporting girdles (pectoral & pelvic girdles).

Pectoral Girdle

Scapula and Clavicle

Scapula

• Attach the upper arm to the thorax

• Makes up part of the shoulder

Clavicle

Rigid support for scapula and humerus

Keeps the upper limb away from the thorax to allow maximum range of movement

Upper Limbs

Humerus, Radius, Ulna, Carpals, Metacarpals, Phalanges

Humerus

• Largest bone in the arm

• Powerful muscles that manipulate the upper arm at the shoulder and the forearm at the elbow are anchored to the humerus

Radius

• Slightly shorter of the two forearm bones

• On the thumb side of the forearm and rotates to allow the hand to pivot at the wrist

Ulna

Together with the radius, the ulna enables the wrist joint to rotate

Carpals

• Facilitate effective positioning of the hand

• Increase the freedom of movements at the wrist

Metacarpals

Stabilizes the palmar and dorsal regions of the hand

Phalanges (Hand)

Produce fine and skilled movements of the hands

Pelvic Girdle

Sacrum, Coccyx, Ilium, Ischium, Pubis

Pelvis

• Transfer of weight from the upper axial skeleton to the lower appendicular components of the skeleton

• Provides attachment for a number of muscles and ligaments used in locomotion.

• Protects abdominal and pelvic area

Ilium

• Muscle attachment

• Helps hold head of femur

Ischium

Supports weight while sitting

Pubis

• Protects organs, nerves, arteries and veins in the pelvis

• Place for muscular attachment

Femur

• Transmits forces from the tibia to the hip joint

• It acts as the site of origin and attachment of many muscles

Lower Limbs

Tibia, Fibula, Patella, Tarsals, Metatarsals, Phalanges

Tibia

Weight bearing

Fibula

Act as an attachment for muscles and not as a weight-bearer

Patella

• Leg extension

• Protects the anterior aspect of the knee joint

Tarsals

• Talus articulates with the bones of the lower leg to form the ankle joint

• Weight-bearing

Metatarsals

• Use to push off when we step or run

• Propels us forward

Phalanges (Foot)

• Weight Transmission

• Balance and Posture

• Ambulation

Scapula

• Acromion process

• Coracoid process

• Glenoid fossa (cavity)

• Scapular spine

Ulna

• Olecranon process

• Styloid process of ulna

Radius

Styloid process of radius

Pelvis

• Iliac crest

• Greater sciatic notch

• Acetabulum

• Pubic symphysis

• Obturator foramen

Femur

• Head of femur

• Neck of Femur

• Greater trochanter

• Lesser trochanter

• Medial condyle

• Lateral condyle

Patella

Apex of Patella

Tibia

• Tibial tuberosity (patellar ligament)

• Anterior Crest

• Medial malleolus

• Lateral malleolus

Fibula

Head of fibula

Gluteus Maximus, Medius and Minimus

• One of the strongest muscles in the human body

• Responsible for movement of the hip and thigh

• Standing up from a sitting position, climbing stairs, and staying in an erect position

Hamstrings

• Three muscles make up the Hamstring:

  • Biceps Femoris

  • Semitendinosus

  • Semimembranosus

• Allows the leg to flex, rotate, extend

• Properly warming up and stretching before exercise will help prevent injury to this muscle

Quadriceps

• Four separate muscles

  • Vastus Lateralis

  • Vastus Medialis

  • Vastus Intermedius

  • Rectus Femoris

• Each originates on the femur bone and attaches to the patella

• Assist in extending the knee

• Used for walking and running

Adductors (Magnus, Longus, Brevis) Pectineus, Gracilis

• Controls the femur’s ability to move inward and from side to side

• walking, sprinting, and a variety of other bipedal motions

Iliopsoas

• Divided into two parts:

  • iliacus

  • psoas major

• Flexion and external rotation of the hip joint.

• If this muscle tightens, the action may result in lower back pain.

Sartorius

• Longest muscle in the human body

• Helps flex, adduct, and rotate the hip

• Knee flexion

Gastrocnemius

• Calf muscle

• Helps with walking and bending

• Causes the knee to bend

• Joins onto the Achilles tendon (strongest and thickest tendon in the human body)

Soleus

• Plantar flexion

• Pushing off the ground while walking

• Helps to maintain posture by preventing the body from falling forward.

Plantaris

Plantar flexion

Tensor Fasciae Latae

• Can medially rotate and abduct the femur at the hip joint.

• Assists in flexion and stabilization of the knee when it is extended as well as when we walk and run.

Tibialis Anterior

• Help to dorsiflex the foot

• Inverts the foot

• Holds up the arch of the foot

Fibularis Longus (Peroneus) and Brevis

• Everts and flexes the ankle

• Lateral compartment

• Helps to stabilize the leg on top of the foot

Flexor Digitorum Longus and Flexor Hallucis Longus

• Flexes the foot at the ankle, along with the four smallest toes.

• Flexes the big toe

• Assists in dorsiflexing

• Helps with inversion of the foot

Extensor Digitorum Longus and Extensor Hallucis Longus

• Extends the foot at the ankle, along with the four smallest toes.

• Extends the big toe

• Assists in plantar flexion

• Helps with eversion of the foot

Popliteus

Plays a role in unlocking the knee during extension

Lumbricals

Flexion and adduction of the toes

SSIT

• Rotator Cuff Muscles

  • Subscapularis

  • Supraspinatus

  • Infraspinatus

  • Teres Minor

• Rotate upper limb at the shoulder joint

Subscapularis

Helps to stabilize the head of the humerus in the glenoid fossa during shoulder movements.

Supraspinatus

• Helps the deltoid muscle initiate the abduction of the arm.

• Helps stabilize the shoulder joint

Infraspinatus

• Laterally rotates the arm at the shoulder joint

• Helps stabilize the shoulder

Teres Minor

• Laterally rotates the arm at the shoulder

• Weakly image adducts the arm

Deltoid

• Named after the Greek letter Delta due to the similar shape

• Anterior, middle, and posterior fibers

• Arm rotation

• Allows a person to keep carried objects at a safer distance from the body

Teres Major

• Adducts and internally rotates the arm

• Assists the latissimus dorsi in wood-chopping

Coracobrachialis

Flexor of the arm

Biceps Brachii

• Double-headed muscle

• Helps control the motion of two different joints (Shoulder and the elbow)

• Functions to lift the forearm

Brachialis

Works with biceps brachii to flex the elbow

Triceps Brachii

• Enables extension and retraction of the forearm

• When the triceps are contracted, the forearm extends and the elbow straightens

• If the triceps are relaxed and the biceps flexed, your elbow will bend, pulling your forearm toward your upper arm

Brachioradialis

• Elbow flexor

• Shaking hands muscle

Flexor-Pronator Group

• Inside of forearm

• Flex and abduct the hand

Pronator Teres

Pronates forearm

Extensor-Supinator Group

Back of forearm

Supinator

Abductor Pollicis Longus

Extensor Pollicis Longus and Brevis

Extensor Indicis

Lumbricals

flex, extend, abduct, and adduct fingers