Yr 11 ATAR Phys Ed Studies - Functional Anatomy

Functions of the skeleton

1. Provides framework and gives body shape.

2. Provides attachment points for muscles. When muscle contracts, bone inserts inserts into moves, creating a lever.

3. Protects vital organs

   e.g. Skull - brain

   Ribs - hearts, lungs, kidneys

   Spinal column - spinal cord

4. Stores essential minerals (calcium and phosphate)

5. Produces red blood cells in bone marrow especially during childhood and adolescence.

Superior

Towards the head.

e.g. arms are superior to the legs.

It refers to a position higher than another part of the body.

Inferior

Towards the bottom of the body.

e.g. feet are inferior to the head.

Medial

Towards the midline of the body.

e.g. the nose is medial to the eyes.

It refers to a position closer to the center of the body than another part.

Lateral

Towards the side of the body.

e.g. the ears are lateral to the nose.

It refers to a position further away from the midline of the body than another part.

Anterior

Front of the body.

e.g. Pectorals are anterior to the latissimus dorsi.

Posterior

The back of the body.

e.g. the hamstrings are posterior to the quadriceps.

Distal

Further away.

e.g. the fingers are distal to the wrist.

Proximal

Close to the point of origin.

e.g. the carpals are proximal to the metacarpals.

Flexion

When a joint angle decreases.

e.g. flexing the bicep causes the angle at the elbow to decrease.

Extension

Joint angle increases.

e.g. extending the leg at the knee increases the angle between the thigh and the lower leg.

Adduction

Moves body part toward the midline of the body.

e.g. bringing down a raised arm.

Abduction

Takes body part away from the midline of the body.

e.g. raising your arm.

Rotation

Twisting movement around a long axis.

e.g. rotating your head.

Circumduction

Movement of body reign in a circular manner (one end stays stationary).

e.g. moving arm in a circle.

Pronation

Palm down position.

Supination

Palm up position.

Dorsiflexion

Toes brought closer to shin.

e.g. flexing foot upwards.

Plantarflexion

Toes brought further away from body.

e.g. standing on tip toes.

Muscle Attachment Points - Origin

• The attachment to the bone that does not move when muscle contracts.

• Origin is attachment point at proximal end.

  e.g. The scapular is the origin point for the biceps muscle.

Muscle Attachment Points - Insertion

• Attached to the bone that moves when muscle contracts.

• Insertion is attachment point at distal end.

  e.g. The ulnar and the radius are the insertion points for the biceps muscle.

Agonist

• The prime mover

• The muscle responsible for the movement.

Antagonist

The muscle which relaxes to allow the movement.

Reciprocal Inhibition

Describes the coordinate relaxing of muscles on one side of a joint to accommodate contraction on the other side.

e.g. Bicep curl

Bicep - agonist - contracts

Triceps - antagonist - relaxes

Antagonist Pairs

• Muscles are arranged in antagonistic pairs

• As one muscle contracts (shortens), its partner relaxes (lengthens).

Examples of Antagonistic Pairs

• Biceps and triceps

• Tibialis Anterior and Gastrocnemius

• Hamstrings and Quadriceps

• Hip Flexor and Gluteus Maximus