Core 2-The Body in Motion

The skeletal System

Skeletal SystemAn anatomical reference system called

directional terms is used to identify the location of bones.

The starting point assumes that the body is in the Anatomical position; that is, a reference position where the subject is standing erect, facing front on and with palms facing forward. (Diagram next slide)

This enables us to locate a bone in reference to how it is relative to another part of the body.

Anatomical Position

Sagittal PlaneFrontal (Coronal) Plane

Transverse Plane

Directional Terms DefinedSuperior-towards the head; for example, the chest is superior to the

hips.Inferior- towards the feet; for example, the foot is inferior to the leg.Anterior-towards the front; for example, the nose is anterior to the

ear.Posterior-towards the back; for example, the backbone is posterior

to the heart. Medial-towards the midline of the body; for example, the big toe is

on the medial side of the foot.Lateral-towards the side of the body; for example, the little toe is on

the lateral side of the foot. Proximal- towards the body’s mass; for example, the shoulder is

proximal to the elbow.Distal- away from the body’s mass; for example, the elbow is distal

to the shoulder.

Skeletal System IntroductionThe adult human skeleton has 206 bones.

They range in shape and size, a feature that allows them to perform specialised functions.

Functions of bones:1. Protection to vital organs, for example the

cranium and ribs.2. Support framework for the body3. Movement-site of muscle attachment4. Storage- minerals, for example calcium 5. Production of Red Blood Cells and White

Blood Cells

Skeletal System IntroductionThe skeleton is divided into two (2) major

portions: The axial skeleton and the appendicular skeleton.

1. Axial skeleton-consists of the bones of the skull, the vertebral column and the rib cage.

Skeletal System Introduction2. Appendicular skeleton-consists of the bones of the upper and lower limbs and the bony girdles that support them on the body trunk. Pectoral girdle

Types of BoneThere are five (5) types of bone-long, short, flat, irregular and

sesamoid.1. Long Bones- are hollow, tubular in shape and have along shaft. The ends of long bones form the articulating or connecting surfaces at joints. - these bones can withstand heavy stress and are important in weight bearing.- examples: humerus, femur, radius, tibia, ulna and phalanges.

2. Short Bones- are shaped like a cube and almost equal in length and width.- examples: bones in the wrist (carpals) and ankle bones (tarsals)

3. Flat Bones- generally thin with a layer of spongy bone in their centre. - they are usually broad in shape and have a smooth surface allowing a large area for muscle attachment.-examples: scapula, cranial bones, sternum and ribs

Types of Bone4. Irregular Bones- complex shapes, for example vertebrae

5. Sesamoid Bones- this type of bone is small and found in special tissue called tendons, where there can be more than usual pressure applied.- examples: the patella

Overview of skeletal bones

Overview of skeletal bones

Vertebral Column

Joint Types (page 133-Outcomes)Joint Classification

Definition Movement actions allowed

Examples

Fibrous

Cartilaginous

Synovial

Types of synovial jointsType of synovial joint

Definition Examples

Hinge joint

(Uniaxial)

Hinge joints are UNIAXIAL like a door hinge.-movement restricted to flexion and extension

• Knee Joint• Elbow Joint

Ball and socket joint

(Multiaxial)

Consists of a head that fits into a cup like depression.-Most flexible joint-MULTIAXIAL joint

• Shoulder• Hip

Condyloid/ellipsoidal joint

(Biaxial)

Convex condyle that fits into a concave surface. -BIAXIAL

• Metacarpophalangeal joint (Knuckles)

• Flexion, Extension, Abduction, Adduction and Circumduction

Types of synovial jointsType of synovial joint

Definition Examples

Pivot Joint

(Uniaxial)

Consist of a bony pivot projection with a osteoligamentous.

• C1 and C2-move head from side to side.

• Radius and ulna joint at proximal end. (supination/pronation)

Plane/gliding Joint

(Non-Axial)

-Only example of a non-axial joint. Articular surfaces are flat and only allow slipping or gliding movements.

• Carpals• Tarsals

Saddle Joint

(Biaxial)

Each articular surface has both a concave and convex areas that fit together. It is shaped like a saddle.

• Carpometacarpal joints of the thumbs.

• Flexion, Extension, Abduction, Adduction and Circumduction

Function and structure of the knee joint

Feature of synovial jointsWrite notes on features from page 133-134 outcomes textbook. (Ligaments, tendons, synovial fluid and hyaline cartilage).