Core 2-The Body in Motion The skeletal System

Skeletal System An 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 Transverse Plane Frontal (Coronal) Plane Sagittal Plane

Directional Terms Defined Superior-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 Introduction The adult human skeleton has 206 bones. They range in shape and size, a feature that allows them to perform specialised functions. Functions of bones: Protection to vital organs, for example the cranium and ribs. Support framework for the body Movement-site of muscle attachment Storage- minerals, for example calcium Production of Red Blood Cells and White Blood Cells

Skeletal System Introduction The skeleton is divided into two (2) major portions: The axial skeleton and the appendicular skeleton. Axial skeleton-consists of the bones of the skull, the vertebral column and the rib cage.

Skeletal System Introduction 2. 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 Bone There 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 Bone 4. 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 joints Type 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 joints Type 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 joints Write notes on features from page 133-134 outcomes textbook. (Ligaments, tendons, synovial fluid and hyaline cartilage).