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The Skeletal System.  The human skeleton is an endoskeleton of bone and cartilage. Major Functions  Support for the soft tissues and largely responsible.

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Presentation on theme: "The Skeletal System.  The human skeleton is an endoskeleton of bone and cartilage. Major Functions  Support for the soft tissues and largely responsible."— Presentation transcript:

1 The Skeletal System

2  The human skeleton is an endoskeleton of bone and cartilage. Major Functions  Support for the soft tissues and largely responsible for the shape of the human body.  Movement: the strong rigid bones function as levers moved by the contraction of muscles.  Protection: the tough bones protect delicate vital organs the brain is protected by the skull heart and lungs are protected by the rib cage spinal cord is protected by the backbone  Axial Skeleton: skull, backbone, ribs and sternum.

3  Bone is made of mineral compounds of Calcium that are strong yet brittle.  Inside bone there is a network of cells, blood vessels and nerves.  Large bones are hollow, the outside (matrix) being hard while the centre (marrow) soft and fatty and rich in blood and leucocytes.  Smaller bones (like the ribs) are not hollow but have several smaller holes.  In these holes there is red bone marrow, where red blood corpuscles are made.

4  The Spine or Backbone is divided into different sections:  Cervical Vertebrae (Neck region)  The Thoracic Vertebrae (Ribs area)  The Lumbar Vertebrae (Lower back)  The Sacrum (Sacral region)  The Caudal region (The tail)  Composed of 33 small bones in a line - cervical (7), thoracic (12), lumbar (5), sacrum (5), coccyx (4).  The vertebrae of the sacrum and coccyx are fused.

5  A joint is the junction between two or more bones.  There are three major types of joints.  Fused Joints: skull, sacrum, pelvis, and coccyx.  Slightly Moveable: between the vertebrae.  Synovial: freely moveable - the movement is lubricated by synovial fluid.

6  Hinge: movement in one plane during flexion and extension.  Examples: bending the elbow or knee.  Ball and Socket: permits movement in three planes, i.e., in all directions.  Examples: the shoulder and hip joints.  Gliding: the bones move across each other, back-and- forth and side-to-side.  Examples: between the carpals of the wrist and tarsals of the ankle.  Pivot: allows a turning movement.  Examples: between the first and second vertebras when turning the head, between the ulna and the radius of the lower arm when turning the palm of the hand up or down.

7  Muscles are used for movement and are attached to bones via tendons.  For effective movement there are two muscles connected to each limb.  These muscles are said to be antagonistic muscles.  This means that will one contracts, the other relaxes and vice versa.  The biceps and triceps are examples of antagonistic muscles.  There are three types of muscle in the body:  Striated Muscle (Voluntary muscle attached to bones etc)  Smooth Muscle (Involuntary muscle found in our stomachs and intestines)  Cardiac Muscle (Involuntary muscle only found in the heart)

8  Muscle is an extremely contractile connective tissue.  There are a number of different types of muscle: Skeletal, Cardiac and Smooth.  The contraction of muscle performs four important functions: Movement Posture maintenance Support the joints Heat production  Skeletal muscle is connected to the skeleton by tendons.  It is under conscious control.  Its contraction is fast and strong.  Skeletal muscle tires easily.

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