THE SKELETON Objectives To learn and understand 1

THE SKELETON Objectives To learn and understand 1. 2. 3. 4. 5. Functions of the skeleton. Classification of bones. Joints and Movement. Connective Tissue. Types of Movements at Joint

Functions of the Skeleton The skeleton performs many functions in the body. 1. Shape – The skeleton gives us our shape and determines our size. 2. Support – The skeleton supports muscles and organs. 3. Protection – The skeleton protects delicate parts of the body like the brain and lungs. 4. Movement – The skeleton allows us to move. Muscles are attached to the bones and move them as levers. 5. Blood cell production – blood cells are made in the bone marrow.

Shape and Size u u u Your skeleton affects your body shape and size. Bones play an important part in determining your height and build. People with long, light bones are usually tall and thin, whilst people with short, thick bones are likely to be short and more heavily built. Some sports are more suited to people of a particular size or body shape. This means that your skeleton and bone size can affect your performance in different sports.

Support u u u The skeleton acts as a framework. It gives the body support, enabling us to stand walk upright. The bones of the back and chest support internal organs and help to keep them in place. The bones of the body are held together by ligaments. The skeleton provides a framework for the muscles, which are attached to bones by tendons.

Movement u u u Bones work with muscles to produce movement. Muscles are attached to bones by tendons. Bones have surfaces that allow for strong attachment. Tendons fuse with the tough Periosteum membrane on the outside of the bone. Muscle Tendon Periosteum Bone

Protection u u Some of our body parts, such as the brain, are very delicate and need protection from external forces. Bones can protect body parts from impacts and injuries. The cranium protects the brain. It encloses the brain entirely in a shell of bone. The rib cage protects the delicate organs of the chest.

Blood Cell Production u u u Red and white blood cells and platelets are made in the bones. The ends of long bones and some other bones including the ribs, humerus, femur and even vertebrae bones, contain red bone marrow. This is where the blood cells are produced. Red marrow embedded in spongy bone

Types of Bones u There are 4 types of bone found within the human body. These are long, short, flat and irregular.

Long Bones Long bones include the femur, humerus, tibia, fibula, the metatarsals, metacarpals and phalanges. u They are responsible for a lot of movement and often act as levers. u Long bones contain red bone marrow for producing blood cells. u

Flat Bones u u Flat bones perform a variety of functions. These include: protection for delicate areas, for example, the cranium protects the brain. areas for muscle attachment, for example, many of the muscles of the lower back and legs attach to the wide flat bone of the pelvis. They have a large surface area.

Short Bones u u u Short bones are very light and very strong. They are small and squat in shape. The carpals in the wrist and the tarsals in the foot are examples of short bones. carpals tarsals

Irregular bones u u Irregular bones are specially shaped to perform a particular function. Examples include the patella and the vertebrae.

Test yourself ! u u u Patella Clavicle Tibia Humerus Femur Ulna Pelvis Fibula Sternum Cranium Radius Ribs

Test Yourself! u u u u Vertebral Column Metatarsal Tarsal Carpal Metacarpal Scapula Phalanges

Check You Are Right Clavicle Ribs Cranium (skull) Sternum Humerus Pelvis Radius Ulna Patella Femur Tibia Fibula

Check You are right Scapula Vertebral column HAND Carpals Metacarpals FOOT Tarsals Metatarsals Phalanges

Naming bones

Bones and joint movements

Connective tissues are vital to the functioning of joints. There are 3 types of connective tissue: Tendons connect muscles to bones. Ligaments are tough, elastic fibres that link bones to bones. Cartilage prevents the ends of bones rubbing together at joints. Its slippery surface also helps to lubricate the joint.

Tendons and ligaments Ligaments are responsible for holding joints together. They prevent bones moving out of position during the stresses of physical activity. If they are pulled or twisted too far by extreme physical movements, ligaments can tear and the joint may dislocate. Tendons anchor muscles to bones, allowing the muscles to move the skeleton. Tendons are not very elastic – if they were, then the force produced by muscles would be absorbed instead of creating movement. Tendons can also be torn if subjected to too much force. Ligaments and tendons are strengthened by training.

Joints u u A joint is a place where two or more bones meet. Without joints, our bodies would not be able to move. Joints, along with the skeleton and muscular system, are responsible for the huge range of movement that the human body can produce. There are several different types of joint, each producing different types and amounts of movement.

Types of Joint There are 3 different types of joint: 1. Immovable (or fixed) joints 2. Slightly movable joints 3. Movable (or synovial) joints

Different types of joint

Ball and Socket Joint In ball and socket joints, the rounded end of one bone fits inside a cup-shaped ending on another bone. Ball and socket joints allow movement in all directions and also rotation. The most mobile joints in the body are ball and socket joints. Hip Examples: Shoulders and hips. During the butterfly stroke, the ball and socket joint of the shoulder allows the swimmer’s arm to rotate.

Pivot Joint Pivot joints have a ring of bone that fits over a bone protrusion, around which it can rotate. These joints only allow rotation. Atlas Axis Examples: The joint between the atlas and axis in the neck which allows you to shake your head. You might head a football using the pivot joint in your neck, which allows your head to rotate.

Saddle Joint In saddle joints, the ends of the two bones fit together in a special way, allowing movement forwards and backwards and left to right, but not rotation. Examples: The thumb is the only one. The saddle joint allows the thumb to curl around a canoe paddle to give a firm grip.

Hinge Joints Hinge joints – as their name suggests – only allow forwards and backwards movement. Elbow Examples: The knee and elbow. The hinge joint at the knee allows the leg to flex and extend, for example when a hurdler extends their trail leg at take-off and then flexes it as they clear the hurdle.

Condyloid Joints Condyloid joints have an oval-shaped bone end which fits into a correspondingly shaped bone end. They allow forwards, backwards, left and right movement, but not rotation. Examples: between the metacarpals and phalanges in the hand. Condyloid joints are vital in tennis, badminton , golf, hockey, cricket or any sport with an handheld implement !

Gliding Joints Gliding joints have two flat faces of bone that slide over one another. They allow a tiny bit of movement in all directions. Examples: between the tarsals in the ankle.

Types of synovial joints

TYPES OF MOVEMENT AT JOINTS u Joints allow us to move in different ways- u Abduction- movement of a bone or limb away from the body. u Adduction – movement of limb or bone towards the body.

u Extension – when angle is increased between two bones i. e. straightening of leg at knee. u Flexion – opposite of extension i. e. decreasing angle – bend at knee.

u Rotation- where a bone can move round freely in a curve i. e. arm at shoulder.

Joint movement Joints enable us to make an extremely wide range of movements under our conscious control. The different types of joints allow us to move in many different ways and to perform many different actions. Consider this dancer. The hinge joints at her elbows and her right knee are extended. Her left knee is flexed. There is abduction at her shoulders and right hip. The spine shows extension as the head moves back.

Sporting movement

Joints in action