Musculo-skeletal system

L.O understand the gross structure of the musculo-

skeletal system

Explain which bones are important for each of the functions above

So what does the skeleton do?

The skeleton has 5 The skeleton has 5 major functions.major functions.

1) To give the body its shapeshape2) To produce bloodproduce blood3) To protectprotect the vital organs4) Allow movementmovement through

joints5)5) SupportSupport the body in the up-

right position (the bones of the skeleton are also used to suspend some of the vital organs, keeping them in the correct place.

GCSE PE Week 2

The Skeleton is divided into 2 main parts

The skeleton is divided into two main parts, the axial skeletonaxial skeleton and the appendicular skeleton.appendicular skeleton.

The axial skeletonaxial skeleton – consists of the skull, vertebral column, Thorax (ribs and sternum) and its forms the support of the body.

The appendicular skeletonappendicular skeleton consists of the arms and shoulder girdle and the legs and hip girdle.

GCSE PE

Lets look at the bones of the Skeleton The human skeleton consists of

206 bones. These bones support your body

and allow you to move. Bones contain a lot of calcium

(an element found in milk, broccoli, and other foods).

Bones manufacture blood cells and store important minerals.

The longest bone in our bodies is the femur (thigh bone).

The smallest bone is the stirrup bone inside the ear.

Each hand has 26 bones in it. Your nose and ears are not made

of bone; they are made of cartilage, a flexible substance that is not as hard as bone.

Develop your knowledge by identifying which types of bone there are.

Secure your knowledge by locating the types of bones in the body.

Excel your knowledge by explaining the characteristics of each bone and how its structure enables the function of

the skeleton.

To know the types of bones of the skeleton

There are 5 types of bones in the human body. These are long bones, short bones, flat bones, irregular bones and sesmoid bones.

Looking at the pictures below could you come up with your own description of each?

1. Colour code your own skeleton with the five types of bone.

2. Reading and interpreting the information come up with your own descriptions for the types of bones.

3. Attempt to excel your knowledge further (see me in class)

Types of bone in the skeleton

To understand the three classifications of JOINTS,

Develop your knowledge by describing the three classifications.

Secure your knowledge by labelling a joint and understanding the parts of a

joint.Excel by understanding the location of

different types of joints.

A joint is the point where two bones or more bones meet in the body and enable our skeleton to move.

There are three main types of joints; Fibrous (immoveable), Cartilaginous (partially moveable) and the Synovial (freely moveable) joint.

Held together by only a ligament. Examples are where the teeth are held to their bony sockets and at both the radioulnar and tibiofibular joints (legs)..

Cartilaginous: These joints occur where the connection between the articulating bones is made up of cartilage for example between vertebrae in the spine.

Synovial JointsSynovial joints are by far the most common classification of joint within the human body. They are highly moveable and all have a synovial capsule surrounding the entire joint, a synovial membrane (the inner layer of the capsule) which secretes synovial fluid (a lubricating liquid) and cartilage known as hyaline cartilage which pads the ends of the articulating bones. There are 6 types of synovial joints which are classified by the shape of the joint and the movement available.

Types of synovial joints Gliding Joints - Gliding joints allow for smooth

movement in several directions along a plane or other smooth surface. The articulation is like two plates sliding across each other.

Condyloid Joints - Similar to gliding joints, although have an irregular surface where the bones move past one another. This type of joint is like two bowls nested together.

Synovial Joints Saddle Joints - characterized by two

bones that fit together in a manner similar to a rider in a saddle. This sort of articulation allows bending motion in several directions without sliding.

Hinge Joints - are hinged joints formed between two bones. A hinge joint allows for flexion and extension without sliding.

Synovial Joints Ball and Socket Joint - allow for stable movement

in several directions without slippage. Like a saddle joint, the ball and socket joint allows bending in several directions without slipping, creating a highly stable, strong joint.

Pivot Joints - rotational motion occurs without gliding movement. This type of joint allows for turning motions without sideways displacement or bending.

components and supporting structures of a synovial joint

Muscle

Tendons attach muscles to bones.

Cartilage protects the ends of the bone from friction.

Joint capsule – the tough outer layer that surrounds the joint. The capsule ‘sticks’ to the periostium of the bones that form the joint.

Synovial membrane – lines the joint capsule and seals it. The synovial membrane secretes synovial fluid.

Synovial fluid – a clear fluid which lubricates the joint.

Ligaments join bone to bone. They stabilise the joint by supporting it and limiting its movement.

Bone – the place where two or more bones meet is the site of the joint

Label a joint - Secure your knowledge by

labelling a joint and understanding the

parts of a joint.

To understand the different movements at joints

Learning Intention Success Criteria

To secure knowledge of joints Identify types of joints, be able to label them onto the skeleton

To develop knowledge of movement at joints

Be able to discuss and talk about the joint movements and demonstrate the action.

Achieve excellence by stating when joint movements are used in sports.

Be able to break down the movements of different joints during different sports. Be able to explain why this action occurs.

Can you locate the different

joints?

To understand the different movements at joints

Learning Intention Success Criteria

To secure knowledge of joints Identify types of joints, be able to label them onto the skeleton

To develop knowledge of movement at joints

Be able to discuss and talk about the joint movements and demonstrate the action.

Achieve excellence by stating when joint movements are used in sports.

Be able to break down the movements of different joints during different sports. Be able to explain why this action occurs.

Action at the joint Flexion – decrease of an angle at a

joint.

Extension – Increase of an angle at a joint.

Adduction – ADD when action is towards the body

Abduction – Abduct is when its moving away from the body

Rotation – a turning movement around a certain point or pivot.

Circumduction - A Movement which causes part of the body to move in a complete circle.

Pronation – an inward rotation of the forearm so that the palm of the hand is facing backwards and downwards.

Supination – an outward rotation of the forearm so that the palm of the hand is facing forwards and upwards.

Plantar Flexion – a movement that points the toes downwards by straightening the ankle. Eg when jumping to shoot in basketball.

Dorsiflexion – an upward movement, as in moving the foot to pull the toes towards the knee in walking. Eg kick in karate.

Each of your muscles is made up of thousands of thin, long, cylindrical cells called muscle fibres. The muscle fibre is a highly specialized structure which enables the muscles to relax and contract to produce movement. Muscles vary greatly in their shape and size, depending on their function.

Muscles Most muscles are attached to

bones in at least two place. When a muscle contracts and its

fibres shorten, the moveable bone moves toward the immovable (or toward the less movable) bone. Muscles lengthen or shorten to straighten or bend a joint

Body movement Most muscles are connected to

bones in at least two places Body movement takes place when

muscles contract across freely moveable or synovial joints

To explain the function of the muscular system and understand antagonistic muscle pairs. Types of muscle

Skeletal muscle – also known as striped muscle because of the striped appearance when viewed under a microscope. These muscles are voluntary which means you have conscious control over them.

Smooth muscle – involuntary muscles which function under the nervous system. The digestive system which regulates digestion and blood vessels which help control blood pressure.

Cardiac Muscle's – found in the heart. Involuntary and works continuously. Its contractions help to force blood through blood vessels and around the body.

The function of the muscular system Muscles must cross the joints they move. When a muscle contracts, it exerts a pulling force on

the bone causing them to move around the joint. Muscles are normally in a state ready to react to a

stimulus from your nervous system. Muscles work on a ‘all or nothing’ basis - either contracting or not.

The strength of the muscle contraction depends on the number of muscle fibres that come into use. (Muscle fibre recruitment)

oxygen and either fats or glucose (fuel source) is required for muscular contractions.

When you exercise your muscles use energy. This energy needs replacing otherwise muscles will not be able to maintain their work rate and you may have to reduce the intensity or stop.

Antagonist Muscle Pairs Muscles do not work in isolation

How do you

know this?

Antagonistic muscle pairs Muscles act by contracting and

pulling. They hold joints firm in certain positions.

When one muscle shortens the opposing muscle lengthens

Do a bicep curl… what is happening?

Key factors Agonist – the muscle that shortens to

move a joint/the prime mover. It is the muscle that is mainly responsible for the contraction.

Antagonist – the muscle that relaxes in opposition to the agonist. It is the muscle responsible for the opposite movement. They exert a ‘breaking’ control over the movement.

So which muscle is the agonist in each

picture?

Synergist – muscles that work together to enable the agonists to control and direct movement by altering the direction of pull on the agonists to the best position.

Fixator – muscles that stop unwanted movement throughout the whole body by stabilising the joints and the origin so that the agonist muscle can achieve maximum and effective contraction.

Think about when riding a bike…..

So where are the

synergists and

fixators?

Types of Contraction

The opposite to this is eccentric… what do you

think this means?