Physiology - muscles and joints. Different types and their use in sports.

AS and A Level Physical Education (Sport & Coaching)

Physiology

Cardiac muscle = cardiovascular system

Cardiac muscle is striated but, unlike skeletal striated muscle, it is made up of a continuous, morphologically distinct network of branching and anastomosing cells. Cardiac muscle, like striated muscle, has actin and myosin microfilaments organized into sarcomeres.

Skeletal muscle = outer muscles

A whole skeletal muscle is considered an organ of the muscular system. Each organ or muscle consists of skeletal muscle tissue, connective tissue, nerve tissue, and blood or vascular tissue.

Smooth muscle = inner muscles

Smooth muscles are found in the hollow parts of the body. This would be in places like the stomach, intestines, blood vessels and the. Smooth muscles are arranged in layers with the fibers in each layer running in a different direction. This makes the muscle contract in all directions.

Antagonistic muscle action

The definition of antagonistic muscle is: “A muscle that opposes the action of another the biceps and triceps are antagonistic muscles (1)”

When a muscle contracts to produce movement it is called the agonist and its opposite, relaxing muscle is known as the antagonist. Agonist and antagonist both have to work together to product the desired action. The role of the muscles is to stabilise the organs so that the agonist can produce the most effective contraction. To raise the upper arm, the anterior and poster parts of the deltoid muscle balance each other while the fibres in the middle of the muscle contracts to pull the arm upwards. The teres major muscle, which connects the scapula, relaxes to allow the movement. Sometimes stabilizing muscle also play a role in this coordinated muscle action.

Joint types

There are 9 different types of joints in the body. Joints are the place where two bones meet. All of your bones, except for one the hyoid bone in your neck, form a joint with another bone. Joints hold your bones together and allow your rigid skeleton to move.

Ball and socket joint

The rounded head of one bone fits into the cup-like cavity of another bone. Of all joints structures, a ball and socket type allows for the greatest range of movement. The shoulder and the hip are ...

This is a preview of the whole essay

Joint types

Ball and socket joint

Saddle joint

The joint surface of each bone has both concave and convex areas so that the bone can rock back and forth and from side to side but have limited rotation. The only saddle joints in the body are at the base of the thumbs.

Gliding joint

The two surfaces of bone that meet in a gliding joint are almost flat, and slide over one another. Movement is limited, however, by strong encasing ligaments. Some joints in the foot and wrist move in this way.

Ellipsoidal joint

An ovoid or egg shaped, bone end is held within an elliptical cavity. The radius bone of the forearm and the scaphoid bone of the hand meet in an ellipsoidal joint. This type of joint can be flexed or extended and moved from side to side but rotation is limited.

Hinge joint

In this simplest of joints, the convex surface of one bone fits into the concave surface of another bone. This allows for movement like a hinged door in only one place. Both the elbow and the knee are modified hinge joints. They bend up and down in one place quite easily in but are also capable of very limited rotation.

Pivot joint

A projection from one bone turns within a ring shaped socket of another bone or the ring turns around the bony projection. A pivot joint formed by the top two cervical vertebrae allows the head to turn from side to side.

Fixed and semi-movable joints

Not all joints are freely movable. After growth is completed, the bones of the skull become fixed together by fibrous tissue forming immovable suture joints. In the lower leg, the tibia and fibular are stabilized by ligaments that allow only a small amount of movement.

Spinal joints

Individual spinal joints do not have a wide range of movement, but working together they give the spine great flexibility, letting it arch backwards, twist around and curve forwards.

Bone types

The shapes of bones reflect their functions. There are 5 different types of bone in the body these are:

Long bones. Such as the femur. This acts as a lever to raise and lower the leg.
Short bones. Such as the talus. This acts as a bridge in the ankle.
Flat bones. Such as the parietal. This acts as a protective shell.
Sesamoid bones. Such as the patella. This is embedded within the tendons. Of the knee.
Irregular bones include vertebrae, the ilium and some skull bones such as the sphenoid.

Skeletal system

The living human skeleton is a tough, flexible structure that supports weight and protects internal organs. The bones provide a light but strong framework for the body’s soft tissues. The ribcage surrounds the heart, lungs and other organs to protect them from most types of harm. Bone tissue is constantly renewed and stores minerals essential to the body, such as calcium that helps blood clotting and nerve transmission and phosphorus that helps acid-base balance. The joints where bones meet mostly permit a wide range of movement. The less mobile types of joints such as those in the spine provide greater stability. Bones are made up of specialized cells in a matrix composed mainly of protein fibres, water and minerals. In the centre of a bone is the medullary canal, which contains bone marrow and blood vessels. Around the marrow are layers of cancellous bone, whish also contains marrow and cortical bone. A membrane, the periosteum, covers the bone surface.

Lever system

Most bodily movements employ the mechanical principles by which a force applied to one part of a rigid lever arm is transferred via a pivot point, or fulcrum, to a weight elsewhere on the lever. In the body, muscles apply force, bones serve as levers, and joints function as fulcrums in order to move a body part.

First-class lever

In a first-class lever, the fulcrum lies between the force and the weight.

i.e. the muscle at the back of the neck tilting back the head. The lever at the base of the skull pivots on the fulcrum of the joint between the skull and the spine.

Second-class lever

In the second-class lever, the weight lies between the force and the fulcrum.

i.e. in the action of raising the heel, the calf muscle is the force that lifts the body weight. The heel and most of the foot is the lever and the toe and sole joints provide the fulcrum.

Third-class lever

In the third-class lever, the force is applied to the lever between the weight and the fulcrum.

i.e. flexing the elbow joint (fulcrum) by contracting the biceps to lift the forearm and hand.

Table on 5 types of actions and there sporting movement’s

Reference page