Long
Long bones are longer than they are wide, consisting of a long shaft (the ) plus two articular (joint) surfaces, called epiphyses. They are comprised mostly of compact bone, but are generally thick enough to contain considerable spongy bone and marrow in the hollow centre (the medullary cavity).
Flat
Flat bones are thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the are flat bones, as is the . They provide mechanical protection and also have a large surface area for muscle attachments.
Sesamoid
Sesamoid bones are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the force of the muscle is increased. Examples of sesamoid bones are the and the
Irregular
Irregular bones consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated. The bones of the spine and hips are irregular bones.
Bone marrow
There are two types of bone marrow: red marrow and yellow marrow. , and most arise in red marrow; some white blood cells develop in yellow marrow. The color of yellow marrow is due to the much higher number of . Both types of bone marrow contain numerous blood vessels and capillaries. Bone marrow stores minerals such as calcium and phosphorus which are released into the blood
Compact bone tissues
Compact bone tissues are dense making it able to provide protection, support and strength.
Spongy bone tissue
They are the thinner end of bones and contain large spaces like a honey comb and these are filled with red marrow. It makes up most tissue of short, flat and irregular shaped bones
Joints in the body
There are many different types of joints in the human body, including some that allow very little, or no movement. Joints are very important in movements related to sport.
There are 6 basic types of synovial joints in the body;
- Ball and socket
Joint between bones that allows considerable movement in three dimensions, for instance the joint between the C). To facilitate movement, such joints are rimmed with cartilage and lubricated by synovial fluid. The bones are kept in place by ligaments and moved by muscle.
- Condyloid
Similar to the ball and socket joint, the condyloid joint allows circular motion. In the condyloid joint, the ball rests up against the end of a bone rather than inside a socket. Example: The carpals of the wrist rest against the end of the radius bone of the forearm.
- Saddle
The saddle joint allows movement in various directions. For example, where the thumb meets the wrist the bones fit up against each other like a saddle fits over the back of a horse.
- Pivot
A pivot joint allows bones to pivot or rotate against each other. The atlas (first cervical vertebrae) and the axis (second cervical vertebrae) pivot against each other.
- Hinge
The hinge joint allows flexion and extension of the joint. The joint acts like a hinge on a door, allowing the joint to “open” and “close”
- Gliding
Gliding joints occur between the surfaces of two flat bones that are held together by ligaments. Some of the bones in your wrists and ankles move by gliding against each other.
The structure and functions of the muscular system
The muscular system is composed of specialized cells called muscle fibres. Their predominant function is contractibility. Muscles, where attached to bones or internal organs and blood vessels, are responsible for movement. Nearly all movement in the body is the result of muscle contraction. Your body contains around 650 muscles in your body and make up roughly half of your body weight.
There are 3 types of muscles that are found in the body;
- Involuntary muscles
Smooth, uninucleated, and non-branching muscles that are not directly controllable at will. These include the radially arranged muscles, the digestive system, reproductive system, major blood vessels, the skin and internal organs, and are all controlled by the
- Voluntary muscles
Skeletal muscle is a type of , attached to the . Skeletal muscles are used to facilitate , by applying to and ; via . They generally contract (via stimulation), although they can contract involuntarily.
- Cardiac muscle
Your heart is made of cardiac muscle. This type of muscle only exists in your heart. Unlike other types of muscle, cardiac muscle never gets tired. It works automatically and constantly without ever pausing to rest. Cardiac muscle contracts to squeeze blood out of your heart, and relaxes to fill your heart with blood
Muscle fibres
There are two broad types of voluntary muscle fibres, slow twitch (slow oxidative) and fast twitch (fast glycolytic)
Fast-twitch (fast glycolytic)
Fast-twitch muscle fibres are selectively recruited when heavy work is demanded of the muscles, and strength and power are needed. They contract quickly, providing short bursts of energy, and are therefore used for high-intensity, low-endurance activities, such as sprinting, weightlifting, shot-putting, and swinging a golf club. However, fast-twitch muscle fibres become exhausted quickly. Pain and cramps rapidly develop from the build-up of lactic acid, which is a by-product of the of this kind of muscle fibre
∙ White in colour
∙ Contract quickly
∙ Exert large amounts of force
∙ Anaerobic
∙ Fatigue quickly
Slow-twitch (slow oxidative)
Slow -twitch muscle fibres produce a steady, low-intensity, repetitive contraction. They do not tire easily and are recruited when endurance is needed. Therefore, slow-twitch muscle fibres are used for low-intensity, high-endurance activities, such as long distance running, cyclists and swimming
∙ Red in colour
∙ Contract slowly
∙ Exert less force
∙ Aerobic (long distance running)
∙ Can contract repeatedly
∙ Slow nerve impulse
Individuals have a different mix of each muscle fibres. Therefore people with more fast-twitch muscle fibres will tend to be better at sports such as sprinting.
But people with more slow-twitch muscle fibres will be more talented at sports such as long distance running.
Your body contains around 650 muscles in your body and make up roughly half of your body weight. Differences between each muscle are defined by;
∙ Function
∙ Structure
∙ Contraction
∙ Location
The type of joint in which the muscle occurs will reflect the possible movement.
The skeletal muscles are able to expand and contract. Therefore muscles usually work in pairs. As on muscles contracts, the other muscles will extend. The muscle that contracts is known as the agonist and the muscle that extends is called the antagonist.
The main functions of the muscular system in the body are as follows;
∙ Posture
∙ Heat production
∙ Joint stability
∙ Contraction and extension (movement)
∙ Protection
Sliding filament theory
When a muscle contracts, the actin is pulled along myosin toward the center of the sarcomere until the actin and myosin filaments are completely overlapped. The H zone becomes smaller and smaller due to the increasing overlap of actin and myosin filaments and the muscle shortens. Thus when the muscle is fully contracted, the H zone is no longer visible. The actin and myosin filaments themselves do not change length, but instead slide past each other. This is known as the sliding filament theory of muscle contraction
Movement analysis
The first sport for my movement analysis will be football. I will describe 3 different types of movement
Example 1
Example 2
Example 3
Movement Analysis
The second sport I will use as an example is rugby
Example 1
Example 2
Example 3
Example 1
The 3rd sport I will use is cricket
Example 2
Example 3
