Skeletal and muscular systems
Explain the structure and function of the skeletal and muscular systems and their role in affecting sporting movements
The structure and functions of the skeletal system
The function of the skeletal system in divided into 5 different groups, each group is very important. Its 206 bones form a rigid framework to which the softer tissues and organs of the body are attached. The 4 groups are as follows;
. Support
The skeletal system supports the whole of our body. The skeleton supports the body against the pull of gravity. The large bones of the lower limbs support the trunk when standing. If we did not have this support we would not be able to stand.
2. Movement
The skeletal system allows movement; this is achieved because of the joints where the bones join. This is where the movement takes place
3. Protection
Vital organs are protected by the skeletal system. The brain is protected by the surrounding skull as the heart and lungs are encased by the sternum and rib cage. Also the spinal column and the nerves which run through vertebral column is protected
4. Blood production
Blood cells are produced by the marrow located in some bones. Averages of 2.6 million red blood cells are produced each second by the bone marrow to replace those worn out and destroyed by the liver.
5. Storage of minerals
Bones serve as a storage area for minerals such as calcium and phosphorus. When an excess is present in the blood, build-up will occur within the bones. When the supply of these minerals within the blood is low, it will be withdrawn from the bones to replenish the supply.
The human skeleton is divided into two distinct parts:
Axial Skeleton
The axial skeleton, making up 80 of your 206 bones, encompasses all your upper body bones. It is subdivided into three groups: the skull, the vertebral-sound column, and the bony thorax-sound. Its main purposes are to protect your vital organs, such as the brain, heart, and lungs, and to provide an efficient structure to perform a variety of work.
Appendicular skeleton
The appendicular skeleton makes up 126 of your 206 bones. It refers to your arms and legs. They are called appendicular because they are attached by girdles, which bridge each with the main body; as if they had been appended after the main body was formed. These girdles give these appendages a remarkable range of movement unique from anywhere else in the body. Obviously the arms are the same allowing symmetry, and the legs are too. But ignoring size and shape, and instead focusing on joints and relative placement, your arms and legs are the same, too.
Types of bones
The types of bones that make up the skeletal system are the;
* Short
* Flat
* Long
* Sutural
* Sesamoid
Short
Sort bones are found in the wrist and ankle, carpals and tarsals respectively. They have no shaft, as they do not increase dramatically in size in one dimension during growth, and tend to be cuboidal in shape. They are rather like a malteser in construction, with cancellous bone in the centre and a hard outer shell of compact bone.
Long
Long bones are longer than they are wide, consisting of a long shaft (the diaphysis) 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 skull are flat bones, as is the sternum. They provide mechanical protection and also have a large surface ...
This is a preview of the whole essay
Long
Long bones are longer than they are wide, consisting of a long shaft (the diaphysis) 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 skull are flat bones, as is the sternum. 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 Patella and the Pisiform
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. Red blood cells, platelets and most white blood cells 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 fat cells. 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.
2. 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.
3. 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.
4. 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.
5. 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"
6. 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 iris muscles, the digestive system, reproductive system, major blood vessels, the skin and internal organs, and are all controlled by the autonomic nervous system
2. Voluntary muscles
Skeletal muscle is a type of striated muscle, attached to the skeleton. Skeletal muscles are used to facilitate movement, by applying force to bones and joints; via contraction. They generally contract voluntarily (via nerve stimulation), although they can contract involuntarily.
3. 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 metabolism 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
Activity
Bones
Muscles
Joints
Type of movement
Footballer shooting
Tibia
Fibula
Femur
Patella
Tarsals
Metatarsals
Phalanges
Gastrocnemius
Semitendinosus
Biceps femoris
Gracilis
Rectus femoris
Peroneus-longus
Peroneus brevis
Adductor-magnus
Hamstrings
Ball and socket (hip, pelvis)
Hinge joint
(knee)
Abduction
Planterflextion
Dorsiflexion (left leg)
Flexion of knee
Extension of knee
Example 2
Activity
Bones
Muscles
Joints
Type of movement
Goalkeeper saving a shot
Humerus
Clavicle
Scapula
Radius
Ulna
Carpal
Metacarpal
Phalanges
Trapezius
Pectoralis major
Serratus anterior
Rectus abdominis
External abdominal oblique
Biceps
Triceps
Brachioradialis
Retinaculum
Deltoid
Hinge joint
(elbow) (fingers)
Ball and socket joint
(Shoulder)
Gliding joint
(wrist)
Abduction
Circumduction
Supination
Pronation
Lateral rotation
Extension
Example 3
Activity
Bones
Muscles
Joints
Type of movement
Footballer passing the ball with the inside of his foot.
Fibula
Tibia
Patella
Femur
Tarsels
Metatarsals
Phalanges
Semitendinosus
Biceps femoris
Semimembranosus
Gastrocnemius
Preoneus longus
Peroneus brevis
Soleus
Gracilis
Adductor magnus
Gluteus maximus
Vastus medialis
Sartorius
Adductors
Rectus femoris
Tibialis digitoium longus
Peroneus brevis
Ball and socket (hip, pelvis)
Hinge joint
(knee)
Gliding joint
(Ankle)
Abduction and
Adduction
(pulling your leg back and moving it forward hitting the ball
Movement Analysis
The second sport I will use as an example is rugby
Example 1
Activity
Bones
Muscles
Joints
Movement
Rugby player passing the ball
Humerus
Ulna
Radius
Phalanges
Metacarpels
Biceps
Triceps
Brachioradialis
Deltoid
Trapezius
Pectoralis major
Serratus anterior
Hinge
(elbow) (finger)
Ball and socket
(shoulder)
Gliding joint
(wrist)
Medial rotation
Flexion
Extension
Abduction and
Adduction
Supination, pronation
Example 2
Activity
Bones
Muscles
Joints
Movement
Rugby player kicking the ball
Femur
Fibula
Tibia
Tarsels
Metatarsals
Phalanges
Patella
Adductor magnus
Gracilis
Semitendinosus
Biceps femoris
Gastrocnemius
Peroneus longus
Peroneus brevis
Vastus medialis
Sartorius
Adductors of the thigh
Hinge
(knee)(toes)
Ball and socket
(hip)
Condyloid
Abduction
Planterflextion
Dorsiflexion (left leg)
Flexion of knee
Extension of knee
Example 3
Activity
Bones
Muscles
Joints
Movement
Rugby player tackling another player
Femur
Ulna
Radius
Carpals
Metacarpals
Phalanges
Scapula
Clavicle
Trapezius
Pectoralis major
Sarratus anterior
Sternocleidomastoid
Deltoid
Biceps brachii
Linea alba
Brachioradialis
Retinaculum
Hinge (elbow/knee)
Hip/Shoulder (Ball and socket)
Gliding (wrist)
Flexion
Extension
Example 1
The 3rd sport I will use is cricket
Activity
Bones
Muscles
Joints
Movement
Bowling in cricket
Humerus
Radius
Ulna
Phalanges
Metacarpals
Scapula
Clavicle
Vertebra
Latissimus dorsi
Brachioradialis
Biceps brachii
Deltoid
Trapezius
Pectoralis major
Serratus anterior
Hinge
Gliding
Ball and socket
Flexion
Extension
Abduction
Adduction
Example 2
Activity
Bones
Muscles
Joints
Movement
Backwards phase of batting
Humerus
Radius
Ulna
Phalanges
Metacarpals
Clavicle
Scapula
Pelvis
Pectoralis major
Brachioradialis
Trapezius
Serratus anterior
Deltoid
Latissimus dorsi
Biceps brachii
Triceps
Gliding
Hinge
Ball and socket
Flexion
Extension
Abduction
Example 3
Activity
Bones
Muscles
Joints
Movement
Diving to catch the ball
Radius
Ulna
Femur
Phalanges
Metacarpals
Clavicle
Scapula
Pelvis
Pectoralis major
Brachioradialis
Trapezius
Serratus anterior
Deltoid
Latissimus dorsi
Biceps brachii
Triceps
Gliding
Hinge
Ball and socket
Hyper-extension
Abduction
Lateral rotation
Extension