Alexandra Nedelcu
This report describes the structure of the musculoskeletal system and its importance for the human
body and an introduction of some of the disorders affecting this system.
The musculoskeletal system
The musculoskeletal system is a human body system which provides a range of different functions.
This system is subdivided into two systems: the muscular system and the skeletal system.
The human skeleton supports the body and allows it to move.
The functions of the skeletal system include :
● Shape and support as it holds all the organs in place and allows posture
● protection of vital organs, for example the brain is protected by the cranium; the lungs and
the heart are protected by the rib cage
● Attachment for skeletal muscle: it has locations where skeletal muscle tendons can be
attached
● mineral storage: holds the body’s supply of minerals like calcium and vitamin D
● producing blood cells: they contain bone marrow which produces red and white blood cells
● maintaining homeostasis: when mineral levels in the blood are too high, bones can absorb
some of them and store them as mineral salts and when levels are too low bones release
some of the minerals they stored, therefore restoring homeostasis
The skeletal system is made of many parts that work together to enable movement, the main part
consists of bones and the other components are cartilages, ligaments, joints and tendons.
Each part of the skeletal system contributes to the effective functioning of the whole system.
The skeleton supports the body and helps it stand and move freely,the joints are movable
connections between bones, ligaments support the joints and allow them to move more freely and
the tendons join muscles to bones.The bones also produce blood cells as they contain bone marrow.
Different parts of the skeletal system provide protection and support, for example the skull shields
the brain, the ribs protect the heart and the lungs and the backbone protects the spine.Another
function of the bones is to store minerals such as calcium and vitamin D for supply.
The muscular system
The muscular system is made of skeletal, cardiac and smooth muscles and they all work together to
allow the body to move.
The skeletal muscles provide important functions and those include:
● Movement: skeletal muscles pull on the bones causing movements at the joints
● Support:Muscles of the body wall support the internal organs
● Protection:They shield the internal organs of the body from force applied from the outside
● Heat generation: When the human body's temperature drops too low, the muscular system
produces shivering to keep the body warm.
● Blood circulation: cardiac muscles help pumping action of the heart by supporting blood
circulation
1
, Alexandra Nedelcu
Cardiac muscles
Cardiac muscle tissue can only be found in your heart, where it produces coordinated contractions
that enable your heart to pump blood throughout your circulatory system.Cardiac muscle tissue uses
involuntary movements to keep your heart flowing. This is one trait that distinguishes it from
controllable skeletal muscle tissue
Smooth muscles
Smooth muscle is present throughout the body, in the stomach and intestine where it helps with
digestion and nutrient collection and throughout the urinary system where it helps get rid of the
toxins in the body.
Major muscle groups
As we can see in figure 1 skeletal muscles are grouped together into muscles that are attached to the
skeleton. They can contract and relax which allows bones to move and they also stabilise the joints
The major muscle groups are the chest, back, arms, shoulder, legs and the calves.
Fast and slow twitch fibres
Most muscles are made of those two twitch fibres, slow twitch muscle fibres move more slowly but
allow movement for a longer period of time and fast twitch fibres move faster but for a shorter
period of time.
2
, Alexandra Nedelcu
Muscle fibres
Each skeletal muscle consists of muscle fibres, connective tissues, blood vessels and nerve fibres.
Each muscle fibre contains smaller units of repetitive tick and thin filaments which cause the muscle
tissue to have a striped appearance. Their main function is contractibility whereas bones’ main
function is movement.
3
, Alexandra Nedelcu
Connective tissues and their composition
A ligament is a fibrous connective tissue that attaches bone to bone and they are located around the
joints, and usually serves to hold structures together and keep them stable. Its composition is made
of a dense connective tissue containing collagen bundles which give stability and ligaments also
contain elastin fibres which give flexibility. Tendons attach muscles to bones and they serve to move
the bone or structure, they are located at each end of a muscle. Its composition is made of a dense
connective tissue which contains bundles of collagen which makes them strong but they contain less
elastin fibre which makes tendons less flexible than ligaments
Cartilage is a connective tissue in the body and it serves for a lot of functions such as cushioning the
joints and giving shape, support and structure to other body tissues. They are found in many areas of
the body and this includes joints between bones e.g. the elbows, knees and ankle;ends of the ribs
and between the vertebrae in the spine.
Body movement
Movement results from contraction. The sliding filament theory explains how the muscles contract in
order to allow us to move.
In order for the muscle to contract the following actions take place in the body:
● A nerve signal goes down the lower neuron and releases acetylcholine which binds to
acetylcholine receptors
● This allows for sodium to move in to the sarcolemma, depolarising it and this depolarization
continues down to T tubules, causing calcium ions to be released in the muscle fibre
● Ca2+ binds to troponin, causing it to move and expose the myosin binding site
● Myosin heads are now able to bind to the exposed actin binding sites
● ADP and Pi are released which allows the neck region of the myosin heads to rotate and this
pulls the actin filament towards the centre of the sarcomere
● A new ATP binds to the myosin heads, causing the myosin head to detach from the actin
filament
● The ATP is then hydrolysed and the chemical released when it is hydrolysed is converted to
potential energy and stored in the myosin neck so the cycle can begin again.
4
This report describes the structure of the musculoskeletal system and its importance for the human
body and an introduction of some of the disorders affecting this system.
The musculoskeletal system
The musculoskeletal system is a human body system which provides a range of different functions.
This system is subdivided into two systems: the muscular system and the skeletal system.
The human skeleton supports the body and allows it to move.
The functions of the skeletal system include :
● Shape and support as it holds all the organs in place and allows posture
● protection of vital organs, for example the brain is protected by the cranium; the lungs and
the heart are protected by the rib cage
● Attachment for skeletal muscle: it has locations where skeletal muscle tendons can be
attached
● mineral storage: holds the body’s supply of minerals like calcium and vitamin D
● producing blood cells: they contain bone marrow which produces red and white blood cells
● maintaining homeostasis: when mineral levels in the blood are too high, bones can absorb
some of them and store them as mineral salts and when levels are too low bones release
some of the minerals they stored, therefore restoring homeostasis
The skeletal system is made of many parts that work together to enable movement, the main part
consists of bones and the other components are cartilages, ligaments, joints and tendons.
Each part of the skeletal system contributes to the effective functioning of the whole system.
The skeleton supports the body and helps it stand and move freely,the joints are movable
connections between bones, ligaments support the joints and allow them to move more freely and
the tendons join muscles to bones.The bones also produce blood cells as they contain bone marrow.
Different parts of the skeletal system provide protection and support, for example the skull shields
the brain, the ribs protect the heart and the lungs and the backbone protects the spine.Another
function of the bones is to store minerals such as calcium and vitamin D for supply.
The muscular system
The muscular system is made of skeletal, cardiac and smooth muscles and they all work together to
allow the body to move.
The skeletal muscles provide important functions and those include:
● Movement: skeletal muscles pull on the bones causing movements at the joints
● Support:Muscles of the body wall support the internal organs
● Protection:They shield the internal organs of the body from force applied from the outside
● Heat generation: When the human body's temperature drops too low, the muscular system
produces shivering to keep the body warm.
● Blood circulation: cardiac muscles help pumping action of the heart by supporting blood
circulation
1
, Alexandra Nedelcu
Cardiac muscles
Cardiac muscle tissue can only be found in your heart, where it produces coordinated contractions
that enable your heart to pump blood throughout your circulatory system.Cardiac muscle tissue uses
involuntary movements to keep your heart flowing. This is one trait that distinguishes it from
controllable skeletal muscle tissue
Smooth muscles
Smooth muscle is present throughout the body, in the stomach and intestine where it helps with
digestion and nutrient collection and throughout the urinary system where it helps get rid of the
toxins in the body.
Major muscle groups
As we can see in figure 1 skeletal muscles are grouped together into muscles that are attached to the
skeleton. They can contract and relax which allows bones to move and they also stabilise the joints
The major muscle groups are the chest, back, arms, shoulder, legs and the calves.
Fast and slow twitch fibres
Most muscles are made of those two twitch fibres, slow twitch muscle fibres move more slowly but
allow movement for a longer period of time and fast twitch fibres move faster but for a shorter
period of time.
2
, Alexandra Nedelcu
Muscle fibres
Each skeletal muscle consists of muscle fibres, connective tissues, blood vessels and nerve fibres.
Each muscle fibre contains smaller units of repetitive tick and thin filaments which cause the muscle
tissue to have a striped appearance. Their main function is contractibility whereas bones’ main
function is movement.
3
, Alexandra Nedelcu
Connective tissues and their composition
A ligament is a fibrous connective tissue that attaches bone to bone and they are located around the
joints, and usually serves to hold structures together and keep them stable. Its composition is made
of a dense connective tissue containing collagen bundles which give stability and ligaments also
contain elastin fibres which give flexibility. Tendons attach muscles to bones and they serve to move
the bone or structure, they are located at each end of a muscle. Its composition is made of a dense
connective tissue which contains bundles of collagen which makes them strong but they contain less
elastin fibre which makes tendons less flexible than ligaments
Cartilage is a connective tissue in the body and it serves for a lot of functions such as cushioning the
joints and giving shape, support and structure to other body tissues. They are found in many areas of
the body and this includes joints between bones e.g. the elbows, knees and ankle;ends of the ribs
and between the vertebrae in the spine.
Body movement
Movement results from contraction. The sliding filament theory explains how the muscles contract in
order to allow us to move.
In order for the muscle to contract the following actions take place in the body:
● A nerve signal goes down the lower neuron and releases acetylcholine which binds to
acetylcholine receptors
● This allows for sodium to move in to the sarcolemma, depolarising it and this depolarization
continues down to T tubules, causing calcium ions to be released in the muscle fibre
● Ca2+ binds to troponin, causing it to move and expose the myosin binding site
● Myosin heads are now able to bind to the exposed actin binding sites
● ADP and Pi are released which allows the neck region of the myosin heads to rotate and this
pulls the actin filament towards the centre of the sarcomere
● A new ATP binds to the myosin heads, causing the myosin head to detach from the actin
filament
● The ATP is then hydrolysed and the chemical released when it is hydrolysed is converted to
potential energy and stored in the myosin neck so the cycle can begin again.
4
