The musculoskeletal systems functions are to support the bodys shape, to protect important organs, to help the bodys movement, to produce blood cells

Scott Mckeown

OCR L3 PW2N

AO5

The musculoskeletal system

The musculoskeletal systems functions are to support the body’s shape, to protect important organs, to help the body’s movement, to produce blood cells and to store Calcium and phosphorus. The musculoskeletal system is made up of bones, cartilage, tendons and ligaments.

There are around 213 bone sin the human body and they are all linked through tendons and ligaments. These form the protective and supportive framework for muscles. Men’s bones are usually larger and heavier than the bones that are in women. Also women’s pelvises are wider than the ones that are in men’s, this is so women can have and support their babies more.

There are 3 types of joints that connect bones; these are fixed joints, mobile joints and ball and socket joints. Fixed joints are the joints that are between the bones in the skull. Mobile joints are like hinge joints of the elbow or pivotal joint like the joint between the first and second vertebrae. This allows the head to turn from side to side. Ball and socket joints allow the widest range of movement like the shoulder and hip joints.

Bones contain calcium and phosphorus and these make them hard and rigid (steady). The surface on each bone is covered in periosteum which is a thin membrane and it has in it a network of blood vessels and nerves. The layer on top of this is hard and dense and is known as compact, ivory or cortical bone. The centre cavity in some bones and the spaces in some spongy bones contain fatty tissue and this is called bone marrow which contains red blood cells, platelets and almost all of the white blood cells.

Cartilage is not as hard as bone but it is an important part of the skeletal system because it is used mainly as connective tissue and in joints. Most of the skeleton is cartilage when a foetus in the womb which is, over time, turned into bone by a process called ossification.

Tendons are structures like cords and they join muscles together, they are strong and flexible but they aren't elastic.

Ligaments are an important part in the structure of joints because they bind the bone ends together and they prevent a lot of joint movement. They ...

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Tendons are structures like cords and they join muscles together, they are strong and flexible but they aren't elastic.

Ligaments are an important part in the structure of joints because they bind the bone ends together and they prevent a lot of joint movement. They are also used to support organs like the uterus, bladder and liver and they also help to keep the shape of the breasts.

Movement – there are 3 main types of muscles in the body, these are:

cardiac or heart muscle - Cardiac muscle tissue forms the bulk of the wall of the heart. The muscle fibres contain alternating light and dark bands that are called striations and they are perpendicular to the long axes of the fibres. Cardiac muscle's contraction is usually not under conscious control, this means that it is involuntary.
smooth muscles (internal organs) - Smooth muscle tissue is in places like blood vessels, the stomach, intestines, and urinary bladder. Smooth muscle fibres are usually involuntary which means they aren't under conscious control and they are smooth. Certain smooth muscle fibres like the ones in the uterus, keep their shape and size.
skeletal muscles (striped or voluntary muscles) – Skeletal muscles areattached to bones and it is striated. Skeletal muscle tissue can be made to contract or relax by conscious control so this means it is voluntary.

The skeletal muscles are around 40-45% of a persons total body weight. They are called skeletal because they are attached to the bones of the skeleton and are also called voluntary muscles because a persons body can control their movement and actions. Each muscle is can contract and relax to make the body move. There are around 600 muscles in a human body and each are organized into categorise to what action they perform, these are;

extensors – these open a joint and flexors close a joint.
Adductors – these draw part of the body inwards
abductors – move the body outwards
levators raise a part of the body depressors lower part of it.
Constrictors or sphincter muscles surround and close an orifice.

Each muscle is made up of a group of muscle fibres. A small muscle can be made up of a few bundles but larger muscles are made up of hundreds of bundles. Movement of these muscles are under voluntary control of the brain which means that our body can control them. This happens through chemical and electrical impulses that are sent to the brain through nerve endings. Skeletal muscles are used when the body isn't moving because the muscles of posture are used for when the body is sat down or standing to prevent it from falling over or becoming limp. The muscles that cause us to breath are always working even when the body is asleep. Speaking, writing, texting all use communication of the skeletal muscles.

A dysfunction of the musculoskeletal system is Osteoporosis, this is a condition that makes bones very brittle and makes them weak which fracture easily and these fractures mostly happen in the spine, wrist and hips but can happen in other bones like the arm or pelvis. It is more common with post-menopausal women, osteoporosis can also affect men, younger women and children. Osteoporosis develops slowly over many years and it is likely that there will be no warning symptoms before a small fall or sudden impact that causes a bone fracture. Healthy bones should be able to handle a fall from standing height, so a bone that breaks in these circumstances is known as a fragility fracture. When the bones are really weakened (a low bone mass), breakages of the wrist, hip or spinal bones are most common. A cough or a sneeze could cause the fracture of a rib or the collapse of one of the bones of the spine. A fractured bone in an older person can be serious depending on where it happens in the body. It may lead to long-term disability, an example of this would be a hip fracture may lead to long-term problems with mobility. Bones are at their strongest in adult life and are constantly repaired through a process called bone turnover. As the body ages, this process is no longer balanced and bone loss happens a lot more. This means that bone is very slowly broken down over time, leading to a decrease in bone density as the body gets older. This can cause the bone to become weaker and increase the risk of breaking a bone. The Department of Health (DH) published a National service framework (NSF) for old people. This givesdoctors, nurses and all healthcare staff guidance on how to provide care to patients. It sets basic standards for the care of older people, including: