Unit 8- Assignment A Musculoskeletal system

Unit 8- Assignment A Musculoskeletal system. BTEC Applied Science Unit 8: Musculoskeletal System Assignment.The musculoskeletal system provides form, stability and movement to the human body. It consists of the body's bones (which make up the skeleton), muscles, tendons, ligaments, joints, cartilage and other connective tissue. The term "connective tissue" is used to describe the tissue that supports and binds tissues and organs together. Its chief components are collagen and elastic fibres, which are composed of different proteins. The bones of the skeletal system serve to protect the body's organs, support the weight of the body and give the body shape. The muscles of the muscular system attach to these bones, pulling on them to allow for movement of the body. The human skeleton: The skeleton consists of the bones of the body. For adults, there are 206 bones in the skeleton. Younger individuals have higher numbers of bones because some bones fuse together during childhood and adolescence to form an adult bone. The primary functions of the skeleton are to provide a rigid, internal structure that can support the weight of the body against the force of gravity and to provide a structure upon which muscles can act to produce movements of the body. The lower portion of the skeleton is specialised for stability during walking or running. In contrast, the upper skeleton has greater mobility, ranges of motion and features that allow you to lift and carry objects. In addition to providing for support and movements of the body, the skeleton has protective and storage functions. It protects the internal organs, including the brain, spinal cord, heart, lungs and pelvic organs. The bones of the skeleton serve as the primary storage site for important minerals such as calcium and phosphate. The bone marrow found within bones stores fat and houses the blood-cell producing tissue of the body. The human skeleton is divided into two parts: the axial skeleton and the appendicular skeleton. Figure 1: 3 lOMoARcPSD| Structure and Function of the Musculoskeletal System Arslan Mahmood The axial skeleton forms the vertical, central axis of the body and includes all bones of the head, neck, chest and back. It serves to protect the brain, spinal cord, heart and lungs. It also serves as the attachment site for muscles that move the head, neck and back and also for muscles that act across the shoulder and hip joints to move their corresponding limbs. The axial skeleton of the adult consists of 80 bones, including the skull, the vertebral column and the thoracic cage. The skull is formed by 22 bones. Also associated with the head are an additional seven bones, including the hyoid bone and the ear ossicles (three small bones found in each middle ear). The vertebral column consists of 24 bones, each called a vertebra, also the sacrum and coccyx. The thoracic cage includes the 12 pairs of ribs and the sternum, the flattened bone of the anterior chest. The appendicular skeleton includes all bones of the upper and lower limbs, also the bones that attach each limb to the axial skeleton. There are 126 bones in the appendicular skeleton of an adult. The muscles of the body: Figure 2: Figure 3: Name Function Example in sport Deltoid Abduction of the shoulder (moving the arm outwards and away from the body) Outward arm action in a jumping jack Pectoralis major Adduction of the shoulder Upwards phase of a press up 4 lOMoARcPSD| Structure and Function of the Musculoskeletal System Arslan Mahmood (moving the arm towards the body); Shoulder horizontal flexion (moving the arms forwards in front of the body) Triceps Extend the elbow (straightening the arm) Shooting in netball Biceps Flex the elbow (bending the arm) Drawing a bow in archery External obliques Trunk rotation (turning the body sideways) Turning the body to breathe to the side when performing front crawl in swimming Latissimus dorsi Shoulder adduction (moving the arm towards the body); Shoulder horizontal extension Butterfly stroke in swimming Hip flexors Hip flexion (moving knee up towards the chest) Performing a rugby conversion kick Gluteus maximus Hip extension (moving the leg backwards) Pulling back leg before kicking a ball Quadriceps Extend the knee (straightening the leg) Kicking a ball Hamstrings Flex the knee (bending the leg) Performing a hamstring curl on a weights machine Gastrocnemius Plantar flexion of the ankle (pointing the toes downwards) Standing on tiptoe to mark a goal shoot in netball Tibialis anterior Dorsiflexion of the ankle (bringing the toes up towards the shin) Foot making contact with a football Muscles transfer force to bones through tendons. They move our bones and associated body parts by pulling on them – this process is called muscle contraction. One muscle of the pair contracts to move the body part, the other muscle in the pair then contracts to return the body part back to the original position. Muscles that work like this are called antagonistic pairs. In an antagonistic muscle pair as one muscle contracts the other muscle relaxes or lengthens. The muscle that is contracting is called the agonist and the muscle that is relaxing or lengthening is called the antagonist. The following groups of muscles are antagonistic pairs: Biceps Triceps Hamstrings Quadriceps Gluteus maximus Hip flexors 5 lOMoARcPSD| Structure and Function of the Musculoskeletal System Arslan Mahmood Gastrocnemius Tibialis anterior Pectoralis major Latissimus dorsi To allow antagonistic pairs to work efficiently, other muscles called fixators assist by supporting and stabilising the joint and the rest of the body. Some fixators also assist the agonist and act as a synergist. The trapezius muscle can act as a fixator when the biceps is flexing the elbow joint. The abdominals can act as fixators to stabilise the body for hip and knee movements. 1. Flat Bones Protect Internal Organs Figure 4: There are flat bones in the skull (occipital, parietal, frontal, nasal, lacrimal and vomer), the thoracic cage (sternum and ribs) and the pelvis (ilium, ischium and pubis). The function of flat bones is to protect internal organs such as the brain, heart and pelvic organs. Flat bones are somewhat flattened and can provide protection. 2. Long Bones Support Weight and Facilitate Movement Figure 5: 6 lOMoARcPSD| Structure and Function of the Musculoskeletal System Arslan Mahmood The long bones, longer than they are wide, include the femur (the longest bone in the body) as well as relatively small bones in the fingers. Long bones function to support the weight of the body and facilitate movement. Long bones are mostly located in the appendicular skeleton and include bones in the lower limbs (the tibia, fibula, femur, metatarsals and phalanges) and bones in the upper limbs (the humerus, radius, ulna, metacarpals and phalanges). 3. Short Bones Are Cube-shaped Figure 6: Short bones are about as long as they are wide. Located in the wrist and ankle joints, short bones provide stability and some movement. The carpals in the wrist (scaphoid, lunate, triquetral, hamate, pisiform, capitate, trapezoid and trapezium) and the tarsals in the ankles (calcaneus, talus, navicular, cuboid, lateral cuneiform, intermediate cuneiform and medial cuneiform) are examples of short bones. 4. Irregular Bones Have Complex Shapes Figure 7: 7 lOMoARcPSD| Structure and Function of the Musculoskeletal System Arslan Mahmood Irregular bones vary in shape and structure and therefore do not fit into any other category (flat, short, long, or sesamoid). They often have a fairly complex shape, which helps protect internal organs. For example, the vertebrae, irregular bones of the vertebral column, protect the spinal cord. The irregular bones of the pelvis (pubis, ilium and ischium) protect organs in the pelvic cavity. 5. Sesamoid Bones Reinforce Tendons Figure 8: Sesamoid bones are bones embedded in tendons. These small, round bones are commonly found in the tendons of the hands, knees, and feet. Sesamoid bones function to protect tendons from stress and wear. The patella, commonly referred to as the kneecap, is an example of a sesamoid bone. Overall Functions of the Musculoskeletal System:  The musculoskeletal system’s primary functions include supporting the body, allowing motion and protecting vital organs.  To allow motion, different bones are connected by articulating joints. Cartilage prevents the bone ends from rubbing directly on to each other while the muscles contract to move the bones associated with the joint.  Produce blood cells: Red blood cells, white bloo+d cells, and other blood elements are produced in the red marrow, which fills the internal cavities of many bones.  Protect body organs: Many soft tissues and organs are surrounded by skeletal elements. For example, the rib cage protects the heart and lungs, the skull protects the brain, the vertebrae protect the spinal cord and the pelvis protects the delicate reproductive organs.  Store minerals and lipids: Calcium is the most abundant mineral in the body. (Ninety-nine percent of the body's calcium is found in the skeleton.) The calcium salts of bone are a valuable mineral reserve that maintains normal concentrations of calcium and phosphate ions in body fluids. The bones of the skeleton also store energy reserves as lipids (fats) in areas filled with yellow marrow. Major Joints in the body: