The Structure and Functions of the Skeleton and Muscles in the Human Body - Case Study Example

The Structure and Functions of the Skeleton and Muscles in the Human Body The human skeletal system form a rigid internal body framework and consists of the cartilages, bones, and ligaments. Bones provide support to body weight allowing body movements, and protection of internal organs. Cartilages provide support for structures like the external ear, thoracic cage, and the larynx and trachea (Jenkins & Tortora 2011). Cartilage also unites and cushion bones at the joints. Ligaments are strong connective tissue bands holding the bones at moveable joints and prevent excessive joint movements that would cause injury. Tendons provide movement of the skeleton through a connective tissue. Muscles contract and pull the bones producing body movements. Without a skeleton, one would be unable to run, stand or even feed. Based on bone functions, they vary in shape, size, and strength to serve particular functions. A good example is the bones of the lower limb, and lower back is strong and thick to support body weight. In a similar case, the size of anatomical landmark acts as a site for muscle attachment on an individual bone (Rizzo 2015). Muscles can apply powerful pulling forces to the bones. Bones possess enlarged bony landmarks at the powerful muscles attachment sites to be able to resist the forces. This information shows that about function, it is not just the size of the bone, but also its shape. Bones are dynamic and can change their thickness and strength in response to muscle strength changes or weight of the body. Muscle attachment sites thicken if a subject commences workout program. In a similar case, the walls of the bones with such weight, thicken in gain body weight (Saladin 1998). A reduction in body weight causes bones becoming thinner in contrast to prior information. If there is a change in diet, like consumption of soft food, the result is a decrease in the thickness and size of the jaw bones

Human Skeletal System Main bones Diagram.

Skeletons: Axial and Appendicular The human skeleton has two divisions. Axial Skeleton. Comprises of the: Hyoid bone; Skull; Auditory ossicles; Vertebral column also referred to spine or backbone; Sternum bone; and Ribs (with the sternum, they form the thorax). The Appendicular Skeleton. Comprises of the; 1. Shoulder girdles, which include shoulder blades (scapulae) and collar bones (clavicle) on each side. 2. Upper limbs or arms comprise wrists and hands. 3. Pelvic girdle (hip), which includes the ilium, (coxal bones), hip bones, pubis, and ischium, and 4. Lower Limbs.

Skeletal System Functions The adult body has 206 bones performing five core functions. Provision of Body Support; The entire body, is provided structural support by the skeletal system. Individual specific bones and groups of bones offer a framework in which organs and soft issues are attached. Store Minerals and Lipids. 1. The most abundant mineral is calcium with ninety-nine percent stored in the skeleton. 2. The skeletal bones also store lipids as energy reserves in areas yellow marrow filled areas. Produce Blood Cells. Erythrocytes, lymphocytes, and other main blood components are manufactured in the red marrow, filling many bone internal cavities. Protect Body Organs; skeletal elements surround most if not all organs and soft tissues. The rib cage and the skull protect the lungs, heart, and the brain respectively. The vertebrae and the pelvis protect the backbone or spinal cord, and delicate reproductive organs. Provide Leverage and Movement; Many bones act as levers in changing the direction and magnitude of the generated muscle forces.

The Structure of Bone Tissue There are two categories of bone tissue namely compact and spongy tissue. Particular body bones can be formed from either of these types of bone tissue. The diagram below shows the physical long bone structure (femur).

Above long bone structure provides the best resolve of any bone part. It is categorized into parts, the epiphysis, and the diaphysis (Steele & Bramblett 1988). The tubular shaft referred to diaphysis, is the part between distal ends and the proximal part. Medullary cavity is the hollow section with yellow marrow in the diaphysis. The diaphysis walls are composed of dense, compact bone. Types of Joints in Human Skeleton A joint or articulation is any section where a bone or adjacent bones and cartilage articulate with each other and form a connection. Fibrous Joints Adjacent bones at a fibrous joint are connected directly by fibrous connective tissue, and therefore there is no joint cavity between the bones.

Fibrous joints between bones. (a) Sutures joining bones of the skull. (b) Interosseous membranes forming syndesmosis between the ulna and the radius bones. (c) A specialized fibrous joint (gomphosis), anchoring teeth to jaw sockets.

Cartilaginous Joints

The adjacent bones are connected by cartilages, a flexible but tough type of connective tissue. There are two categories of cartilaginous joints, synchondrosis, and symphysis. In synchondrosis cartilaginous joint, hyaline cartilage joins the bones. In the symphysis cartilaginous joint, fibrocartilage joins the bones.

(a) The epiphyseal plate hyaline cartilage. (b) The pubic portions joined by fibrocartilage.

Synovial Joints These are common types of body joints. The presence of a joint cavity is a major structural trait not seen in other types of joints, but present in synovial joint. The joint cavity filled with a fluid is the site of contact with the articulating surfaces (Rizzo 2015). The articulating surfaces are not directly connected in the synovial joint, unlike from other joints. This fluid in the synovial joint gives smooth movement ability allowing for improved joint mobility.

Synovial joints allow for smooth movements. The articular capsule surrounding the joint defines a synovial fluid joint cavity. Articular cartilage covers the bones articulating surfaces. The joints are supported by ligaments by resisting excess motions and holding the bones together.

Types of Muscle Tissue An approximate of half of the body’s weight is made of muscle. Muscle tissue is categorized into three types: skeletal, smooth, and cardiac. Each muscle tissue category has a unique structure and a particular role (Saladin 1998). Skeletal muscle helps moving bones and other structures. Cardiac muscle assists in pumping of blood by heart through a contraction and relaxation process. The smooth muscle tissue found in organs like the stomach and bladder helps in changing shapes and facilitating bodily functions.

Skeletal System Disorders The main human skeletal disorders are metabolic bone diseases like osteoporosis, osteomalacia, and a few others. Leukaemia This is the cancer of the blood. Cause; the cause is unknown, but some risk factors such as exposure to radiation and benzene might result in the disorder. Common Symptoms; swollen lymph nodes, aching bones, and joints, feeling weak, bleeding easily, swelling of the abdomen, fevers and night sweats, and loss of appetite and weight. Diagnosis; Blood and marrow examination and medical history and review. Treatment; Depends on the type, features of leukemia cells, disease extent, prior treatment, health and age of patient. Treatment involves chemotherapy and others radiation therapy. Osteoporosis This is a condition resulting in decreased bone density, strength, and fragility. Symptoms; The subject may not be aware until they experience a backache, stooped posture and gradual loss of height, and spine, wrist, or hip fractures. Risk Factor in Women; Women generally have bones with lower density in comparison to male counterparts. They also lose bone mass in a quicker manner as they age leading to osteoporosis in some of them. The average white woman between ages 20-80 years, loses a third of hip bone density. Treatment; Individuals are advised on enough intake of vitamin D and calcium. Patients diagnosed with osteoporosis also go through pharmacology therapy. A lot of exercise and osteoporosis medication.

Rickets This is a disorder of the skeleton resulting from a lack or deficiency of vitamin D, phosphate, and calcium. These nutrients are essential in developing robust and healthy bones. People suffering from rickets have weak and soft bones, skeletal deformities in severe cases, and stunted growth. Symptoms; pain in arm, pelvis, legs and spine bones. Stunted growth, muscle cramps, and bone fractures. Teeth deformities that include; delayed tooth formation and enamel holes, abscesses, tooth structure defects, and the number of cavities increase. Skeletal deformities that include bowlegs, oddly shaped skull, or legs that bow out, ribcage bumps, protruding breastbones, pelvic deformities, and a curved spine. Risk Factor in the UK; Human body produce increased levels of vitamin D when exposed to the sunshine. Children in the UK are more at risk for rickets since most of the time they experience long periods of little sunlight. Also, people have increased the choices substituting outdoor activities for indoor pursuits like social networking through the internet, texting and to add insult to this, children are driven to and from school on a daily basis without getting the chance of walking half-hour or so.