Essay Example on Long bones support body weight and aid in Movement

Task 2 Long bones support body weight and aid in movement They are extremely dense and hard so they give the body strength and structure Other than their structural role long bones also produce stromal manufactures cartilage fat cells and store adipocytes whose triglycerides are a source for energy and hematopoietic manufactures white and red blood cells and platelets marrow Long bones can also function as levers This aids the muscles to function to their highest potential and allows speedy movement and application of strength for e g picking up heavy things Short bones primary function is to provide support and stability however they allow little no movement Sesamoid bones are a type of short bone that develop in a tendon They differ in quantity and size in between different people Some sesamoid bone work to adjust the direction of pull of a tendon This protects tendons from wear and stress The purpose of other sesamoid bones elsewhere in the body is unknown Other than their structural role short bones also produce stromal manufactures cartilage fat cells and store adipocytes whose triglycerides are a source for energy and hematopoietic manufactures white and red blood cells and platelets marrow Irregular bones differ in structure and shape compared to long short and flat bones Their complex shape protects internal organs for e g irregular bones in the vertebral column safeguard the nervous tissue in the spinal cord protecting it from shock which can possibly squash the nervous tissue and irregular bones in the pelvis safeguard organs contained in the pelvic cavity 

Other functions include affording various anchor points for skeletal muscle attachment as with the sacrum and maintaining pharynx and trachea support and tongue attachment such as the hyoid bone Irregular bones connect all components of the spinal column hence why most of the irregular bones are found in the spinal cord Irregular bones also interact with the tendons and muscles which allows movement of the pelvis especially during childbirth and back Similar to other bones irregular bones also store calcium sodium magnesium and phosphorus which are needed for physiological mechanisms of the body Flat bones serve as shields for the brain heart pelvic organs protecting them from trauma They are also a scaffold for large muscle groups to attach to Flat bones have a flat shape which helps to provide protection for large areas that need muscle attachment The Cranium protects the brain from injury In children cranial bones are parted by sutures which allow skull expansion as the brain enlarges After the brain has stopped growing the sutures close and cranial bones fuse to form one continuous bone The rib cage safeguards the aorta heart and lungs The lower cage covers the upper abdomen so it protects the spleen and liver During exhalation the rib cage moves outwards with the help of intercostal muscles around them filling the lungs with air The Scapula protects the back of the chest Part of the scapula forms the socket of the shoulder joint and takes part in shoulder motions like arm elevation The scapula is also the point of attachment for each of the rotator cuff muscles which keep the shoulder joint stable In adults the highest number of red blood cells are formed in flat bones Task 3 Bones are composed of 4 types of cells mainly osteoblasts osteocytes osteoclasts and lining cells 

The formation of the bones is carried out by active osteoblasts Osteoblasts synthesise type 1 probe collagen molecule into the extracellular matrix later forming collagen matrix They also synthesise osteocalcin and osteonectine that bind the collagen into hydroxyapatite crystals a crystalline mineral of the bone Calcium is then deposited in the form of calcium phosphate while hydroxide and bicarbonate are added and the hydroxyapatite crystals are formed As the bone matrix is formed osteoblasts see synthetic activity and become osteocytes embedded in the bone matrix These osteocytes are interconnected by a canaliculus which allow transfer of calcium ions from the interior of bone to surface in the process called osteocytic osteolysis Dietary phosphorus has a significant function in the development of peak bone mass Phosphate makes up approximately half the weight of bone mineral and must be present in adequate amounts in diet to mineralise and maintain the skeleton Task 5 Skeletal muscle fibres are packaged into the organs called skeletal muscles that attach to the body s skeleton Each fibre is made from bundles of myofibrils which are extremely long cylindrical muscle cells Every muscle is covered by epimysium a connective tissue sheath The connective tissue outside the epimysium fascia encloses and parts the muscles Parts of the epimysium project inward to split the muscle into sections Each section has a bundle of muscle fibres Each bundle known as a fasciculus and is surrounded by perimysium layer of connective tissue Every single muscle fibre inside the fasciculus is surrounded by endomysium layer of connective tissue Similar to other body cells skeletal cells are sensitive and delicate The connective tissue coverings safeguard and support for the cells and assist to endure contraction forces The connective tissue coverings also create passageways for the nerves and blood vessels Normally perimysium endomysium and epimysium extend past the fleshy area of the muscle to create a bulky tendon like a rope or a wide flat sheet like aponeurosis The aponeurosis and tendon create indirect attachments from muscles to periosteum of bones or to the connective tissue of nearby muscles A muscle spans a joint and is connected to bones by tendons at both ends One of the bones stays somewhat stationary immovable while the other is able to move through muscle contraction Skeletal muscles have plenty of nerves and blood vessels running through them This is to assist with the primary function of muscles to contract To initiate contraction in a muscle fibre it first needs to receive an impulse from a nerve cell