Biology – Anatomy and Physiology of the Human Skeleton and Muscles Essay


The construction of castanetss consists of the chief part ; the shaft, the terminals of the bone ; the epiphysis and the articular gristle which covers the epiphysis and forms a joint with another bone. The periosteum surrounds the castanetss which allow the ligaments and sinews to attach. It besides contains blood vass, lymph vass and nervousnesss which pass into the bone. Inside the castanetss there is marrow pit ; dwelling of xanthous marrow and ruddy marrow. Yellow marrow chiefly consists of fat cells whereas ruddy marrow is where blood cells are made.

The human skeleton plays an of import function in the organic structure and its alone construction is designed to assist it to make this. The skeleton plays a cardinal function in protecting soft variety meats in the organic structure for illustration the lungs and bosom are encase within the rib coop construction and the encephalon within the skull. The skeleton besides serves to back up the organic structure for illustration the axial skeleton is made up of big castanetss in the Centre of the organic structure like the skull, anchor and ribs. These allow the organic structure to hold form and signifier. In add-on to this some castanetss within the skeleton produce both white and ruddy blood cells. Finally, the construction of the skeleton is critical in enabling the organic structure to be able to travel.

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Describe the categorization of freely movable articulations. Examine and discourse the scope of motion at different articulations.

Joint Joint Type Motion Scope
Elbow/knee Hinge Hinge articulations such as the cubitus and articulatio genus can both flex and widen. This means they are able to be dead set or straightened as necessary
Atlas/axis ( castanetss at top of the cervix ) Pivot Pivot articulations allow rotary motion in different waies – backwards & A ; forwards, left and right
Shoulder/hip Ball & A ; Socket Ball and socket articulations allow legion types of motion. They can flex and widen. They are besides able to adbuct or adduct, which is traveling either towards or off from the spinal column.

They can besides revolve, but offer full 360 degree rotary motion, described as both internal and external.

Wrist/MCD & A ; MTP articulations Condyloid Condyloid articulations are able to flex and widen every bit good as abduct and adduct. They can besides revolve but merely externally, intending off from the midplane of the organic structure
Intercarpal articulations Gliding/sliding Intercarpal articulations move by skiding against each other
Base of pollex Saddle Saddle articulations are merely able to flex or widen and adduct or kidnap. A limited grade of rotary motion is besides possible

When running, legion articulations and musculuss in the organic structure are used for motion and position. The chief drive force of running is chiefly in the lower organic structure, from the hips to the balls of the pess. The hip and articulatio genus flex and widen to make the form and signifier whilst the quadriceps and hamstrings work as an counter brace, undertaking and loosen uping to acquire the drive force.

The ankle extends and flexes as impact is made with the land. At the nucleus, the lower abdominal musculuss are flexed to back up the dorsum and spinal column. The spinal column in heterosexual and the cervix and skull should stay consecutive and facing forwards. The shoulders besides rotate to impel the weaponries backwards and forwards, and the cubitus is flexed in the procedure.

When sitting at a computing machine in an office there are still a great figure of articulations and musculuss used for motion and position. Despite staying comparatively still as the organic structure is sitting, the nucleus abdominal musculuss are still flexed to let the back/spine to sit up directly against the forces of gravitation and keep good position. Hip, articulatio genus and ankle articulations are flexed so the organic structure is sat comfortably in the chair whilst the pess remain on the land.

The primary motion is in the upper organic structure. The cubituss are dead set so that the forearms and carpuss are parallel to the desk. The shoulders are besides somewhat extended to let this. The carpus will besides flex and revolve when typewriting and utilizing a mouse. It’s besides probably that the Atlass and axis castanetss at the top of the cervix will revolve as the caput moves from side to side. Finally, the wrist bones, metacarpals and flexor wrist bones in the forearm are besides all flexed whilst utilizing the computing machine, and the fingers move utilizing the extensor and flexor musculuss on the posterior side of the arm.

Muscles have at their nucleus 100s or 1000s of musculus fibers. These have a cell membrane called the sarcolemma which allows electrochemical signals to go through through and excite the cells. Another of import portion of fiber cells are the chondriosome, which break down sugars and supply the musculus with energy in the signifier of ATP. Finally, the chief portion of the construction is the sarcomere groupings of sarcostyles which have both thick and thin fibrils. The thick fibrils are made of myosin which causes musculuss to contract.

Muscle fibers are grouped together tightly into constructions called a fiber bundle. Between each fiber is connective tissue called endomysium. Each fiber bundle is itself surrounded by connective tissue, known as perimysium. The overall construction has a concluding bed of connective tissue which surrounds the whole musculus, called the epimysium.

The musculus fibers are soft and delicate cells, so their formation in big groups with assorted beds of connective tissue allows them to be protected from forces that contract the musculus. This formation besides allows for a huge figure of blood vass and nervousnesss to be present. These vass and nervousnesss are indispensable for musculus motion as musculus fibers require an urge from a nervus cell before they can contract.

Another of import function for musculuss is to be able to organize strong and stable connexions with castanetss. To make this, the connective tissue beds are longer than the musculus fibre groupings ( or belly ) themselves and organize together to make a strong and thick sinew. Unlike the abdomen of the musculus, the sinews need to stay highly steadfast when force per unit area is applied to them to be able to travel the bone that they are connected to.

When a musculus contracts a musculus fiber generates tenseness when stimulated, for case by the nervous system or by electrical urges. Whilst under tenseness, the musculus may reach or stay the same length. Muscles are attached to the bone by strong sinews. When a musculus contracts, it pulls on the bone and the bone can travel if it is portion of a joint.

However musculuss can merely draw and can non force, this job is solved by counter musculuss. Antagonistic musculuss come in braces ; the premier mover and the adversary. The premier mover contracts and the adversary relaxes. For illustration, to raise the forearm, the bicep contracts and the tricep relaxes. In order to take down the forearm the tricep contracts and the bicep relaxes. Without hostility musculuss would contract and remain contracted, therefore it is critical that musculus contraction and hostility work together to organize the motion of an being.