BTEC NATIONAL CERTIFICATE IN SPORT (SPORTS DEVELOPMENT, COACHING AND FITNESS)

UNIT 1 BODY IN ACTION

ASSIGNMENT 1

Scenario

You have been appointed as a sports science lecturer at a local college. You must produce a set of resources to be used by your pupils.

Task1

Describe the structure and function of the axial and appendicular skeleton, including all the major bones, and the different classifications of joints and the range of movement at each. (P1)

The human skeleton consists of both fused and individual  supported and supplemented by , ,  and . It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the ,  and .   At birth a newborn baby has approximately 270 bones, whereas on average an adult human has 206 bones.

Axial skeleton

The axial skeleton (80 bones) is formed by the  (26), the  (12 pairs of  and the ), and the  (22 bones and 7 associated bones). The axial skeleton transmits the weight from the head, the trunk, and the upper extremities down to the lower extremities at the , and is therefore responsible for the upright position of the human body. Most of the body weight is located in front of the spinal column which therefore have the  muscles and a large amount of  attached to it resulting in the curved shape of the spine. The 240 skeletal muscles acting on the axial skeleton position the spine, allowing for small movements in the thoracic cage for , and the head, where they control the minute and complex facial movements.

Appendicular skeleton

The appendicular skeleton (126 bones) is subdivided into the  and : The axial skeleton is connected to the upper extremity (60) through the  (4) and to the lower extremity (60) through the  (2). Some 300 muscles attach to the appendicular skeleton.

The only joint between the pectoral girdle and the thorax is between the  and the  (i.e. the ), the  instead being controlled by muscles. The  articulates to the scapula at the  and to the two parallel bones of forearm, the  and , in the elbow joints (, , and ). The distal ends of the forearm bones form the  joints with the . In the hand, eight  arranged in two rows articulate with the  of the  which articulate with the 14 finger bones (the ).

The pelvic girdle is a composite structure which includes bones from both the axial skeleton, the  and the , and the lower extremities, the two . Because the lower limbs have to bear the weight of the human body — reaction forces at the feet can be 5-10 times the body weight during sprinting and jumping — the bones of the pelvic girdle, the thigh, and the lower leg are massive and have a network of fibers and many strong muscles to maximize strength and stability. Similarly, and in contrast to the elbow, in the knee the , a  formed in the tendon of the large  muscles of the thigh, protects the knee from damage while helping the muscles in extending the knee. In each ankle there are 7 , including the , and in each foot 5  and 14 phalanges.

Function

The skeleton has five main functions:

Support

The skeleton provides the framework which supports the body, and maintains its shape. The joints between bones permit movement, some allowing a wider range of movement than others, e.g. the ball and socket joint allows a greater range of movement than the pivot joint at the neck.

Movement

Movement in  is powered by , which are attached to the skeleton by tendons. Without the skeleton to give , movement would be greatly restricted. However, biologically speaking, the skeleton does not enable movement.

Protection

  • The skeleton protects many vital :
  • The  protects the , the , and the  and .
  • The  protects the .
  • The , spine, and  protect the ,  and major .
  • The  and  protect the .
  • The  and spine protect the digestive and urogenital systems and the .
  • The  and the  protect the  and the  respectively.
  • The  and  protect the  and  respectively.

Blood cell production

The skeleton is the site of , which takes place in red .

Storage

Bone matrix can store  and is involved in , and  can store  in  and is involved in .

Five types of bones

There are five types of bones in the human body: long, short, flat, irregular and sesamoid.

  •  are characterized by a shaft, the  that is much greater in length than width. They are comprised mostly of  and lesser amounts of , which is located within the , and . Most bones of the limbs, including those of the  and , are long bones. The exceptions are those of the ,  and .
  •  are roughly cube-shaped, and have only a thin layer of compact bone surrounding a spongy interior. The bones of the wrist and ankle are short bones, as are the .
  •  are thin and generally curved, with two parallel layers of compact bones sandwiching a layer of spongy bone. Most of the bones of the  are flat bones, as is the .
  •  do not fit into the above categories. They consist of thin layers of compact bone surrounding a spongy interior. As implied by the name, their shapes are irregular and complicated. The bones of the spine and hips are irregular bones.
  •  are bones embedded in tendons. Since they act to hold the tendon further away from the joint, the angle of the tendon is increased and thus the force of the muscle is increased. Examples of sesamoid bones are the patella and the  

Ossification

  • Ossification is the process of  formation, in which connective tissues, such as  are turned to bone or bone-like tissue. The ossified tissue is invaginated with blood vessels. These blood vessels bring  like  and deposit it in the ossifying tissue. Bone formation is a dynamic process, with cells called  depositing minerals, and  removing bone. This process, termed  continues throughout life.
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Describe (P2) and explain (M2) how the skeletal system responds to exercise. (P2, M2)

The condition of bone may be improved by exercise as it responds to mechanical stresses. These mechanical stresses usually take the form of  pulling at their points of attachment being their origins and insertions. Where these mechanical stresses are applied, most it has been shown that more mineral salts are deposited and more collagenous fibres are produced. Therefore, both the density and size of bone in these areas may be increased and these changes in bone structure are stimulated by increased loads being placed ...

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