pdhpe 11

• The human skeleton has 206 bones that allow support for the body giving it shape, form, posture, protection of vital organs and soft tissue, assistance in body movement by providing attachment to muscle and serving as lever, manufacturing blood cells in the marrow cavities, and provision of a storehouse for essential minerals like calcium and phosphorus
• Main types of bones

  • Long bones - levers or to transfer forces
  • Short bones - levers or to transfer forces
  • Flat bones - protection for vital organs
• Compact bone


  Outer part of bone, consists of dense, strong, compact bone tissue, forms the actual shaft of long bones
• Cancellous bone


  Located at the extremities or ends of long bones, a criss cross network of spongy bone tissue, strong but light, able to withstand stress, flares out to meet adjacent bones, forming joints
• Bone marrow


  Fills the centre cavity and the spaces of spongy bone, contains blood vessels, fat and blood, forming tissue
• Articular cartilage


  On the articular surface (where bones meet) of compact bones, softer but highly resilient, prevents jarring, allows bones to freely move on each other
• Not all bones are involved in movement. Some bones move only because muscles pull them
• Large long bones move considerably while others move marginally, or not at all, as they anchor joint structures
• Directional terms - anatomical reference system used to identify location of bones

  • Superior - towards the head
  • Inferior - towards the feet
  • Anterior - towards the front
  • Posterior - towards the back
  • Medial - towards the midline
  • Lateral - towards side of the body
  • Proximal - towards body's mass
  • Distal - away from the body's mass
• Clavicle


  Long bone, provides attachment between the shoulder girdle and the vertebral column, gives greater mobility to shoulder joint
• Scapula


  Large, triangular flat bone, allows arm to attach to the trunk position of skeleton, many muscles involved in movement attach to this bone
• Humerus


  Long bone, joining shoulder to elbow, can move in most directions and rotate within the shoulder joint
• Radius


  Long bone, on thumb side of forearm, provides structure to forearm, allows rotation through the elbow joint
• Ulna


  Longer forearm bone, connect to the pinky, structures the forearm, allows rotation through the elbow joint
• Carpals, metacarpals, phalanges


  Bones of the wrist and fingers, carpals = short bones, metacarpals and phalanges = long bones, provide structure to hand, allow performance of fine motor movements
• Pelvic girdle


  Allows for the attachment of the lower limbs and muscles of the lower leg and lower back, allows less movement than the shoulder girdle because the supporting ligaments are short and strong, the hip joint is deep adding to stability
• Femur


  Longest and strongest bone, capable to support 30 times the weight of an adult, bone is covered in large muscles that external from pelvic girdle to shin
• Patella


  Small, flat triangular bone, provides protection to the knee
• Tibia


  Bears most of the body's weight, involved in all lower body movements
• Fibula


  Parallel on the lateral side of the tibia, provides support and stability to the lower leg while allowing slight rotation from knee joint
• Tarsals, metatarsals, phalanges


  Provides structure that enables leg movements
• Fibrous joint


  Immovable, example - bones of cranium fused with sutures
• Cartilaginous joint


  Slightly movable, example - cartilage between the disks of the vertebral column
• Synovial joint


  Freely movable, allows maximum movement
• Ligaments


  Well defined, fibrous bands that connect articulating bones, assist the joint by restraining excessive movement and controlling the degree and direction of movement, inelastic that may stretch or permanently lengthened when stretched excessively (can occur in injury and causes joint instability)
• Tendons


  Tough, inelastic cords of tissue that attach muscle to bone, further strengthen joints as they extend across it, assist ligaments to hold the joint closed
• Synovial fluid


  Acts as a lubricant, no two joints surfaces fit together perfectly and so the fluid forms a cushion between them, provides nutrition for the cartilage and carries away waste, the amount of synovial fluid is produced depending on the amount and type of physical activity of the joint, when the articular cartilage is under pressure fluid is pumped into the joint space, the viscosity or stickiness also varies with it becoming more viscous with decreases in temperature
• Hyaline cartilage


  Bones covering a layer of smooth, shiny cartilage which allows them to move freely over each other, has a limited supply of blood but receives nourishment through synovial fluid, thicker in leg joints where there is a greater weight bearing
• Joint actions - terminology to describe movement on joints and hence muscles

  • Flexion - decrease in angle of the joint
  • Extension - increase in angle of the joint
  • Abduction - a body part moving away from the midline
  • Adduction - a body part moving towards the midline
  • Circumduction - end of the bone moving in a circular rotation
  • Rotation - a body part moving around a central axis
  • Pronation - thumb moves towards the body
  • Supination - thumb moves away from the body
  • Eversion - sole of the foot moves away from the body
  • Inversion - sole of the foot moves towards the midline
  • Dorsi flexion - decrease of the angle between foot and lower leg
  • Plantar flexion - increased angle between foot and lower leg
  • Elevation - shoulders moving towards head
  • Depression - shoulders moving away from the head
• There are over 600 muscles in the body and they are attached to bones
• Muscles


  • Their role is to contract so we can move
  • They are unable to push to enable movement, instead they shorten causing joint movement
• Origin


  Usually attached to bone via tendon
• Insertion


  Attachment usually by a tendon at the movable end which tends to be away from the bodies main mass
• Muscle action


  Movement caused by muscle contractions
• Palpation


  Feeling a muscle or muscle group because they are close to the skins surface
• Deltoid


  • Origin - scapula, clavicle
  • Insertion - humerus
  • Action - abduction of the arm
• Lattisimus dorsi


  • Origin - spine, iliac crest
  • Insertion - humerus (proximal end)
  • Action - adduction, extension and rotation of arm
• Biceps brachii


  • Origin - humerus, scapula
  • Insertion - radius
  • Action - flexion of arm and forearm, supination of forearm
• Trapezius


  • Origin - base of skull, spine
  • Insertion - scapula (upper surface), clavicle
  • Action - adduction of scapula, elevation of shoulders
• Triceps


  • Origin - scapula, humerus
  • Insertion - ulna (proximal end)
  • Action - extension of arm and forearm