pdhpe - skeletal system

• Skeletal System


  The adult human skeleton has 206 bones. They range in shape and size, a feature that allows them to perform specialised functions.
• Anatomical reference system


  • Directional terms are used to identify the location of bones
  • The starting point assumes that the body is in the Anatomical position; that is, a reference position where the subject is standing erect, facing front on and with palms facing forward
• Skeletal system


  • Axial skeleton - consists of the bones of the skull, the thoracic/rib cage and the vertebrae column
  • Appendicular skeleton - consists of the bones of the upper and lower limbs and the bony girdles that support them on the body trunk
• Types of bone


  • Long
  • Short
  • Flat
  • Irregular
  • Sesamoid
• Long bones


  • Are longer than they are wide, the function as levers
  • Examples: humerus, femur, radius, tibia, ulna and phalanges
• Short bones


  • Have a short axis and are found in small spaces such as the wrist. They serve to transfer forces
  • Examples: bones in the wrist (carpals) and ankle bones (tarsals)
• Flat bones


  • Have a broad surface and serve as places of attachment for muscles and to protect vital organs
  • Examples: scapula, cranial bones, sternum and ribs
• Irregular bones


  • Do not fall into any category due to their non-uniform shape. Primarily consist of cancellous bone, with a thin outer layer of compact bone
  • Example: vertebrae
• Sesamoid bones


  • Usually short and irregular bones, imbedded in a tendon where it passes over a joint which serves to protect the tendon
  • Example: the patella
• Bones


  • Long bones
  • Short bones - Carpals, Tarsals
  • Flat bones
  • Sesamoid bone - Patella
  • Irregular bones - Vertebral column
• Synovial joints have common structural features that enable them to move freely
• Structural features of synovial joints


  • Synovial cavity—a space where two bones meet
  • Synovial fluid—a rich viscous fluid that acts as lubrication to the bones in the synovial cavity. It also plays a role in the cleanup of tissue debris from daily wear and tear on the joint
  • Articular cartilage—covers the end of the bones, provides cushioning and reduces friction between the bones in the joint
  • Joint capsule—encloses the cavity and keeps the fluid contained
  • Fibrous capsule—encloses the bones, tissues and fluid
  • Synovial membrane—secretes the fluid into the joint
  • Meniscus—cartilage that grows inwards from the joint capsules to absorb shock, reduce pressure and enhance stability
• The human body is made up of many complex systems that enable it to function
• Anatomy


  The physical structures of the body and how they interrelate

  
• Physiology


  The function of these structures, or how they work
• In this core module, we will study the interrelationships between the skeletal, muscular, cardiovascular and respiratory systems and their role in enabling our bodies to move effectively
• Anatomical position


  A reference point within the body used to describe and locate body parts
• Features that characterise the anatomical position

  • Face/eyes forward
  • Palms facing forward
  • Relaxed shoulders
  • Arms to side
  • Feet together
• Sagittal plane


  A vertical plane that divides the body into left and right parts
• Frontal plane


  A vertical plane that divides the body into anterior (front) and posterior (back) parts
• Transverse plane


  A horizontal plane that divides the body into superior (top) and inferior (bottom) parts; this is also known as a cross-section
• Superior


  Towards the head
• Inferior


  Towards the feet
• Anterior


  Towards the front
• Posterior


  Towards the back
• Medial


  Towards the midline of the body
• Lateral


  Towards the side of the body
• Proximal


  Towards the body's mass
• Distal


  Away from the body's mass
• The skeletal system consists of bone tissue, bone marrow, cartilage and periosteum (the membrane around the bones)

  
• The adult human skeleton consists of 206 bones, which range in shape and size in order to perform specific functions
• Axial skeleton


  Forms the long axis of the body and includes the skull, vertebrae, ribs and sternum
• Appendicular skeleton


  Includes the bones of the shoulder girdle, arms, hands, pelvis, legs and feet
• Functions of the skeletal system

  • Support - gives body its shape, form, posture
  • Protection of vital organs and soft tissue
  • Assist in body movement - provides attachments for muscles and serves as levers
  • Manufacture blood cells - in marrow cavities
  • Store essential minerals e.g. calcium, phosphorus
• Categories of bones based on shape

  • Long bones
  • Short bones
  • Flat bones
  • Irregular bones
• Long bones


  • Long and elongated, longer than they are wide, two ends and a shaft, hard shell casing (compact bone) and contains spongy bone on the inside, functions as levers or transfers force
• Examples of long bones

  • radius, clavicle, humerus, metacarpals phalanges, femur, tibia, fibula
• Short bones


  • Cube like and made of spongy bone, a thin layer of compact bone provides shape, functions as levers and transfers force

  
• Examples of short bones

  • carpals, tarsals
• Flat bones


  • Flat and thin, provide protection for vital organs