Movement, skeletal system and bone

Frontal/ coronal plane

divides body into anterior and posterior parts

medial (midsagittal)

lies on middle of body, splits into left and right

sagittal plane

splits body into two uneven halves

transverse (horizontal) plane

divides body into superior and anterior parts

anatomical position

universal reference point for anatomical description. standing with palms facing forward

flexion

reducing angle of the lamp (bending elbow)

extension

increasing angle of the joint

abduction

movement laterally away from the body

adduction

movement towards the body

rotation

movement along axis of a bone (bone is spinning)

circumduction

distal end of limb draws a circle

inversion

turning foot medially (sole in)

eversion

turning sole of foot laterally (out)

5 functions of the skeleton

1 support and attachment

2 movement

3 protection

4 storage (calcium in bones, fats in yellow bone marrow)

5 haematopoiesis

haematopoiesis

blood cell formation in red bone marrow

axial skeleton

longitudunal axis of the body, contains the skull, verebral column and thoracic cage

appendicular skeleton

upper limbs and attatching pectoral and pelvic girdle

what is a bone

a form of supporting connective tissue

why is a bone an organ

it has 2 tissue types and blood vessels

what forms a bone

calcium phosphate crystallised around protein fibres made by osteoblasts

osteoblast

bone making cells

long bone

longer than they are wide. Found in the limbs and act as
levers for movement. eg humerus

short bone

Cube shaped found in the wrist and ankles and provide strength
and stability. eg talus

flat bone

thin and flattened, protects organs and serves as muscle attatchment eg sternum

irregular bones

vertebrae of the spine

sesamoid bone

bone embedded into tendon that resembles a sesame seed.

function of sesamoid bone

acts as a pulley to increase tendon’s mechanical advantage and protects from stress eg patella

closed fracture

open fracture

greenstick

impacted fracture

comminuted

spiral fracture

transverse

oblique fracture

compact bone

dense tube like structures (osteons) running in one direction. Very strong in longitudinal directions

spongy (cancellous bone)

looser meshworks of struts (trabeculae) giving strength in all directions

osteon

structural and functional unit of compact bone. Consists of concentric layers of bone matrix (lamellae)

function of osteons

1. structural support

2. nutrient supply (vascular network within canal ensures bone cells receive nutrients)

3. 
   

bone remodeling (formed and reabsorbed during continuous bone remodeling to adapt to mechanical loads

first few days after fracture

fracture haematoma (blood clot) formation and phagocytosis (breakdown) of damaged material

few weeks after fracture

periosteum cells lay external soft callus made of cartilage and spongy bone across break to stabilise broken ends

6-12 weeks post fracture

cartilage tissue in callus is replaced with spongy bone (withstands gentle stresses- cast can be removed)

several months post fracture

compact bone replaces spongy bone where appropriate

what affects healing process of a fracture

nutritional status, age, general health, nature and extent of the break

why are some bones more difficult to heal?

some bones have poor circulation eg scaphoid, neck of femur and shaft of tibia