skeleton and muscles Flashcards
Functions of the skeleton
Support
Proctect internal organs
Movement of bones attached to muscles
Marrow & Blood cell production
Source/ sink for calcium via bone remodelling process
What does the periosteum do?
fibrous membrane that covers the outside of the bone, rich with blood capillaries
What % of the outer layer of the bone is compact?
80
What % of The bone is spongy bone ?
20, it an inner spongy structure, sponge is designed for strength
What is produced in red bone marrow ( in inner bone cavities)?
Red blood cells
What is produced where yellow bone marrow is?( in the innercavities )
Fat, cartilage and bone
What are ends of the bone covered with? What does this do?
Cartilage, to reduce friction
What are the stages of bone remodelling
Resorption and ossification
What is resorption?
Bone absorbing cells break bone down and discard worn cells, depositing calcium ions in the blood
What is ossification?
After a few weeks, bone repairing cells, come to repair the bone raking calcium ions from the blood
What bones does the axial skeleton consist of?
Skull, vertebrae, sternum, ribs
How many bones are in the axial skeleton?
80
What is the function of the axial skeleton?
To house and protect vital organs
Creates a surface for attachment of muscles
What bones does the appendicular skeleton contain
Arms, legs, shoulder blades, collarbone, pelvis
How many bones are in the appendicular skeleton
126
What is the function of the appendicular skeleton
Movement ( legs ), manipulation of objects in environment ( arms )
Describe the structure of bone
Hard tissue that provides scaffolding
Matrix of calcium salts and protein fibres
Has blood vessels to supply nutrients & oxygen
Describe the structure of cartilage
Flexible supporting tissue that protects bones
Matrix with collagen fibres embedded in it
No blood vessels run through ( cells rely on diffusion for nutrients and oxygen
What are synovial joints?
Characterised by presence of joint cavity
Walls of this space are formed by the articular capsule
Thin layer of cartilage covers the entire articulating surface of each joint cavity
Synovial membrane lines innersurface of the articular capsule.
Bones are connected to each other by ligaments ( strong bands of fibrous connective tissue.
Additional support is provided by muscles and tendons acting along that joint
How does the joint cavity help movement
Cells of inner joint capsule layer make synovial fluid, this nourishes the cartilage so the joint’s surfaces glide smoothly over each other
Increases joint mobility
How does cartilage covering the surface of bone help movement
Cartilage acts as shock absorber at end of bones reducing friction & preventing bones from rubbing together
How does synovial fluid help movement
Fluid cushions and protects the ends of bones, reducing friction during movement
How do ligaments help movement
Attach ends of 2 joints together so joint is stabilized so in doesn’t become dislocated
Strengthens and support the joint
gliding joint
Where? Ankles/ wrists
Range of movement? Gliding movement in any direction along plain of joint
Hinge joint
Where? In the elbow / knee
Range of movement? 1 plane only ( flexion and extension)
Ball & socket joint
Where? Hip/ shoulder
Range of movement? Many planes
Pivot joint
Where? Neck
Range of movement? One bone around the other
Structure of skeletal muscle
What happens to width of I band in contraction?
Shortens
What happens to width of A band in contraction?
Stays the same
