The Human Skeleton Y8 B Flashcards
How many bones does the human skeleton have? 🦴
206 bones, but some fuse together later in life
What are the 4 main functions of the human body?
It supports the body enabling it to stand upright, it protects vital organs, it enables movement by allowing muscles to connect the bones and pull them up, it creates red blood cells to carry oxygen and white blood cells to fight disease and platelets to help blood clot.
What are bones made of?
Bones are made of a combination of a hard calcium compound, which is very hard, and a protein called collagen which gives the bones a little bit of flex
Where does a joint exist?
Where 2 or more bones meet
What do joint enable us to do?
They enable the skeleton to move and limbs to bend
What are the types of joints
Ball and socket joint, hinge joint, pivot joint, fixed joints
Name a fixed joint
Skull
Name a ball and socket joint
Shoulder
Name a pivot joint
Neck
Name a hinge joint
Elbow
What attaches bone to bone?
Ligaments (which also stabilise joints)
Why do ligaments have to stretch?
So joints can bend without snapping
What attaches muscle to bone?
Tendons
What happens when the muscle contracts?
The bone is pulled towards it
Do tendons stretch?
No, so that the movement is immediate and all the force is transmitted to move the bone.
Why do we need ligaments?
They hold bones together, and without them, bones could move out of place
Why do we need tendons?
They attach muscle to bone, with allows movement.
Why do we need cartilage?
It prevents bones from rubbing together, which is very painful. Over time the cartilage can wear down, which is called arthritis.
What are muscles mostly made of?
Muscle cells
What is special about muscle cells?
They can expand and contract
Does exercise increase the amount of muscle cells you have ?
No, but it increases the size and strength of each individual cell
What happens when a muscle contracts?
It shortens, with creates a pull on bone
What is the name for a pair of muscles ? (One muscle witch pulls a bone, one with pulls it back)
An antagonist pair
