Skeletons Flashcards
What types of skeleton can animals have
Internal
Extenal
No skeleton
Describe internal skeletons made from bone and cartilage
Framework and shape for body
Grow with body
Easy to attach muscles to
Joints to allow flexibility
Where does the human body have lots of cartilage
Outer ear
Nose
Ends of long bones
What is the human internal skeleton mainly made from
Bone and cartilage - living tissues
Describe internal skeletons made only from cartilage
Eg. Sharks
Light and flexible
Not rigid enough for animal to live on land
Describe exoskeletons
Eg. Insects 🐞
Hard, heavy and inflexible
Made of chitin
Some organisms have soft bodies eg. Worms
Describe long bones
Hollow shaft containing bone marrow and blood vessels
Lighter, stronger than other bones
Head of bone covered in hard but slippery cartilage to lubricate movement against other bones
Describe the process of foetus bones changing to hard bone
This is called ossification
Bones in foetus are made from soft flexible cartilage
During growth, the cartilage is replaced by calcium and phosphorus salts making bone hard
What is the difference between children and adults bones
Children have a high percentage of cartilage in their bones
Adults have stopped growing and only have cartilage on ends of bones to protect them
The proportion of cartilage to bone can be used to measure growth
Simple fracture
Bone breaks cleanly
Greenstick fracture
Bone does not break completely
Compound fracture
Broken bone breaks through muscle and skin
Describe osteoporosis and issues with it
As people age, bones get softer and more brittle (osteoporosis)
So bones can break easier
Joint
Two or more bones meet
Muscles
Contract to make bones move💪🏼
How are muscles attached to bone
Tendons
Fixed joints
Found in skull
Bony plates fused together
What are the categories of synovial joints
Hinge joints- bend in one direction only eg, knee
Ball and socket joints- rotation eg, shoulder
Describe what can happen to cartilage and bone if damaged and how this is solved
Cartilage and bone are LIVING TISSUES meaning they can become infected if damaged
However they can grow and repair themselves
Why shouldn’t you move someone with a fracture
It could make the injury worse
Describe how arm moves with antagonistic muscles
BEND ARM- Biceps contract pulling on radius, triceps relax
STRAIGHTEN ARM- triceps contract pulling on ulna, biceps relax
In the bending and straightening of the arm:
what does the elbow joint act as
The fulcrum
In the bending and straightening of the arm:
Where is the bicep muscle attached
Describe force of the contraction
Bicep is attached close to the elbow and contracts at a short distance.
Force of contraction required is very high
In the bending and straightening of the arm what does the radius act as
What is this arrangement called
A lever
A distance multiplier, hand moves at greater distance than the muscles
Why is a distance multiplier necessary
Muscle fibres only contract short distances
Advantages of replacement joints
Tailor made to fit patient
Not rejected by immune system
Replaces worn out joints or repair damaged joints
Returns mobility
Disadvantages of replacement joints
Major surgery required
Cannot repair or replace diseased and/or weakened bones
Synovial joint structure-
Describe synovial membrane
Secretes synovial fluid
Connective tissue
Synovial joint structure-
Describe synovial fluid
Lubricates and cushions bones during movement
Absorbs shock
Synovial joint structure-
Describe smooth cartilage
Prevents friction between bones
Absorbs shock
Synovial joint structure-
Describe ligaments
Join bones together
Prevents dislocation
What does antagonistic mean
When one muscle contracts, the other relaxes, found in the arm
