Body Systems - 3.5 Muscles and Bones [ARCHIVE] Flashcards
What is your skeleton?
Your main frame, it is made up of bones.
What is your skeleton’s main functions?
- supporting your soft tissues
- protecting your organs
- allowing movement
Why does your skeleton need to support your soft tissues?
As it allows our body to remain its shape.
What part of the skeleton helps protect your organs?
The axial skeleton, which is made up of 80 bones (including skull, vertebrae, ribs, sternum and breastbone).
What part of the skeleton allows movement?
The appendicular skeleton, which is made up of 126 bones (including pelvis, shoulder blades, collarbones and bones in arms and legs).
Why do bones need to be strong?
So they don’t snap or crumble in daily activity.
What do compression and tension forces do to your bones and what are examples of this?
Compression forces squash bones, like with your legs when you are standing.
Tension forces stretch bones, like in your arms when you are holding something.
Why do bones need to be slightly elastic?
They need to twist and return to their normal shape when force is removed.
Why do bones need to be light?
So your muscles can move, the strength and lightness comes from the structure.
What are the two different forms of bone tissue?
- Compact bone
- Spongy bone
What is compact bone?
The dense outer layer of the bone that provides most of its strength.
What does spongy bone do?
It is light yet provides a strong inner structure to the bone.
What is bone marrow?
A fatty, jelly-like substance in bones where red and white blood cells and platelets form.
What is the substance that makes the bone hard and elastic?
Calcium phosphate - hard.
Collagen (which is in calcium phosphate) - elastic.
What do blood vessels supply bones with?
Nutrients they require.
Are bones living?
Yes, they contain living cells, repair themselves and replace worn-out cells.
What is a joint?
A place in the body where two bones meet, most allow movement, and the type determines the range of movement.
What do joints have to protect bones from wear?
- Cartilage: smooth material that covers end of bones that move against each other.
- Synovial fluid: lubricates bone ends and allows them to slide over each other.
What is a hinge joint?
Where bones are shaped so movement is only back and forwards. (ex. arms, knees, fingers).
What is a ball-and-socket joint?
A ball-and-socket joint allows full movement, with a ball fitting into a cup-shaped socket. (e.g: hips and shoulders)
What is a pivot joint?
A ring-shaped bone rotates around a finger-shaped bone, allowing wide movement (e.g: skull base).
What is a saddle joint?
A joint that allows movement in two directions (NOT the same as ball-and-socket idfk why) (ex. ankle, thumb).
What are ligaments?
Bands of tough, flexible tissue that hold bones in a joint together, preventing bones of a joint moving far apart.
What are muscles and what do they do?
Tissues that are able to contract or be stretched, they move bones. There are 640 of these bad boys.
What are tendons?
Tissues that attach muscles to bones and hold muscles in that position.
What happens when muscles are activated?
They contract, becoming fatter and shorter. They pull on bones they are attached to, causing them to move.
Why is another muscle required to return the bone to its original position?
As muscles can only pull.
How are muscles arranged?
In antagonistic pairs, meaning they work in opposition to each other.
