Zusammenfassung der Ressource
The Skeleton and Muscles
- Functions of the skeleton
- Support: skeleton supports the
body and keeps it upright
- Protection: skull protects the brain, backbone
protects spinal cord, ribs protect the lungs
- Manufacture of blood cells: red cells, white cells and
platelets are made in bone marrow of the long bones
- Movement: bones provide rigid levers
against which the muscles can pull
- The Axial Skeleton
- Composed of the skull (cranium), facial
bones, vertebral column (spine), rib cage
and sternum (breastbone)
- Spine
- A pad of fluid enclosed by cartilage, called a
disk act as shock absorbers and protect the
vertebrae from rubbing each other
- The Appendicular Skeleton
- Consists of the pectoral and pelvic girdles,
and their attached limbs
- Pectoral (shoulder) girdle
- Consists of scapula (shoulder
blade) and clavicle (collar bone)
- Function is to give upper body mobility and strength
- Pelvic (hip) girdle
- Consists of the pelvis (made up
of three fused bones called
innominate bones)
- Gives strength and support
to the body and allows
mobility of lower limbs
- Structure of a Long Bone
- Compact Bone
- The inorganic material gives strength to the bone
- The organic material gives the bone flexibility
- Contains blood vessels and nerve fibres
- Medullary Cavity
- Contains a soft material
called bone marrow
- Red marrow is active in
making blood cells
- Yellow marrow is inactive and
contains numerous
fat-storage cells
- Can convert to red marrow if needed
- Spongy Bone
- Consists of a mixture of
compact bone with
pockets of bone marrow
- Function is to give strength
and rigidity to bones without
making them too heavy
- Cartilage
- It protects the end of
long bones and acts as a
shock absorber
- Made of collagen
- Bone Growth
- Osteoblasts produce and
lay down new bone
- Osteoclasts digest and
remove old bone
- Cartilage slowly converted to
bone (ossification)
- In growth plate, osteoblasts
form bone matrix to extend
the length of bones
- Joints
- A joint is where
two or more
bone meet
- Immovable Joints: allow no
movement between the
bones. Their function is
strength and protection
- Slightly Movable Joints: allow a small
amount of movement between bones.
e.g. joints between vertebrae
- Freely Movable Joints: contain synovial
fluid in joint cavity which allows
greater friction-free movement
- Hinge Joints: allow movement in
one direction only
- Ball and Socket: allow
movement in all direction
- Muscles
- Cardiac muscle:
located in the heart
- Voluntary (skeletal) is the muscle
that cause body movement. They
work as antagonistic pairs
- Antagonistic muscle pairs are
composed of two muscles that have
opposite effects to each other
- Involuntary (smooth) muscle is
located in the intestines,
bladder and blood vessels
- Muscles can
only contract
- Arthritis
- Caused by
swelling of joints
- Prevention:
reducing wear
and tear
- Treatment: rest; surgery
to repair damage in
severe cases