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The Musculoskeletal System
There are 206 bones in an adult body and up
to ~640 muscles in the body.
The Musculoskeletal system is made up of all
of the bones in the body and all of the
muscles that help make them move.
Function
The main role of the musculoskeletal system
is to provide:
a) Movement to the body
b) Structure
c) Support
d) Protection
e) Anchor points for our muscles
Structural Features
Skeleton consists of three different types of
connective tissue:
1) Bones
- hard and dense
- have canals inside for nerves and blood
vessels
- made up of bone cells within a matrix of
minerals (calcium, phosphorus)
-long bones contain bone marrow  blood
cells
2) ligaments
-tough, elastic connective tissue
-connects bone to bone; holding bones
together at joints
Ex.
3) Cartilage
-dense connective tissue
-provide a smooth surface, strong, flexible,
low-friction support for bones and other
tissues
Ex.
Muscle Tissue
-consists of long cells called muscle fibres
-contain specialized proteins
- allow the muscle to contract
-when a muscle contracts, it gets shorter and
thicker
-when a muscle relaxes, it gets longer and
thinner
3 types of muscles:
1) skeletal muscle
-voluntary (under conscious control) and
striated (allows the muscle to contract and
shorten)
Ex.
2/3) smooth muscle & cardiac muscle
-involuntary
Ex.
How muscles make bones move
Tendons – attach muscles to bones which
allow the movement of body parts
-In order for muscles to work, it has to cross a
joint
-Skeletal muscles contract in response to
signals from the nervous system
-Muscles work in opposing pairs or groups
Ex.
Physical Impacts and Stresses on the Body
-bones can break/fracture
-muscles, ligaments and tendons can tear
Skeletal System in Other Animals
-All vertebrates have musculoskeletal
systems similar to ours
-Invertebrates have no rigid frame to give
them structure
-Insects and arthropods – have skeletal
system on the outside of their body – called
exoskeleton