Download Body Systems - Bishop Ireton High School

Skeletal
Function
 Provide support for body tissues
 Protects organs
 Movement
 Production of blood cells(red, white, and platelets)- in
the red marrow of the humerus, femur, sternum, ribs,
vertebrae, and pelvis
 Store minerals-Ca and P
Skeleton
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Made of CaCO3
206 bones
Joints- where 2 bones meet to allow for movement
Bones held together by ligament-tough piece of connective
tissue.
Cartilage- flexible bone- ears, nose
Some joints have cartilage for smooth movement of the
bones against each other
Muscle held to bone by tendon
Some joints like shoulder have a bursae –fluid filled sac to
decrease friction.
4 kinds of movable joints
 Ball and socket- shoulder and hip
 Hinge- knee and elbow
 Pivot- arm can twist
 Saddle- wrist- bones slide across each other
 Immovable joints- skull plates
 Slightly movable- joint between tibia and fibula of
lower leg
2 different types of bone
 Compact- hard ,outer surface called periosteum.
Has blood vessels and nerve endings that travel through
Haversian canals.
 Spongy- less dense.Found at the end of long bones and in
the middle of short flat bones
 Osteoblasts- produce new bone cells.
 Marrow- red produces blood cells
yellow- fat
Bone Formation and Growth
 Embryos begin with skeleton made of flexible
cartilage. This is replaced by bone called ossification
 Bones grow in length and diameter as you age.
 During puberty- sex hormones produced increase
osteoblast mitosis which leads to growth spurt.
Skeletal Disorders
 Arthritis- inflammation of the joints
 Osteoporosis- loss of Ca.