Skeletal System
SupportAll living organisms need a support
structureOne-cell organisms have cytoskeletonArthropods have exoskeleton (exo = out) (i.e.
insects, snails)Vertebrates have endoskeleton (endo = in)
Skeletal System PartsBones and other connective tissues, such
as cartilage and ligaments, form the skeletal system.
FunctionsOur skeletal system and its joints
allows special movementsHips allows us to walk upright on 2
legsHands allow us to have an opposable
thumb = ability to grasp objects.Size of skull says we have a well
developed brain. (Remember evolution of late ancestors. Small skull, big jaw.)
FunctionsThe skeleton supports the body,
protects internal organs, provides for movement, stores mineral reserves, and provides a site for blood cell formation.
Examples:Skull protect brainRibs and sternum protects lungs, kidneys,
liver, stomach, heart, etc.
DivisionsThere are 206 bones in 2 parts
Axial – supports the central axis of the body
Skull, vertebrae and ribs
DivisionsAppendicular Skeleton
The bones of the arms and legs, along with the bones of the pelvis and shoulder area, form the appendicular skeleton.
StructureThe bone is surrounded by a tough layer of
connective tissue called the periosteumBlood vessels pass through here to supply bone
w/ oxygen and nutrientsBelow periosteum is compact bone. (Really dense,
but not solid)Running through compact bone are tubes called
Haversian canals that have blood vessels and nerves.
Spongy bone is less dense found inside the outer layer of compact bone.Its not soft or spongy. Its pattern provides strong
support without adding too much mass.
Structurehttp://www.pearsonsuccessnet.com/snpapp
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StructureOsteocytes
Mature bone cellsOsteoclasts
Break down boneOsteoblasts
Build up boneBone remodel even when we stop growing.
Example: Exercise puts stress on our bones and forces bone to become stronger. Broken bone need to rebuild. Also, if not used, bones become weaker and break down.
StructureBone marrow are in cavities within our
bones2 types:
Yellow – made up of fat cellsRed – makes RBCs, WBCs and platelets
Bone Marrow
Bone DevelopmentEmbryo is almost entirely cartilage.Cartilage is replaced by bone by
ossificationStarts 7 months before birth. Here’s where
osteoblasts come into play.
Types Of JointsPivot Hinge
Ball & Socket Gliding
Top of the neck
Shoulder/Hip
Elbow/Knee
Intercarpal joints
Structure of JointsCartilage covers surfaces where bone
meet. Bone on bone hurts!
A capsule surrounds the joint made of 2 layers1. ligaments2. cell that make synovial fluid (reduces
friction)
DisordersResearch and find a disorder of the skeletal
system. Name, how it affects a person and how to
treat it.Write 1 paragraph about it. Will count as 1 homework and 1 project grade.
Cranium
Mandible
Sternum
Rib
Vertebral ColumnPelvisSacrum
Coccyx
Clavicle
Scapula
Humerus
Ulna
Radius
Carpals
Metacarpals
PhalangesFemur
Patella
Tibia
Fibula
Tarsals
MetatarsalsPhalanges