Name _________________________
Date ____________ Period _______
Skeletal System Notes
Functions of the Skeletal System
1. ___________________ – provides a ______________________ for softer tissues and organs of the
body to attach
2. ___________________ – ______________________________________ vital organs; sites for
blood cell production
3. ___________________ – bones act as levers when attached muscles contract, causing movement
about joints
4. ___________________ – red bone marrow of an adult ___________________________________
_____________________________________
5. _______________________________________ – matrix of bone is composed of _____________
_______________________, which can be withdrawn in small amounts to be used elsewhere in the
body; small amounts of magnesium & sodium also stored; yellow bone marrow stores energy
(adipose)
Categorization of Bones
 Long bones: longer than wide
o Found in ______________________

Short bones: more or less cubical
o Found in ______________________

Flat bones: protection
o Found: _________________________________

Irregular bones: odd shapes
o Found: _________________________________
Structure of a Long Bone
 Diaphysis: _________________

Epiphysis: ________; consist of spongy bone (contains
red bone marrow) surrounded by compact bone

Medullary cavity: in the diaphysis, contains fatty _______
______________________________________

Endosteum: thin layer of ________________________
that lines the medullary cavity

Periosteum: _____________________ made of dense
connective tissue where tendons and muscles attach
Bones of the Axial Skeleton
-Includes: ____________________________________________________________________
Bones of the Cranium
Frontal View
Lateral View
Sutures
Bones of the Rib Cage


Sternum (aka breastbone)
o Covers the heart, ribs attach to it
12 Pairs of Ribs
o 1 – 7: ________________ – cartilage joins the sternum
o 8 – 12: ________________ – do not connect to sternum
 Pairs 8, 9, & 10 join to cartilage of rib above it and indirectly to the sternum
 Pairs 11 & 12 are ______________________ – they do not connect to the sternum in
any way
Bones of the Vertebral Column

Composed of _____ vertebra
o _____ cervical (neck)
o _____ thoracic
o _____ lumbar
o _____ fused sacral
o _____ fused coccyx
Bones of the Appendicular Skeleton
-Includes: ____________________________________________________________________
Bones of the Hand
Bones of the Foot
Joints and Fractures
Joints
Joints are ______________________________________________________________ – classified
according to movement:
 SYNOVIAL FLUID – lubricating substance in joints
-BALL AND SOCKET JOINT – bone with ball- shaped head fits into concave socket of 2nd bone
(Found in: __________________________________________)
-HINGE JOINTS – move in one direction or plane.
(Found in: __________________________________________)
-PIVOT JOINT – those with an extension rotate on a 2nd, arch shaped bone.
(Found in: __________________________________________)
-GLIDING JOINTS – flat surfaces glide across each other.
(Found in: __________________________________________)
-SADDLE JOINT – one bone is shaped like a saddle, while the other bone rests on it like a rider on a horse
(Found in: __________________________________________)
-SUTURE – immovable joint
(Found in: __________________________________________)
Fractures
FRACTURE – a break
 Treated by:
o CLOSED REDUCTION – cast or splint applied
o OPEN REDUCTION – surgical intervention with devices such as wires, metal plates or screws to hold the
bones in alignment (internal fixation)
o TRACTION – pulling force used to hold the bones in place – used for fractures of long bones
 CLOSED or SIMPLE fracture – bone broken, broken ends do not break the skin
 OPEN or COMPOUND – broken bones pierce the skin, can lead to infection
 GREENSTICK – in children, bone bent and splintered but never completely separates
 COMMINUTED – splintered or broken into many pieces
 SPIRAL – bone twists, resulting in one or more breaks