Bones have five main functions: providing structure and support, protecting organs, allowing muscle attachment and movement, housing marrow that produces blood cells, and storing minerals. Bone is made of living tissue with different types, including compact bone, spongy bone, and cartilage. Bones come together at joints, which can be immovable or movable, including pivot, ball-and-socket, hinge, and gliding joints, and are held together by ligaments while being lubricated and cushioned to allow smooth movement.

1. Chapter 15

2. Functions
Includes all the bones in your body and has five major
functions.
 Gives shape and support to your body.
 Bones protect your internal organs
 Major muscles are attached to bones and help them
move
 Blood cells form in the red marrow of many bones
 Major quantities of calcium and phosphorous
compounds are stored in the skeleton for later
use…make bones hard.

3. Bone Structure
 Bones are not smooth. They have bumps, edges,
round ends, rough spots and many pits and holes.
 What is attached to the bumps and pits?
 What enters and leaves through the holes in bones?

4. Bone Tissue
 Living bone is an organ made of several different
tissues.
 Surface is covered with periosteum. (what is the
definition?)
 Blood vessels are in the periosteum…what do they do?
 Under the periosteum are spongy bone and compact
bone.

5.  Compact bone
 Gives bones strength
 Framework containing deposits of calcium phosphate
that make bone hard
 Spongy bone
 Located toward the ends of long bones
 Has many small, open spaces that make bones
lightweight

6.  Cavities and the spaces in spongy bone are filled with
marrow.
 Yellow marrow
 Composed of fat cells
 Red marrow
 Produces red blood cells

7.  Cartilage
 On the ends of bones
 Flexible and important in joints—it’s a shock absorber
 Makes movement easier by reducing friction…bones do
not rub together

8. Bone Formation
 Months before birth…skeleton is cartilage
 Birth you have more than 300 “bones”
 Bones fuse together so now you have 206 bones
 Gradually, cartilage is replaced with bones
 Osteoblasts…what do they do? (p. 445)
 Osteoclasts…what do they do? (p. 445)

9. Joints
 Joint—any place where two or more bones come
together
 Ligament—bones are held in place at joints by this
tough band of tissue
 Some joints are held together by more than one
ligament

10.  Immovable joints
 Allows little or no movement
 Skull, pelvis

11.  Movable joints
 All movements require movable joints
 Allows the body to make a wide range of motions
 Several types:
 Pivot
 Ball and socket
 Hinge
 Gliding

12.  Pivot joint
 One bone rotates in a ring of another bone that does not
move
 Example: turning your head, arms
 Ball and Socket
 Provides a wider range of motion that a pivot joint does
 Example: legs and arms swinging in almost any
direction (shoulder)

13.  Hinge joint
 Back and forth movement like hinges on a door
 Examples: elbows, knees, fingers
 Gliding joint
 One part of a bone slides over another bone
 Move in a back-and-forth motion
 Examples: ankles, wrists, between vertebrae
 Used the most in your body

14. Moving Smoothly
 Cartilage helps make joint movement easier
 Pads of cartilage, called disks, are located between the
vertebrae in your back. They act as cushions and
prevent injury to your spinal cord
 A fluid that comes from blood vessels also lubricates
the joint.

15. Common joint problems
 Arthritis is the most common problem.
 Over 100 different arthritis diseases
 Symptoms: pain, stiffness, swelling of joints