Skeletal SystemChapter 15 Lessons 1 and 2

Lesson 1The Skeletal System

PURPOSE OF BONES1. Serve as a place

for muscles to attach.

2. Serve as protection for internal organs.

3. Principle storage for essential minerals that promote strong bones.

4. Center for production of red and white blood cells.

SKELETAL DIAGRAM

NUMBER OF BONES ADULT SKELETAL SYSTEM

BABY SKELETAL SYSTEM

206 BONES IN ADULTHOOD AFTER OSSICFICATION (FUSION OF BONES)

350 BONES AT BIRTHMANY OF THESE

BONES WILL GO THROUGH OSSIFICATION

STRUCTUREAXIAL SKELETON:

includes the 80 bones of the skull, spine, ribs, and sternum or breastbone, Protects spinal cord…vertebrae. Protects heart and lungs…rib cage.

AXIAL SKELETON BREAKDOWNSkull = 8cranium, 3 in the inner ear, and the hyoid (a

single bone in the neck, the only bone that does not attach to another bone).

Vertebral Column = 26 individual bones

Thorax (chest cavity) = the sternum and 12 pairs of ribs

First 7 pair are true ribs – attach directly to sternumNext 3 pair are false ribs – attach indirectly to

sternumLast 2 pair are floating ribs – do not attach to

sternum

STRUCTUREAPPENDICULAR

SKELETON: includes the 126 bones of the shoulders, arms, hands, hips, legs, and feet. Main purpose is movement.

TYPES OF BONES…LONG – greater length that

width and slightly curved for strength. Curved to absorb stress of body weight.FemurArms and LegsEnds form joints and

connect to other bones.

SHORT… nearly equal in length and width.Wrists, ankles,

hands, feet.50% are found

in the hands and feet.

FLAT…offer protection for internal organs and provide attachment for muscles.

Ribs, skull bones.

Protect vital organs such as the Brain.

IRREGULAR…unusual shapes that do not fit in other types.

Vertebrae.Bones that

don’t have a specific shape.

CARTILAGEStrong, flexible, connective tissue.Line the surfaces of joints to allow smooth

movement.Cushion adjoining vertebrae.Support nose and ears.OSSIFICATION: the process by which bone

is formed, renewed, and repaired.

CARTILAGE

LigamentsTough bands of fibrous, slightly elastic tissue

that bind the bond ends at the joint. Prevent excessive movement at the joint.

TENDONS: Fibrous cords that join muscle to bone or to other muscles.

http://www.mun.ca/science/inquisitor/features/bonezone/joints.html

JOINTSThe point at which two bones meet.PIVOT JOINT: a bony projection allows rotation.

Joint between head and neck that allows head to rotate.

JOINTSThe point at which two bones meet.BALL-AND-SOCKET-JOINT: allows the widest range of movement.

Shoulder and Hip Joints

GLIDING JOINTAllow bones to slide over one

another.WristAnkle

HINGE JOINTAllow a joint to bend and straighten

Fingers, knee and elbow.

CHAPTER 15 LESSON 2

CARE AND PROBLEMS OF THESKELETAL SYSTEM

CARE of the SKELETAL SYSTEMGood

nutrition/CALCIUMExercise (Bone

Mass)Safety

FRACTURESA FRACTURE IS ANY TYPE OF BREAK IN A BONE….

Fractures can be detected by Doctors through the use of

X-Ray

TYPES OF FRACTURESCOMPOUND – fracture in which the broken

end of the bone protrudes through the skin.SIMPLE – fracture n which the bone does not

protrude through the skin.HAIRLINE-the fracture is incomplete and the

two parts of the bone do not separate.TRANSVERSE – the fracture is completely

across the bone.COMMINUTED – the bone shatters into more

than two pieces.

INJURIES TO THE JOINTSDISLOCATION – ligaments that attach the bone

at the joint are torn as the bone slips out of place.TORN CARTILAGE – cartilage tears as the result

of a hard blow or twisting of a joint.BURSITIS – inflammation of the bursa sac, which

is a fluid filled sac that helps to provide smooth movement inside a joint.

BUNION – swelling of the bursa in the joint of the big toe.

ARTHRITIS – the inflammation of a joint, usually caused by wear and tear on the joints.