THE SKELETAL AND MUSCULAR SYSTEMS

SKELETAL SYSTEM

THE AVERAGE PERSON HAS 206 BONES

BONES ARE HELD TOGETHER BY LIGAMENTS

LIGAMENT

TENDONS ARE CONNECTIVE TISSUES THAT ATTACH BONE TO MUSCLE

ACHILLES TENDON

FUNCTIONS

• GIVES SHAPE AND SUPPORT

• ALLOWS MOVEMENT

• PROTECTS TISSUES AND ORGANS

• STORES CERTAIN SUBSTANCES

• PRODUCE BLOOD CELLS

DEVELOPMENT OF BONES

• CARTILAGE CONNECTIVE TISSUE THAT FORMS BONES

• STRONG ENOUGH TO SUPPORT WEIGHT BUT FLEXIBLE

• BONE REPLACES CARTILAGE ABOUT SEVEN MONTHS BEFORE BIRTH

• CARTILAGE REMAINS IN JOINTS, EARS, AND NOSE

– ACTS AS A CUSHION

– PROVIDES SLIPPERY SURFACE FOR BONE MOVEMENT

STRUCTURE OF BONES

• BONE IS ONE OF TOUGHEST AND LIGHTEST MATERIALS IN THE BODY

• 206 BONES MAKE UP ABOUT 14% OF BODY MASS

• BONES ARE ALIVE – NERVES, BONE-FORMING CELLS, AND BLOOD VESSELS

http://users.tpg.com.au/users/amcgann/body/skeletal/large_bone.gif

• BONES ARE LIKE ROCKS – HARD AND STRONG

– MINERALS MAKE BONES HARD AND STRONG

• CALCIUM AND PHOSPHORUS

THE BONE

• HOLLOW SHAFT

– YELLOW MARROW – FAT AND BLOOD VESSELS

– RED MARROW – PRODUCES BLOOD CELLS

SURROUNDING THE SHAFT – MEMBRANE CONTAINS BONE-FORMING CELLS AND BLOOD VESSELS

• MUSCLES ATTACH TO BONE SURFACE

• RUNNING THROUGH THE BONE SYSTEM IS A SYSTEM THAT BRINGS FOOD AND OXYGEN

• IT ALSO CONTAINS NERVES

SKELETAL JOINTS

• JOINT – WHERE BONES COME CLOSE TOGETHER

• MOVEABLE JOINTS – ALLOW BONES TO MOVE

BALL AND SOCKET

ALLOWS FOR CIRCULAR MOTION

HINGE JOINT

ALLOWS FORWARD AND BACKWARD MOVEMENT

PIVOT JOINT

ALLOWS BONES TO MOVE OVER EACH OTHER

THE MUSCULAR SYSTEM

• THE ONLY TISSUE THAT CONTRACTS OR SHORTENS

• MORE THAN 600 MUSCLES WORK WHILE YOU SLEEP TO KEEP YOU ALIVE

MUSCLES ARE MADE OF FIBERS THAT RUN PARRALLEL TO ONE ANOTHER AND ARE HELD TOGETHER BY BUNDLES OF CONNECTIVE TISSUE

SKELETAL MUSCLES

• ALLOWS MOVEMENT

• ASSOCIATED WITH BONES

• STRIATED OR BANDED

• VOLUNTARY – YOU CAN CONTROL

SMOOTH MUSCLE

• CONTROL BREATHING, BLOOD PRESSURE, ETC.

• DO NOT HAVE BANDS

• INVOLUNTARY YOU DO NOT CONTROL

CARDIAC MUSCLE

• HEART

• WEAVE A COMPLEX MESH

• INVOLUNTARY

ACTIONS

• MUSCLES WORK IN PAIRS

• NERVE TISSUE IS INVOLVED

• MUSCLE CONTRACTS COMPLETELY OR NOT AT ALL

INJURIES TO SKELETAL AND MUSCULAR SYSTEM

SPRAIN

LIGAMENT IS TORN OR PULLED BEYOND NORMAL RANGE

FRACTURE

BREAK IN BONE

– HEALING BEGINS IMMEDIATELY– BROKEN BLOOD VESSELS FORM CLOT– MINERALS FROM SHARP ENDS

ABSORBED– CONNECTIVE TISSUE GROWS TO HOLD

BONE ENDS TOGETHER

DISLOCATION

• A BONE IS FORCED OUT OF IT’S JOINT– THIS NEEDS A

DOCTOR TO PUT IT BACK