The Skeletal The Skeletal SystemSystem

What organs comprise What organs comprise the skeletal system?the skeletal system?

What organs comprise What organs comprise the skeletal system?the skeletal system?

• Bones!

What are the functions of What are the functions of bones?bones?

• Support for the body• Movement

• Provide points of attachment for muscles

• Protect internal organs• Storage place for calcium and fat• Synthesis of blood cells

• house blood-producing cells

A Bone is an OrganA Bone is an Organ

Organs are made of _____________.Organs are made of _____________.

A Bone is an OrganA Bone is an Organ

Organs are made of Organs are made of tissues..

Bones are made of:Bones are made of:– Bone tissueBone tissue– Connective tissueConnective tissue– Blood tissueBlood tissue

Bone TissueBone Tissue

Osteocytes (bone cells) embedded inbone cells) embedded in

a hard a hard matrix made of: made of:• Calcium salts (for strength)• Collagen fibers (for flexibility)

Bone TissueBone Tissue

Bone tissue can have two appearances:

• CompactCompact• SpongySpongy

Bone TissueBone Tissue

Where are the blood vessels in:• Compact bone?Compact bone?• Spongy bone?Spongy bone?

Bone TissueBone Tissue

Where are the blood vessels in:

Compact bone!!!

Four Major Types of Four Major Types of BoneBone

• Flat bone Irregular bone• Long bone Short bone

Flat boneFlat bone

Irregular boneIrregular bone

Long boneLong bone

Short boneShort bone

Bone MarrowBone Marrow

• Located inside Medullary Cavity.• Two types:

– Red: makes blood cells– Yellow: stores fat

Bone as a Storage OrganBone as a Storage Organ

• Fat is stored in yellow bone marrow.

Bone as a Storage OrganBone as a Storage Organ

• Fat is stored in yellow bone marrow.• Calcium is stored in the matrix of

bone tissue.– Important for function of nerves &

muscles.– What kinds of food have lots of calcium?

Calcium in the DietCalcium in the Diet

Homeostasis of CalciumHomeostasis of Calcium

• Extra calcium is stored in bone matrix.

• If body needs calcium, it is removed from bones.

Homeostasis of CalciumHomeostasis of Calcium

• Extra calcium is stored in bone matrix.

• If body needs calcium, it is removed from bones.

OsteoporosisOsteoporosis• Most common in adults over 50.• Cause: too little calcium.• Result:

– Bone density decreases– Easier to break bones

Normal: Osteoporosis:

OsteoporosisOsteoporosis

OsteoporosisOsteoporosis• Most common in adults over 50.• Cause: too little calcium.• Result:

– Bone density decreases– Easier to break bones

• Prevention:– Get plenty of calcium in diet– Regular exercise

Accessory Structures Accessory Structures

•Cartilage

•Ligaments & Tendons

•Joints

CartilageCartilage•Made of:

•Cells

•Collagen fibers

•Matrix

•More flexible than bone.

•Located where bones connect.

Ligaments & TendonsLigaments & Tendons•Ligaments:

•Connective tissue:

•Collagen

•Some elastin

•Connect bone to bone

•Tendons:

•Connective tissue

•Connect bone to

muscle

Joints (Articulations)Joints (Articulations)

• Place where 2 or more bones come together.

• 3 types:– Fixed joint– Semimoveable joints– Movable joints

Fibrous (Fixed) jointsFibrous (Fixed) joints

•Little or no movement

•Best examples in the skull

Cartilaginous jointsCartilaginous joints (Semimoveable) (Semimoveable)

•Some movement between bones can occur.

•Examples:

•Spine (intervertebral disk)

•Between pubic bones

•Ribs.

Synovial JointsSynovial Joints(Movable)(Movable)

•Allow for easy movement

•Synovial cavity contains synovial fluid (cushion)

•Cartilage covers bone surfaces.

ArthritisArthritis• Arthro = joint -itis = inflammation• Osteoarthritis

– Cartilage wears down– Movement is painful– People over 60 years old

• Rheumatoid Arthritis– Synovial fluid builds up in cavity– Autoimmune (body attacks itself)– Can occur at any age

Bone Bone GroupsGroups

•Skull

•Axial Skeleton

•Appendicular Skeleton

The SkullThe Skull

The Axial SkeletonThe Axial SkeletonThe Spine

The Axial SkeletonThe Axial Skeleton

Ribs and Sternum

The Appendicular The Appendicular SkeletonSkeleton

Arm and Shoulder

The Appendicular The Appendicular SkeletonSkeleton

Leg and Pelvis

Name the major bonesName the major bones

Check Check Your Your AnswerAnswers!s!

1) Mandible2) Clavicle3) Humerus4) Pelvic girdle5) Radius6) Ulna7) Phalanges8) Cranium9) Scapula10) Ribs11) Vertebral column12) Carpals13) Femur14) Patella15) Tibia16) Fibula17) Tarsals

VocabularyVocabulary

• Skeleton• Axial skeleton• Appendicular skeleton• Periosteum• Compact bone• Haversian canal• Osteocyte• Spongy bone• Bone Marrow• Fracture• Diaphysis

• Ossification• Epiphyseal plate• Joint• Fibrous joint• Cartilaginous joint• Synovial joint• Ligament• Synovial fluid• Rheumatoid arthritis• Osteoarthritis