Human Body Systems Unit

The Skeletal System

The Skeletal SystemThe bones in a human body are living organs made of several different tissues.

Bone Marrow Extraction

Bone TissueBone tissue is made of cells that take in nutrients and use energy. There are 206 bones in a human body

Skeletal System

Stanley the SkeletonVIDEO

5 Major FunctionsThe skeletal system is the framework of your body and has five major functions.

1. The skeleton gives shape and support to your body.

2. Bones protect your internal organs.a. Rib cage protects your lungs and heart.b. Skull protects your brain.

3. Major muscles are attached to bone to help them move.

4. Blood cells are formed in the center of many bones in soft tissue called red marrow.

5. Major quantities of calcium and phosphorous compounds are stored in the skeleton for later use.

a. Calcium and phosphorous make bones hard.

Structure of BoneA living bone’s surface is covered with a tough, tight-fitting membrane called the periosteum. The periosteum contains small blood vessels to carry nutrients and cells for growth and repair.

Structure of Bone

Compact BoneHard, strong layer of bone found directly under the periosteum.

Gives bones strength and hardness (calcium phosphate deposits).

Compact BoneContains bone cells and blood vessels.

Arranged in circular structures called Haversian Systems. Haversian Systems are tiny, connected channels through which blood vessels and nerve fibers pass.

Compact BoneKeeps bone from being too rigid, brittle, or easily broken.

DID YOU KNOW???

Pound for pound…BONE is

as strong as STEEL.

Spongy BoneLocated toward the ends of long bones such as those in your thigh and upper arm.

Has many small, open spaces that make bones lightweight.

Spongy BoneAlso found in the center of cavities of long bone. The spaces are filled with marrow. Yellow marrow contains fat cells and red marrow produces red blood cells.

4.______

2.______ 3.______1.______

5.______

Spongy Bone Yellow Marrow Periosteum

Red Marrow Compact Bone

Spongy Bone

Compact Bone Yellow

Marrow

Red Marrow

Periosteum

Cartilage

Smooth, slippery, thick layer of tissue located at the ends of bones.

Cartilage

Yes, cartilage can be damaged.

CartilageThere are no blood vessels or minerals present.

Acts as shock absorber (cushion to prevent injury), reduces friction from movement.

Cartilage

Hip Replacement…

Bone FormationHealthy bone tissue is always being formed and reformed.

Bone FormationOsteoblasts build up bone by depositing the minerals calcium and phosphorous in bones making bone tissue hard.

Osteoclasts break down bone by releasing calcium and phosphorous in your blood.

Video

Part 2

JointsA joint is any place in the body where two or more bones come together.

JointsA layer of cartilage is between healthy joints to keep the bones from rubbing against one another.

Creating a new joint

JointsLigaments are tough bands of tissue that hold bones together at joints.

Tendons attach bone to muscle to allow movement at the joint.

Types of Joints1. Immovable Joints – Allow

little to no movement. Bones in your skull and pelvis are examples of immovable joints.

QUESTION: Why would your skull have immovable joints?

Types of Joints2. Moveable Joints – Allows your body to make a

wide range of movements. There are four types of moveable joints.

Moveable Joints

a. Pivot joint – One bone rotates in a ring of another bone that does not move.

a. Head/neck

b. Ball and socket joint – Bone with a rounded end that fits into a cuplike cavity of another bone.

a. Shoulder and hip

Moveable Jointsc. Hinge joint – Allows back

and forth movement.a. Knee, elbow, finger

d. Gliding joint – One bone slides over another. Movement occurs in a back and forth gliding motion.

a. Wrist, ankle, vertebrae

Joint ProblemsArthritis –

Most common joint problem.Describes more than 100 different diseases that can damage the joints.1 in 7 people suffer from arthritis.Begins with symptoms of pain, stiffness, and swelling of the joints.

Joint ProblemsCommon Types of Arthritis –

1. Osteoarthritis – Common in older aged individuals where cartilage breaks down.

2. Rheumatoid arthritis – Can occur in young and old adults. The body’s immune system tries to destroy its own tissues.

DID YOU KNOW?

Bee stings may help cure arthritis…

Bee TherapyVideo