By: Brett Oosdyke

32.1: The Skeletal System

Function: Provides shape and support Allows movement Protects tissues and organs Stores certain minerals Produces blood cells

The Skeletal System

Bones- A solid network of living cells and protein fibers that are surrounded by deposits of calcium.

Structures of a bone: Periosteum- The tough layer outer layer of the bone. Compact Bone- contains Haversian canals that contain blood vessels

and nerves Spongy Bone- found in the ends of bones and produces RBC. Yellow bone Marrow- made of fat cells. Red Marrow- Produces RBC, WBC, and platelets.

The Skeletal System

The Skeletal System

Cartilage- Strong, connective tissue that supports the body. Softer and more flexible than bone

*There are approximately 206 bones in the human body.*

Cartilage is gradually replaced by bone during a process called ossification.

Osteoblasts secrete mineral deposits that replace cartilage in developing bones.

Osteocytes help maintain the minerals in bone tissue and continue to strengthen the growing bone.

The Skeletal System

Ligaments- Hold bone to bone. Example: Hold bones together in knee;

ACL.

Tendons- Hold muscle to the bones. Example: Achilles tendon attaches

to the calf.

The Skeletal System

Joint- is any place where two bones come together.

-Types of Joints:

① Movable- prevent movement in one or more directions. Examples: pivot joint (radius and ulna); ball and socket (arm into shoulder)

② Semi-movable- allow a little bit of restricted movement. Example: Vertebrae.

③ Immovable- allow no movement at all. Example: Skull

The Skeletal System

The Skeletal SystemSkeletal Disorders:

Arthritis: Inflammation of joints

Osteoporosis: loss of calcium in bones leading to weakening of bones

32.3 The Integumentary System: Hair, Skin, and Nails

Function: • Communication of pain, pressure, temperatureProtection of body: • Prevents dehydration• Regulates body temperature • Barrier for disease/infection • Covers and holds in organs• Removes waste products• Barrier for sun’s UV rays

Epidermis: Outermost layer

-Two layers:-Inner layer: living cells

-Outer layer: dead cells

-Contains:

-Keratin- waterproofing

-Melanocytes- produces pigment

The Integumentary System

The Integumentary System

• Dermis: middle layerContains:

-Hair follicles/roots-Sweat glands-Sebaceous (oil) glands-Arrector pili muscle-Nerves-Blood Vessels

The Integumentary System

• Hypodermis (Subcutaneous Layer): Innermost layerContains:

• Adipose (fat) cells: cushion, insulation, anchors skin.• Blood vessels: temp. regulation,

nutrients, etc.• Nerves: temp., pressure, pain

The Integumentary System • Hair- made of dead epidermal cells.

• Function: protect skin from UV rays (on head); provide insulation from cold; hairs in nose, ears, eyelashes prevent dirt and other particles from entering body.

• Nails- Sheets of keratinized cells• Function: protects tips of fingers/toes

The End