Unit 10Chapter 34Protection, Support, and Locomotion

Skin: the Body’s Protection

Integumentary System Contains skin and its related parts—hair, nails

& glands

Functions: Regulates body temperature Receives stimuli from environment Produces vitamin D Protection of underlying tissues

Skin: the Body’s Protection

Epidermis: Outer layer of skin,

composed of dead, flattened cells

Contains Melanin, a pigment that colors the skin & protects cell from damage by radiation

Skin: the Body’s Protection

Dermis Inner, thicker

portion of the skin Contains blood

vessels, nerve endings, hair follicles, sweat & oil glands

Skin: the Body’s Protection

Hypodermis (subcutaneous layer)

Below the dermis Contains primarily of fat

for cushioning & insulation

Bones: the Body’s Support

Skeletal System divisions:

Axial skeleton Includes the skull,

vertebrae, ribs & sternum Appendicular skeleton

Includes bones of the arms & legs, and shoulder & hip bones

Bones: the Body’s Support

Skeletal system functions: Protection Support Attach muscles Produce blood cells Store minerals

Bones: the Body’s Support

Joints Where two bones

meet Facilitates the

movement of bones in relation to one another

Bones: the Body’s Support

Ligaments Connective tissue

that attaches one bone to another

Tendons Connective tissue

that attach muscles to bones

Bones: the Body’s Support Spongy bone

Soft bone containing many spaces filled with red marrow

Compact bone Dense bone with an inner cavity

containing yellow marrow Haversian system

Circular area in compact bone containing blood vessels, nerves, and living cells called osteocytes

Muscles for Locomotion

Muscles for Locomotion

Smooth muscle Involuntary movement Found in hollow body

organs, i.e. stomach, arteries, iris of eye

Spindle-shaped cells, non-striated, one nucleus per cell

Muscles for Locomotion

Cardiac muscle Involuntary movement Found only in the heart Branching, striated

(striped) cells, with one nucleus per cell

Muscles for Locomotion

Skeletal muscle Voluntary movement Found attached to bones,

i.e. biceps, triceps, hamstrings, etc

Long, striated (striped) cells, with many nuclei

Extensor and flexor muscles

Click on image to play video.

Muscles for Locomotion

CommonSkeletalmuscles

Muscles for Locomotion Muscle contraction: Muscle fibers (cells) are made up of smaller

units called myofibrils Myofibrils contract (shorten) as filaments, called

myosin & actin, slide toward one another

Sliding filament model