Download Bones, Muscles, and Skin Body Organization and Homeostasis

Chapter 13:
Bones, Muscles,
and Skin
Body Organization and
Homeostasis
• Levels of
Specific
1.
2.
3.
4.
Broad
5.
organization in the body:
Cell
Tissue
Organ
Organ System
Organism
Cells
• Remember cell structure and
function (cell membrane,
nucleus, cytoplasm, other
organelles)
• Functions of cells
1. Undergo chemical reactions
2. Grow and reproduce
3. Get rid of wastes
Tissues
A tissue is a group of cells that perform
the same function. There are 4 main types.
• Muscle Tissue- can contract or shorten
• Nervous Tissue- directs and controls the
body
• Connective Tissue- supports your body
and connects its parts.
• Epithelial Tissue- covers the surfaces
of your body (skin, digestive tract,
etc.)
Organs and Organ Systems
Homeostasis
• Maintaining a stable internal body
environment.
• Your body temp is close to 98.6° no
matter what the temp is outside.
• When you are hot you sweat, when
you’re cold you shiver.
• Stress- your body’s reaction to
potentially threatening events.
The Skeletal System
• Your skeleton is made up of all of the
bones in your body.
• A newborn baby has about 275 bones.
• An adult has about 206 bones.
• As a baby grows, some of its bones
fuse together.
Five major functions of the skeleton
• Provides shape and support
Vertebrae- 26 bones of the spine
• Enables movement
• Protects organs
• Produces blood cells
• Stores minerals and other materials
- The Skeletal System
Joints of the Skeleton
• A joint is a place in the body where
two bones come together. Joints allow
bones to move in different ways.
• Ligaments- connect bones together
• Cartilage- covers the ends of bones
and keeps them from rubbing
together.
• Compact Bone- hard and dense
• Spongy Bone- beneath compact bone,
contains many small spaces
• Marrow- soft connective tissue
1. Red Marrow- produces most
of the body’s red blood
cells. You have more red
marrow as a child than as
an adult.
2. Yellow Marrow- stores fat
that can serve as energy
reserves.
- The Skeletal System
Bones—Strong and Living
• Bones are complex living structures
that undergo growth and development.
Bone Care
• Eat a balanced diet and exercise
• Osteoporosis- mineral loss in the
bones; they get weak and easily
break
• To prevent osteoporosis, eat lots of
calcium-rich foods!
The Muscular System
• Involuntary Muscles- Muscles that you
DON’T control (heartbeat,
breathing, digestion)
• Voluntary Muscles- muscles that you
DO control (smiling, moving, talking)
Three Types of Muscle
Tissue
Smooth
Muscle
Skeletal
Muscle
Cardiac
Muscle
Skeletal Muscle
• Attached to bones
• Provide force for movement
• Voluntary Muscles
• Tendon- connective tissue that attaches
muscle to bone
• Striated muscle- skeletal muscle is called
striated because the cells appear to be
banded.
Smooth Muscle
• On the inside of many organs
• Involuntary muscle
• Not striated
Cardiac Muscle
• Found only in your heart
• Involuntary muscle
• Striated muscle
• Never gets tired (good thing!)
Muscles at Work
- The Muscular System
• Because muscle cells can only contract, not
extend, skeletal muscles must work in
pairs. While one muscle contracts, the
other muscle in the pair relaxes to its
original length.
The Skin
Functions of the skin:
• Protects the body from injury,
infection, and water loss
• Homeostasis
• Eliminates wastes
• Gathers info about environment
• Produces vitamin D
Layers of the Skin
• The Epidermis- outer layer, usually thin, no
blood vessels or nerves
- Melanin- pigment that gives skin
color
• The Dermis- inner layer, has nerves and
blood vessels
- Pores- openings in the skin
- Follicles- where hairs grow on the
skin
The Epidermis
- The Skin
• The skin is organized into two main
layers: the epidermis and the dermis.
Caring for the Skin
• Three simple habits can help keep your skin
healthy:
1. Eat a healthy diet
2. Keep your skin clean and dry
3. Limit sun exposure
- Cancer- when body cells divide
uncontrollably
- Wear hat, sunglasses, and
sunscreen
- Don’t go out between 10am & 4pm