How does a person stay alive
even though the environment
around him or her is so cold?
• The answer:
– Your body did not allow its internal
conditions to change enough to stop
the cells from working properly.
– The maintenance of a stable internal
environment is called homeostasis
– Homeostasis is not an easy task.
– Your body must perform many
different “jobs” to maintain homeostasis
– Cells are organized into different
“teams” to perform these jobs.
– Each cell in your body has a specific job
in maintaining homeostasis.
• A group of similar cells working
together forms a tissue.
• Your body contains four main
types of tissue
• Epithelial tissue
• Connective tissue
• Muscle tissue
• Nervous tissue
• Covers and protects underlying issue.
• When you look at the surface of your
skin, you see epithelial tissue.
• The cells stick tightly and form a
continuous sheet.
• Sends electrical
signals through
the body
• It is found in the
brain, nerves,
and sense
organs
• Is made of cells
that can contract
and relax to
produce
movement.
• Joins, supports,
protects, insulates,
nourishes, and
cushions organs.
• It also keeps
organs from falling
apart
• Two or more tissues
working together from
an organ.
• One type of tissue alone
cannot do all the things
that several types
working together can do.
The stomach is an organ
• The four types of tissue work together so that the
stomach can carry out digestion
– Nervous tissue in the stomach partly controls the
production of acids that aid in the digestion of food.
Nervous tissue signals when the stomach is full.
– Epithelial tissue lines the stomach.
– Layers of muscle tissue break up stomach contents
– Blood and a connective tissue called collagen are found
in the wall of the stomach.
Organs Form Systems
• Your stomach does
much to help you digest
your food, but it doesn’t
do it all.
• It works together with
other organs, such as the
small intestine and large
intestine, to digest your
food.
• Integumentary system
– Skin, hair, and nails protect underlying tissue
• Muscular system
– Skeletal muscles move your bones
• Skeletal system
– Bones provide a frame to support and protect
body parts
• Cardiovascular system
– Heart pumps blood through all your blood vessels
• Respiratory system
– Lungs absorb oxygen and release carbon
dioxide
• Urinary system
– Removes wastes from the blood and
regulates the body’s fluids
• Reproductive system (male)
– Produces and delivers sperm
• Reproductive system (female)
– Produces eggs and nourishes and shelters
the unborn baby
• Nervous system
– Receives and sends electrical messages throughout
the body
• Lymphatic system
– Returns leaked fluids to blood vessels. It also
helps you get rid of germs that can ham you
• Digestive system
– Breaks down the food you eat into nutrients that
can be absorbed into your body.
• Endocrine system
– Glands regulate body functions by sending out
chemical messengers. The ovaries, in females, and
testes, in males, are part of this system