Download Cell Specialization And Organization 2

Body Systems in Humans
The 3 main body systems in humans include:
1) The Circulatory System
 consists of the heart, blood, and the
blood vessels (arteries and veins).
 this system circulates the blood around
the body, delivering food particles (nutrients)
and oxygen to every cell in the body.

This system also carries away cell
wastes such as carbon dioxide.
Which animal has the largest heart?
1)
Hippo
2)
Elephant
3)
Giraffe
Did you know that the average heart rate
(beats per minute) of a _____________ is
______________.
a)
human; 65-75 bpm
b)
elephant; 25 bpm
c)
shrew; 600 bpm
Lab on your pulse rate.
To get you pulse rate, locate your pulse on
your neck.
Then count the number of pulses/beats in 15
seconds;
- multiply this number by 4
- this gives the beats per minute
(bpm).
We will get your pulse rate at rest, sitting,
standing, after 1, 2, 3, and 4 minutes of
exercise.
We will graph and interpret your results and
the classes.
2)
The Digestive System
Breaks down food into small soluble
particles that can be used by cells.
3)
The Respiratory System
Brings air into the body, so oxygen can be
delivered to the blood, and removes carbon
dioxide from the body
See page 146
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The Respiratory System and the
Circulatory System Connection
The respiratory system exchanges oxygen
and carbon dioxide while the circulatory
system transports those gases throughout
the body.
How does it happen?
Answer –
You breathe in air, it travels down the
windpipe  into the lungs  into tiny air sacs
called alveoli. Oxygen diffuses across the
thin membranes (epidermal cells) into the
circulatory system, while carbon dioxide
diffuses into the lungs from the circulatory
system.
The circulatory system is composed of tubes
(or blood vessels).
- Arteries carry blood away from the
heart. This blood is rich in oxygen.
- Veins carry blood back to the heart.
This blood is low in oxygen and high
in carbon dioxide.
- Capillaries are made of epithelial
tissue. They connect the arteries to
the veins and is the place where
oxygen and carbon dioxide are
exchanged with the cells and alveoli.
See figure 2.29 on page 148.
Consider the following: the purpose of alveoli
is to provide very large surface area for gas
exchange to occur. To total surface area of
the 300 million alveoli in a pair of lungs is
about 70 m2.
Draw figure 2.30A
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The Circulatory and Digestive System
Digestion breaks food down into smaller
components. These nutrients are transferred
into the circulatory system, which are then
passed on to supply each cell with energy.
The transfer of food from the digestive
system to the circulatory system takes place
at the inner lining of the small intestine. This
lining is covered in tiny, finger-like
projections called villi, which increases the
surface area of the small intestine.
Each villi contains a network of capillaries.
Dissolved food particles are absorbed into
the capillaries and onward the nutrients go to
every part of the body
How much surface area do all the villi supply
for absorption? Nearly 300m2!
Draw figure 2.31 into notes.
Read “Off the Wall” on page 150.
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The Excretory System
- it is involved in getting rid of wastes
- the main organ involved in this
system is the kidney. The kidney
filters waste materials from the
blood.
- The lungs and the skin are also
grouped into this system because
they excrete wastes. Lungs
eliminate carbon dioxide and water,
and skin can eliminate water and
excess salt through sweating
(perspiration).
- The excretory system also controls
the concentration of important
substances in the blood (such as
sodium, calcium, potassium) by
regulating how much of these
substances are lost in the urine.
The Sensory Awareness System
-your body’s response to stimuli (such as
temperature) is coordinated by the nervous
system (the brain, spinal cord, and nerves)
and the endocrine system (glands that
produce chemical messengers called
hormones)
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