Chapter Four
Respiration and Excretion
I.
The Respiratory System
A. Functions1. Taking in Oxygena. Respiration-The process in
which oxygen and glucose
undergo a complex series of
chemical reactions inside cells
b. Breathing- The movement of
air into and out of lungs.
2. Removing Carbon Dioxide and
Water- respiration eliminates CO2
and H2O
3. Systems working togetherRespiration also requires Digestive
and Circulatory system to move
oxygen to the lungs and expel
carbon dioxide
B. The Path of Air
1. Nose- enters the body into the nasal
cavities lined with mucus
a. Cilia- hair like extensions that
can move together to seep the
mucus into the throat.
2. Pharynx- Air then enters the
Throat, also in the digestive system
3. Trachea- Air then moves into the
windpipe. Lined with mucus, cilia,
and rings of cartilage. The
epiglottis protects from trachea
from food entering
4. Bronchi and Lungsa. Bronchi- Passages that direct
air into the lungs
b. Lungs- Main organ of the
respiratory system.
c. Alveoli- The end of the
smallest tubes of bronchi are
tiny sacs of lung tissue
specialized for the movement
of gases between air and
blood.
C. Gas Exchange
1. Air enters alveolus
2. Oxygen passes through the wall of
the alveoli into the blood.
3. Carbon Dioxide and Water move
from the blood to the alveoli
(backwards)
4. How Gas Exchange Occurs- Oxygen
and Carbon Dioxide attach to the
Hemoglobin on the red blood cells and
transfers
5. Surface Area for Gas Exchange-The
larger the surface area, the more
efficient the exchange of oxygen and
carbon dioxide.
D. How you Breathe- more than 20,000 times
a day.
1. Muscles for Breathing- ribs and
diaphram
a. Diaphragm- dome shaped
muscle that plays an important
role in breathing
2. The Process of Breathing-
a. When you inhale, the
diaphragm moves downward
and pressure in the lung
decreases causing air to flow in
b. When you exhale, the
diaphragm moves upward and
the pressure in the lungs
increases, pushing the air out.
3. Relating Breathing and Speaking
a. Larynx- Voice Box contains
two folds of tissue that stretch
across the opening (vocal
cords).
b. Vocal Cord-contract from
muscles and vibration contains
sounds
II. The Excretory System- excretion- removal of
waste
A. The Excretory System- The system in the
body that collects wastes produced by
cells and removes the wastes from the
body
1. Kidneys- Major organs that remove
urea (chemical coming from the
breakdown of protein). Filter
2. Ureters- Carry urine from the
kidneys through these narrow tubes
to the urinary bladder
3. Urinary Bladder- Sack like
Muscular organ that stores urine
4. Urethra- Small tube that carries
urine out of the body
B. Filtration of Wastes
1. Nephrons- Tiny filtering factories
that remove wastes in stages
a. Filtering out waste- First waste
and needed materials such as
glucose are filtered out of the
blood.
b. Formation of Urine- The
needed material is returned to
the blood and the waste are
eliminated in urine.
2. Analyzing Urine for Signs of
Disease- If urine contains glucose
or protein it may indicate a medical
problem.
C. Excretion and Homeostasis- (review
section 1-1) Excretion maintains
homeostasis by keeping the body’s
internal environment stable and free of
chemicals.
1. Kidneys- Filter blood and regulate
the amount of water in the body.
2. Lungs and Skin- Remove some
waste by exhaling or perspiring.
3. Liver- Breaks down waste and even
converts hemoglobin to bile
D. Diagram of the Excretory System (p 129)