1. Indicate the importance of gas exchange in all living organisms.
Respiration is gas exchange (Oxygen and Carbon Dioxide) with the external environment.
All living things respire. Gas exhange is important so that cellular respiration can take place
and energy can be made for the cells.
2. Distinguish amoung the terms cellular respiration, external respiration and internal
Cellular respiration is cells using oxygen in the reaction where glucose is converted into a
chemical known as ATP (adenosine triphosphate). ATP is used to provide energy to the cell
and carbon dioxide is a byproduct of cellular respiration. External respiration is air moving in
through the nose or mouth and into the lungs, and oxygen diffusing out of the alveoli and
into the capillaries. The alveoli wall is only one cell thick and the alveoli have a greater
concentration of oxygen then the blood. The oxygen is bound on to the blood cells by the
protein hemoglobin. Carbon dioxide diffuses from the blood and into the alveoli. Internal
respiration is when oxygen is transported to the cells by the blood in the circulatory system.
Oxygen is released from the red blood cells and diffuses into the body cells. Carbon dioxide
diffuses into the blood from the cells.
3. Indicate the importance of external and internal respiration(and the respiratory system) to
the process of cellular respiration.
External respiration brings in air through the external enviroment and diffuses oxygen into
the blood cells. Internal respiration diffuses oxygen into the body cells. Cells use the oxygen
in cellular respiration to make energy.
4. Identify the Structures of the human respiratory system and identify their functions.
Nasal cavity conducts air into hollow nasal passages, oral cavity conducts air into hollow
nasal passages. The Nasal passages contain thin hanging bones called turbinates that
increase the surface area of the nasal passages and clean the air. The mucous covering
the turbinates moisten the air and the capillaries within the epithelial lining warm and moisten the air. The Pharynx connects the mouth and nasal cavity to the larynx and the
esophagus. The Epiglottis prevents food from falling into the trachea and protects the
opening of the glottis. The Larynx houses the vocal cords and when speaking, muscles
around larynx contract which close the gap between the chords and different sounds are
made from the vibration of the chords. The trachea transports air down the trachea and into
the lungs. The Bronchi transports air through the trachea to the bronchioles. The
Bronchioles transports air and the ciliated mucous membrane moistens air passing through
it. The Alveoli site of gas exchange and most of gases are exhanged by simple diffusion.
The Diaphragm seperates the region of lungs and stomach and it contracts during
inhalation and relaxes during exhalation.
6. The right lung has 3 lobes and left has 2 lobes and is enveloped in layers of tissue called
pleura, where gas exhange occurs, has alveoli in it, located deep within body.
7. External Respiration is alveoli have greater concentration of oxygen then the blood and
internal respiration is oxygen transported to cells by blood and is released from red blood
cells and diffuses into body cells, carbon dioxide diffuse into blood from the cells.
8. Oxygen is bound to the blood cells by the protein hemoglobin and carbon dioxide diffuses
from the blood into the alveoli.
9. Inhaling is thoracic cavity increases volume and to achieve equilibrium the air pressure
decreases and cavity pressure decreases and the outside pressure is higher then inside, so
the air is taken in. Exhaling is when the diaphragm relaxes and thoracic cavity decreases
volume and to achieve equilibrium the air pressure increases and air goes out of body.
10. Tidal volume is the volume of air inhaled and exhaled in normal breathing. Insipiratory
reserve volume is the extra amount of air that can be taken in past regular volume.
Expiratory reserve volume is the extra amount of air that can be forced out from the lungs
past regular volume. Vital capacity is the total amount of gas that can be moved in or out
from lungs and the