review questions) with Verified Answers |2026/2027
Update | A+ Graded
4 phases of respiration
1. Pulmonary ventilation
2. External gas exchange
3. Gas transport in the blood
4. Internal gas exchange
Respiration
Inhalation and exhalation of air. The process by which O2 is obtained from the environment and
delivered to the cells.
Structures of the Respiratory System
Nasal cavity,Pharynx, Larynx, Trachea, Bronchi, Alveoli
pulmonary ventilation
movement of air into and out of the lungs/exchange of air between the atmosphere and the air
sacs (Alveoli)
External gas exchange
occurs in the lungs as oxygen diffuses from the air sacs into the blood and carbon dioxide
diffuses out of the blood to be eliminated
Gas transport in the blood
The circulating blood carries gases between the lungs and the tissues, supplying oxygen to the
cells and bringing back carbon dioxide.
Internal gas exchange
occurs in the tissues as oxygen diffuses from the blood to the cells, whereas carbon dioxide
travels from the cells into the blood
compliance
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, The ease with which one can expand the lungs and thorax
Diffusion
Movement of molecules from an area of higher concentration to an area of lower
concentration/concentration gradient
two phases of ventilation
inhalation and exhalation
Surfactant
chemical produced in the lungs to maintain the surface tension of the alveoli and keep them
from collapsing
Difference between the left and right bronchi
right bronchi is larger and extends more vertically. (this is where a foreign object will most likely
lodge)
hypoventilation
causes increased CO2/H+ in blood & acidosis
Hyperventilation
causes decreased CO2/H+ in blood and Alkalosis
Part of the brain controls the HR and Resp
Medulla/Brainstem
What is the process that controls respiration
The brain senses arterial levels of H+, sends signals to the phrenic nerve to stimulate the
diaphragm to increases respiration to remove excess CO2 and H+
Hydrogens role in respiration
Hydrogen stimulates the central chemoreceptors in the brain stem to either increase or
decrease the rate and Depth of breathing
superior vena cava
#4
right ventricle
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