Download Respiratory System – Assignment #1

9.1 Respiratory System
1. What are the functions of the respiratory system.
The respiratory system supplies oxygen to the cells and removes carbon dioxide. It also
produces sound for speaking and assists in regulating body fluid pH.
2. What are the components of respiration? Explain each one.
The components of respiration are:
1) Ventilation (breathing)
2) External respiration
3) Internal respiration
4) Cellular respiration
Ventilation: taking in oxygen from the external environment – i.e. inhaling and exhaling
External Respiration: exchange of gases between the air sacs and the blood
Internal Respiration: exchange of gases between blood and tissues
Cellular Respiration: use of oxygen to release energy in mitochondria
3. What are the components of the respiratory system?
The respiratory system consists of the nasal and oral cavities, the pharynx, (the
epiglottis), the larynx, the trachea, the bronchi, the bronchioles, and the alveoli.
4. Why is it better to breathe through the nose than the mouth?
It is better to breathe through the nose than the mouth because the nose warms, moistens
and filters the air. Hair and mucus play a large role in this.
5. What is the pharynx?
The pharynx is the common pathway for both air and food that is found after the oral and
nasal cavities join.
6. What is the function of the epiglottis?
The epiglottis prevents food from entering the windpipe (trachea).
7. What is the significance of the larynx?
The larynx is the voice box. It is made of several pieces of cartilage of which the largest
is the Adam’s apple. It contains two elastic folds of tissue called the vocal cords.
8. What happens to dirt and debris in the trachea?
Dirt and debris in the trachea is trapped by mucus. This mucus is swept along by cilia
toward the upper part of the trachea until it reaches the pharynx where it is swallowed.
9. What occurs at the alveoli?
Gas exchange occurs at the alveoli. Oxygen diffuses through the cell membrane into the
blood in the capillaries and carbon dioxide diffuses from the capillaries into the air in the
lungs.
9.2 The Physiology of Respiration
1. Describe the process of breathing:
Breathing consists of inhalation (air moves into the lungs) and exhalation (air moves out
of the lungs).
Inhalation occurs when the diaphragm contracts. This increases the volume of the lung
cavity and the lungs. The increase in volume decreases the air pressure within the lungs
which creates a pressure gradient (the pressure inside the lungs becomes lower than air
pressure) and air is drawn into the lungs.
Exhalation occurs when the diaphragm relaxes. This decreases the volume of the lung
cavity and the lungs. The decrease in volume increases air pressure within the lungs
which creates a pressure gradient (the pressure inside the lungs becomes greater than air
pressure) and air exits the lungs.
2. What part of the brain controls breathing?
Breathing is controlled by the medulla oblongata.
3. What chemical in the blood determines the rate of breathing?
The rate of breathing is determined by the concentration of CO2. Dissolved CO2 forms
carbonic acid.
CO2 + H2O  H2CO3
The pH of blood can be detected by chemoreceptors in the medulla oblongata to which
alters breathing rate.
4. Describe the different lung volumes.
Tidal volume: amount of air entering and leaving lungs in a normal breath
Inspiratory reserve: the amount of air that can be inhaled with effort
Expiratory reserve: the amount of air that can be exhaled with effort
Vital capacity: the maximum amount of air that can be moved into and out of the lungs
Residual volume: the amount of air that always remains in the lungs
Total lung volume: the maximum amount of air that can be held in the lungs
5. What is special about breathing in outer space?
In outer space, carbon dioxide must be ‘scrubbed’ out of the air because it will become
fatal if allowed to build up.
9.3 Respiratory Disorders
1. What is asthma?
2. What is cause of asthma?
3. What is the function of bronchodilators?
4. What is bronchitis?
5. What are the causes of bronchitis?
6. What is the function of bronchodilators?
7. What is emphysema?
8. How does the body compensate for the reduced surface area?
9. What is cystic fibrosis?
10. What causes cystic fibrosis?
11. How is cystic fibrosis treated?
12. What do nasal sprays do?
13. What situations can cause asthma attacks?
14. How can you maintain a healthy respiratory system?
15. What is the effect of asbestos on the lungs?
16. What things contain asbestos?
17. What does ‘fibrotic’ mean?
18. What are the effects of smoking?
19. What can you do to improve air quality?
9.4 Respiration
Complete the chart:
Organism
Earthworm
Insect
Fish
Frog
Bird
Plants
Mechanism for gas exchange