16 Questions
What is the main function of the diaphragm in the human body?
To facilitate inhalation
Which of the following statements is true about ventilation?
It occurs by negative pressure breathing
What happens to the rib cage during inhalation?
It expands, increasing chest cavity volume
What is the role of the medulla oblongata in breathing?
It controls the rate and depth of breathing
What happens to the pH of the cerebrospinal fluid when CO2 rises?
It decreases
What is the function of hemoglobin in the blood?
To carry oxygen and carbon dioxide, and buffer blood
How many molecules of oxygen can each hemoglobin molecule carry?
4
What is the role of hemoglobin in buffering blood?
It helps to maintain a constant pH
What is the primary function of the respiratory system?
To provide oxygen for cellular respiration
What is the term for the process of gas exchange between the body and the environment?
Respiration
Which part of the respiratory system contains the vocal cords?
Larynx
What is the purpose of the rings of cartilage in the trachea?
To keep the passageway always open
Where does gas exchange occur in the respiratory system?
In the alveoli
What is the term for the tiny grape-like clusters of air sacs where gas exchange occurs?
Alveoli
What is the purpose of the nasal cavity in the respiratory system?
To filter, warm, and humidify the air
What is the term for the movement of oxygen from the lungs to the body's tissues?
Transport
Study Notes
Gas Exchange in Humans
- Gas exchange involves breathing, transport of gases, and exchange with body cells to provide oxygen for cellular respiration and remove waste CO2.
- The process involves inhalation, transport, and exchange of gases between the environment and body cells.
Pathway of Air
- Air enters the respiratory system through the nostrils, where it is filtered, warmed, and humidified in the nasal cavity.
- Air then passes through the pharynx, a common passageway for air and food, and into the larynx, which contains vocal cords.
- The trachea, a tube with cartilage rings, leads to the bronchi, which branch into smaller bronchioles that eventually dead-end into alveoli, tiny grape-like clusters of air sacs.
Gas Exchange in Alveoli
- Alveoli are surrounded by blood capillaries, where gas exchange occurs through diffusion.
- Oxygen diffuses into the blood and carbon dioxide diffuses out of the blood into the alveoli.
Ventilation by Negative Pressure Breathing
- Ventilation occurs through negative pressure breathing, which creates a pressure gradient by changing the volume of the lungs.
- During inhalation, the diaphragm contracts, the rib cage expands, and air moves in due to the decrease in air pressure inside the lungs.
- During exhalation, the diaphragm relaxes, the rib cage gets smaller, and air pressure increases, pushing air out of the lungs.
Control of Breathing
- Breathing is controlled by involuntary mechanisms, with the medulla oblongata in the brain regulating breathing rhythm.
- Sensors in the medulla monitor the pH of cerebrospinal fluid, responding to changes in CO2 levels.
- When CO2 levels rise, the medulla increases breathing rate and depth to eliminate excess CO2 and maintain homeostasis.
Hemoglobin and Gas Transport
- Hemoglobin, an iron-containing pigment in red blood cells, carries oxygen and helps transport carbon dioxide.
- Each hemoglobin molecule can bind to four oxygen molecules, which bind to the four iron atoms.
- Hemoglobin also helps buffer the blood by binding to excess hydrogen ions.
Learn about the respiratory system, gas exchange in humans, breathing, and transport of gases and exchange with body cells.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
