Podcast
Questions and Answers
What is the average number of breaths per minute for a healthy adult?
What is the average number of breaths per minute for a healthy adult?
The medulla oblongata is responsible for voluntary control of breathing.
The medulla oblongata is responsible for voluntary control of breathing.
False
What is the primary mechanism that determines breathing rate?
What is the primary mechanism that determines breathing rate?
Level of CO2 in the blood
Breathing rate increases due to a high level of __________ in poorly ventilated rooms.
Breathing rate increases due to a high level of __________ in poorly ventilated rooms.
Signup and view all the answers
Match the following factors with their effect on breathing rate:
Match the following factors with their effect on breathing rate:
Signup and view all the answers
Which of the following factors is a secondary mechanism for determining breathing rate?
Which of the following factors is a secondary mechanism for determining breathing rate?
Signup and view all the answers
The breathing rate can be decreased by high altitude.
The breathing rate can be decreased by high altitude.
Signup and view all the answers
What role do stretch receptors in intercostal muscles play in breathing?
What role do stretch receptors in intercostal muscles play in breathing?
Signup and view all the answers
Study Notes
Control of Breathing
- Breathing is involuntary, controlled by the medulla oblongata in the brainstem.
- Breathing rate (how quickly/slowly you inhale/exhale) averages 12-20 breaths per minute for a healthy adult.
- Breathing rate must adjust to respond to changing oxygen demands.
Role of the Brain
- The brain stem sends nerve impulses via the spinal column to the muscles of the diaphragm and rib cage.
- This causes the diaphragm and external intercostal muscles to contract during inhalation.
- Stretch receptors in the intercostal muscles send signals back to the brain, indicating inhalation has occurred.
- The brain stops signaling inhalation, signalling relaxation and causing exhalation.
Factors Affecting Breathing Rate
- Strenuous activity: Increases breathing rate due to the body's need for more oxygen.
- Poor ventilation: Leads to increased carbon dioxide (CO2) levels, increasing breathing rate.
- Sickness (like colds and emphysema): Reduced respiratory efficiency leads to an increase in breathing rate.
- High altitude: Lower oxygen levels and reduced air pressure cause an increase in breathing rate.
What Determines Breathing Rate
-
Level of CO2 in the blood:
- Primary mechanism
- Chemical receptors in the brain, carotid artery, and aorta are sensitive to CO2 and pH.
- A decrease in pH (caused by increased CO2) triggers an increase in breathing rate and volume.
-
Level of O2 in the blood:
- Secondary mechanism
- Receptors in arteries monitor blood O2 levels as they leave the heart.
- Will only trigger an increase in breathing rate when oxygen levels fall significantly below normal. CO2 levels are important first.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the mechanisms behind the control of breathing, including the roles of the brain and factors that influence the breathing rate. Understand how the medulla oblongata regulates involuntary breathing and how various conditions can affect respiratory functions.
