Questions and Answers
What is one of the defense mechanisms of the lungs?
During which process is water evaporated and lost from the body?
What is the role of the lungs in maintaining acid-base balance?
What is the function of endothelial cells in the pulmonary capillaries?
Signup and view all the answers
What is the primary function of external respiration?
Signup and view all the answers
What is the process by which the body loses heat?
Signup and view all the answers
What is the term for the exchange of gases between the atmosphere, lungs, blood, and tissues?
Signup and view all the answers
What is the stage of respiration during which air enters the lungs?
Signup and view all the answers
What is the name of the enlarged structure that each alveolar duct enters?
Signup and view all the answers
Which of the following is NOT part of the respiratory unit?
Signup and view all the answers
What process occurs when the diaphragm contracts during inhalation?
Signup and view all the answers
During passive exhalation, what happens to the external intercostal muscles?
Signup and view all the answers
Which of the following statements about inhalation is true?
Signup and view all the answers
What is the role of the ribs in breathing?
Signup and view all the answers
What is the primary function of the respiratory system?
Signup and view all the answers
Which of the following is NOT part of the upper respiratory tract?
Signup and view all the answers
What is the role of olfactory receptors in the respiratory system?
Signup and view all the answers
What structures make up the conducting portion of the respiratory system?
Signup and view all the answers
How does the respiratory system prevent dust particles from reaching the lungs?
Signup and view all the answers
Which function of the respiratory system is associated with vocalization?
Signup and view all the answers
In which part of the respiratory system does gas exchange primarily occur?
Signup and view all the answers
Which component is part of the lower respiratory tract?
Signup and view all the answers
Study Notes
Respiratory System Overview
- The respiratory system provides oxygen (O2) to the body and removes carbon dioxide (CO2), a waste product of cells.
- The system consists of two parts: the upper respiratory tract and the lower respiratory tract.
Respiratory Tract Structure
- The respiratory tract is the anatomical structure through which air moves in and out.
- The organs of the respiratory tract can be divided into two groups: the upper tract (nose, nasal cavity, sinuses, pharynx, and larynx) and the lower tract (trachea, bronchial tree, and lungs).
Conducting and Respiratory Portions
- The conducting portion is a system of interconnecting cavities and tubes that conduct air into the lungs.
- The respiratory portion is where the exchange of respiratory gases occurs.
Non-Respiratory Functions
- The respiratory tract is involved in several non-respiratory functions, including:
- Olfaction (olfactory receptors in the mucous membrane of nostrils)
- Vocalization (larynx forms the speech apparatus)
- Prevention of dust particles (filtration action of hairs in nasal mucous membrane)
- Defense mechanism (defenses and various cell types in the mucous membrane lining alveoli)
- Maintenance of water balance (water loss through expiration)
- Regulation of body temperature (heat loss during expiration)
- Regulation of acid-base balance (lungs regulate carbon dioxide content in blood)
- Anticoagulant function (mast cells in lungs secrete heparin)
- Secretion of angiotensin converting enzyme (endothelial cells of pulmonary capillaries)
- Synthesis of hormonal substances (lung tissues synthesize hormonal substances)
Respiration
- Respiration is the movement of oxygen (O2) from the environment to cells within tissues and the transport of carbon dioxide (CO2) in the opposite direction.
- It involves the exchange of gases between the atmosphere, lungs, blood, and tissues.
- Respiration is classified into two types: external respiration (exchange of gases between lungs and blood) and internal respiration (exchange of gases between blood and tissues).
Stages of Respiration
- Pulmonary ventilation: inhalation and exhalation of air, involving the exchange of air between the atmosphere and lungs alveoli.
- External respiration: exchange of gases between lung alveoli and blood in pulmonary capillaries.
- Transport of respiratory gases: O2 and CO2 transported to and from the lungs and tissue cells via the bloodstream.
- Internal respiration: exchange of gases between blood and tissue cells.
Lung Structure and Function
- Lungs are paired, soft, spongy, and cone-shaped organs separated medially and enclosed by the diaphragm and thoracic cage.
- Each lung is enclosed by a bilayered serous membrane called pleura or pleural sac.
- The respiratory unit includes respiratory bronchioles, alveolar ducts, alveolar sacs, antrum, and alveoli, where the exchange of gases occurs.
Lung Expansion and Contraction
- Lungs can be expanded and contracted in two ways:
- Downward and upward movement of the diaphragm to lengthen or shorten the chest cavity.
- Elevation and depression of ribs to increase and decrease the anteroposterior diameter of the chest cavity.
Inhalation and Exhalation
- Inhalation (active process) involves:
- External intercostal muscle contraction and internal intercostal muscle relaxation, expanding the rib cage.
- Rib cage moving upward and forward.
- Diaphragm contraction and flattening, increasing thoracic volume vertically.
- Decreased intrapulmonary pressure, allowing air to push in.
- Exhalation (passive process) involves:
- External intercostal muscle relaxation and internal intercostal muscle contraction, reducing the rib cage.
- Rib cage moving downward and backward.
- Diaphragm relaxation, decreasing thoracic volume vertically.
- Increased intrapulmonary pressure, allowing air to move out.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about the structure and function of the human respiratory system, including the upper and lower respiratory tracts.
