Respiration Flashcards
What is the primary function the respiratory system?
The primary function is gas exchange in the respiratory system occuring in the lungs, where oxygen (O2) is taken in during inspiration, and carbon dioxide (CO2) produced during oxidative processes is exhaled.
How are oxygen (O2) and carbon dioxide (CO2) transported in the body during respiration?
transported by the blood.
What is the path of airflow in the respiratory tract starting from the nose?
Air flows through the nose (nasal septum + turbinates), then through the pharynx, larynx, trachea, bronchi, and eventually to the periphery of the lungs.
How does the respiratory system clean the air of large particles?
Large particles are cleaned from the air as it flows through the nose, which contains the nasal septum and turbinates.
What are the divisions of the trachea, and how do they further branch?
The trachea divides into two main bronchi, which further divide into lobar and segmental bronchi. The right bronchus has three lobar bronchi, while the left bronchus has two.
What is the role of the pleura in the respiratory system? (+name the 2 pleuras and what they do)
The pleura is a thin cellular sheet forming two enclosed pleural sacs around each lung. The parietal pleura is attached to the internal thoracic cage, and the visceral pleura is attached to the lung surface.
Explain the function of conducting and respiratory zones in the respiratory system.
Conducting airways, from the mouth and nose to terminal bronchioles, form the anatomical dead space and do not contribute to gas exchange. The functions of conducting airways include defense against foreign particles, warming and moistening inhaled air, production of sound speech, and regulation of airflow through smooth muscle contraction/relaxation.
The respiratory zone is responsible for gas exchange.
How does mucociliary defense work in the respiratory system?
Mucociliary defense involves epithelial glands secreting thick mucus lining the respiratory passages. Foreign particles stick to the mucus, and cilia sweep them away. Nicotine can momentarily stop ciliary beating, leading to mucus accumulation.
What are the functions of the epithelial lining of bronchi in the respiratory system? (4 functions)
The functions of the epithelial lining of bronchi include
-defense against foreign particles through mucociliary defense
-warming and moistening inhaled air via blood vessels and fluid lining the airway
-production of sound speech as air passes over vocal cords
-and regulation of airflow through smooth muscle contraction/relaxation.
What structures make up the Respiratory Zone in the lungs? (3 things)
The Respiratory Zone consists of respiratory bronchioles, alveolar ducts, and alveoli. It serves as the site of gas exchange and features extensive branching, with the acinus being the smallest physiological unit of the lungs.
What is the role of Pulmonary Circulation in the respiratory system?
Pulmonary Circulation brings mixed deoxygenated blood to the lungs, allowing it to get oxygenated in the alveolar capillaries. Pulmonary arteries carry deoxygenated blood from the right ventricle, and pulmonary veins bring oxygenated blood from alveolar capillaries to the left heart.
Describe Bronchial Circulation and its role in the respiratory system.
Bronchial Circulation brings oxygenated blood from the systemic circulation to the tracheobronchial tree. Bronchial arteries, supplied by the aorta, provide blood to the airway walls.
What are the main types of cells found in the alveoli, and what are their functions?
The main alveolar cell types are Epithelial Type 1 and 2 Cells, Endothelial Cells, and Alveolar Macrophages. Type 2 Cells produce surfactant to decrease surface tension, while macrophages eliminate foreign particles.
Explain the concept of surface tension in the alveoli.
Surface tension in the alveoli arises because molecules at the film’s surface tend to arrange themselves for the lowest energy configuration. This tension, as per LaPlace’s Law, is inversely proportional to the radius, potentially producing pressure in curved surfaces like alveoli.
How do Pulmonary Surfactants prevent alveolar collapse?
Pulmonary surfactants, secreted by Type 2 Epithelial cells, decrease surface tension inside alveoli with lung volume changes. This prevents pressure from getting too high in small alveoli, reducing overall surface tension and allowing for proper breathing.
What are the primary respiratory muscles involved in inspiration?
The primary inspiratory muscles include the diaphragm (innervated by phrenic nerves), external intercostal muscles, and parasternal intercartilaginous muscle. Accessory muscles like SCM and Scalenus can also be involved at higher ventilation levels.
How does expiration occur during quiet breathing?
During quiet breathing, expiration is passive and occurs as a result of the relaxation and recoil of inspiratory muscles.
Describe the role of inspiratory and expiratory muscles during active breathing.
Active breathing involves the diaphragm moving up and forcing air out of the lungs. Internal intercostal muscles depress ribs, and abdominal muscles depress lower ribs and compress abdominal contents.
What does a spirometer measure, and what are the measurable volumes in spirometry? (5 volumes)
A spirometer measures volumes of inhaled or exhaled gas. Measurable volumes include Tidal Volume (VT), Inspiratory Reserve Volume (IRV), Expiratory Reserve Volume (ERV), Inspiratory Capacity (IC), and Vital Capacity (VC).
What volumes are not measurable with a spirometer? (3 volumes)
Residual Volume (RV), Functional Residual Capacity (FRC), and Total Lung Capacity (TLC) cannot be directly measured.
How is Functional Residual Capacity (FRC) measured in spirometry?
FRC can be measured using helium gas dilution techniques. The equation is FRC = (C1 * V1 / C2) – V1, where C1 is the initial helium concentration, V1 is the volume in the spirometer, and C2 is the helium concentration after equilibration.
Define ventilation and explain Minute Ventilation (VE).
entilation is the amount of air inspired into the lungs over time. Minute Ventilation (VE) is the amount of air inspired or expired in one minute, calculated as VE = VT * f, where VT is the tidal volume, and f is the breaths per minute.
What comprises Physiological Dead Space, and how is Alveolar Ventilation (VA) calculated?
Physiological Dead Space includes Anatomical Dead Space (150 mL) and Alveolar Dead Space. Alveolar Ventilation (VA) is calculated as (VT – 150 mL) * f, representing the amount of air reaching the respiratory zone per minute available for gas exchange.
Differentiate between Alveolar Hyperventilation and Alveolar Hypoventilation.
Alveolar Hyperventilation involves more O2 supplied and more CO2 removed than the metabolic rate requires. Alveolar Hypoventilation, on the other hand, indicates less O2 supplied and less CO2 removed than the metabolic rate requires.
How is Normal Alveolar Ventilation related to arterial pressure of CO2 (PaCO2)?
Normal Alveolar Ventilation maintains the arterial pressure of CO2 (PaCO2) at a constant level.
Explain Gas Partial Pressures using examples.
Gas Partial Pressures (Px) can be calculated using the formula
Px = P * Fx
where P is the total pressure, and Fx is the fractional concentration in dry gas.
For example, PO2 = (760mmHg – 47mmHg) * 21/100 = 150mmHg, and PCO2 = (760mmHg – 47mmHg) * 0.03/100 = 0.2mmHg.
How does gas diffusion occur across the alveolar-capillary membrane (passive or active), and what is Fick’s Law?
Gas diffusion across the alveolar-capillary membrane is passive. Fick’s Law states that diffusion rate is proportional to surface area, the gas partial pressure between two sides, and inversely proportional to thickness.
