Week 5 Respiratory System Flashcards
What are the major components of the human respiratory system?
Nasal cavity, pharynx, larynx, trachea, bronchi, lungs, and diaphragm.
What is the function of the nasal cavity?
Filters, warms, and humidifies incoming air.
What structure prevents food from entering the trachea?
The epiglottis.
What is the function of the alveoli?
Site of gas exchange between air and blood.
What is the bronchial tree?
A branching system of airways from the trachea to the alveoli.
What is Boyle’s Law and how does it relate to breathing?
Boyle’s Law states that pressure and volume are inversely related. When lung volume increases, pressure decreases, causing air to enter the lungs.
What happens during inspiration?
The diaphragm contracts and external intercostal muscles lift the ribs, increasing thoracic volume and decreasing pressure, causing air to flow in.
What happens during expiration?
Diaphragm and intercostal muscles relax, decreasing thoracic volume and increasing pressure, forcing air out.
What role do the pleural membranes play in breathing?
They reduce friction and help the lungs expand and contract with the chest wall.
How does gas exchange occur in the lungs?
Oxygen diffuses from alveoli into blood, and carbon dioxide diffuses from blood into alveoli.
What percentage of oxygen is transported by hemoglobin?
98.5% of oxygen is carried by hemoglobin in red blood cells.
How is most carbon dioxide transported in the blood?
As bicarbonate ions (HCO3-) after reacting with water and carbonic anhydrase.
What is the Bohr effect?
A decrease in pH or increase in CO2 reduces hemoglobin’s affinity for oxygen, facilitating oxygen release in tissues.
What is tidal volume?
The volume of air inhaled or exhaled during normal breathing (500 mL).
What is vital capacity?
The maximum amount of air a person can exhale after a maximum inhalation (about 4500 mL).
What is residual volume?
Air remaining in the lungs after maximal exhalation (about 1500 mL).
What is dead space volume?
Air that remains in the trachea and bronchi and does not participate in gas exchange.
What part of the brain controls breathing?
The medulla oblongata and pons.
What is the function of the dorsal respiratory group (DRG)?
Acts as the respiratory pacemaker, stimulating inspiration.
What is the role of the ventral respiratory group (VRG)?
Controls forced breathing by stimulating accessory muscles.
What do peripheral chemoreceptors monitor?
Levels of O2, CO2, and H+ in blood, influencing breathing rate.
What is hypoxia?
A condition where tissues receive insufficient oxygen.
What are some causes of hypoxia?
High altitude, lung disease, anemia, or circulatory obstruction.
What is hyperventilation?
An increased breathing rate leading to decreased CO2 levels in the blood.
