unit 7 Flashcards
What is the function of the respiratory bronchiole?
Gas-exchange airway
Respiratory bronchioles are the last generation of bronchioles before the alveoli where gas exchange occurs.
What are the conducting airways?
Nasopharynx, trachea, larynx
These airways move air to and from the gas exchange zone.
What type of cell is responsible for surfactant production in the lungs?
Type II alveolar cell
Surfactant reduces alveoli surface tension, aiding in lung function.
What is the primary function of surfactant?
Reduces alveoli surface tension
This is crucial for preventing alveolar collapse.
What is the role of the Type I alveolar cell?
Provides structural support
Type I alveolar cells make up the majority of the alveolar surface.
What do macrophages do in the respiratory system?
Offer immune protection
They help clear pathogens and debris from the lungs.
What type of epithelial cell lines the larger airways?
Ciliated columnar epithelial cell
These cells help move mucus out of the airways.
What do airway glands produce?
Bronchial mucus
This mucus helps trap particles and pathogens.
What is a key function of pulmonary circulation?
Acts as a reservoir for the left ventricle
Pulmonary vessels store blood and assist with venous return.
What causes pulmonary artery vasoconstriction?
Low alveolar PO2
This mechanism diverts blood from poorly ventilated areas.
What happens to pulmonary arteries when alveolar PO2 is high?
Produces pulmonary artery dilation
This improves blood flow to well-ventilated areas.
What is the primary driver of inspiration?
Diaphragm
The diaphragm contracts and moves downward to increase thoracic volume.
Which muscles are involved in forced expiration?
Internal intercostals and rectus abdominis
These muscles help expel air from the lungs.
What accessory muscles are used in inspiration?
Sternocleidomastoid and scalene
These muscles assist in expanding the thoracic cavity.
What is the normal ventilation perfusion (V/Q) ratio in a healthy lung?
Around or >0.8
A ratio of 1.0 indicates perfectly matched ventilation and perfusion.
What does a V/Q ratio of 0.8 indicate?
80% of air breathed in is used in perfusion
This suggests some mismatch between ventilation and perfusion.
What is orthopnea?
Difficulty breathing while lying flat
Commonly seen in various respiratory conditions.
What is obstructive atelectasis?
Collapse of lung tissue caused by airway obstruction
This condition can lead to reduced lung capacity.
What causes compression atelectasis?
Results from external pressure
This can occur due to pleural effusion or tumor.
What is bronchiectasis?
Chronic airway dilation
This condition often results from long-term infection or inflammation.
What is the strongest modifiable risk factor for COPD?
Smoking
Quitting smoking can significantly reduce risk.
What primarily causes asthma airflow obstruction?
Bronchial hyperresponsiveness causing reversible bronchoconstriction
Inflammation leading to bronchial spasm is a key feature.
What is emphysema characterized by?
Irreversible destruction of alveolar walls
This leads to reduced surface area for gas exchange.
What is acute respiratory distress syndrome (ARDS)?
Loss of surfactant
This condition results in severe respiratory failure.
When does the exudative phase of ARDS typically begin?
Within 72 hours
Characterized by inflammation and fluid accumulation.
What are Cheyne-Stokes respirations?
Alternating deep and shallow respirations followed by apnea
Commonly seen in neurological disorders and heart failure.
What characterizes Kussmaul respirations?
Consistent rapid, deep breaths
Often seen in metabolic acidosis.
What are Biot respirations?
Irregular breathing with apnea
Caused by brainstem damage and increased intracranial pressure.
What is agonal breathing?
Sporadic shallow and labored breaths that resemble gasps
Typically occurs in cardiac arrest situations.
What viral group is characterized by a harsh, seal-like barking cough?
A result of inflammation of the subglottic area
This symptom is often associated with croup.
What is pertussis also known as?
Paroxysmal whoop
This is a hallmark symptom of whooping cough.
What are the main characteristics of cystic fibrosis?
Mucus plugging, hyperplasia of goblet cells, chronic airway infection
This genetic disorder significantly affects respiratory function.
What muscles are considered accessory muscles for expiration?
Abdominal muscles, internal intercostals
They assist in forcefully expelling air from the lungs.
What are the major muscles of inspiration?
Diaphragm, external intercostals
These muscles are essential for normal breathing.
What is the cause of low CO2 levels?
hyperventilation
Hyperventilation leads to excessive breathing, reducing CO2 levels in the blood.
What does vital capacity refer to?
amount person can exhale
Vital capacity is a measure of the maximum volume of air that can be exhaled after a maximum inhalation.
What is forced vital capacity?
maximum amount someone can exhale
Forced vital capacity measures the total volume of air that can be forcibly exhaled after taking the deepest breath possible.
Define tidal volume.
normal breath in and out
Tidal volume is the amount of air inhaled or exhaled in a normal breath.
What is residual volume?
amount of air remaining in lungs after maximal expiration; amount of air that cannot be exhaled
Residual volume prevents the lungs from collapsing completely.
What does total lung capacity represent?
maximum amount of air lungs can hold after full, deep inhalation; includes residual volume
Total lung capacity is the sum of all lung volumes, indicating the full capacity of the lungs.
What causes coughing from exposure to irritants?
irritants in trachea and airways
Coughing is a reflex to clear the airways of irritants.
What is it called when there is adequate ventilation but poor alveolar perfusion?
dead space ventilation; i.e. pulmonary embolism
Dead space ventilation occurs when air reaches the alveoli but is not involved in gas exchange due to poor blood flow.
What are the functions of upper respiratory mucosa?
warm, filter, humidify, immune defense, sensory functions
The upper respiratory mucosa plays a crucial role in preparing the air for the lungs and protecting against pathogens.
