1What are the major functions of the respiratory system?
Supply O₂ for cellular respiration, remove CO₂, assist in speech and olfaction
2What is pulmonary ventilation?
Movement of air into and out of the lungs
3What is external respiration?
Gas exchange between lungs and blood
4What is internal respiration?
Gas exchange between blood and body tissues
5What is the respiratory zone?
Region where gas exchange occurs (respiratory bronchioles, alveolar ducts, alveoli)
6What is the conducting zone?
Air passages that move, warm, humidify, and clean air
7What are type I alveolar cells?
Simple squamous cells forming most of alveolar wall for gas exchange
8What are type II alveolar cells?
Cuboidal cells that secrete surfactant
9What is surfactant?
Substance that reduces surface tension and prevents alveolar collapse
10Why is surfactant important?
Keeps alveoli open and improves lung compliance
11What are alveolar macrophages?
Cells that engulf dust and debris
12What are alveolar pores?
Openings connecting neighboring alveoli
13What is perfusion?
Blood flow to alveoli
14What is ventilation?
Airflow to alveoli
15What is ventilation-perfusion coupling?
Matching of airflow and blood flow for efficient gas exchange
16What is atmospheric pressure (Patm)?
Pressure of air outside body (~760 mmHg at sea level)
17What is intrapulmonary pressure (Ppul)?
Pressure inside alveoli
18What is intrapleural pressure (Pip)?
Pressure in pleural cavity (always negative)
19What is transpulmonary pressure?
Difference between Ppul and Pip that keeps lungs open
20What is atelectasis?
Collapse of alveoli
21What is pneumothorax?
Total lung collapse due to air in pleural cavity
22What happens during inspiration?
Diaphragm contracts, external intercostals lift ribs, thoracic volume increases, pressure drops
23What happens during expiration?
Muscles relax, thoracic volume decreases, pressure increases
24What muscles are used in forced expiration?
Abdominal muscles and internal intercostals
25What is tidal volume (TV)?
Air inhaled or exhaled in one normal breath (~500 mL)
26What is inspiratory reserve volume (IRV)?
Extra air inhaled after a normal breath
27What is expiratory reserve volume (ERV)?
Extra air exhaled after normal expiration
28What is residual volume (RV)?
Air that always remains in lungs
29What is inspiratory capacity (IC)?
TV + IRV
30What is functional residual capacity (FRC)?
ERV + RV
31What is vital capacity (VC)?
TV + IRV + ERV
32What is total lung capacity (TLC)?
TV + IRV + ERV + RV
33What is anatomical dead space?
Air in passageways that does not participate in gas exchange
34What is partial pressure?
Pressure contributed by a single gas in a mixture
35Why do gases diffuse in lungs?
Due to partial pressure gradients
36What is venous blood PO₂ entering lungs?
40 mmHg
37What is alveolar PO₂?
104 mmHg
38How is CO₂ transported in blood?
Dissolved in plasma, bound to hemoglobin, as bicarbonate ions
39What percent of CO₂ is transported as bicarbonate?
~70%
40How is oxygen transported in blood?
1.5% dissolved, 98.5% bound to hemoglobin
41What is the Bohr effect?
High CO₂, low pH, or high temperature decreases hemoglobin’s affinity for O₂
42Why is carbon monoxide dangerous?
It binds hemoglobin 200× more strongly than oxygen and blocks oxygen transport
43What is hypoxia?
Inadequate oxygen delivery to tissues
44What is anemic hypoxia?
Low RBC or hemoglobin
45What is ischemic hypoxia?
Poor blood flow
46What is hypoxemic hypoxia?
Low blood oxygen levels
47What is histotoxic hypoxia?
Cells cannot use oxygen
48What structures filter air in the nose?
Vibrissae, mucus, cilia
49What do nasal conchae do?
Increase surface area and turbulence to warm, filter, and moisten air
50What is respiratory mucosa?
Ciliated epithelium with goblet cells that produce mucus
51What is the function of the pharynx?
Air and food passageway
52What are the three parts of the pharynx?
Nasopharynx, oropharynx, laryngopharynx
53Where are the tonsils located?
Pharyngeal (nasopharynx), palatine (oropharynx), lingual (tongue)
54What is the larynx?
Voice box that maintains open airway and produces sound
55What are vocal folds?
Ligaments that vibrate to produce sound
56What determines pitch?
Length and tension of vocal folds
57What determines loudness?
Force of air
58What is the epiglottis?
Elastic cartilage that prevents food from entering airway
59What are bronchioles?
Small branches of bronchi less than 1 mm wide
60What are terminal bronchioles?
Last part of conducting zone
61What is the bronchial tree?
Branching system of bronchi and bronchioles
62What are primary bronchi?
Right and left main bronchi
63What are secondary bronchi?
Lobar bronchi
64What are tertiary bronchi?
Segmental bronchi
65How many lobes does the right lung have?
Three
66How many lobes does the left lung have?
Two
67What is the cardiac notch?
Indentation for heart in left lung
68What are pleurae?
Double-layered membranes around lungs
69What is pleural fluid?
Lubricating fluid that reduces friction and helps lungs expand
70What is pleurisy?
Inflammation of pleura
71What is pleural effusion?
Fluid buildup in pleural cavity
72What causes lung collapse?
Loss of negative intrapleural pressure
73What is pneumonia?
Infection causing fluid-filled alveoli
74What is emphysema?
Destruction of alveolar walls reducing surface area
75What is asthma?
Inflammation and narrowing of airways
76What is lung cancer?
Uncontrolled growth of lung cells
77What structures clean air in the trachea?
Cilia and mucus
78What happens to cilia in smokers?
They are damaged or destroyed
79What is the developmental order of the respiratory system?
Upper structures first, lungs later
80When can a premature baby breathe independently?
Around week 28
81What is the function of alveoli?
Gas exchange
82What is the function of bronchioles?
Control airflow to alveoli
83What is the function of the pharynx?
Direct air and food
84What is the function of the nose?
Filter, warm, moisten air