A&P 2 — Exam 2 Study Guide (Complete)
Respiratory System | Digestive System
Lecture slides + OpenStax Ch. 22-23 + all study guide topics covered
PART 1: RESPIRATORY SYSTEM - ANATOMY
1. Functional Zones
• Conducting zone: nasal cavity to pharynx to larynx to trachea to bronchi to bronchioles. No gas exchange;
filters, warms, humidifies air.
• Respiratory zone: respiratory bronchioles to alveolar ducts to alveolar sacs to alveoli. Gas exchange occurs
HERE.
• TRAP: Terminal bronchioles = still conducting zone. Respiratory bronchioles = START of respiratory zone.
2. Upper Respiratory Tract
Nasal Cavity
• Lined with pseudostratified ciliated columnar epithelium (respiratory epithelium)
• Goblet cells produce mucus to trap debris and pathogens
• Conchae (turbinates): increase surface area; warm and humidify incoming air
• Cilia beat toward throat (mucociliary escalator) to sweep debris away
Pharynx - 3 Regions
Region Location Key Facts
Nasopharynx Posterior to nasal apertures, AIR ONLY; pharyngeal tonsil; auditory (Eustachian)
above soft palate tubes; 90 degree turn traps large particles (>10
micrometers)
Oropharynx Soft palate to epiglottis Air AND food; palatine tonsils; connects via fauces
to oral cavity
Laryngopharynx Epiglottis to cricoid cartilage Air AND food; esophagus begins here; larynx
anteriorly
• TRAP: Nasopharynx = air ONLY. Oropharynx and laryngopharynx = air and food.
Larynx
• Epiglottis: elastic cartilage; covers larynx (glottis) during swallowing; prevents aspiration into trachea
• Thyroid cartilage: largest laryngeal cartilage; forms Adam's apple
• Cricoid cartilage: ONLY complete ring of cartilage in entire respiratory tract
• True vocal cords (vocal folds): produce sound as air passes; made of elastic tissue
• TRAP: If the epiglottis is damaged, food and liquid can enter the trachea instead of the esophagus, causing
aspiration and possible pneumonia.
Trachea
• 16-20 C-shaped hyaline cartilage rings keep lumen open
, • Trachealis muscle fills posterior gap; allows esophagus to expand during swallowing
• Lined with respiratory epithelium (pseudostratified ciliated columnar + goblet cells)
• The trachea has: C-shaped cartilage, smooth muscle fibers (trachealis), AND cilia - all three
3. Bronchial Tree Hierarchy
Level Cartilage? Key Fact
Primary (main) bronchi Yes - C-shaped Right: wider, shorter, more vertical - inhaled objects lodge
rings here more often
Secondary (lobar) bronchi Yes - crescent 3 right (3 lobes), 2 left (2 lobes)
plates
Tertiary (segmental) bronchi Yes - crescent Each serves one bronchopulmonary segment; 10 right, 8
plates left
Bronchioles NO - smooth muscle Less than 1mm; pulmonary lobule = tissue ventilated by
only one bronchiole
Terminal bronchioles NO Last of conducting zone; no goblet cells; less than 0.5mm
Respiratory bronchioles NO FIRST of respiratory zone; alveoli bud from their walls;
lead to alveolar ducts
• TRAP: Bronchi = have cartilage. Bronchioles = NO cartilage, smooth muscle only. Classic test question.
• TRAP: Alveoli are NOT part of the bronchial tree. The bronchial tree ends at respiratory bronchioles/alveolar
ducts.
4. Alveoli
• Type I alveolar cells (squamous pneumocytes): cover 95% of surface; primary gas exchange cells;
extremely thin
• Type II alveolar cells (great alveolar cells): cover 5%; cuboidal; secrete surfactant; repair damaged
alveolar epithelium
• Surfactant: phospholipids and proteins; reduces surface tension; prevents alveolar collapse on exhalation.
Absent in premature infants - causes respiratory distress syndrome
• Alveolar macrophages (dust cells): phagocytize debris and pathogens - they REMOVE pathogens, not
secrete surfactant
• TRAP: Type I = gas exchange only. Type II = surfactant secretion AND repair. Don't mix them up.
• TRAP: Alveolar macrophages REMOVE pathogens/debris. Type II cells SECRETE surfactant. These are
two different cell types.
Respiratory Membrane
• Air-blood barrier: alveolar epithelium (Type I) + fused basement membranes + capillary endothelium
• Approximately 0.5 micrometers thick; total surface area approximately 70 square meters
• Thinness allows rapid simple diffusion of O2 and CO2
5. Lungs
• Right lung: 3 lobes (superior, middle, inferior); shorter and wider; separated by oblique and horizontal
fissures
• Left lung: 2 lobes (superior, inferior); cardiac notch to accommodate heart; separated by oblique fissure only
• Visceral pleura covers lung; parietal pleura lines chest wall; intrapleural fluid between them for lubrication
AND adhesion
, • Intrapleural pressure: always NEGATIVE (sub-atmospheric) - keeps lungs expanded against chest wall
• Pulmonary artery: brings deoxygenated blood FROM heart TO lung capillaries
• Pulmonary veins: return oxygenated blood FROM lungs TO heart
• TRAP: Left = 2 lobes. Right = 3 lobes. This is intentionally flipped on many exams.
• TRAP: Pulmonary circulation is the OPPOSITE of systemic - pulmonary ARTERY carries deoxygenated
blood.
Respiratory System | Digestive System
Lecture slides + OpenStax Ch. 22-23 + all study guide topics covered
PART 1: RESPIRATORY SYSTEM - ANATOMY
1. Functional Zones
• Conducting zone: nasal cavity to pharynx to larynx to trachea to bronchi to bronchioles. No gas exchange;
filters, warms, humidifies air.
• Respiratory zone: respiratory bronchioles to alveolar ducts to alveolar sacs to alveoli. Gas exchange occurs
HERE.
• TRAP: Terminal bronchioles = still conducting zone. Respiratory bronchioles = START of respiratory zone.
2. Upper Respiratory Tract
Nasal Cavity
• Lined with pseudostratified ciliated columnar epithelium (respiratory epithelium)
• Goblet cells produce mucus to trap debris and pathogens
• Conchae (turbinates): increase surface area; warm and humidify incoming air
• Cilia beat toward throat (mucociliary escalator) to sweep debris away
Pharynx - 3 Regions
Region Location Key Facts
Nasopharynx Posterior to nasal apertures, AIR ONLY; pharyngeal tonsil; auditory (Eustachian)
above soft palate tubes; 90 degree turn traps large particles (>10
micrometers)
Oropharynx Soft palate to epiglottis Air AND food; palatine tonsils; connects via fauces
to oral cavity
Laryngopharynx Epiglottis to cricoid cartilage Air AND food; esophagus begins here; larynx
anteriorly
• TRAP: Nasopharynx = air ONLY. Oropharynx and laryngopharynx = air and food.
Larynx
• Epiglottis: elastic cartilage; covers larynx (glottis) during swallowing; prevents aspiration into trachea
• Thyroid cartilage: largest laryngeal cartilage; forms Adam's apple
• Cricoid cartilage: ONLY complete ring of cartilage in entire respiratory tract
• True vocal cords (vocal folds): produce sound as air passes; made of elastic tissue
• TRAP: If the epiglottis is damaged, food and liquid can enter the trachea instead of the esophagus, causing
aspiration and possible pneumonia.
Trachea
• 16-20 C-shaped hyaline cartilage rings keep lumen open
, • Trachealis muscle fills posterior gap; allows esophagus to expand during swallowing
• Lined with respiratory epithelium (pseudostratified ciliated columnar + goblet cells)
• The trachea has: C-shaped cartilage, smooth muscle fibers (trachealis), AND cilia - all three
3. Bronchial Tree Hierarchy
Level Cartilage? Key Fact
Primary (main) bronchi Yes - C-shaped Right: wider, shorter, more vertical - inhaled objects lodge
rings here more often
Secondary (lobar) bronchi Yes - crescent 3 right (3 lobes), 2 left (2 lobes)
plates
Tertiary (segmental) bronchi Yes - crescent Each serves one bronchopulmonary segment; 10 right, 8
plates left
Bronchioles NO - smooth muscle Less than 1mm; pulmonary lobule = tissue ventilated by
only one bronchiole
Terminal bronchioles NO Last of conducting zone; no goblet cells; less than 0.5mm
Respiratory bronchioles NO FIRST of respiratory zone; alveoli bud from their walls;
lead to alveolar ducts
• TRAP: Bronchi = have cartilage. Bronchioles = NO cartilage, smooth muscle only. Classic test question.
• TRAP: Alveoli are NOT part of the bronchial tree. The bronchial tree ends at respiratory bronchioles/alveolar
ducts.
4. Alveoli
• Type I alveolar cells (squamous pneumocytes): cover 95% of surface; primary gas exchange cells;
extremely thin
• Type II alveolar cells (great alveolar cells): cover 5%; cuboidal; secrete surfactant; repair damaged
alveolar epithelium
• Surfactant: phospholipids and proteins; reduces surface tension; prevents alveolar collapse on exhalation.
Absent in premature infants - causes respiratory distress syndrome
• Alveolar macrophages (dust cells): phagocytize debris and pathogens - they REMOVE pathogens, not
secrete surfactant
• TRAP: Type I = gas exchange only. Type II = surfactant secretion AND repair. Don't mix them up.
• TRAP: Alveolar macrophages REMOVE pathogens/debris. Type II cells SECRETE surfactant. These are
two different cell types.
Respiratory Membrane
• Air-blood barrier: alveolar epithelium (Type I) + fused basement membranes + capillary endothelium
• Approximately 0.5 micrometers thick; total surface area approximately 70 square meters
• Thinness allows rapid simple diffusion of O2 and CO2
5. Lungs
• Right lung: 3 lobes (superior, middle, inferior); shorter and wider; separated by oblique and horizontal
fissures
• Left lung: 2 lobes (superior, inferior); cardiac notch to accommodate heart; separated by oblique fissure only
• Visceral pleura covers lung; parietal pleura lines chest wall; intrapleural fluid between them for lubrication
AND adhesion
, • Intrapleural pressure: always NEGATIVE (sub-atmospheric) - keeps lungs expanded against chest wall
• Pulmonary artery: brings deoxygenated blood FROM heart TO lung capillaries
• Pulmonary veins: return oxygenated blood FROM lungs TO heart
• TRAP: Left = 2 lobes. Right = 3 lobes. This is intentionally flipped on many exams.
• TRAP: Pulmonary circulation is the OPPOSITE of systemic - pulmonary ARTERY carries deoxygenated
blood.
