respiratory

Chapter 23: Respiratory System – Study Guide

1. What are the 5 primary functions of the respiratory system?

1. Provides extensive gas exchange surface area between air and circulating blood

2. Moves air to and from exchange surfaces of the lungs

3. Protects respiratory surfaces from outside environment

4. Produces sounds (voice)

5. Participates in olfactory sense (smell)

2. What structures are included in the upper vs. lower respiratory systems?

• Upper respiratory system: Includes structures above the larynx (nose, nasal cavity, pharynx)

• Lower respiratory system: Includes the larynx, trachea, bronchi, bronchioles, and alveoli

3. What are the lobes of the lungs and their anatomical features?

• Right lung: 3 lobes – superior, middle, inferior; wider and displaced upward by liver

• Left lung: 2 lobes – superior, inferior; longer and displaced leftward by heart, forming the cardiac notch

• Apex of the lungs: Superior, extends above clavicles

• Base of the lungs: Rests on the diaphragm

4. What are alveoli and what is their function?

• Alveoli are air-filled sacs within the lungs where gas exchange occurs

• They provide a surface area 35x greater than the body surface for gas exchange

5. What are the conducting vs. respiratory portions of the respiratory tract?

• Conducting Portion: Nasal cavity → terminal bronchioles (no gas exchange)

• Respiratory Portion: Respiratory bronchioles and alveoli (gas exchange occurs)

6. What are the functions of the nose and nasal cavity?

1. Hair in nasal vestibule traps large particles

2. Serves as an airway when mouth is closed

3. Moistens and warms air to prevent alveolar chilling

4. Keeps surfaces moist and clean

5. Resonating chamber for voice

6. Houses olfactory receptors

7. Exhalation through nose recaptures heat and moisture

7. What is the pharynx and its subdivisions?

• Common passageway for food and air

• Subdivided into:
  

  • Nasopharynx

  • Oropharynx

  • Laryngopharynx

8. What structures protect and maintain respiratory surfaces?

• Cilia: Move mucus and trapped particles up or down the respiratory tract

• Goblet cells & mucous glands: Produce mucus

• Tears: Add moisture to nasal cavity

• Lamina propria: Connective tissue with mucous glands and smooth muscle cells

9. What are alveolar macrophages and what do they do?

• Called dust cells

• Engulf small particles that reach the alveoli for immune protection

10. What are the main cartilages of the larynx?

• Thyroid cartilage (Adam’s apple – hyaline)

• Cricoid cartilage (hyaline)

• Epiglottis (elastic)

11. What is the function of the epiglottis?

• Folds back over the glottis during swallowing to prevent entry of food into the respiratory tract

• Stimulates the cough reflex if food touches the glottis

12. How is sound produced in the larynx?

• Phonation: Sound production at the larynx

• Articulation: Modification of sound by teeth, tongue, lips

13. What are the components of the trachea?

1. Mucosa: Ciliated epithelium + lamina propria

2. Submucosa: Connective tissue with glands

3. Hyaline cartilage: 15–20 C-shaped rings

4. Adventitia: Outer layer

14. What is the bronchial tree and what changes occur in its structure?

• Primary (1°) bronchi → Secondary (2°) → Tertiary (3°)

• Cartilage decreases; smooth muscle increases

• ANS controls constriction/dilation

• Bronchodilation: Sympathetic activation

• Bronchoconstriction: Parasympathetic activation or histamine release

15. What is surfactant and what is its function?

• An oily secretion by type II pneumocytes

• Contains phospholipids and proteins

• Reduces surface tension in alveoli to prevent collapse

16. What are the types of respiration?

• External respiration: Gas exchange between lungs and blood

• Internal respiration: Gas exchange between blood and tissues

• Cellular respiration: ATP production using O2

17. What is Boyle’s Law and how does it relate to breathing?

• Boyle’s Law: Pressure (P) and Volume (V) are inversely related

• When thoracic volume increases → pressure decreases → air flows in

• When volume decreases → pressure increases → air flows out

18. What are the respiratory muscles?

• Primary: Diaphragm (75%), external intercostals (25%)

• Accessory (inhalation): Sternocleidomastoid, scalene, pectoralis minor, serratus anterior

• Accessory (exhalation): Internal intercostals, transversus thoracis, abdominal muscles

19. What affects lung compliance?

• Connective tissue structure

• Surfactant levels

• Mobility of the thoracic cage (arthritis, etc.)

20. How is ventilation measured and calculated?

• Respiratory Minute Volume (Ve) = Respiratory Rate x Tidal Volume

• Alveolar ventilation = (Tidal Volume - Anatomical Dead Space) x Respiratory Rate

21. What is Dalton’s Law?

• Total pressure of a gas mixture is the sum of individual partial pressures

22. What is Henry’s Law?

• Gas dissolves in liquid proportionally to its partial pressure and solubility

23. How is oxygen transported in the blood?

• 98.5% bound to hemoglobin as oxyhemoglobin

• 1.5% dissolved in plasma

24. How is CO2 transported in the blood?

1. 7% dissolved in plasma

2. 70% converted to bicarbonate by carbonic anhydrase

3. 23% bound to hemoglobin (not same site as O2)

25. What factors affect O2-Hb saturation?

• pH (Bohr effect): ↓pH → ↓Hb affinity for O2

• Temperature: ↑temp → ↓Hb affinity

• 2,3-BPG: ↓Hb affinity for O2 (enhances O2 delivery)

26. How does fetal hemoglobin differ from adult hemoglobin?

• Fetal Hb has higher affinity for O2 than adult Hb

• Allows O2 transfer from mother to fetus

27. What are the brain’s respiratory control centers?

• Medulla Oblongata:
  

  • DRG (quiet breathing)

  • VRG (forced breathing)

• Pons: Modifies pace of respiration

• Voluntary control: From cerebral cortex (e.g., talking, singing)

28. What sensory inputs affect respiration?

• Chemoreceptors (PCO2, PO2, pH)

• Baroreceptors (blood pressure)

• Stretch receptors (lung inflation)

• Irritants (sneezing, coughing)

• Emotions, pain, temperature

29. What are the effects of aging on the respiratory system?

1. Elastic tissue deterioration → decreased compliance & vital capacity

2. Arthritis → limits rib cage movement → decreased minute volume

3. Emphysema risk increases (especially with smoking)