Chapter 25: Respiratory System

Question 1

List the functions of the respiratory system. (6)

Answer 1

1. Breathing (inspiration/expiration)
2. Gas exchange
3. Gas conditioning (warm and humidify air?)
4. Sound production
5. Olfaction
6. Defense

Question 2

Define inhalation and exhalation.

Answer 2

Inhalation: gases are drawn INTO the lungs
(aka: inspiration)

Exhalation: gases are forced OUT OF the lungs
(aka: expiration)

Question 3

List the structures of the upper respiratory tract. (4)

Answer 3

1. Nose
2. Nasal Cavity
3. Paranasal Sinuses
4. Pharynx
   (5. Associated structures)

Question 4

List the basic functions of the sinuses. (3)

Answer 4

1. Decrease weight of the skull bones
2. Warm the air
3. Humidify the air

Question 5

List the divisions of the pharynx and be able to label them on a diagram. (3)

Diagram Pg. 749

Answer 5

Pharynx is commonly called the “throat.”

Divisions:

1. Nasopharynx
2. Oropharynx
3. Laryngopharynx

Question 6

List the structures of the lower respiratory tract. (3)

Answer 6

1. Larynx (“voice box”)
2. Trachea (“windpipe”)
3. Progressively smaller airways from Primary bronchi to the bronchioles

Question 7

Discuss the structure and basic function of pleura.

Answer 7

Pleura
- serous membrane formed from simple squamous epithelium

• lines the outer surface of each lung (visceral pleura)
• lines the internal surfaces of the thoracic walls, lateral surfaces of the mediastinum, and the superior surface of the diaphragm (parietal pleura)
• produces a thin fluid that circulates in the pleural cavity and acts as a lubricant to reduce friction during breathing

Question 8

List and surfaces, external features, and lobes of the lungs. Be able to identify these on the diagram. (11)

Diagram Pg. 762

Answer 8

1. Apex
2. Base
3. Hilum
4. Root of lung
5. Cardiac notch (Left lung only)
6. Cardiac impression (Left lung only)

Lobes:

7. Superior Lobe
8. Middle Lobe (Right lung only)
9. Inferior Lobe

Fissures:

10. Horizontal Fissure (Right lung only)
11. Oblique Fissure

*FYI, “lingular” portion of left lung is homologous to the middle lobe of the right lung.

Question 9

List and identify the muscles that assist with respiration. (7)

Answer 9

1. Diaphragm
2. Scalenes
3. Internal intercostals
4. External intercostals
5. Transversus thoracic
6. Serratus posterior superior and inferior
7. Some accessory muscles (Pec. minor, SCM, serratus anterior, and abdominal muscles - external and internal obliques, transverses abdominis, rectus abdominis)

Question 10

Identify nervous system structures that regulate ventilation. (3)

Answer 10

1. Autonomic Nervous System (ANS)
   - innervates the heart and also sends nerve fiber branches to the respiratory structures: trachea, bronchial tree, and lungs
2. Brainstem
   - regulates involuntary, rhythmic activities that deliver and remove respiratory gases
3. Medulla Oblongata and Pons
   - house reticular formation where regulatory respiratory centers can be found

Question 11

Identify common diseases that affect ventilation/respiration.

Answer 11

1. Asthma - chronic condition characterized by episodes of bronchoconstriction and wheezing, coughing, SOB, and excessive pulmonary mucous
2. Emphysema - irreversible loss of pulmonary gas exchange areas due to inflammation of the terminal bronchioles and alveoli; plus widespread destruction of pulmonary elastic connective tissue. There’s a loss of gas exchange surface area b/c the individual alveoli are dilated or increase in diameter. Air gets trapped in the nonfunctional alveoli and therefore the patient is not able to exhale effectively.
3. Lung Cancer - 85% of cases caused by smoking; highly aggressive and frequently fatal; symptoms include: chronic cough, coughing up blood, excess pulmonary mucus, and increased likelihood of pulmonary infections; there are 3 basic types: squamous cell carcinoma, adenocarcinoma, small-cell carcinoma
4. SIDS - sudden an unexplained death of an infant less than 1 year of age; SIDS babies have trouble regulating body temp, BP, and breathing; infants sleeping on their stomach are at greater risk

Question 12

Discuss the organization of the respiratory system.

Answer 12

1. Conducting portion
   - Transports air
   - Upper and Lower Respiratory tract
   (nose, nasal cavity, pharynx, larynx, trachea, and everything from primary bronchi to the bronchioles)
2. Respiratory portion
   - Carries out gas exchange
   - Smaller respiratory airways
   (respiratory bronchioles, alveolar ducts, alveoli)

Question 13

Discuss the process of gas exchange

Answer 13

The thin wall of the alveoli is specialized to promote diffusion of gases between the alveolus and the blood in the pulmonary capillaries.

See Pg 760 for diagram.