properties of Resp. 1

Question 1

What is the function of Upper airway

Answer 1

• “condition” inspired air so that it is at body temp. and fully humidified
• via resistance to airflow

Question 2

Resistance to Airflow

Answer 2

Upper respiratory tract:
- nose during quiet breathing = 50% of total resistance
- NASAL resistance INCREASES with viral infections and increase airflow (exercise)
- Infection causes larynx to become edematous (swollen) and contribute to airflow resistance.
LOWER RESPIRATORY RESISTANCE
- bronchioles and bronchi (muscle contraction, secretions from glands)
- alveolar wall is designed primarily for gas exchange, rather than structural support

Question 3

Define Goblet/surface secretory cells

Answer 3

• produce mucous i the airways
• INCREASE due to chronic cigarette (pollutants) smoke and contribute to increased mucus and airway obstruction in smokers

Question 4

Define Submucosal tracheobronchial glands

Answer 4

• Present wherever there is cartilage in tracheobronchial tree and lined by mucus-secreting mucous and serious cells
• INCREASE in # and SIZE in CHRONIC BRONCHITIS
• EXTEND to BRONCHIOLES in PULMONARY DISEASE

Question 5

CLARA cells

Answer 5

• found at level of bronchioles where goblet and submucosal glands have disappeared
• contain granules with NON-mucinous material and MAY have secretory function

Question 6

Squamous lining cells (Type I)

Answer 6

• Fewer in number than type II cells, but make up 95% of surface area
• flat cells with large cytoplasmic extension that are the PRIMARY LINING CELLS

Question 7

Granular pneumocytes (type II)

Answer 7

• are thicker and contain numerous LAMELALAR INCLUSIONS BODIES
• PRODUCE and SECRETE SURFACTANT –> lowers surface tension on alveolar surface

Question 8

Pores of Kohn

Answer 8

INTER-ALVEOLAR CONNECTIONS

• Between adjacent alveoli there are pores that allow COLLATERAL VENTILATION (allows for ventilation to continue in partially deflated lungs)
• Pores also allow transmission of other material such as bacteria and fluid between alveoli

Question 9

Respiratory membrane

Answer 9

• Basic site of gas exchange in lungs
• Consists of layer of fluid lining the alveolus containing sulfactant, alveolar epithelium, epithelial basement membrane, interstitial space, capillary basement membrane and capillary endothelial membrane

Question 10

Lung Interstitium

Answer 10

• Under NORMAL conditions the interstitial space is VERY SMALL
• Under pathological conditions it can become ENLARGED with the INFLUX of inflammatory cells and edema fluid (INTERFERES WITH GAS EXCHANGE)

Question 11

Define Fibroblasts

Answer 11

• prominent cells in the interstitium
• SYNTHESIZE and SECRETE Collagen and elastin which provide STRUCTURE that limits DISTENSIBILITY (COLLAGEN) and ELASTIC RECOIL of the lung (ELASTIN)

Question 12

Mucociliary clearance system

Answer 12

• Bronchioles lined by pseudostratified, ciliated columnar epithelium
• Cilia beat in direction of airway opening, propelling a BLANKET of MUCUS secreted by goblet cells away from lungs
• Epithelial cells maintain level of periciliary fluid layer by movement of CHLORIDE SECRETION AND SODIUM ABSORPTION across epithelium

Question 13

Parietal viscera

Answer 13

• contains STOMATA = exit points for pleural liquid, proteins, and cells removed from pleural space and communicate directly with lymphatic lacunae
• SUPPLIED by branches of adjacent intercostal arteries and drains into bronchial veins

Question 14

Visceral pleura

Answer 14

Supplied by BRONCHIAL circulation and drains largely into pulmonary veins

Question 15

What causes of PLEURAL EFFUSION

Answer 15

• Increase in microvascular HYDROSTATIC PRESSURE due to CONGESTIVE HEART FAILURE
• decrease in microvascular ONCOTIC PRESSURE due to Kidney/liver disease
• Decrease in pressure in pleural space due to ATELECTASIS
• Decreased CLEARANCE RATE due to systemic venous hypertension or BLOCKAGE of CLEARANCE (lymphatic drainage system)