Lecture 21- Respiratory Control And Lung Disease

Question 1

Ventral respiratory group

Answer 1

Within medulla oblongata

Rhythm generating and integration centre for respiration

Contains peerage groups of neurons; some fire during exhalation and others during inhalation

Question 2

Dorsal respiratory group

Answer 2

Within medulla oblongata

Integrates input from peripheral stretch and chemoreceptors and communicates with ventral respiratory group

Question 3

Pontine respiratory group

Answer 3

Within the pons

Modifies breathing rhythm set by ventral respiratory group to smooth out transitions between inspiration and expiration

Question 4

What are the most important factor that influences breathing rate and depth?

Answer 4

Changing levels of CO2 and O2 and H+ in arterial blood

Question 5

Central chemoreceptors

Answer 5

In medulla oblongata

Stimulate regulatory respiratory centres to cause increase in breathing rate and depth

Question 6

Peripheral chemoreceptors

Answer 6

In aortic arch and carotid arteries

Sensitive to arterial Po2 but levels must drop substantially before oxygen levels become a major stimulus for increased ventilation

Question 7

Hyperventilation

Answer 7

Increase depth and rate of breathing that exceeds body’s need to remove CO2

Leads to decreased blood CO2 levels

Question 8

What does hyperventilation cause?

Answer 8

Cerebral vasoconstriction and ischemia

Dizziness and fainting

Question 9

Hypocapnia

Answer 9

Decreased blood CO2 levels

Question 10

Pulmonary irritant reflexes

Answer 10

Respond to inhaled irritants in the nasal passages or tranches by causing reflexive brochoconstriction in the respiratory airways

Question 11

Inflation (hearing-Breuer) reflex

Answer 11

Activated by stretch receptors in visceral pleurae and conducting airways, protecting lungs from overexpansion

Question 12

Hyperpnea

Answer 12

Deeper,more vigorous respirations

Question 13

What are the three neural factors that contribute to change in respirations?

Answer 13

Psychological stimuli

Stimulate our cortical motor stimulation of skeletal muscles and respiratory centres

Excitatory impulses to respiratory areas from proprioreceptors in muscles, tendons and joints

Question 14

What happens to neural factors when excessive ends?

Answer 14

They are shut off and there is a gradual decline to baseline

Question 15

Acute mountain sickness

Answer 15

Result from a. Rapid transition from sea level altitudes to above 8000 feet

Question 16

Pulmonary function tests

Answer 16

Evaluate losses in respiratory function using a spirometer to distinguish between obstructive and restrictive pulmonary disorders

Question 17

Obstructive pulmonary diseases

Answer 17

Involve hyperinflation of the lungs

Characterized by increased total lung capacity, functional residual capacity and residual volume

Initially a problem in the tubes along respiratory tract

Question 18

Restrictive pulmonary disorders

Answer 18

Expansion of lungs is limited, display low vital capacity, total lug capacity, functional residual capacity, and residual volume

Question 19

chronic obstructive pulmonary diseases (COPD)

Answer 19

Seen in patients with smoking history

Result in progressive dyspnea, coughing and frequent pulmonary infections and respiratory failure

Question 20

Emphysema

Answer 20

Permanently enlarged alveoli and deterioration of alveolar walls

Question 21

Chronic bronchitis

Answer 21

Result from inhaled irritants

Causes excessive mucus production in bronchi, inflammations and fibrosis of lower respiratory mucosa

Question 22

Asthma

Answer 22

Inflammatory disease of airways

Causes coughing, dyspnea, wheezing and chest tightness

Question 23

Adenocarcinoma

Answer 23

Approx. 40% of cases

Originates in peripheral lung areas as nodules that develop from bronchial glands and alveolar cells

Question 24

Squamous cell carcinoma

Answer 24

Approx. 20-40% of cases

Arises in the epithelium of the bronchi and tends to form masses that hollow out and bleed

Question 25

Small cell carcinoma

Answer 25

Approx 20% of cases

Contains lymphocyte-like cells that originate int he primary bronchi, form clusters within the mediastinum and rapidly metasize