Physiology - Ganong - 37

Front 1

During exercise, the amount of O2 entering the blood, and CO2 being exported, increases to

Back 1

1) From 250 mL/min to 4000 mL/min
2) From 200 mL7min to 8000 mL/min

Front 2

The abrupt and gradual increase in ventilation, is probably due to

Back 2

1) Abrupt: Psychic stimuli and afferent impulses in muscles, tendons, and joints
2) Presumably humoral, despite the fact that pH, PCO2, and PO2 remain constant under moderate exercise

Front 3

When exercise becomes more vigorous, ventilation increases further. What may the mechanism be?

Back 3

Buffering of the increased amounts of lactic acid that are produced, liberates more CO2, further increasing ventilation

Front 4

Following ended exercise, how long does it take to reach basal levels of respiratory rate?

Back 4

As long as it takes to repay the O2 debt, which may be as long as 90 minutes after ended exercise.

Front 5

Processes taking place during repayment of the O2-debt

Back 5

1) [O2] of muscle myoglobin rises slightly
2) ATP and phosphorylcreatine is re-synthesized
3) Lactic acid is removed: 80% is converted to glycogen, 20% to CO2 and H2O

Front 6

Factors contributing to the feeling of fatigue (5)

Back 6

1) Bombardment of the brain by neural impulses from muscles
2) Decline in blood pH
3) Rise in body temperature
4) Dyspnea
5) Activation of J receptors

Front 7

Four types of hypoxia

Back 7

1) Hypoxic hypoxia: PO2 of arterial blood is reduced
2) Anemic hypoxia: Normal PO2, but too few Hb-molecules
3) Stagnant/ischemic hypoxia: Too low blood flow, other parameters are normal
4) Histotoxic hypoxia: All parameters are normal, but a toxic agent prevents utilization of O2

Front 8

What are HIFs?

Back 8

Hypoxia-Inducible Factors. Made up of alpha and beta subunits, of which the alpha-subunit is normally ubiquinated, but not in hypoxic cells.

Front 9

Threshold for cyanosis

Back 9

Must exceed 5 g/dL of reduced Hb in capillaries

Front 10

Conditions in which you would think hypoxia would occur, but does in fact not

Back 10

1) Anemic hypoxia: Too little Hb
2) CO-poisoning: CO-Hb obscure the reduced Hb-colour
3) Histotoxic hypoxia: Because the blood gas content is normal

Front 11

Effects of acetazolamide

Back 11

Inhibits carbonic anhydrase, producing increased HCO3- excretion in the urine, stimulating respiration, increasing PaCO2, and reducing formation of CSF

Front 12

Disorders causing hypoxic hypoxia

Back 12

1) Lung failure (gas exchange failure)
a. Pulmonary fibrosis
b. V/Q imbalance
2) Shunt
3) Pump failure (ventilatory failure)
a. Fatigue
b. Mechanical defects
c. Depression of respiratory control in the brain

Front 13

Causes of atelectasis include (5)

Back 13

1) Obstruction of bronchus or bronchioles
2) Absence or inactivation of surfactant
3) Pneumothorax
4) Hydro-/chylothorax
5) Hemothorax

Front 14

Three abnormalities found in asthma patients

Back 14

1) Partially reversible airway obstruction
2) Airway inflammation
3) Airway hyper-responsiveness to various stimuli

Front 15

Why are asthma attacks more severe late-night and early-morning?

Back 15

This is the period in the circadian rhythm of maximal bronchial constriction

Front 16

What is emphysema? (4)

Back 16

1) A potentially fatal pulmonary disease
2) The lungs lose their elasticity as a result of disruption of elastic tissue, and breakdown of the walls between the alveoli
3) As a result dead space is greatly increased
4) Hypoxia develops, barrel chest follows, and so does polycythemia, pulmonary HTN, and cor pulmonale (enlarged right side)

Front 17

Diseases causing hypoxic hypoxia (7)

Back 17

1) V/Q imbalance
2) Ventricle-to-Arterial shunts
3) Lung collapse
4) Pneumothorax
5) Asthma
6) Emphysema
7) Cystic Fibrosis

Front 18

Treatment of CO-poisoning

Back 18

1) Terminate exposure
2) Adequate ventilation, preferably with O2, as it hastens dissociation of CO-Hb
3) Hyperbaric oxygenation is useful

Front 19

Oxygen toxicity is likely due to

Back 19

Production of super oxide anion (O2-) and H2O2

Front 20

Situations in which hyperbaric O2 therapy is of value (7)

Back 20

1) CO-poisoning
2) Radiation-induced tissue injury
3) Gas gangrene
4) Very severe blood loss anemia
5) Diabetic leg ulcers and of slow-healing wounds
6) Rescue of skin flaps and grafts
7) Decompression sickness and air embolism

Front 21

Hypercapnia occurs in (4)

Back 21

1) V/Q inequality
2) Inadequate alveolar ventilation
3) Febrile patients
4) Diet high in carbohydrates

Front 22

Consequences of hypocapnia (4)

Back 22

1) PO2 rises to 120-140 mmHg
2) Reduced cerebral blood flow --> Light-headedness, dizziness, and paresthesias
3) Increased cardiac output
4) Respiratory alkalosis

Front 23

Effects of asphyxiation (3)

Back 23

1) Hypoxia and hypercapnia
2) Pronounced stimulation of respiration
3) Increased HR and BP

Front 24

What is Cheyne-Strokes respiration?

Back 24

Periodic breathing. Most commonly seen in congestive heart failure and uremia, but also in patients with brain disease, and in sleeping, normal individuals

Front 25

Symptoms of sleep apnea (4)

Back 25

1) Loud snoring
2) Morning headaches
3) Fatigue
4) Daytime sleepiness

Front 26

Factors causing pulmonary hypertension? (4)

Back 26

1) Hypoxia
2) Inhalation of cocaine
3) Increased extracellular serotonin levels
4) Systemic lupus erythematosus

Front 27

What is the standard treatment of decompression sickness?

Back 27

1) Prompt recompression
2) Gradual decrompression

Front 28

Potential problems associated with exposure to increased barometric pressure ("5")

Back 28

1) Oxygen toxicity
a. Lung damage
b. Convulsions
2) Nitrogen narcosis
a. Euphoria
b. Impaired performance
3) High-Pressure Nervous Syndrome (HPNS)
a. Tremors
b. Somnolescence
4) Decompression sickness
a. Pain
b. Paralyses
5) Air embolism
a. Sudden death