Deck XII

Question 1

What happens to the pressure-volume relationship of the lung in the event of reduced compliance?

Answer 1

For any given volume, the pressure is significantly increased.

Question 2

Reduced pulmonary parenchymal compliance is the hallmark of what condition?

Answer 2

Pulmonary fibrosis.

Question 3

What conditions are caused by an alpha-1 antitrypsin deficiency?

Answer 3

Panacinar emphysema and liver cirrhosis. The lung parenchyma has increased compliance.

Question 4

How does idiopathic pulmonary arterial hypertension affect lung compliance?

Answer 4

It doesnt significantly affect lung compliance.

Question 5

Where is ACE produced?

Answer 5

In vascular endothelial cells, especially those in the pulmonary vasculature.

Question 6

What is the difference in presentation of an acute salicylate overdose vs. that of approximately 4-5 hours after ingestion?

Answer 6

Immediate respiratory alkalosis which progresses to an anion gap metabolic acidosis due to accumulation of organic acids in the blood (this causes a mixed respiratory alkalosis- metabolic acidosis condition at about 4-5 hrs after ingestion). Metabolic acidosis effects progress with time.

Question 7

What are the three phases of acid secretion in the stomach?

Answer 7

Cephalic (vagal/ cholinergically induced- triggered by thought, sight smell, taste), gastric (mediated by presence of gastrin which stimulates histamine secretion and thus acid secretion and is triggered by chemical stimulus of food and distension of the stomach), intestinal (when protein containing food enteres the duodenum (minor role))

Question 8

What helps down regulate gastric secretion after a meal?

Answer 8

Intestinal influences (inhibit gastrin release); somatostatin; prostaglandins

Question 9

What is the function of secretin?

Answer 9

Stimulation of release of bicarbonate from exocrine pancreas

Question 10

Where is secretin produced?

Answer 10

S enteroendocrine cells in the duodenum

Question 11

What is the most potent stimulator of secretin release?

Answer 11

HCl.

Question 12

What is human placental lactogen (hPL)?

Answer 12

A hormone secreted from the syncytiotrophoblast with structural and biologic properties similar to prolactin and growth hormone– it increases maternal insulin resistance which increases blood glucose levels allowing glucose to be shunted towards the fetus. It also increases maternal lipolysis and proteolysis.

Question 13

How do hPL levels change throughout pregnancy?

Answer 13

They increase with increasing gestational age to meet energy requirements of the fetus.

Question 14

What causes gestational diabetes mellitus?

Answer 14

When a woman’s pancreatic function cant over come the pregnancy related increase in insulin resistance due to placental secretion of hPL, GH, estrogens, progesterone, and glucocorticoids.

Question 15

An EKG with bradycardia, narrow QRS complexes and desynchronization of P and QRS waves indicates that cells from what region are leading the pacing?

Answer 15

The AV node.

Question 16

What are the EKG findings in a patient with a heart that is paced by the purkinje system?

Answer 16

Bradycardia (as low as 20 beats/ minute) with prolonged, abnormally shaped QRS complexes due to aberrant impulse conduction through the ventricles.

Question 17

How does exercise increase glucose uptake by muscle cells?

Answer 17

Through sensitization of the muscle cells to the action of insulin and to increased insulin-independent glucose uptake into the exercising muscles.

Question 18

Infections and stressors cause what condition in a diabetic?

Answer 18

Hyperglycemia

Question 19

Upon muscle relaxation, calcium efflux from the cytoplasm occurs through what mechanism?

Answer 19

The Ca2+-ATPase and Na/Ca exchange mechanisms

Question 20

What is the function of calmodulin?

Answer 20

An indirect contributor to calcium efflux from the cell upon muscle relaxation. It binds and activates plasma membrane Ca2+-ATPase which removes Ca2+ by hydrolyzing ATP.

Question 21

What is the function of the thyroid peroxidase enzyme?

Answer 21

Responsible for thyroglobulin iodination, oxidation of iodide to iodine, and the iodotyrosine coupling reaction that forms T3 and T4.

Question 22

What is the pathophysiology associated with Hashimoto’s Thyroiditis?

Answer 22

Autoantibodies to the thyroid peroxidase enzyme.

Question 23

Vagal stimulation of bronchi would most increase what pulmonary parameter?

Answer 23

Work of breathing due to increased bronchial smooth muscle constriction.

Question 24

Stimulation of vagus nerve branches that supply the lung will cause what physiologic changes?

Answer 24

Bronchoconstriction an increased bronchial mucus secretion. This will increase airway resistance and work of breathing.

Question 25

What drugs act to counteract work of breathing due to increased vagal stimulation?

Answer 25

Anticholinergic agents (tiotropium, ipratropium)

Question 26

What is a risk of using tPA in arterial re-opening?

Answer 26

Reperfusion arrhythmia on arterial re-opening (these are usually benign)

Question 27

PAH clearance is dependent on what factor?

Answer 27

Renal plasma flow (at low concentrations, PAH is filtered and completely secreted by the proximal tubules)

Question 28

What is beta endorphin?

Answer 28

An endogenous opioid peptide that is derived from POMC

Question 29

POMC is a polypeptide precursor that undergoes enzymatic cleavage and modification to produce what products?

Answer 29

Beta endorphins, ACTH, MSH.

Question 30

What is somatomedin C?

Answer 30

A peptide that is structurally similar to insulin- is also called Insulin Like Growth Factor and it stimulates growth in target cells