Exercise bullSHIT

Question 1

ECG changes with exercise

Answer 1

exercise activates beta-1 receptors in the SA node, increasing the frequency of impulse generation and in the AV node, increasing the rate of impulse conduction from the atria to the ventricles; on ECG there is increasing frequency of P waves and shortening of the PR interval and RR interval (sinus tachycardia)

Question 2

Exercise-associated collapse (EAC)

Answer 2

typically occurs after intense exercise in well-conditioned athletes; characterized by loss of postural tone or syncope immediately following cessation of exercise and occurs due to impaired venous return to the heart

Question 3

Exercise-associated collapse (EAC) overview

Answer 3

Question 4

ATP production during exercise

Answer 4

intense exercise creates a high demand for ATP and the primary method of ATP production varies with the duration of exercise; the phosphocreatine shuttle is the primary source of ATP at the beginning of exercise, followed sequentially by anaerobic glycolysis and then oxidative phosphorylation

Question 5

ATP production during exercise

Answer 5

the phosphocreatine shuttle is the primary source of ATP at the beginning of exercise, followed sequentially by anaerobic glycolysis and then oxidative phosphorylation

Question 6

limitations of hemoglobin A1c interpretations

Answer 6

Hemoglobin A1c is produced by non enzymatic glycosylation of the hemoglobin molecule; provides an estimate of chronic glycemic control over the span of 3 months (circulating RBCs 120 days); rapid RBC turnover (hemolytic anemia) can give misleading low readings

Question 7

Acromegaly

Answer 7

caused by an excessive production of GH, usually due to a pituitary somatotropin adenoma; manifests as bony hypertrophy (frontal bossing, enlarged jaw, hands and feet) and osteoarthritis; LV hypertrophy is often common and may progress to HF

Question 8

Congenital hypothyroidism tx

Answer 8

treated w prompt initiation of levothyroxine in early infancy, late or inadequate tx is associated w cognitive and neurological dysfunction

Question 9

Postpartum thyroiditis histology

Answer 9

occurs within 12 months of pregnancy and is characterized by autoimmune destruction of thyroid follicles; beings w a hyperthyroid phase due to release of preformed antibodies and then followed by a transient hypothyroid phase due to depletion of thyroid hormone; histology shows lymphocytic infiltration, sometimes w formation of germinal centers

Question 10

BPH tx

Answer 10

5-alpha reductase inhibitors (ex: finasteride) reduce conversion of testosterone to DHT, in men w BPH reduction in prostate volume alleviates obstruction of urinary flow

Question 11

physiologic age-related cardiovascular changes

Answer 11

aortic compliance progressively decreases w age, especially those over 65 yrs; this leads to an increase in pulse pressure, a slight decrease in diastolic pressure and the characteristic isolated systolic HTN commonly seen in the elderly population