Protein A has four identical subunits, each of which binds one molecule of ligand Y. The binding of one molecule of Y to one of the subunits induces a conformational change in neighboring subunits that enhances the binding of additional units of Y. This is an example of________.

#Question id: 11018

#Unit 7. System Physiology – Animal

A 50-year-old man has a blood pressure of 140/85 and weighs 200 lb. He reports that he is not feeling well, his EKG has no P-waves, he has a heart rate of 46, and the QRS complexes occur regularly. What is his likely condition?

#Question id: 11019

#Unit 7. System Physiology – Animal

An 80-year-old man had an EKG taken at his local doctor’s office, and the diagnosis was atrial fibrillation. Which of the following statements are likely conditions in someone with atrial fibrillation?

#Question id: 11020

#Unit 7. System Physiology – Animal

Circus movements in the ventricle can lead to ventricular fibrillation. Which of the following conditions in the ventricular muscle will increase the tendency for circus movements?

#Question id: 11021

#Unit 7. System Physiology – Animal

A 75-year-old man goes to the hospital emergency department and faints. Five minutes later he is alert. An EKG shows 75 P waves per minute and 35 QRS waves per minute with a normal QRS width. Which of the following is the likely diagnosis?

#Question id: 11022

#Unit 7. System Physiology – Animal

A 55-year-old man had the following EKG recorded at his doctor’s office during a routine physical examination.

What is his diagnosis?

#Question id: 11023

#Unit 7. System Physiology – Animal

A male patient had a myocardial infarction at age 55. He is now 63 years old. Standard limb lead I is shown here.

What is his current diagnosis?