Chapter 15- Heart Beat

Question 1

autonomic nervous system

Answer 1

Branch of the peripheral nervous system that controls involuntary (automatic) functions of all internal organs and smooth and cardiac muscles; further divided into parasympathetic and sympathetic groups of neurons

Question 2

AV bundle

Answer 2

The extension of the atrioventricular node from the atrium across the heart to the ventricles

Question 3

AV node

Answer 3

Located on the bottom surface of the right atria, is responsible for initiating the contraction of the ventricles

Question 4

cardiac control center

Answer 4

Changes in the heartbeat are controlled by the automatic nervous system, specifically the cardiac control center in the medulla oblongata

Question 5

epinephrine (adrenaline)

Answer 5

Stress hormone

Question 6

heartbeat

Answer 6

The pulsing of the heart caused by contractions of the atria and ventricles

Question 7

medulla oblongata

Answer 7

The lower portion of the brainstem; controls basal metabolic functions- breathing, blood pressure, heart rate, and many reflective actions, such as coughing, vomiting, hiccupping, and swallowing

Question 8

pacemaker

Answer 8

The sinoatrial (SA) node is called the pacemaker of the heart and initiates a heartbeat every 0.85 seconds; the SA node is located on the upper inside wall of the right atrium

Question 9

purkinje fibers

Answer 9

Located in the inner ventricular walls of the heart, just beneath the endocardium. These fibers are specialized myocardial fibers that conduct an elexctrical stimulus or impulse that enables the heart to contract in a coordinated fashion

Question 10

SA node (sinoatrial)

Answer 10

Located on the upper inside wall of the right atrium and known as the pacemaker of the heart as in initiates a heartbeat every 0.85 seconds