Pharm-Ch. 42

Question 1

Actin

Answer 1

Thin filament, a component of a sarcomere, or muscle unit.

Question 2

ADH

Answer 2

Antidiuretic Hormone, released from the posterior pituitary, causes retention of water.

Question 3

Aldosterone

Answer 3

Hormone released from the adrenal cortex, which causes retention of sodium and water.

Question 4

Angiotensin

Answer 4

Peptide hormone that causes vasoconstriction, stimulates aldosterone and ADH release; part of the renin-angiotensin system.

Question 5

Arrhythmia

Answer 5

Disruption in cardiac rate or rhythm.

Question 6

Arteries

Answer 6

Vessels that take blood away from the heart; muscular, resistance vessels.

Question 7

Atrium

Answer 7

Top chamber of the heart, receives blood from veins.

Question 8

Auricle

Answer 8

Appendage on the atria of the heart, holds blood to be pumped out with atrial contraction.

Question 9

Automaticity

Answer 9

Property of heart cells to generate an action potential without an external stimulus.

Question 10

Capacitance System

Answer 10

The venous system; distensible, flexible veins that are capable of holding large amounts of blood.

Question 11

Capillary

Answer 11

Small vessel made up of loosely connected endothelial cells that connect arteries to veins.

Question 12

Cardiac Cycle

Answer 12

A period of cardiac muscle relaxation (diastole) followed by a period of contraction (systole) in the heart.

Question 13

Conductivity

Answer 13

Property of heart cells to rapidly conduct an action potential of electrical impulse.

Question 14

Diastole

Answer 14

Resting phase of the heart; blood is returned to the heart during this phase.

Question 15

Dysrhythmia

Answer 15

A disruption in cardiac rate or rhythm, also called an arrhythmia.

Question 16

Ectopic Focus

Answer 16

A shift in the pacemaker of the heart from the sinoatrial node to some other site.

Question 17

Electocardiogram

Answer 17

An electrical tracing reflecting the conduction of an electrical impulse through the heart muscle; does not reflect mechanical activity.

Question 18

Myocardium

Answer 18

The muscle of the heart

Question 19

Myosin

Answer 19

Thick filament with projections, a component of a sarcomere, or muscle unit.

Question 20

Natriuretic Peptide

Answer 20

A peptide produced by the brain, heart, and vasculature which causes natriuresis, excretion of sodium in the urine; degraded by the enzyme neprilysin.

Question 21

Oncotic Pressure

Answer 21

The pulling pressure of the plasma proteins, responsible for returning fluid to the vascular system at the capillary level.

Question 22

Pulse Pressure

Answer 22

The Systolic blood pressure minus the diastolic blood pressure; reflects the filling pressure of the coronary arteries.

Question 23

Resistance System

Answer 23

The arteries; the muscles of the arteries provide resistance to the flow of blood, leading to control of blood pressure.

Question 24

Sarcomere

Answer 24

Functional unit of a muscles cell, composed of actin and myosin molecules arrangedin layers to give the unit a striped or striated appearance.

Question 25

SA Node

Answer 25

Sinoatrial Node. The normal pacemaker of the heart; composed of primitive cells that constantly generate an action potential.

Question 26

Starling’s Law of the Heart

Answer 26

Addresses the contractile properties of the heart: the more the muscle is stretched, the stronger it will react, until it is stretched to a point at which it will not react at all.

Question 27

Syncytia

Answer 27

Intertwining networks of muscle fibers that make up the atria and the ventricles of the heart; allow for a coordinated pumping contraction.

Question 28

Systole

Answer 28

Contracting phase of the heart, during which blood is pumped out of the heart.

Question 29

Tropinin

Answer 29

Chemical in heart muscle that prevents the reaction between actin and myosin, leading to muscle relaxation; it is inactivated by calcium during muscle stimulation to allow actin and myosin to react, causing muscle contraction.

Question 30

Veins

Answer 30

Vessels that return blood to the heart; distensible tubes.

Question 31

Ventricle

Answer 31

Bottom chamber of the heart, which contracts to pump blood out of the heart.

Question 32

Cardiovascular System

Answer 32

System is responsible for delivering oxygen and nutrients to all of the cells of the body and for removing waste products for excretion. Consists of a pump-the heart- and an interconnected series of vessels that continually move blood throughout the body.