Chapter 18 - Circulatory

Question 1

Systemic circuit

Answer 1

Transports oxygenated blood and nutrients to all organs and tissues, ultimately returning deoxygenated blood to right atrium

Left ventricle –> right atrium

Question 2

Trunks

Answer 2

Several large arteries connected and branching from one another

Question 3

Aorta

Answer 3

Large elastic artery extending from left ventricle of the heart

Question 4

Superior and inferior vena cava

Answer 4

Two large veins that all the vessels of systemic venous system merge into.

Question 5

Dual venous drainage

Answer 5

Important for controlling body temperature. Hot weather - venous blood flows through superficial veins, cold weather - blood is routed to deep veins.

Question 6

Arteriosclerosis

Answer 6

A thickening and toughening of arterial walls. Account for half of all deaths in U.S.

Question 7

Atherosclerosis

Answer 7

Formation of lipid deposits in the arterial tunica media associated with damage to the endothelial lining.

High bp
High blood cholesterol
Smoking

Question 8

Balloon angioplasty

Answer 8

Tip of a catheter contains an inflatable balloon. Once in position the balloon is inflated, pressing plaque against the vessel walls.

Question 9

Coronary artery disease CAD

Answer 9

Areas of complete or partial blockage of coronary circulation.

Question 10

Coronary ischemia

Answer 10

Reduced circulatory supply.

Question 11

Thrombus

Answer 11

Blood clot

Question 12

Stent

Answer 12

Fine wire-mesh tube that is inserted into a vessel following an angioplasty.

Question 13

Cardiac cycle

Answer 13

Period between the start of one heartbeat and the beginning of the next. A complete round of systole and diastole.

Question 14

Systole

Answer 14

Contraction - chamber contracts and pushes blood into an adjacent chamber or into an arterial trunk.

Question 15

Diastole

Answer 15

Relaxation - chamber fills with blood an prepares for the next contraction.

Question 16

Isovolumetric contraction

Answer 16

Ventricular contraction pushes the AV valves closed, but does not create enough pressure to open the semilunar valves.

First phase of ventricular systole

Question 17

Ventricular ejection

Answer 17

Ventricular pressure rises and exceeds pressure in arteries, semilunar valves open and blood is forced out of the ventricles.

Second phase of ventricular systole

Question 18

Pre potential or pacemaker potential

Answer 18

Gradual spontaneous depolarization of the sa and AV nodes.

Question 19

Slowing rate of spontaneous depolarization

Answer 19

Acetylcholine released by parasympathetic neurons opens chemically gated K+ channels, slowing rate of spontaneous depolarization.

Question 20

Speeding rate of spontaneous depolarization

Answer 20

Norepinephrine released by sympathetic neurons binds to beta-1 receptors, leading to the opening of ion channels

Question 21

Cardiac centers

Answer 21

In the medulla oblongata, contain autonomic headquarters for cardiac control.

Cardioinhibatory center - parasympathetic neurons

Cardioacceleratory center - sympathetic neurons

Question 22

Sympathetic innervation

Answer 22

Via postganglionic fibers within cardiac nerves

Question 23

Parasympathetic innervation

Answer 23

Via vagus nerve and synapses with ganglion cells in cardiac plexus.

Question 24

P wave

Answer 24

Depolarization of atria

Question 25

P-R interval

Answer 25

Time from beginning of p wave to beginning of QRS complex. Too long of a time can indicate damage to conducting pathways or AV node

Question 26

QRS complex

Answer 26

Depolarization of ventricles.

Question 27

Q-T interval

Answer 27

Beginning of q wave to end of t wave. Indicates time for ventricles t undergo a cycle of depolarization and repolorization. Can be lengthened by electrolyte disturbances, medications, conduction problems, ischemia, or myocardial damage.

Question 28

Pulmonary circuit

Answer 28

Composed of arteries and veins that transport blood between the heart and lungs. Begins at right ventricle, ends at left atrium