Cardiovascular (The Heart)

Question 1

The Heart: Layers

Answer 1

• Pericardium
• Myocardium
• Endocardium

Question 2

Pericardium

Answer 2

• Fibrous Pericardium: tough, loose-fitting sac
• Serous pericardium: Parietal layer inside fibrous pericardium
• Pericardial space: bw. visceral and parietal layers - provides protection against friction

Question 3

Myocardium

Answer 3

Thick, contractile middle layer; compressed heart cavities and blood

Question 4

Endocardium

Answer 4

Delicate inner layer of endothelial tissue; protects myocardium from contact with blood

Question 5

Chambers of the Heart

Answer 5

Right Atrium, Right Ventricle, Left Atrium, Left Ventricle

Question 6

Atria (Atrium)

Answer 6

Not very thick; little pressure needed to move blood short distances

Question 7

Auricle

Answer 7

Earlike flap protruding from each atrium increasing volume of blood that the atria can contain

Question 8

Ventricles

Answer 8

Thicker; great force needed to pump blood further

Left ventricle wall thicker than right; pushes blood farther

Question 9

Flow of Blood Through the Heart

Answer 9

LA - LV - systemic circ - RA - RV - pulmonary circ.

Question 10

Atria: Blood Flow

Answer 10

“Receiving chambers”, receive blood from veins

Question 11

Ventricles: Blood Flow

Answer 11

“pumping chambers”, push blood into large network of vessels

Question 12

Valves of the Heart

Answer 12

• Open: when pressure in the first compartment is higher than that of the second
  Close: when pressure in the second compartment is higher than that of the first; prevent blood from moving backwards

Question 13

Atrioventricular (AV) Valve: Location

Answer 13

bw. atria and ventricles

Question 14

Semilunar (SV) Valves: Location

Answer 14

bw. ventricles and great vessels

Question 15

Atrioventricular Valves

Answer 15

• Tricuspid Valve (Right AV valve)

- Bicuspid (mitral) valve

Question 16

Semilunar (SL) Valves

Answer 16

• Aortic Valve

- Pulmonary Valve

Question 17

Tricuspid Valve

Answer 17

Bw. RA and RV

Question 18

Bicuspid Valve

Answer 18

bw. LA and LV

Question 19

Aortic Valve

Answer 19

Entrance to aorta

Question 20

Pulmonary Valve

Answer 20

Entrance to pulmonary artery

Question 21

Cardiac Muscles: Name them.

Answer 21

• Trabeculae Carneae
• Chordae Tendinae
• Papillary Muscle

Question 22

Trabeculae Carneae

Answer 22

• Beamlike projections of myocardial tissue

- Help add force to inward contraction of the heart

Question 23

Choarae Tendinae

Answer 23

• Tendinous cord which anchors papillary muscles to cusps of AV valves
• Hold AV valves shut

Question 24

Papillary Muscle

Answer 24

• Muscles attached to cusps of AV vales
• Located in both ventricles
• When ventricles contract, pap. muscles also contract, pulling cusps together; stops backflow of blood into atria

Question 25

Conduction System of Heart

Answer 25

Sinoatrial (SA) node (pacemaker) Atrioventricular (AV) node AV bundle Purkinje Fibers

Question 26

Sinoatrial (SA) Node

Answer 26

- Initiates heartbeat; sets pace

Question 27

Atrioventricular (AV) Node

Answer 27

- Action potential comes form right atrium and relayed into AV bundle into ventricles

Question 28

AV bundle & purkinje fibers

Answer 28

conduct impulses throughout muscles of both ventricles, stimulating them to contract

Question 29

ECG

Answer 29

Record of hearts electrical activity

Question 30

Events shown by an ECG

Answer 30

P Wave: depolarization of atria QRS complex: depolarization of ventricles and repolarization of atria T wave: repolarization of ventricles

Question 31

Cardiac Cycle: consists of what?

Answer 31

Contraction (systole), relaxation (diastole)

Question 32

Atrial Contraction (systole)

Answer 32

Starts: when atria contracts Ends: Ventricles contract - Atria are contracting - Ventricular pressure increases - AV valves open when pressure becomes greater - SL valves remain closed - Blood moves from atria to relaxed ventricles

Question 33

Isovolumetric Ventricular Contraction (systole)

Answer 33

Starts: ventricles contract Ends: Ventricular pressure higher than aortic pressure - Volume remains constant, pressure increases rapidly - Atria relaxes - AV valves close - SL valves remain closed - First heart sound due to AV valves closing