Heart

Question 1

Describe the blood flow through the heart

Answer 1

R atria-tricuspid valve-R ventricle-pulmonary valve-L atria-mitral valve-L ventricle-aortic valve

Question 2

Describe the pulmonary circulation

Answer 2

R atria-tricuspid valve-R ventricle-pulmonary valve-lungs-L atria

Question 3

Describe the systemic circulation

Answer 3

L atria-mitral valve-L ventricle-body-R atria

Question 4

What are the three types of cardiac muscle?

Answer 4

Atrial M
Ventricular M
Excitatory/conductive muscle fibers

Question 5

Autorythmic cells

Answer 5

1%
Pacemaker cells
Conductive system

Question 6

What are the conductory pathway?

Answer 6

SAN-AVN-bundle of HIS-L+R bundle branches-purkinje fibers

Question 7

Contractile cells

Answer 7

99%

Muscular walls of atria and ventricles

Question 8

Where do you perform auscultation?

Answer 8

Left- pulmonary, aortic, mitral

Right- tricuspid

Question 9

Phases of cardiac cycle

Answer 9

S1- systolic, closure of T+M valves, systole starts by opening of P+A valves
S2- diastolic, closure of P+A valves, systole ends, opening of M+T valves
S3- fast ventricle filling
S4- atrial contraction

Question 10

Stenosis

Answer 10

Valves rigid, not opening enough

Question 11

Leaky valves

Answer 11

Regurgitation (re-pumping blood)

Mitral valve prolapse- backflow

Question 12

Cardiac output

Answer 12

Stroke volume*heart rate

Amount of blood ejected by each ventricle per minute

Question 13

Cardiac output: Intrinsic regulation

Answer 13

Preload
Contractility
Afterload

Question 14

Cardiac output: extrinsic regulation

Answer 14

Cardiovascular center

Hormones

Question 15

Preload

Answer 15

Volume of blood entering ventricles
Myocardial stretching
End diastolic volume EDV
Increase when hypervolemia, valves regurgitation, heart failure

Question 16

Frank starlings law

Answer 16

Amount to f blood entering heart=blood leaving heart

Question 17

Ionotropy

Answer 17

Contractility
How hard the myocardium contracts for a given preload
Depends on integrity of myocardial fibers and Ca++ available
Increase with sympathetic stimulation, hypercalcemia, hyperkalemia, low O2
Decrease with parasympathetic stimulation, hypocalcemia, hypokalemia

Question 18

Afterload

Answer 18

The restistance/pressure ventricles must overcome to circulate blood
Arterial pressure related ESV
Increase caused by hypertension and narrowing of arteries

Question 19

Cardiovascular center

Answer 19

Part of CNS (medulla oblongada)
Regulates heartbeat through nervous and endocrine systems
Input/to brain- chemoreceptors, baroreceptors
Output/to heart- ANS= sympathetic and parasympathetic fibers

Question 20

Hormonal control

Answer 20

Epinephrine, norepinephrine, ADH, angiotensin II

Question 21

Other control

Answer 21

Age
Sex
Temperature
Drugs
Pain
Emotions
Exercise

Question 22

ECG

Answer 22

Representation of electrical events of cardiac cycle

Record of potential differences in AP in heart muscle contraction

Question 23

Major components of ECG

Answer 23

Atrial depolarization- atrial systole
Ventricular depolarization- ventricular systole
Ventricular repolarization- ventricular diastole

Question 24

P-wave

Answer 24

Atrial activation

Question 25

QRS-complex

Answer 25

Activation of ventricles

Question 26

T-wave

Answer 26

Recovery wave

Question 27

Respiratory sinus arrhythmia

Answer 27

Irregular heartbeat
Speeds up with inhale, slows with exhale
Normal for dogs

Question 28

Tachycardia

Answer 28

Increased heart rate

Question 29

Bradycardia

Answer 29

Decreased heart rate