cardiac system

Question 1

serves as a pump that establishes the pressure gradient needed for blood to flow to tissues

Answer 1

heart

Question 2

passageways through which blood is distributed from heart to all parts of body and back to heart

Answer 2

blood vessels

Question 3

transprot medium within which materials being transported are dissolved or suspended

Answer 3

blood

Question 4

facts about the heart

Answer 4

-hollow muscular organ the size of a clenched fist
-lies midline in the thoracic cavity between the sternum and the spine
-top broad portion of the heart is the base
-bottom pointed portion is the apex
-oriented at an angle so the base lies on the right and apex on the left
-when beating forcefully the apex thumps against the left chest wall

Question 5

what are the two separate cardiovascular circulations

Answer 5

pulmonary circulation
-closed loop of the vessels carrying blood between heart and lungs
systemic circulation
-circuit of vessels carrying blood between heart and other body sysyems

Question 6

basic components of pulmonary circulatory circuits

Answer 6

heart
blood vessels
blood

Question 7

what are the two circulations driven by the heart

Answer 7

-systemic circulation
-pulmonary circulation

Question 8

pulmonary side

Answer 8

low pressure and low resistance to flow

Question 9

systemic side

Answer 9

high pressure and high resistance to flow

Question 10

what muscle of the heart does more work

Answer 10

heart muscle of the left ventricle of heart does more work becasue same volume is being pumped at a higher pressure against higher resistance

Question 11

volume of blood pumped by either side of the heart

Answer 11

volume of blood pumped by right side becomes volume pumped by left side

Question 12

what does heart valves ensure

Answer 12

that blood flow is unidirectional

Question 13

what does heart valves ensure

Answer 13

that blood flow is unidirectional

passively open when there is a higher forward pressure gradient

close when there is a higher backward pressure gradient

Question 14

atria and ventricular cells

Answer 14

do not have gap junctions between each other
separated by non conductive barrier

Question 15

what are the two consequences of high connectivity by special system

Answer 15

-spontaneous impulse generated at one place spreads thoughout entire heart
-all cardiac fibres contract or none do

Question 16

what are the specialized conduction pathways

Answer 16

-sinoatrial node (SA node)
-atrioventricular node (AV node)
-bundle of His
-purkinje fibres

Question 17

what is the efficiency criteria for cardiac functino

Answer 17

1. atrial excitation and contraction complete before onset of ventricular contraction
2. cardiac muscle excitation coordinated for heart chamber to contract as a unit
3. pair of atria and pair of ventricles coordinated so a pair contracts simultaneously

Question 18

spread of cardiac excitation steps

Answer 18

1. keep atrai beating together
2. 30ms delay keeps atria beating before ventricle
3. AV nodal delay allow atria time to fully contract and fill ventricles
4. from AV node to entire cardiac purkinje ssytem, 30ms. keep ventricles beating together

Question 19

what does SA failure lead to

Answer 19

abnormal pacemaker activity produced by latent pacemakers (non SA node)

Question 20

complete heart block

Answer 20

loss of conduction between atria and ventricles
-artificial pacemakers

Question 21

ectopic focus

Answer 21

overly excitable region that depolarizes faster than SA node
-can lead to premature ventricular contaction (PVC)