The Heart & Circulation

Question 1

myocardium is the..

Answer 1

heart ms

Question 2

what supplies the right atrium?

Answer 2

superior & inf vena cava

Question 3

LV pumps blood via the ..

Answer 3

aorta

Question 4

when do the AV valves close? & what is their purpose?

Answer 4

close when ventricular walls contract; prevent backflow of blood during ventricular systole

Question 5

what is the purpose of semilunar valves?

Answer 5

to prevent backflow of blood from aorta & pulmonary artery during diastole

Question 6

systole is the period of..

Answer 6

ventricular contraction

Question 7

diastole is the period of..

Answer 7

ventricular relaxation

Question 8

when does teh blood circulate throughtout the myocardium? and via what?

Answer 8

during diastole via coronary arteries

Question 9

what coronary artery supplies the AV node & bundle of His?

Answer 9

RCA

Question 10

what coronary artery supplies the left ventricle?

Answer 10

LAD

Question 11

what is the purpose of the coronary sinus?

Answer 11

receives venous blood from the heart and empties it into the R atrium

Question 12

the SA node initiates an impulse rate of..

Answer 12

60-100 bpm

Question 13

normal range of stroke volume is..

Answer 13

55-100 mL/beat

Question 14

3 things that influence SV:

Answer 14

1. preload (diastolic filling, aka left ventricle end diastolic volume)
2. contractility
3. afterload - the force the LV must generate to overcome the aortic pressure

Question 15

CO =

Answer 15

SV * HR

Question 16

ejection fracture is..

Answer 16

the % of blood emptied from the ventricle during systole
**a CLINICALLY USEFUL MEASURE OF LV FXN*

EF = SV/LVEDV

Question 17

What is a “normal” EF?

Answer 17

> 55%; LOWER means GREATER DYSFXN

Question 18

atrial filling pressure is..

Answer 18

the difference b/t venous & ATRIAL pressures
-so, when you have a STRONG VENTRICULAR CONTRACTION, the ATRIAL FILLING IS ENHANCED
(high–>low pressure)

Question 19

IF you have an increased HR OR heart disease, what is the effect on diastolic filling time?

Answer 19

decreases (so LOWER end diastolic volume - normally 120 mL)

Question 20

the Myocardial oxygen deman is cliniclaly measures by..

Answer 20

HR * SBP (rate pressure produce)

Question 21

Arteries transport..

Answer 21

Oxygenated blood from areas of high to low pressure

Question 22

Capillaries function for ..

Answer 22

Exchange of nutrients and fluids between blood and tissues

Question 23

Venous circulation is influenced by (4)

Answer 23

Ms contraction, gravity, respiration (insp causes incr return) and compliance of R heart

Question 24

What organs are lymphatic?

Answer 24

Tonsils, spleen, lymph nodes, thymus, & thoracic duct

Question 25

Once lymph has been drained From the lymphatic system it goes,.

Answer 25

To the venous system Lymphatic capillaries --> lymph vessels --> ducts--> left subclavian vein

Question 26

How does the lymphatic system contribute to immune system function?

Answer 26

Lymph nodes collect cellular debris and bacteria, remove excess fluid, blood waste and protein molecules; and produce antibodies

Question 27

Control of PS & sympathetic stimulation is located in..

Answer 27

The medulla oblongata

Question 28

PS stim transmitted via ..

Answer 28

Vagus nerve - releases ACh

Question 29

Sympathetic stimulation transmitted via ..

Answer 29

t1-4 cord segments, upper thoracic to superior cervical chain ganglia; innervates all but the ventricular myocardium (but PS innervates that) -releases epinephrine and norepinephrine

Question 30

Drugs that incr sympathetic functioning are called .

Answer 30

Sympathomimetics

Question 31

The main mechanisms controlling the heart are..

Answer 31

Baroreceptors | -located in aortic arch and carotid sinus

Question 32

The circulatory reflex in response to increased BP is..

Answer 32

PS stimulation , decr rate and force of cardiac contraction, inhib of symp system --> decreased peripheral resistance

Question 33

Chemoreceptors are located --- | - role?

Answer 33

In carotid body | - IF increased CO2, decr O2 OR decr pH(incr lactic acid), an INCREASED HR occurs

Question 34

What two ion concentration imbalances can cause a decreased heart rate ?

Answer 34

HYPERkalemia & HYPOcalcemia

Question 35

What is an adverse effect of HYPOkalemia?

Answer 35

Arrhythmias which could progress to ventricular fibrillation

Question 36

What is an adverse result of hypermagnesium?

Answer 36

Arrhythmia OR cardiac arrest (because incr magnesium is a calcium blocker)

Question 37

What is an adverse response to hypo magnesium?

Answer 37

Ventricular Arrhythmias, coronary artery vasospasm and sudden death