Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
88 Cards in this Set
- Front
- Back
|
Are the cardiac muscles connected to neighboring cardiac cells by intercalated disk?
|
YES
|
|
|
Do intercalated disk contain gap junctions?
|
YES
|
|
|
Will action potential (AP) pass from one cardiac muscle to another cardiac muscle cell by the way of the gap junctions; therefore will the cardiac muscles cells act as one unit?
|
YES;YES
|
|
|
What is the special name for individual cells working together as one unit?
|
Functional syncytium
|
|
|
How many syncytia are in the heart?
|
2 seperate
|
|
|
Name the two type of syncytia and explain the functioning of each
|
1. Atrial syncytium- right & left atria contract at same time and relax at same time 2. Ventricular- rt and lt ventricles contract at same time and relax at same time |
|
|
What structure separates the atrial syncytium from the ventricular?
|
fibroskeleton
|
|
|
The cardiac conduction system must allow for 3 factors they are?
|
1. The 2 atria must contract at the same time and contract from TOP to BOTTOM 2. While the 2 atria are contracting the 2 ventricles must be relaxed 3. The 2 ventricles must contract at the same time and contract from BOTTOM to TOP |
|
|
What is the location of the SA node?
|
located below the epicardium on posterior wall of rt atrium just inferior to the opening of superior vena cava
|
|
|
What structure is commonly called the pacemaker of the heart?
|
SA node
|
|
|
The AP starts at what structure?
|
SA node
|
|
|
NOTE* wherever the AP starts is where the contraction of the heart starts |
|
|
|
What is the location of the AV node?
|
located in the floor of the rt atrium
|
|
|
At what structure does the delay of the AP occur?
|
slow conduction rate at the bottom of the 2 atria
|
|
|
What structure prevents the AP from traveling into the ventricles?
|
fibroskeleton
|
|
|
What structure pierces the fibroskeleton?
|
A-V bundle aka bundle of his
|
|
|
What structure gives the AP to the contracting ventricles cells?
|
? purkinje fibers
|
|
|
The heart has how many different types of cardiac muscle cells?
|
2
|
|
|
What are the two types of cardiac muscle cells?
|
1. autorhythimic 2. contractile |
|
|
List examples of autorhythmic cells
|
SA node, AV node, and AV bundle
|
|
|
Can the autorhythmic cells start in an AP?
|
YES
|
|
|
What percentage of myocardial cells are authorhytmic cells?
|
2%
|
|
|
What percentage of myocardial cells are contractile cells?
|
98%
|
|
|
Can the contractile cells start an AP?
|
NO
|
|
|
Will the contractile cells contract when they receive an AP through its gap junctions?
|
YES
|
|
|
What structure is commonly called the pacemaker of the heart?
|
SA node
|
|
|
Define cardiac output?
|
the total volume of blood that leaves the LEFT ventricle in ONE min
|
|
|
What is the formula for cardiac output?
|
heart rate x stroke volume
|
|
|
Define heart rate and stroke volume
|
heart rate- number of heart beats per min stroke volume- the average amount of blood that leaves the left ventricle during ONE contraction |
|
|
Does the SA node set the heart rate?
|
YES
|
|
|
Your heart rate at any moment during the day primarily depends on the sum total of the ___ and ___?
|
SNS and PNS
|
|
|
Define chronotropic effect?
|
effect on heart rate
|
|
|
An increase in SNS or a block of the PNS at the SA node would lead to a ___ chronotropic effect?
|
positive
|
|
|
An increase in PNS or a block of the SNS at the SA node would lead to a __ chronotropic effect?
|
negative
|
|
|
What are the factors that effect stroke volume?
|
1. end diastolic volume EDV 2. mean arterial pressure MAP 3. contractility |
|
|
Define end diastolic volume EDV?
|
the volume of blood in the ventricle at the end of the relaxed phase (diastole)
|
|
|
What is another name for EDV?
|
preload
|
|
|
Is EDV an intrinsic control mechanism?
|
YES
|
|
|
Is this intrinsic control mechanism also called the FRANK-STARLING LAW of the HEART?
|
YES
|
|
|
Does the Frank-starling law of heart state that as in volume in the ventricle increase it increases the stretch on the ventricle and the ventricle responds by contracting with more force resulting in an increase in stroke volume?
|
YES
|
|
|
Does mean arterial pressure effect stroke volume? If MAP increases what would happen to stroke volume?
|
YES; decrease
|
|
|
Does contractibility effect stroke volume?
|
?YES
|
|
|
Is contractibility an extrinsic factor that effects stroke volume?
|
YES
|
|
|
Does contractibility depend on the activity of the sympathoadrenal system?
|
YES
|
|
|
Does the PNS have any effect on contractility?
|
NO
|
|
|
Define inotropic effect
|
effect on force of contraction
|
|
|
An increase in SNS would cause a __ inotropic effect
|
positive
|
|
|
A decrease in SNS would cause a __ inotropic effect
|
No change
|
|
|
Define blood pressure
|
is the force exerted on the wall of the vessel by the contained volume of blood
|
|
|
What is the formula for blood pressure
|
cardiac output x total peripheral resistance
|
|
|
Where would a change in blood volume enter into this formula
|
cardiac output
|
|
|
Where would a change in the size of the vessel enter into this formula?
|
total peripheral resistance
|
|
|
What is the formula for resistance
|
1/(radius^4)
|
|
|
Most vascular resistance occurs in the
|
arterioles
|
|
|
Are arterioles also called resistance vessels?
|
YES
|
|
|
Vasoconstriction of an arteriole would be caused by an __ of the SNS
|
increase
|
|
|
Vasodilation of an arteriole would be caused by a __ of the SNS
|
decrease
|
|
|
What effect does the PNS have on vasodilation or vasoconstriction of an arteriole?
|
NO effect
|
|
|
The autonomic nervous system is involved with immediate or long term blood pressure control?
|
immediate (short term)
|
|
|
Are the baroreceptors monitoring the blood pressure for the ANS?
|
YES
|
|
|
Where are the baroreceptors located?
|
located at the aortic arch and the rt and lt carotid sinuses
|
|
|
List the 2 medulla reflex centers that receive information from the baroreceptors
|
vasomotor control center and cardiac control center
|
|
|
What activity does the vasomotor cc regulate?
|
vasoconstriction and vasodilation of blood vessels
|
|
|
What activities does the cardiac cc regulate?
|
heart rate and force of contraction
|
|
|
Are the osmoreceptors of the hypothalamus monitoring the osmolarity of the blood?
|
YES
|
|
|
Do these osomoreceptors only react to an increase in osmolarity of the blood?
|
YES
|
|
|
Does the activation of these receptors cause the release of ADH from the posterior pituitary gland?
|
YES
|
|
|
What is the action of ADH at the kidneys?
|
reabsorb more water
|
|
|
Using the osmolarity formula, show how the release of ADH leads to a decrease in blood osmolarity
|
solute/ solvent (h2o)
|
|
|
Using the BP formula show how the release of ADH leads to an increase in BP
|
? increase in blood volume leads to an increase in BP
|
|
|
The kidneys monitor BP. The kidneys will only respond to a __ in BP?
|
low
|
|
|
If BP is low the kidneys will release __ into the blood?
|
rennin
|
|
|
Rennin reacts with __ in the blood?
|
angiotensinogen
|
|
|
Is angiotensinogen inactive and in the blood all the time?
|
YES
|
|
|
The rennin will convert antiotensinogen to ___
|
angiotensin 1
|
|
|
angiotensin 1 is converted to ___ by what enzyme?
|
angiotensin 2; ACE
|
|
|
What are the 2 actions of angiotensin 2?
|
1. vasoconstriction of arterioles 2. stimulates the release of aldosterone from the adrenal cortex |
|
|
Using the BP formula show how both of these actions would lead to an increase in BP
|
1. decrease in radius, leads to an increase in resistance, increase in resistance leads to an increase in BP
2. increase in water into the blood gives an increase in blood volume thus increasing BP |
|
|
What is the effect of aldosterone on the osmolarity of the blood? |
NO CHANGE |
|
|
Where are the atrial stretch receptors located? |
rt. and lt. atria |
|
|
The atrial stretch receptors only respond to an ___ in BP. This increase in BP is due to an increase in blood volume |
increase |
|
|
The activation of the atrial stretch receptors causes an ___ in ADH |
inhibition (block) |
|
|
Using the BP formula show how this would decrease blood volume and BP |
Kidneys release more water into the urine and less back into the blood |
|
|
Is atrial naturetic factor ANF released when the atrial stretch receptors are activated? |
YES |
|
|
Would an increase or decrease in blood volume activate these receptors? |
Decrease |
|
|
How does ANF effect aldosterone; how does ANF effect angiotensin 2? |
blocks; blocks |
|
|
Explain how this would cause a decrease in blood pressure |
less water in blood results in less blood volume; results in vasodilation |
|
|
P wave QRS wave T wave |
p wave- atrial depolarization QRS wave- ventricular depolarization t wave- ventricular repolarization |
