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Cardiovascular System Part 1 (Heart)
Chapter 19
68
Anatomy
04/16/2010

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Cards

Term
What are the two circuits that the blood flows from the heart?
Definition

1. Pulmonary-> Right ventricle-> Lung (for gas exchange(Body has to always be unloading CO2))-> Left Atrium

 

2. Systemic-> Left ventricle-> Everywhere (Every cell w/ nutrients)-> Right Atrium

 

Systemic Circuit even nourishes lung and heart tissue

Term
Describe the base of the heart
Definition
Wide and Superior
Term
Describe the Apex of the heart
Definition

More narrow and Inferior

Points toward the left

Term
Where does 2/3 of the heart lie?
Definition
Left of median plane
Term
What does the pericardium form?
Definition
The pericardium forrms a sac around the heart
Term
What is the parietal pericardium?
Definition
The outer layer
Term
What is the visceral pericardium?
Definition

-Inner layer

-In contact with the heart

-Produces serous fluid

Term
What is the pericardial cavity?
Definition

-Its a space located between parietal and visceral membrane.

-It produces pericardial fluid between layers and this reduces friction

Term
What is Pericarditis?
Definition
Inflammation of pericardium
Term
Endocardium
Definition

-Inner layer of the heart wall

-Continuous with endothelium (inside of the heart that lines the vessel) of blood vessels

Term
Myocardium
Definition

-Middle layer of the heart wall

-Cardiac muscle

Term
Visceral
Definition
sits right on the organ
Term
Epicardium
Definition

-The outer layer ofthe heart wall

-Visceral pericardium

Term

(Blood supply to Myocardium?)

1. What does the Coronary Arteries do? 

 

2. What do they branch off of?

 

3. Where does used blood collect and where does it empty into?

Definition

1. Supply heart tissue with blood

2. Branch off aorta immediately after aortic valve

3. Used blood collects in coronary sinus and empities into Right Atrium

Term
What is Myocardial Infarction?
Definition

A heart attack which is an interruption of blood supply to heart tissue which is followed by nercrosis (death) of myocardium.

 

Term
Diastole
Definition
Relaxation
Term
Systole
Definition
Contraction
Term

When does blood flow to the heart tissue peak?

(Blood supply to myocardium step 1)

Definition
During Diastole
Term

What does the cusps of aortic valve do during systole?

(Blood supply to the myocardium step 2)

Definition
Cusps of aortic valve cover Coronary artery opeing during systole
Term

What are compressed during systole?

(Blood supply to myocardium step 3)

Definition
Coronary arteries are compressed during systole
Term

What forces blood back into Coronary arteries?

(Blood supply to myocardium step 4)

Definition
Elastic recoil (the heart has to contract after it expands) of aorta forces blood back into the Coronary Arteries opendings during diastole. 
Term
Does the heart spend more time in diastole or systole?
Definition
diastole
Term
What is Angina Perctoris?
Definition
Ischemia (Lack of blood flow (O2)) to myocardium
Term
What is the flow chart for Angina Pectoris?
Definition
Anaerobic resp. --> Lactic acid --> pain/pressure feeling
Term
Autorhythmic
Definition

The heart is Autorhythmic

-This means no nervous system input is required.

Term
What are cardiocytes?
Definition

-Cardiac muscle cells

-

Term

How do cardiocytes (cardiac muscle cells) look?

 

Definition

-Striated and branched

-Joined w/ others by intercalated discs

Term
What do desmosomes do?
Definition

-Are used to resist stress of contraction

 

They are like sutoskeleton that connect to other sytoskelton

 

 

 

Term
What do Gap junctions allow?
Definition

Allow ion flow between cells

 

(Like tubes that allow action potential)

Term
What are the two networks of the conduction system and what do they do?
Definition

Atrial and Ventricular

 

-Each acts in near unison like single cell

Term

What is the Sinoatrial (SA) Node, where is it located, and what does it do first?

(Step 1 of the Conduction System) 

Definition

SA Node is a pacemaker

-Its in the Right Atrium

-Spontainious DEPOLARIZES FIRST

Term

What does SA not cause the atria to do?

(Step 2 of conduction System)

Definition
Causes both atria to depolarize and contract
Term

Where is the Atrioventricular (AV) node located and describe what happens with it. 

(Step 3 of the conduction System)

 

Why is there a slight delay?

Definition

-Located near Right AV valve

-Depolarizes in response to artial depolarization.

 

 

-There is a slight delay prior to AV depolarization to allow ventricles to fill with blood.

Term

Where does AV send waves of depolarization?

(Step 4 of the Conduction System)

 

Is the conduction fast or slow?

Definition
AV sends wave of depolarization through RT and LT AV bundle branches to the apex of the ventricles.
Term

What do Purkinje fibers do?

(Step 5 in the Conduction System)

 

What happens due to arrangement of cardiac muscle?

Definition

Purkinji fivers carry the impulse from the end of the bundle braches superiorly to the cardiocytes of the ventricles.

 

Ventricular contraction from apex upward with a twisting motion do to arrangement of cardiac muscle.

Term
Why is an inferior to superior contraction useful? Consider where the blood must exit the chambers/
Definition
Because the blood has to exit through the aorta.
Term
What is a normal cardiac rhythm?
Definition

SA node rhythm= sinus rhythm (70-80 bpm)-the number of times sa depolarizes- (60-100 are within normal range)

 

normal AV node 70-80 bpm as well because SA controls AV.

Term

ectopic focus

(Cardiac Rhythm)

Definition
Any other firing region (other than the SA node)
Term

What happens during Premature ventricular contraction (PVC)?

 

What kind of feeling does it give and why is it caused?

(Cardiac Rhythm)

Definition
Ventricle depolarizes before the SA node.  Gives an extrasystole (feeling of heart jumping/double beat/ flutter) cased by drugs/ stress/ lack of sleep...
Term

What is the most common ectopic focus?

 

When does it occur?

Definition

AV node= nodal rhythm which = 40-50 bpm

 

Occurs when SA node is damaged.

Term

What is any other ectopic focus cause?

What do you need to live?

What can cause this?

Definition

20-40 bpm

 

Its not survivable

 

Need artificial pacemaker

 

Can be caused by heart block (failure of any part of the conduction system- Action potential stops premmature)

Term

When does action potential occur?

(SA Node Physiology)

 

What is not stable?

 

What determines time to threshold and action potential?

Definition

Action potential ovvurs when threshold membrane potential is reached.

 

RMP is not sbale but always creeps toward threshold as NA+ leaks through the cell membrane.

 

Rate of NA+ leak determines time to threshold and action potential.

Term
What are the stages of SA node physiology?
Definition

1. Slow Na= influx (leak)

2. Thresold reached

3. Ca++ amd Na+ channels opem (rapid depolarization=action potential)

4. K+ channels open (Ca++, Na+ close) repolarization

5. Repeat...

Term

What does a electrocardiogram (ECK or EKG) do?

Where are electrodes placed to record ECG?

Definition

Records heart electrical activity

 

Electrodes are placed on the wrist, ankles, and 6 places on the chest

Term
What are the three principal deflections of an ECG and what do they do?
Definition

-P Wave= Atrial depolarization

-QRS complex= Ventricular depolarization and Atrial repolarization

-T Wave= Ventricular repolarization

Term
What happens if there are extra p waves?
Definition
Heart block (not followed with ventricular wave)
Term
What happens if there and no P Waves?
Definition
AV ectopic focus
Term
What happens if there is and enlarged R?
Definition
Ventricular hypertrophy
Term
Why is an ECG valuable?
Definition
they are very valuable for diagnosis of many heart problems.
Term
What is a cardiac cycle?
Definition
One complete contraction and relaxtion of all 4 heart chambers (high to low)
Term
Definition
Term
To understand the cardiac cycle what do we need to consider?
Definition
fluid dynamics briefly
Term
What is the flood of fluid controled by? (in this case blood)
Definition
Controlled by pressure and resistance
Term
What is blood pressure measured with?
Definition
Sphygmomanometer
Term
How does blood flow?
Definition
Flow occurs from high to low pressure (down a pressure gradient)
Term
How do you get blood to go where you want it?
Definition
The area must have lower pressure than where the blood currently in
Term
How does one achieve lowering pressure to get it where you want it to go?
Definition

1. Increase the blood pressure where it is

2. Decrease the pressure in the area you want it to go

Term
What kind of chamber is sytole and what does it do?
Definition

Contracting chamber

Inc. BP

Term
What kind of chamber is diastole and what does it do?
Definition

Expanding (relaxing chamber)

Decreases BP

Term
What are controlled by pressure in the heart chambers?
Definition
Heart valve function and flow are controlled by pressure in the heart chamber
Term

What do systole and dystole normally refer to?

What is an example?

Definition

Systole and Diastole normally refer to ventricular systole and diastole.

 

(Systolic BP= arterial BP during ventricular systole)

Term

What happens during ventricular filling?

What happens when the atria is 2/3rds full?

What is EDV?

What stage is this in the Cardiac Cycle?

Definition

STAGE 1

 

During ventricular diastole,   AV valves OPEN 

Passive flow of blood into ventricles from RT and LT ATRIA.

 

When 2/3rds full the atria DEPOLARIZES/ CONTRACT FILLING the other 1/3.

 

EDV= End diastolic volume (volume of ventricle after diastole = 130 ml/ventricle

Term
Why do both ventricles have to have equal amounts of ventricular filling?
Definition
If they werent equal it would cause a back up (congestive heart failure)
Term

What is stage 2 of the Cardiac Cycle?

What repolarizes and depolarize?

What happens due to depolarization and what does this make?

Definition

Stage two is Isovolumetric contraction

 

Atria repolarizes/ relaxes

 

Ventricles depolarize/ contract

 

Due to the depolarization there is an increas in pressure= AV valves forced shut from blood pressure against them

 

The shutting of the AV valves in Heart sound 1

Term

What is stage 3 on the Cardiac cycle?

What happens to ventricular pressure?

What does the semi-lunar valves do?

Definition

VENTRICULAR EJECTION

 

Ventricular pressure exceeds Aortic (80mm/hg) and P. Trunk (10mm/hg) pressuer against Semi-lunar valves. 

 

Semi-lunar valves are forced open from blood pressure (120mm/hg from left ventricle and 25mm/hg from right)

Term

Stage three Ventricular ejection

 

What is the EDV=

What does the SV=

What is ESV?

Using ESV, what is left in each ventricle after contraction?

Definition

EDV= 130ml

 

SV (stroke volume)= 70ml  (the amount ejected)

 

EDV-SV= ESV (End systolic volume)  Basically what is left.

 

130-70= 60ml (left in each ventricle after contraction.

Term

What is stage 4?

What happens to the ventricle?

What have high pressure and why does it have high pressure?

What does this high pressure do and what does it make?

Why do AV valves open?

Definition

ISOVOLUMETRIC RELAXTION

 

Ventricle repolarizes/ relaxes.

 

Aortic/ P. Trunk high pressure (Due to elastic recoil of artery walls)

 

The high pressure forces semilunar valves closed

 

The vavles closing makes heart sound 2

 

Av valves open because of low pressure in ventricles...repeat...

 

Term

What is congestive heart failure?

What causes it?

What is the flow chart?

Definition

Insufficient ventricular ejection from either ventricle

 

Cause blood back up in systemic or pulmonary circuit and subsequent edema.

 

Lt. Ventricle -> pulmonary edema

Rt. Ventricle -> systemic edema