AP2 Chapter 18: Heart

0-3 mmHg

What is the approximate BP in the vena cava?

superior vena cava

The upper large vein that returns deoxygenated blood from the head, neck, arms, and upper body to the right atrium of the heart

inferior vena cava

The lower large vein that returns deoxygenated blood from the head, neck, arms, and upper body to the left atrium of the heart

veins

This vessel generally has lower blood pressure than the other type

pulmonary valve

A heart valve located between the right ventricle and the pulmonary artery.

semilunar

Which type of valve prevents backflow of blood into the ventricle?

right atrium

The chamber of the heart that receives deoxygenated blood from the body via the superior and inferior vena cava.

auricle

An ear-shaped pouch attached to each atrium that helps increase its capacity.

coronary sinus

The large vein that collects deoxygenated blood from the heart muscle and empties into the right atrium.

AV node

A group of cells in the heart that coordinate the contraction between the atria and ventricles, acting as a gatekeeper to control electrical signals.

SA node

The natural pacemaker of the heart, located in the right atrium, that generates electrical impulses to initiate each heartbeat.

tricuspid valve

A valve located between the right atrium and right ventricle of the heart that prevents backflow of blood.

trebeculae carne

Muscle ridges found in the ventricles of the heart that help facilitate efficient contraction and blood flow

120mmHg

What is the approximate pressure inside the aorta?

pulmonary arteries

Blood vessels that carry deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation.

deoxygenated

In the pulmonary circuit, what type of blood do arteries carry?

away from vs to heart

what is the difference between arteries and veins

pulmonary veins

Blood vessels that carry oxygenated blood from the lungs to the left atrium of the heart.

oxygenated

In the pulmonary circuit, what type of blood do veins carry?

left atrium

The chamber of the heart that receives oxygenated blood from the pulmonary veins and pumps it into the left ventricle.

bicuspid valve

Also known as the mitral valve, it separates the left atrium and left ventricle, allowing blood to flow in one direction.

chordae tendineae

Fibrous cords that connect the papillary muscles to the atrioventricular valves, preventing backflow of blood during ventricular contraction.

papillary muscles

Muscle projections in the heart that anchor the chordae tendineae and help prevent the inversion of the atrioventricular valves during contraction.

protrusion

The root word of papillary, papilla, means ____

myocardium

the muscular tissue of the heart responsible for contraction and pumping blood.

left

On what side of the heart is the myocardium thicker?

pericardium

the protective sac around the heart

fibrous and serous

What are the layers of the pericardium?

fibrous

What type of pericardium is the outermost layer?

parietal, visceral

Within the serous pericardium, there are 2 layers, the ____ and the _____

pericardial cavity

The fluid filled space between the parietal and visceral pericardium

epicardium

the visceral serous pericardium is also called the

End diastolic volume (EDV)

It represents the maximum volume of blood the ventricle holds during the cardiac cycle, the point just before ventricular contraction begins.

pre-load

EDV is a critical determinant of what that affects the force of contraction via the Frank-Starling mechanism?

End systolic volume

amount of blood remaining in a ventricle at the end of systole, after the heart has contracted

minimum volume of blood

In the cardiac cycle, what does ESV represent?

systolic volume

volume of blood ejected from ventricles

ventricular diastole

This occurs after ventricular systole (contraction), when the ventricular pressure drops, semilunar valves close, and atrioventricular valves open

ventricular systole

when the ventricles contract, pumping blood out of the heart, where AV valves close,

Cardiac output

the output of blood ejected from the ventricles in 1 minute

5 L/min

What is the approximate CO of a person?

CO = SV x HR

What is the equation for cardiac output?

ANS/ autonomic nervous system

What system can be used to adjust HR?

norepinephrine

This neurotransmitter causes faster depolarization that leads to an increase in HR

Aceytlcholine (ACh

This neurotransmitter causes slower depolarization leading to a decrease in HR

K+

The parasympathetic NS affects this type of ion channel resulting in faster HR

Na+

The sympathetic NS affects this type of ion channel resulting in slower HR

preload, contractility, afterload

What 3 factors impact stroke volume?

preload

the initial stretch of heart muscle tissue measured by EDV at the end of diastole (more = greater HR)

contractility

the intrinsic strength of the heart’s contraction at a given preload and afterload (how hard the heart squeezes)

afterload

The resistance the ventricles must overcome to eject blood

contractility

What factor affecting stroke volume is decreased by heart failure and hypoxia/acidosis?

afterload

What factor affecting stroke volume is increased by hypertension and aortic stenosis?

pre-load

What factor affecting stroke volume is dependent on venous return and EDV?

hypertrophy, ventricular, fluid

Chronic hypertension causes ____ of the left ventricle, which results in weakened muscles. Eventually, _____ failure occurs, resulting in ___ in the lungs.

intercalated discs

specialized structures found between cardiac muscle cells that enable the heart to function as a coordinated unit

cardiomyocyte/contractile cell

What type of cell is distributed through the myocardium making up the bulk of it

SA + AV

Pacemaker cells are located in which 2 nodes?

endocardium

the outer layer of the heart wall that is partially infiltrated by fat

atria

What is the name for the upper chambers of the heart that receive blood returning to the heart?

ventricles

What is the name for the lower chambers of the heart where blood goes when it passes through the bicuspid/tricuspid valves?

apex

The lower “point” of the heart

pericardial sac

This is the part of the pericardium that attaches the heart and diaphragm

Great cardiac vein

What vessel collects deoxygenated blood from the anterior surfaces of the left and right ventricles and the left atrium of the heart?

circumflex artery

a branch of the left coronary artery (LCA) that supplies blood to the lateral and posterior walls of the left ventricle and parts of the left atrium.

fossa ovalis

a depression in the interatrial septum of the heart, found in the right atrium, a remnant of a hole in the interatrial septum of the fetal heart

anchoring desmosomes, gap junctions

What two structures prevent cardiac muscle cells from seperating and allow fast electrical conduction across the heart?

midsternal

What line is the heart along?

myocardium

In what layer of the heart are cardiac muscle cells located in?

connective tissue

What anchors myocardiocytes?

endothelial

What type of cells make up the endocardium?

coronary sinus

What vessel dumps blood from the heart into the right atrium?

dense, irregular tissue

What type of tissue makes up the valve flaps of the AV valves?

efficiency

The purpose of the AV valves is ____ via the prevention of backflow

incompetent valve

A valve that does not prevent backflow

valvular stenosis

hardening/stiffening of the valves resulting in more force required to pump blood

calcification

Fen-phan as a drug for weight loss can cause this to happen to the valve

apex

Where do the right and left coronary arteries meet?

great, anterior

What are the two major cardiac veins?

absolute refractory

Cardiac muscle cells have a long ___ ____ period, no matter how much the cell is stimulated, ion channels will not open during it.

-40mV

Pacemaker APs have a threshold of ___

Ca2+

Pacemaker APs have explosive ___ dumped into the cell for quick depolarization, then repolarize

SA node

In the hierarchy of signal, signal should first come from which place?

AV node

In the hierarchy of signal, signal goes second to which place?

AV Bundle/Bundle of His

In the hierarchy of signal, signal third goes to which place?

bundle branches

In the hierarchy of signal, signal fourth goes to which place?

subendocardial conducting network

In the hierarchy of signal, signal last goes to which place?

they depolarize faster

Why do the nodes guide the direction of signal?

SA node

Which node’s normal function is 100x per minute but is downregulated by the ANS to about 75x per min?

coronary artery

Where does the SA node get its blood from?

AV node

Which node delays impulses coming from the SA node so atrial contraction happens before ventricular contraction (normal fxn 50x per min)?

all APs

ECGs/EKGs are a graph of ____ ____.

atrial depolarization

What does the p-wave represent?

ventricular depolarization

What does the QRS complex represent?

ventricular repolarization

What does the T-wave represent?

atrial repolarization

This is not plotted because it is masked by the QRS

cardiac cycle

The blood flow through the heart/heart flow that has 3 cycles is called what?

Ventricular filling

the first phase of the cardiac cycle that occurs as the heart relaxes (during mid-late diastole)

ventricular systole

the second phase of the cardiac cycle where isovolumetric contraction occurs and pressure is building up

isovolumetric relaxation

the third phase of the cardiac cycle that occurs during early diastole