fill in the blank - ch 19 heart

The dark lines connecting cardiac muscle cells are called __________

Intercalated discs

The visible banding pattern in cardiac muscle is called __________

Striations

Cardiac muscle cells typically have __________ (one/multiple) centrally located nucleus/nuclei

One (sometimes two) centrally located nuclei

Intercalated discs contain __________ junctions that allow electrical signals to spread quickly.

Gap junctions

Compared to skeletal muscle, cardiac muscle cells are more __________ (branched/unbranched)

Branched

The tip of the heart is called the __________

Apex

The superior portion of the heart is called the __________

Base

The ear-like flaps on the heart are called __________

Auricles

The __________ ventricle is thicker because it pumps blood to the entire body

Left

The heart is shaped like an upside-down __________

Triangle

The white string-like structures are called __________

Chordae tendineae

Chordae tendineae attach to __________ muscles

Papillary

The function of chordae tendineae is to prevent valves from __________

Prolapsing / flipping backward

Ridges found in the atria are called __________ muscles

Pectinate

Ridges found in the ventricles are called __________

Trabeculae carneae

The wall separating the ventricles is the __________ septum

Interventricular

The fossa ovalis is a remnant of the fetal __________

Foramen ovale

The valve between the right atrium and right ventricle is the __________ valve

Tricuspid

The valve between the left atrium and left ventricle is the __________ valve

Bicuspid / Mitral

The valve leading into the pulmonary trunk is the __________ semilunar valve

Pulmonary

The valve leading into the aorta is the __________ semilunar valve

Aortic

Heart sounds “lub-dub” are caused by valve __________

Closing

Blood returning from the body enters the right atrium through the __________ and __________

Superior vena cava and inferior vena cava

Blood flows from the right ventricle into the __________ trunk

Pulmonary

Blood traveling to the lungs is part of the __________ circuit

Pulmonary

Blood traveling to the body is part of the __________ circuit

Systemic

Blood in pulmonary arteries is __________ (high/low) in oxygen

Low

Blood in pulmonary veins is __________ (high/low) in oxygen

High

Coronary arteries supply oxygen to the __________

Myocardium

A blockage in a coronary artery can cause a __________

Myocardial infarction (heart attack)

Blood from the heart muscle drains into the __________ sinus

Coronary

The __________ cardiac vein collects blood from multiple veins

Great

The heart’s natural pacemaker is the __________ node

SA (sinoatrial)

If the SA node fails, the __________ node takes over

AV (atrioventricular)

Electrical signals travel from the AV node to the __________ of His

Bundle

The final conduction fibers are called __________ fiber

Purkinje

Nodal cells are never at __________

Rest

The P wave represents __________ depolarization

Atrial

The QRS complex represents __________ depolarization

Ventricular

The T wave represents ventricular __________

Repolarization

The PR interval represents the time from atria to __________

Ventricles

There is no atrial repolarization wave because it is hidden by the __________ complex

QRS

S1 (“lub”) is caused by closure of __________ valves

AV (tricuspid and mitral)

S2 (“dub”) is caused by closure of __________ valves

Semilunar

Normal heart rate is __________ to __________ bpm

60 to 100

A heart rate above 100 bpm is called __________

Tachycardia

A heart rate below 60 bpm is called __________

Bradycardia

Pulse pressure = __________ − __________

Systolic − Diastolic

MAP = __________ + 1/3 (pulse pressure)

Diastolic pressure

If MAP falls below __________ mmHg, organs may not receive enough blood

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