Unit Vb - Ch 19 - Heart

Sinoatrial node

In the heart, an action potential originates in the ____

1. the plasma membrane at the end of the cell, folded somewhat like the bottom of an egg carton 2. the folds of adjoining cells interlock with each other and increase the surface area of intercellular contact

Interdigitating Folds

Responsible for: 1. pumps blood to the left ventricle 2. preloads the left ventricle 3. passively fills the blood returning from the lungs

Left Atrium

Responsible for: 1. pumps blood to the aorta 2. the strongest chamber 3. dysfunction of this chamber leads to pulmonary edema 4. greatest contributor to systemic blood pressure

Left Ventricle

1. the fascia adherens is the most extensive type, a broad band in which the actin is anchored to the plasma membrane 2. desmosomes between cells prevent the cardiocytes from pulling apart when they contract

Mechanical Junctions

Coronary arteries Descending aorta Carotid artery Left ventricle

Oxygenated Blood

1. Beginning with the return from the systemic circulation, blood enters the RIGHT ATRIUM 2. Blood enters the right ventricle from the right atrium through the right AV valve, which is also known as the TRICUSPID valve 3. The right ventricle contracts next, which forces blood up through the RIGHT SEMILUNAR valve, which is also known as the pulmonary valve 4. After circulating through the PULMONARY capillaries, blood returns to the left atrium 5. From the left atrium, blood moves through the left AV valve, which is also known as the MITRAL valve 6. From the left ventricle, the blood is pumped up to the AORTA via the LEFT SEMILUNAR valve, which is also known as the aortic valve

Place sentences in logical order beginning with blood entering the right side of the heart

1. Right Atrium 2. Tricuspid Valve 3. Right Ventricle 4. Pulmonary Valve 5. Pulmonary Trunk 6. Pulmonary Artery 7. Lungs 8. Pulmonary Vein 9. Left Atrium 10. Left AV valve

Place the labels in order denoting the flow of blood through the pulmonary circuit beginning with the right atrium

Responsible for: 1. pumps blood to the right ventricle 2. preloads the right ventricle

Right Atrium

Responsible for: 1. pumps blood to the pulmonary trunk

Right Ventricle

Epicardium

Serous membrane; membrane simply squamous epithelium over areolar connective tissue with an adipose covering

AV bundle

Signals leave the AV node and descend along this structure toward the apex

Pulmonary Arteries Pulmonary Trunk Pulmonary Veins Lungs Right Ventricle Respiratory Capillaries

Structures of Pulmonary Circuit

Aorta Carotid Arteries Vena Cavae Left Atrium

Structures of Systemic Circuit

True

T OR F Action potentials are carried by the purkinje fibers from the bundle branches to the ventricular walls

True

T OR F In the ventricles, the action potential travels along the interventricular septum to the apex of the heart, where it then spreads superiorly along the ventricle walls

true

T OR F blood pressure is expressed in mm of mercury bc mercury is so dense it enables pressure to be measured with short columns

true

T OR F blood pressure is usually measured with a sphygmomanometer which is a calibrated mercury manometer

false

T OR F the atria never contract due to passive ventricular filling

false

T OR F the audible heart sounds are caused by the contraction of the atria and ventricles

False

T OR F the beginning of ventricular systole is when blood flowing back toward the relaxed ventricles causes the semilunar valves to close

DEPOLARIZES

The P wave is produced when a signal from the SA node spreads through the atria and ____ them

VENTRICULAR

The QRS complex is produced when the signal from the AV node spreads through the ____ myocardium and depolarizes the muscle

DIASTOLE

The T wave is generated by ventricular repolarization immediately before ____

T

The chart includes 3 principle deflections above and below the baseline, the P wave, QRS complex and the ____ wave

Myocardium

Thickest layer; made of muscle and performs the work of the heart

the AV valves close, and then the semilunar valves open

Which of the following is caused by ventricular contraction

Sinoatrial node AV valve AV bundle Bundle branches Purkinje fibers

Which of the following is the correct sequential path of an action potential in the heart?

action potentials pass slowly through the AV node

Which of the following is true concerning the heart's conduction system?

AMPLIFIES

An instrument called the EKC ____ these signals and produces a record on moving paper chart

cardiac reserve

the difference between the maximum and resting cardiac output is called ____

contraction force

the frank-starling law of the heart states that an additional stretch of the myocardium produces a significant increase in ____ on the next beat

the AV valves open

when the pressure in the ventricles becomes lower than the pressure in the atria, ____

Isovolumic contraction, ejection, isvolumic relaxation, passive ventricular filling, active ventricular filling

which of the following is the correct sequence of events regarding the cardiac cycle

Purkinje fibers

Distributes the electrical excitation to the ventricle

1. gap junctions, forming channels that allow ions to flow from one cardiocyte directly into the next 2. allows the entire myocardium of the two atria to behave almost like a single cell

Electrical Junctions

CURRENTS

Electrical ____ in the heart can be detected by means of electrodes applied to the skin

all of the above

Exercise has which of the following effects on cardiac output

1. firing of the SA node excites atrial cardiocytes and stimulates the two atria to contract almost simultaneously 2. in the AV node, the signal slows down to about 0.05 m/sec bc the cardiocytes have fewer gap junctions over which the signal can be transmitted 3. the entire ventricular myocardium depolarizes within 200 m/sec after the SA node fires, causing the ventricles to contract one after another 4. Signals travel through the AV bundle and purkinje fibers at a speed of 4 m/sec the fastest in conduction system 5. the delay at the AV node is essential bc it gives the atria time to fill with blood before it contracts (all of the above)

Choose the correct statements that accurately explain the impulse conduction to the myocardium

Endocardium

Covers the valve surfaces and is continuous with the endothelium of the blood vessels

Jugular vein Pulmonary trunk Pulmonary arteries Right atrium Superior vena cava Great cardiac vein

Deoxygenated Blood

AV node

The electrical gateway to the ventricles

SA node

The pacemaker that determines the heart rate

ventricular filling

during which complete phase of the cardiac cycle do the atria both relax and contract

isvolumetric - ventricles relax

during which phase of the cardiac cycle do both the atria and ventricles relax

ventricular ejection

during which phase of the cardiac cycle does aortic pressure its maximum

???

if a person's heart is pumping 5000 mL of blood in one minute and the heart rate is 50 bpm, what is the cardiac output