CH 18 HW

False

The moderator band is found on both the right and left side of the heart. False True

Most blood flows passively into the ventricles through open AV valves.

Which of the following is correct about the filling of the ventricles? -Most blood flows passively into the ventricles through open AV valves. -The majority of ventricular filling is caused by contraction of the atria.

epinephrine

Which of the following would increase cardiac output? parasympathetic stimulation high blood pressure epinephrine decreased calcium during contraction

SA node

Which part of the conduction system initiates the depolarizing impulse, which spreads throughout the heart? SA node AV node AV bundle (bundle of His) Purkinje fibers

AV node

Which part of the intrinsic conduction system delays the impulse briefly before it moves on to the ventricles? bundle branches AV bundle (bundle of His) AV node Purkinje fibers SA node

gap junctions

Action potentials generated by the autorhythmic cells spread to the contractile cells through what structures in the membrane? intercalated discs gap junctions tight junctions desmosomes

Pressure in the atria would be greater than the pressure in the ventricles.

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves. Pressure in the ventricles would be greater than in the atria. Pressures in the atria and ventricles would be equal. Pressure in the atria would be greater than the pressure in the ventricles.

Pulmonary semilunar valve

Identfiy the valve located at the exit of the right ventricle. Tricuspid valve Pulmonary semilunar valve Aortic semilunar valve Bicuspid valve

Auricle

Identify the ear like flaps that are attached to the top chambers of the heart. Coronary sinus Auricle Pectinate muscles Atrium

Left ventricle

Identify the most muscular chamber. Right ventricle Left ventricle Left atrium Right atrium

Endocardium

Name the inner lining of the heart. Endocardium Myocardium Pericardium Epicardium

Trabeculae carneae

Name the irregular ridges of muscle lining the ventricles. Chordae tendineae Pectinate muscles Trabeculae carneae Papillary muscles

isovolumetric contraction, ventricular ejection, isovolumetric relaxation

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling. isovolumetric contraction, ventricular ejection, isovolumetric relaxation ventricular ejection, isovolumetric contraction, isovolumetric relaxation isovolumetric relaxation, ventricular ejection, isovolumetric contraction ventricular ejection, ventricular relaxation, isovolumetric contraction

greater pressure in the aorta than in the left ventricle

What causes the aortic semilunar valve to close? -greater pressure in the aorta than in the left ventricle -equal ventricular and aortic pressures -higher ventricular pressure than aortic pressure

electrical activity in the heart

What does the ECG wave tracing represent? electrical activity in the heart contraction of the heart

75 mL

Calculate the stroke volume if the end diastolic volume (EDV) is 135 mL and the end systolic volume (ESV) is 60 mL. 60 mL 75 mL 205 mL 8100 mL

True

Blood on the right never mixes with blood on the left, once the heart is fully developed. True False

P wave

Contraction of the atria results from which wave of depolarization on the ECG tracing? QRS complex T wave P wave

Tricuspid valve

Identify the right atrioventricular valve. Tricuspid valve Aortic semilunar valve Pulmonary valve Bicuspid valve

Bicuspid (mitral) valve

Identify the valve found between the left atrium and left ventricle. Tricuspid valve Bicuspid (mitral) valve Aortic valve Pulmonary valve

the flow of positive ions from adjacent cells

In order to cause cardiac muscle contraction, the contractile cells must also depolarize. What causes the depolarization of the contractile cells? -the flow of positive ions from adjacent cells -the flow of negative ions from adjacent cells -an unstable resting membrane potential in the contractile cells

AV valves only

Increased pressure in the ventricles would close what valve(s)? semilunar valves only both semilunar and AV valves AV valves only

ventricular diastole

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________. ventricular diastole ventricular systole

Pectinate muscles

Name the ridged bundles of muscle found projecting inside the right atrium. Trabeculae carneae Papillary muscles Pectinate muscles Intercalated discs

potassium

One of the changes that occurs in the pacemaker potential (unstable resting membrane potential) in the SA node (an autorhythmic cell) is a decreased efflux of what ion? potassium calcium sodium

False

Oxygenated blood flows through the right side of the heart. False True

voltage-gated potassium channels

Repolarization of an autorhythmic cell is due to the opening of which channels? chemically gated calcium channels voltage-gated sodium channels voltage-gated potassium channels Chemically gated potassium channels

aorta to smaller systemic arteries to systemic capillaries to systemic veins to right atrium, and then through the tricuspid valve

Select the correct partial path. This path is part of the complete blood flow pathway. You should be able to trace flow starting in any location. View Available Hint(s) -systemic veins returning to the left atrium and forward through the mitral valve -pulmonary trunk to pulmonary arteries to pulmonary capillaries to pulmonary veins returning to the right atrium -pulmonary artery into left atrium through mitral valve to left ventricle -aorta to smaller systemic arteries to systemic capillaries to systemic veins to right atrium, and then through the tricuspid valve

False

The base of the heart is located at the bottom of the heart. True False

True

The first branch off the arch of the aorta is the brachiocephalic artery in both the sheep and the human. True False

ventricular depolarization

What does the QRS complex represent in the ECG wave tracing? ventricular depolarization ventricular repolarization atrial repolarization atrial depolarization

Chordae tendineae

What fibrous structure functions to anchor the atrioventricular valves in a closed position? Chordae tendineae Moderator band Papillary muscle Trabeculae carneae

Left ventricle

What heart chamber pushes blood through the aortic semilunar valve? Right atrium Left ventricle Left atrium Right ventricle

Provide a blood supply to the heart

What is the function of the coronary circulation? Provide a blood supply to the pericardium Provide a blood supply to the heart Provide a blood supply to the aortic arch Provide a blood supply to the lungs

A remnant of the ductus arteriosus

What is the ligamentum arteriosum? A remnant of the ductus arteriosus A remnant of the foramen ovale A ligament securing the aorta A ligament attaching the aorta to the superior vena cava

intercalated discs

What structures connect the individual heart muscle cells? chordae tendineae intercalated discs trabaculae carneae anastomoses

fast calcium

When threshold is reached at the SA node (an autorhythmic cell), what channels open causing further depolarization of the membrane? slow calcium fast calcium potassium fast sodium

Right ventricle

Which chamber of the heart exits into the pulmonary trunk? Left ventricle Left atrium Right ventricle Right atrium

increasing afterload

Which of the following is NOT a factor that increases stroke volume? increasing preload increasing contractility increasing afterload increasing sympathetic stimulation

Myofibrils of cardiac muscle tissue vary in diameter and branch extensively.

Which statement regarding cardiac muscle structure is accurate? -Cardiac cells are long, cylindrical, and multinucleate. -Cardiac cells possess few mitochondria. -Cardiac muscle cells are independent of one another both structurally and functionally. -Myofibrils of cardiac muscle tissue vary in diameter and branch extensively.