Chapter 19 the heart

cardiac muscle shares this fetures with skeletal muscle

..

this figures shows a normal electrocardiogram. missing of the waves point _ might indicate SA node damage

1

this figure shows electrical activity of SA node __ indicates when calcium enters the myocytes

2

this figures shows an action potential in a ventricular cardiocyte . ___ indicates when sodium channels are fully open.

2 ventricular systolic

this figure shows a normal electrocardiogram. the deflection at ponts___ is generated by the ventricular repolarization and it is called the ___

4,2 ,5 and QRS complex

If the SA is damaged , the heart will likely beat at

40- 50 bpm

events of cardiac cycle

aortic valve opening

Any abnormal cardiac rhythm is called

arrhythmia

after entering the rigth atrium , the furthest a red blood cell can travel is the

ascending aorta

congestive heart failure (CHF) of the right ventricle

can cause systemic edema

the volume of blood ejected by each ventricle in one minute is called

cardiac output

Cells of sinoatrial node ___ during the pacemaker potential

depolarize slow

most of the ventricle filling occurs

during atrial diastole

The pulmonary circuit is supplied by both the right and left side of the heart

false

desmosomes form channels that allow each cardiocyte to electrically stimulate its neighbors

false

endurance athletes commonly have a resting heart rate as low as 40 bpm and stroke volume as low as 50 ml/beat

false

ventricular pressure increases the fastest during ventricular filling

false

blood in the heart chambers provides most of the myocardiums oxygen and nutrient needs

false.

cardiac muscle can only use glucose as a source of organic fuel

false. Csrdiac muscle depends os aerobic respiration used to make ATP. Rich in myoglobin and glycogen. Huge fill in mitochondria

the ___ performs the work of the heart a. fibrous skeleton b. pericardial cavity c. endocardium d. myocardium e.epicardium

fibrous skeleton

the ventricles are almost empty at the end of ventricular diastole

flase

this figure shows a normal electrocardiogram . two or more consecutive waves at point 1 migth suggest

heart block

Atrial systole begins

immediately after P wave

____ increases stroke volume.

increased venous return

mitral valves stenosis causes blood to leak back into the___ when the ventricles contract

left atrium - not sure

obstruction of the ___ will cause a more severe myocardial infarction (MI) than obstruction of any others

left coronary artery

mitral valves prolapse (MVP) generates a murmur associated with the __ heart sound that occurs when the__

lubb (S1) ; ventricles contract

cardioinhibitory centers in the ___ receive input from___ A.- cortex; propioceptors in the muscles B.- hypothalamus; chemoreceptors in the medulla oblongata C.- hypothalamus; propioceptors in the joints D.- Medulla oblongata; chemoresecptors in the aortic arch E.- Pons, baroreceptors in the internal caratoid

medulla oblongata; chemo receptors in the aortic

when the left ventricle contracts , the __ valve closes and the __ valve is pushed open

mitral ; aortic

____ is the most superficial layer enclosing the heart a.- parietal pericardium b. visceral pericardium c.- endocardium d. epicardium e. myocardium

parietal pericardium

the long absolute refractory period of cardiocytes

prevents tetanus

____ belong to the pulmonary circuit. A. aorta and venae cavae b.- aorta and pulmonary veins c.- pulmonary arteries and venae cavae d.- venae cavae and pulmonary veins e. pulmonary arteries and pulmonary veins

pulmonary arteries and pulmonary veins

_______ carry oxygen poor blood A. pulmonary veins and vena cavae B. Aorta and pulmonary veins C. Aorta and Vena Cavae D. Venae Cavae and pulmonary arteires e. Pulmonary veins and pulmonary arteries

pulmonary veins and pulmonary arteries

During isovolumetric contraction , the pressure in the ventricles

rises rapidly

the ___ provides most of ca needed for myocardial contraction

sarcoplasmic reticulum

the palteu in the action potential of cardiac muscle results from the action of

slow ca channels

this figure shows the events of the cardiac cycle . At 0.2 sec in the graph

the AV valve is open

Atrial depolarization causes

the P wave

the frank staling law of the heart states that strokes volume is proportional to

the end diastolic volume

pericardial fluid is found in between ? a. the visceral pericardium and the myocardium b. the visceral pericardium and the epicardium c.- the parietal and visceral membranes d. myocardium and endocardium e. epicardium and myocardium

the parietal and visceral membranes

oxygen poor blood passes through a. the right AV valve and the pullmonary valve b. the rigth AV valve only c. the left AV ( biscupid) valve and aortic valve d. the left AV biscupid valve only e. the pulmonary and aortic valves

the right AV valve and the pulmonary valve

the triscupid valve regulates the opening between a. the right atrium and right ventricle b. the right atrium and left ventricle c. the left atrium and left ventricle d. the left atrium and the left ventricle e. the left ventricle anthe rigth ventricle

the rigth atrium and the right ventricle

which of these is not part of the cardiac conduction cycle? a. SA node b. the tendinous cords (TC) c. the AV node d. the AV bundle ( bundle of his) e. teh purkinje fibers

the tendinous cords ( TC) . The parts of conduction system are the following SA, AV node, AV bundle, bundle of his, Purkinje fibers

Atrial hypertrophy would probably cause an enlarged P wave on an electrocardiogram

true

hypercpnia and aidosis have positive chronotropic effect

true

papillary muscle prevent the AV valves from prolapsing ( bulging) excessively into the atria when the ventricles contract

true

parasympathetic stimulation reduces heart rate

true

re polarization of ventricular cardiocyte takes longer than re-polarization of a typical neuron

true

the SA node is damaged , nodal rhythm is sufficient to sustain life

true

the fibrous skeleton of the heart serves as electrical insulation between the atria and the ventricles

true

opening and closing of the heart valves is caused by

valves contracting and relaxing

this is the correct sequence of event of cardiac cycle

ventricular filling, isovolumetric contraction- ventricular ejection, isovolumetric realxation.

the long the plateu phase in the action potential observed in cardiocytes related with __ staying longer in their cytosol

CA

explain the relationship between inspironatiation , pressure changes in the thoracic cavity , venous return ( movement of blood in veins) heart rate, stroke volume and cardiac output at rest

During inspiration, intrathoracic pressure is reduced, which will decrease venous return from the pulmonary circulation to the left atrium of the heart and decrease preload; heart rate will therefore increase slightly to compensate and maintain the same cardiac output. The opposite happens during expiration; intrathoracic pressure rises, increasing pulmonary venous return (and therefore preload), so heart rate will decrease to maintain constant cardiac output.

these are features of cardiac muscle fibers except a they depend almost exclusively on aerobic respiration. b. they have a huge mitochondria c. they are very rich in glyocgen d. they are rich in myoglonin e. they have about the same endurance as skeletal muscle

E

the systemic circuit contains oxygen rich blood only

False

the pacemaker potential result is

NA inflow .. not sure

Isovolumetric contraction occurs during the __ of the electrocardiogram

R wave

the__ is the pacemaker that intitiates each heart beat

SA node

this is the correct path of an electrical excitation from the pacemaker to cardiocyte in the left ventricel

SA node, AV node, AV bundle( Bundle of his) and bundle pukinje fibers; cardiocyte in LV

When a pulse is palpated and counted which pressure would be characteristic at that moment diastolic or systolic?

Systolic