BLGY231 Heart Questions

put the layers/spaces of the pericardium and heart wall in order, superficial to deep.

1. fibrous pericardium 2. parietal pericardium 3. pericardial cavity 4. epicardium (visceral pericardium) 5. myocardium 6. endocardium

what is the order of nodal cell activity?

1. voltage-gated Na+ channels open 2. threshold is reached 3. voltage-gated Ca2+ channels open 4. an action potential occurs 5. voltage-gated K+ channels open 6. repolarization occurs

how many half-moon shaped, pocketlike cusps are found in each semilunar valve?

3

on an EKG, this is atrial depolarization?

P wave

on an EKG, this is time between ventricular depolarization and repolarization?

Q-T interval

on an EKG, this is ventricular depolarization?

QRS complex

the heartbeat is initiated by the cells of the?

SA node

what part of the cardiac conduction system is located in the posterior wall of the right atrium, adjacent to the entrance of the superior vena cava?

SA node

what is the sequence of events in the transmission of an impulse through the heart muscle?

SA node, through the atria, AV node, AV bundle, bundle branches, purkinje fibers, through the ventricles

on an EKG, this is ventricular repolarization?

T wave

cardiac output is the amount of blood that is pumped by?

a single ventricle in one minute

metabolically, cardiac muscle relies on?

aerobic metabolism using many mitochondria and multiple types of fuel molecules

the resistance in arteries to the ejection of blood by the heart is known as?

afterload

what would cause a decrease in cardiac output?

an increase in afterload

this is between the left ventricle and aorta?

aortic semilunar valve

the inferior, conical end of the heart is called the?

apex

what structure carries blood away from the heart?

arteries

the pulmonary trunk receives blood from the right ventricle and conducts it toward the lung. the pulmonary trunk is a(n)?

artery

according to the Frank-Starling law, what does it state?

as the volume of blood entering the heart increases, ventricular contractions become more forceful

the anterior part of each atrium is a flaplike extension called a(n)?

auricle

this is between the left atrium and the left ventricle?

bicuspid valve

for the repolarization phase of an SA nodal cell action potential?

calcium channels close and potassium channels open

once an SA nodal cell reaches threshold, the depolarization phase occurs during which?

calcium comes in through fast voltage-gates channels

during the Q-T interval, what is occurring within cardiac muscle cells?

calcium is entering and potassium is leaving ventricular cells

what structure exchanges nutrients and wastes?

capillaries

the period of time from one heartbeat to the next?

cardiac cycle

amount of blood pumped by a single ventricle in one minute?

cardiac output

the papillary muscles attach to the cusps of the atrioventricular valves by means of the?

chordae tendineae

during the plateau phase of a cardiac muscle cell's action potential, the membrane stays?

depolarized as potassium exits and calcium enters

chamber relaxation?

diastole

atrial systole occurs just before?

early ventricular systole

the membrane of a contractile cardiac muscle cell contains?

fast voltage-gated sodium channels and slow voltage-gated calcium channels

what structure pumps blood?

heart

number of beats per minute?

heart rate

what do positive chronotropic agents do?

increase heart rate

the atria are separated from themselves internally by the?

interatrial septum

what are the cell-to-cell contacts of the cardiac muscle fibers called?

intercalated discs

the serous fluid within the pericardial cavity works to?

lubricate membranes of the pericardium

the layer of the heart wall composed of cardiac muscle tissue is the?

myocardium

the cardioinhibitory center is controlled by which division on the autonomic nervous system and causes what to occur?

parasympathetic and decrease in heart rate

the heart valves do what?

permit the passage of blood in one direction

large doses of certain stimulants can lead to dangerous increases in heart rates, which are called a?

positive chronotropic agent

the opening and closing of the heart valves is caused by?

pressure changes of alternating contraction and relaxation during the cardiac cycle

when the ventricles are contracting, what is happening?

pressure is higher in ventricles than atria, atria are relaxed, atrioventricular valves are closed, semilunar valves are closed but pushed open

which of the cardiovascular system's circuits has deoxygenated blood in its arteries?

pulmonary circuit

this is between the right ventricle and pulmonary trunk?

pulmonary semilunar valve

which carries oxygenated blood from the lungs to the heart?

pulmonary veins

oxygenated blood can be found in?

pulmonary veins and aorta

as blood is pumped out of the heart and into the major arteries leaving the heart, it?

pushes against the semilunar valves and opens them

in an ECG, what does the T wave denote?

repolarization of the ventricles

the fossa ovalis appears just above the opening of the coronary sinus within the?

right atrium

the right border of the heart is supplied by the?

right marginal artery

the right coronary artery supplies the?

right side and back of the heart

blood flows from the right atrium to the ___________ then to the __________ to the ___________ where it goes to the ____________.

right ventricle; pulmonary trunk; pulmonary arteries; lungs

volume of blood ejected during 1 beat in 1 ventricle?

stroke volume

which circuit of the cardiovascular system is responsible for sending blood to the kidneys, stomach, and pelvic regions?

systemic circuit

chamber contraction?

systole

the function of the coronary sinus is to?

take blood from the coronary circulation to the right atrium

what depicts differences between cardiac muscle tissue and skeletal muscle tissue?

the sarcoplasm is more folded in cardiac muscle, cardiac muscle has intercalated discs and skeletal muscle does not, and cardiac muscle has more mitochondria than skeletal muscle

during ventricular systole?

the semilunar valves open and the AV valves close

what describes nodal cells?

they are autorhythmic and require no outside stimulation

this is between the right atrium and the right ventricle?

tricuspid valve

to initiate a cardiac muscle cell contraction, calcium binds to?

troponin

parasympathetic innervation of the heart occurs via the ________?

vagus nerve

what structure carries blood towards the heart?

veins

the inferior chambers of the heart are called?

ventricles

the epicardium is another name for the?

visceral pericardium