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57 terms

Ch. 20 The Heart

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arteries
carry blood away from the heart; efferent vessels
veins
carry blood towards the heart; afferent vessels
The heart has how many chambers?
4
What supplies the heart with oxygen?
coronary artery
What are the two functions of the coronary artery besides supplying the heart with oxygen?
Pumps oxygen poor blood to the lungs and pumps oxygen rich blood to the rest of the body
What is is called when the heart doesn't have oxygen?
heart attack
What surgery fixes blockage? And what do they do in the surgery?
Bypass surgery : take arteries from legs to bypass the blockage
What is the inferior point of the heart called?
the apex
What is the pericardial sac and what does it do?
it is a fluid filled sac that hold the heart
The heart sits in the anterior portion of the __________.
mediastinum
What is the function of the pericardial fluid?
lubricant that reduces friction while the heart is beating
The lining of the Pericardial Sacis called the ______________.
pericardium
Located in this sac is normally ____-_____ ML of pericardial fluid.
15-50 ML
What is the infection of the pericardium caused by pathogens or inflammation called?
Pericarditis
The heart wall : (Layer 1:_________)
outer epicardium
The heart wall : (Layer 2:_________)
middle myocardium
The heart wall : (Layer 3:_________)
inner endocardium
What are the two great veins that supply the body with blood? (They are part of the right atrium)
Superior vena cava and inferior vena cava
Superior vena cava sends blood to which parts of the body? (4)
Head, neck, upper limbs, and chest
Inferior vena cava sends blood to which parts of the body? (2)
rest of the trunk and lower limbs
What returns blood to the coronary sinus?
Cardiac veins
What is the coronary sinus?
a large thin walled vein that opens into the right atrium, inferior to the connection with the superior vena cava
What is the wall between the two atria called?
Interatrial septum
The opening between the two atria that allows blood to flow from one atria to the other from the 5th week of embryonic development to birth is called what?
The foramen ovale
What does the forman ovale allow during development?
Allows the lings to develop and at birth the opening is permanently sealed off within three months of delivery
The right ventricle has _______ cusps that separate the right atria and the right ventricle. These cusps are part of the right aortic valve (AV) which is also known as the __________ valve.
three; tricuspid
Aortic valve closes when the right ventricle contracts..... preventing what? (Right ventricle)
back flow of blood
Blood flows through the _________ ______ into the pulmonary arteries that end inside the _______ with small capillaries where the gas exchange takes place. (Right ventricle)
pulmonary valve; lungs
From the capillaries of the pulmonary artery the gas will exchange in the lungs. The blood will unite to form _______ _______________ _______. (left atrium)
four pulmonary veins
There is a left AV valve also called __________ valve that the blood flows through on its way to teh left ventricle.
bicuspid
This left AV valve also prevents backflow of blood during ____________ ______________.
ventricular contractions
Both ventricles hold an equal amount of blood but the _____ ventricle is larger than the ______ ventricle.
left; right
Why is this one larger than the other?
because the walls are much thicker!
What is the purpose of one being larger than the other?
Because it can build up a great amount of pressure that is needed to push the blood out into the body.
The blood goes through another valve... called ______ valve that leads the blood into the __________ aorta. This _____________ valve as it is sometimes called prevents back-flow into the right ventricle.
aortic; ascending; semilunar
THe blood continues into the _______ ______ and then finally into the descending aorta where is will..... ________________.
aortic arch; be distributed throughout the whole body
The heart needs a constant amount of oxygen and nutrients. During maximum exertion the blood flow to the heart may increase up to ___ times the resting stage amount.
9 times
What do the left and right coronary arteries do?
Bring fresh amounts of oxygen and nutrients to the heart
What empties into the coronary sinus?
cardiac veins
What two cells are involved with cardiac physiology?
specialized muscle cells and contractile cells
What is the function of specialized muscle cells?
to control and coordinate the heartbeat
What is the function of contractile cells?
to produce the powerful contractions that propel the blood
What is the first stage of impulse conduction through the heart?
Activation begins at the A.S. Node located on the posterior part of the right atrium where the superior vena cava joins the right atrium.
What is the second stage of impulse conduction through the heart?
Conduction to the AV node
What is the third stage of impulse conduction through the heart?
Atrial contraction begins
What is the fourth stage of impulse conduction through the heart?
Impulse travels along the interventricular septum to the right ventricle
What is the fifth stage of impulse conduction through the heart?
Atrial contraction complete.... ventricular contraction begins
A heart beat only lasts _______ _sec
370 milliseconds
What is phase one called of a heartbeat? And what happens during this phase?
systole; or contraction , the chamber contracts and pushes blood into an adjacent chamber or into an arterial trunk
What is phase two called of a heartbeat? And what happens during this phase?
Diastole; or relaxation, the chambers relax and fill with blood and prepare for the next cardiac cycle
What happens between 0-100 msec? (2things)
atrial systole begins and then atrial diastole
What happens between 100-370 msec? (3things)
ventricular systole first phase, and then second phase and then early ventricular diastole
What happens between 370-800 msec?
ventricular diastole late: all chambers are relaxed. ventricle fill passively.
how do you find cardiac output?
heart rate times stroke volume
What two factors affect cardiac output?
Heart rate or stroke volume
What two factors affect Heart Rate?
Activities and hormones
What two factors affect stroke volume?
changes in the EDV and changes in the ESV