11.2 Structure and Function of the Heart Flashcards
Pulmonary meaning
Latin word meaning “lung”
Aortic meaning
Greek word meaning “to lift”
Vena Cava meaning
Vena= Latin word for vein
Cava= Latin word for cave/hollow
Coronary meaning
Latin word for crowned
Septum meaning
Divides something in half (nasal septum, cardiac septum…)
heart
Hollow organ made entirely of muscle
As your heart ____, blood is pumped out
contracts
When your heart ________, blood fills it
relaxes
This entire process of pumping blood in and out is known as the _______________, and takes approximately 0.8s
cardiac cycle
Heart is enclosed by the ___________
pericardium
pericardium
protective membranous sac that encloses the heart
heart is divided by _______ septum
cardiac
4 chambers of the heart
Right atrium
Right ventricle
Left atrium
Left ventricle
2 ______________ called _______ receive blood returning to the heart
upper chambers; atriums
Atria (s. atrium)
Pump blood a short distance
Have thin walls
2 ______________ called __________ pump blood out of the heart to the body
lower chambers; ventricles
ventricles
Pump blood a far distance
Have thicker walls
Valves in heart prevent blood from ______________
flowing backward
Atrioventricular valves
Valves located between atria and ventricles
Bicuspid/mitral (left); tricuspid (right)
Semilunar valves
-pulmonary valve
-located between the right ventricle and
pulmonary artery
Aortic Valve
Between the left ventricle and the aorta
With each _____ the valves open, allowing blood to ___________
heartbeat; flow through
The valves in the heart then close preventing ______________
backflow
“Lub Dub” sound comes from valves _______
closing
“lub” is ________- valves closing
atrioventricular
“dub” is the ______ and _____ valves closing
pulmonary; aortic
The heart is often considered to be a “_________________”
double pump
One pump pushes blood to the lungs
Pulmonary circuit
One pump pushes blood to the rest of the body
systemic circuit
systemic circuit
O2 rich blood
left Atrium
left ventricle
aorta
arteries
arterioles
capillaries
O2, nutrients, CO2, wastes diffuse in and out of capillaries
in systemic circuits, once capillary exchange has been completed, blood is ___________ and flows back to the ____ ___ of the heart through the _____ _____ veins
deoxygenated; right atrium; vena cava
Superior Vena Cava
vein entering the heart from the upper body
Inferior Vena Cava
vein entering the heart from the lower body
pulmonary circuit
right atrium
right ventricle
pulmonary arteries
lungs to get O2 via diffusion
blood returns to heart through pulmonary veins
The circuit starts all over again
Most arteries in your body carry oxygen-rich blood and most veins carry oxygen-depleted blood. However, the blood vessels in the pulmonary circuit do the ____ _____
exact opposite
in the pulmonary circuit, pulmonary artery carries ________
deoxygenated blood
in the pulmonary circuit, pulmonary vein carries _______
oxygenated blood
The heart receives _____ _____ oxygen for itself
very little
Coronary arteries branch from the _____
aorta
Coronary arteries cover the surface of the heart like a crown and supply the heart muscle with ______________
the necessary nutrients
pacemaker
Aka sinoatrial (SA) node
Region of your heart located in right atrium
Electrically sets the rate at which your heart contracts
pacemaker generates __________________ that spread rapidly over walls of both atria, making them ______
electrical impulses; contract
Impulses from the pacemaker then spread to the _________________
AV node (atrioventricular node)
Electrical impulses spread to _____ causing them to ______
ventricles; contract
Contracting ______ send blood to the rest of the body
ventricles
pacemaker process
-Generates electrical impulses that spread rapidly over walls of both atria, making them contract
-Impulses then spread to the AV node (atrioventricular node)
-Electrical impulses spread to ventricles causing them to contract
-Contracting ventricles send blood to the rest of the body
atria contract
blood forced into relaxed ventricles
ventricles contract
pumping blood to arteries, atria are relaxed
tachycardia
-medical term for a heart rate over 100 beats a minute
-many types of irregular heart rhythms (arrhythmias) can cause tachycardia.
ventricular fibrillation
-type of irregular heart rhythm (arrhythmia)
-during ventricular fibrillation, the lower heart chambers contract in a very rapid and uncoordinated manner
-as a result, the heart doesn’t pump blood to the rest of the body
heart block
when the electrical impulses that control the beating of the heart muscle are disrupted
Sphygmomanometer
blood pressure cuff
what units are used to measure blood pressure?
Measured in millimetres of mercury (mm Hg)
-e.g. 120/80 mm Hg
120/80 mm Hg
what type of pressure is 120?
120 = systolic pressure
120/80 mm Hg
what type of pressure is 80?
80 = diastolic pressure
systolic pressure
Highest pressure in an artery when ventricles contract
diastolic pressure
Lowest pressure in an artery during relaxation phase
blood pressure depends on which 2 factors?
cardiac output and resistance of arteries
Cardiac output
amount of blood pumped by the heart each minute
Resistance of arteries
related to elasticity of arteries
BP varies according to
height, weight, fitness, time of day, physical activity, hydration, etc.
How does a stethoscope work?
-transmits vibrations from the patient through the chest piece, which is a diaphragm or hollow cup.
-the sounds then vibrate through hollow tubes
to the listener’s ears
-the diaphragm transmits higher-frequency vibrations and the hollow cup transmits lower-frequency vibrations
What happens when the heart
muscle contracts?
As your heart contracts,
blood is pumped out
What happens when the heart
muscle relaxes?
When your heart relaxes, blood enters the heart.
What is the function of valves in the heart?
Valves in the heart prevent blood from flowing backward
atrioventricular valves
The valves that are located between the atria and ventricles
pulmonary valve
between the right ventricle and the pulmonary artery
aortic valve
between the left ventricle and the aorta
pulmonary circuit
blood travels from the right side of your heart
through the pulmonary arteries to your lungs
What makes the “lub dub” sound of your
heart beating?
When the valves close, they cause the familiar heart sound of “lub dub.”
-“lub” sound is the atrioventricular valves closing
-“dub” sound happens when the pulmonary and aortic valves close
State one way in which the function of the
pulmonary artery is different from the
function of other arteries in the body.
Pulmonary arteries carry oxygen-depleted
blood to the lungs.
(blood vessels in the pulmonary
circuit do the exact opposite)
What is the difference between the superior
vena cava and the inferior vena cava?
The vein entering the heart from the UPPER body is called the superior vena cava.
The vein entering the heart from the LOWER body is called the inferior vena cava.
How are the cells of the heart supplied with
necessary oxygen and nutrients?
The coronary arteries cover the surface of the heart like a crown and supply the heart muscle with the necessary nutrients
Where in the heart would you find the area
known as the pacemaker?
The pacemaker is located in the wall of the right atrium
About how many times does a heart beat
per minute?
between 60 and 100 times per minute
What is a sphygmomanometer?
pressure cuff used to measure blood pressure
hormones
The pacemaker is controlled by both the nervous system and the endocrine system, which produces chemicals called hormones
diastolic pressure
the second number in a blood pressure measurement, is the lowest recorded pressure
in an artery during the relaxation phase of the heartbeat
systolic pressure
The first number in a blood pressure measurement is the highest recorded pressure in an artery when the ventricles contract.
What two factors does blood pressure
depend on?
cardiac output and resistance of arteries
-the first factor, cardiac output, is the amount of blood that is pumped by the heart each minute.
-e.g. if the volume of blood pumped through an
artery increases, you would expect that the
pressure of the blood would also increase.
-the second factor that affects blood pressure is the resistance of the arteries
-arterial resistance is related to the elasticity in the arteries
-e.g. if the arteries do not expand easily and
instead resist the flow of blood, the pressure of
the blood on the arterial walls increases.
What is an average blood pressure reading
for a healthy adult?
Blood pressure in a healthy young adult might
vary between about 110 and 130 over 70 to 90, with an average of about 120/80
true or false: a blood pressure consistently above 140/90 is considered low
false
-it’s considered high
Explain why the heart is called a “double pump.”
Although it is one organ, the heart functions as two pumps.
One pump pushes blood to the lungs, while the other pump pushes blood to the rest of the body.
benefits of the heart being a “double pump”
ensures that oxygen-rich blood
is constantly delivered to cells.
The two pathways or circuits of blood
through the body are called …
the pulmonary circuit and the systemic
circuit
Suppose you listened with a stethoscope below
a sphygmomanometer and heard sounds beginning
at 140 mm Hg and stopping at 95 mm Hg.
(a) What is the systolic blood pressure reading?
(b) What is the diastolic blood pressure reading?
(c) What is this person’s blood pressure?
a) 140 mm Hg
b) 95 mm Hg
c) 140/95
Suppose you listened with a stethoscope below
a sphygmomanometer and heard sounds beginning at 140 mm Hg and stopping at 95 mm Hg.
(d) Is this a healthy blood pressure? Explain
no because a blood pressure consistently above 140/90 is considered high
