The anatomy of the heart consists of
Chambers, valves, vessels and circulation
The function of the heart is to
circulate blood throughout the lungs and various tissues of the body.
Without the circulation of the heart
nutrients cannot be delivered, waste products cannot be removed, and therefore you would die.
What happens when the heart contracts
blood moves into the lungs to get oxygen, then the oxygen gets into the body's circulation delivering oxygen to the tissues
Blood supplies the tissues with
nutrients and O2
Blood removes
CO2 and waste products
The heart is what shape organ
triangular shaped
The heart is located
in the center of the chest, under the sternum and in between the lungs. 2/3 rds of the heart lies to the left of the sternum
The Approx.
size of the heart is
The size of a fist
The approx weight of the heart is
10.6 oz
Beats average (minutes, Day, lifetime)
72 beats per minute - 100,000 beats per day - 22.5 billion in a lifetime
The heart Pumps about ____ ml blood per beat for a total ___L/minute
140 blood per beat for a total 5L/minute
Heart pumps daily about ______ L or ______ gallons of blood (average bathtub filled 36 times)
7250 L or 1800 gallons of blood average bathtub filled 36 times
The heart is like ____ pumps side by side divided by ________.
2 pumps side by side divided by septum
What are the 4 chambers of the heart
2 upper atria 2 lower ventricles
What keeps blood flowing in one direction
Valves
What prevent the valves from turning inside out
Chodae Tendae
Middle muscular layer
Myocardium
Muscle is thickest in what chamber of the heart
L ventricle
thicker muscle in heart chamber means.
stronger contraction of that chamber giving it the ability to pump blood through body
The valve between the R atrium and the R ventricle is the
Tricuspid valve
The valve between the L atrium and the L ventricle is the
Bicuspid valve AKA mitral valve
Valves that divide the atrium from the ventricles on R & L of heart are known as
Atrioventricular valves
Why are the heart valves one-way
to keep the blood flowing in one direction
What type of valve is named because they look like half moons. And what are the names of the 2 in your heart
semilunar valve Semi (half) lunar (moon) pulmonary and aortic semilunar valves
transports blood back to the heart
Vena cava
returns blood from the head, arms and upper body to heart
Superior vena cava
returns blood from the lower legs and body to heart
Inferior vena cava
when the heart contracts the R ventricle pumps deoxygenated blood to the lungs via this artery
Pulmonary artery
transports oxygenated blood from the lungs back to the heart via L atrium
Pulmonary veins
The largest artery in the body.
It transports oxygenated blood to entire body. t
Aorta
The first of the arteries to branch off of the aorta is
coronary arteries
Trace a drop of blood through the heart to the lungs
Enters via the vena cava to R atrium-Thru the tricuspid valve-Into R ventricle-Thru pulmonary valve-To pulmonary arteries to lungs-There are tiny capillaries and thin walls so O2 and CO2 can pass over through Osmosis
Trace a drop of blood from the lungs through the heart to the body
Blood now has oxygen-Thru pulmonary veins -Into L atrium-Past Mitral (bicuspid ) valve-Into L ventricle-Out the aorta (largest artery in the body)-The aorta after descending past the diaphragm is known as the abdominal aorta
Three types of circulation
Pulmonary - between the heart and lungs-Systemic - between the heart and body-Coronary - the hearts blood supply
The portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart.
Systemic circulation
Refers to the movement of blood through the tissues of the heart
Coronary circulation
Each beat of the heart has two phases that indicate contraction and relaxation periods what are the two phases and what cycle do they make up
Relaxation phase - Diastole Conduction Phase - Systole -These 2 phases together make up the cardiac cycle.
What happens during diastole
Blood from the body returns to the heart via vena cavas.
R atrium fills with blood and contracts, pushing open the tricuspid valve (this allows blood to flow into the R ventricle). At the same time, blood returns from the lungs via the pulmonary veins into the L atrium . (blood fills L atrium prior to atrial contraction). Atrial contraction forces mitral valve to open to allow blood to flow into L ventricle.
What happens during Systole
Heart muscles contract, creating pressure to open the pulmonary and aortic valves.Blood from R ventricle is pushed into the lungs to exchange O2 and CO2.
Blood from the L ventricle is pushed thru the aorta to be distributed throughout the body.
In general women have faster heartbeats then men true or false
true
Children's rates are faster then adults true or false
true
On average adults heart beats
60-100 bpm
what sound is heard during systolic phase by the contraction of the ventricles and the closing of the AV valves
Lubb sound
during the diastolic phase. It is a shorter sound and occurs during the beginning of ventricular relaxation. Caused by the closing of the semilunar valves.
Dubb sound
Each contraction of heart is caused by
electrical impulses throughout the heart
The pumping cycle of heart is controlled by
electrical impulses
______ _______are initiated and transmitted through the heart in a specific pathway.
Electrical impulses
What do Specialized masses of tissues in the heart do
They produce electrical impulses and form the conduction system
The conduction system is necessary
for the heart to pump continuously and rhythmically.
ability of the heart to initiate an electrical Impulse without being stimulated by another source
Automaticity
Ability of the heart muscle cells receive and transmit an electrical impulse
Conductivity
Ability of the heart muscle cells to shorten in response to an electrical stimulus
Contractility
Ability of the heart muscle cells to respond to an impulse or stimulus. Without this quality the heart would nor react to the electrical impulses that are initiated within the heart
Excitability
Where is the SA node located
in upper portion of the R atrium
What is the SA node also known as? /why?
AKA pacemaker of the heart - it initiates the heartbeat
Automatricity of the fibers of SA node produces
the contraction of the R and L atria
SA node fires about
60 - 100 times per minute
Where is the AV node located
on the floor of the R atrium
Impulses travel from the SA node à
AV node because of conductivity
The AV node itself causes a delay (slowdown) of the impulse two reasons why
1) to allow additional blood to travel from the atrium to the ventricles before they contract (known as atrial kick) this will increase the cardiac output (the amount of blood pumped out of the heart into the rest of the body) 2) reduces the number of electrical impulses transmitted onto the ventricles,this is important if the SA node is firing too fast
What is located next to the AV node - Provides transfer of electrical impulses from atria to the ventricles
Bundle of HIS
What is located on the L and R side of the interventricular septum- Impulses travel R and L bundle branches to the R and L ventricles Electrical impulse split and travel down both sides. This activates the myocardium to contract.
Bundle branches
What Speeds impulses thru the ventricles provides an electrical pathway for each of the cardiac cells.
The electrical impulses accelerate and activate the L and R ventricle at the same time to contract.
Purkinje fibers
