1) Superior and Inferior vena cava
2) Right Atrium
3) tricuspid valves
4) right ventricle
6) Pulmonary ateries
9) left atrium
10) Bicuspid valves
11) left venticle
12)Aorta back to the body
Compare the pulmonary and systemic circuits
Pulmonary Circulation carries deoxygenated blood to the lungs to receive oxygen, while the Systemic Circulation carries the oxygenated blood throughout the body so the oxygen can be used, returning to the Pulmonary Circulation as deoxygenated blood.
Explain the operation of the heart vavles
The upper two are the right and left atria. The lower two are the right and left ventricles. Blood is pumped through the chambers, aided by four heart valves. The valves open and close to let the blood flow in only one direction.
the contraction of the chambers of the heart (especially the ventricles) to drive blood into the aorta and pulmonary artery CONTRACTION
the widening of the chambers of the heart between two contractions when the chambers fill with blood
the volume of blood pumped out by a ventricle with each heartbeat
the complete cycle of events in the heart from the beginning of one heart beat to the beginning of the next; an electrical impulse conducted through the heart muscle that constricts the atria which is followed by constriction of the ventricles) "the cardiac cycle can be shown on an electrocardiogram"
Heart sounds (on NC)
First Heart Sound S1, Second heart sound S2, Third heart sound, S3, Fourth heart sound.. S4, lub- closing of atrioventricular valves when ventricles contract, dup- closing of semilunar valves when ventricles relax
an abnormal sound of the heart; sometimes a sign of abnormal function of the heart valves
Explain what information can be gained from an electrocardiogram (EKG)
The underlying rate and rhythm mechanism of the heart.
The orientation of the heart (how it is placed) in the chest cavity.
Evidence of increased thickness (hypertrophy) of the heart muscle.
Evidence of damage to the various parts of the heart muscle.
Evidence of acutely impaired blood flow to the heart muscle.
Patterns of abnormal electric activity that may predispose the patient to abnormal cardiac rhythm disturbances.
Describe the effect stimulation by the vagus nerve has on heart rate
The vagus never innervates the heart and affects the SA node. Otto Loewi discovered that the vagus nerve through the action of Ach (a
Describe the effect exercise has on heart rate
Your heart rate increases directly as you increase your exercise intensity, until you are near the point of exhaustion as in Olympic cross-country skiing. As that point is approached, your heart rate begins to level off. This indicates that you are approaching your maximum value. The maximum heart is the highest heart rate value you achieve in an all-out effort to the point of exhaustion. This is a highly reliable value that remains constant from day to day and changes only slightly from year to year.
Describe the effect of epinephrine on heart rate
When epinephrine ( ner. trans. secreted by adrenal glands) is released, one of its effects is increased heart rate. This is because in a 'fight or flight' situation, the person decides if he should stay and fight the problem or run for his life. Both these activities need extra energy and oxygen. The brain senses this and sends signals to the adrenal glands (in the kidney), which secrete adrenaline into the bloodstream. The heart rate increases as the body girds itself for what it is about to do: fight or run. The blood vessels and air passages dilate, allowing more blood to the muscles and oxygen to the lungs.
describe the effect of various ions on heart rate
epinephrine and thyroxine increase heart rate. electrolyte imbalances pose threat to heart. reduced levels of ionic calcium in the blood depress the heart, excessive blood calcium causes prolonged contractions that heart can stop entirely. excesses or a lack of needed ions such as sodium and potassium modify heart activity. a deficit of potassium ions in the blood cause heart beat feebly, and abnormal heart rhythms appear.
the smallest blood vessels which connect the smallest arteries with the smallest veins. Nourishment and fluid noramlly trapped in thick walled arteries and veins can easily pass through the delicate walls of the capillaries
blood vessels that carry blood away from the heart
blood vessels that carry waste containing blood from the tissues back to the heart
The cardiovascular system
a closed system of the heart and blood vessels
the heart pumps blood
blood vessels allow blood to circulate to all parts of the body
the function is to deliver oxygen and nutrients and to remove co2 and other waste products
Location of Heart
Thorax between the lungs
pointed apex directed toward left hip
about the size of your fist
a double serous membrane, outside covering/skin of the heart
receiving chambers right and left
discharging chambers right and left
allows blood to flow in one direction, valves open as blood is pumped through, held in place by chordae tendiceae (heart strings), close to prevent backflow
Atrioventricular valves - between atria and ventricles
bicuspid valve (left)
tricuspid valve (right)
semilunar valves - between ventricle and artery
pulmonary semilunar valve
aortic semilunar valve
heart for diagram
leaves left ventricle
leave right ventricle
enters right atrium
pulmonary veins (4)
enter left atrium
circulation of blood through the coronary blood vessels to deliver oxygen and nutrients to the heart muscle tissue
intrinsic conduction system (nodal system)
heart muscle cells contract without nerve impulses, in a regular, continuous way
special tissue sets the pace
contraction is initiated by the sinoatrial node
sequential stimulation occurs at other autorhythmic cells
events of one complete heart beat
mid to late diastole - blood flows into ventricles
ventricular systole- blood pressure builds before ventricle contracts, pushing out blood
early diastole - atria finish re-filling ventricular pressure is low
atria contract simultaneously
atria relax then ventricles contract
bradycardia - 46 beats per minute
tachycardia - 136 beats per minute
ventricular - fibrillation
Regulation of heart rate
stroke volume usually remains constant
starlings law of the heart - the more that the cardiac muscle is stretched, the stronger the contraction
changing heart rate is the most common way to change cardiac output
amount of blood pumped by each side of the heart in one minute (CO = heart rate x stroke volume)
stroke volume - volume of blood pumped by each ventricle in one contraction
systolic - pressure at the peak of ventricular contraction
diastolic - pressure when ventricles relax
pressure in blood vessels decreases as the distance away from the heart increases
variations in blood pressure
normal 140-110 mm Hg systolic
80-75 mm Hg diastolic
low systolic below 110 mm Hg
often associated with illness
high systolic above 140 mm Hg
can be dangerous if it is chronic (high blood pressure)
body's major arteries
Carotid artery: runs up both sides of the neck and is the artery felt when taking a pulse from the neck, delivers blood to the brain.
Femoral: runs through the middle of the thigh on both legs, delivers blood to the lower extremities above the elbow.
Brachial: runs from the anterior of the shoulder to the elbow, delivers blood to the upper extremities.
Radial and Ulnar: stems off of the brachial and goes around the radius and ulna respectively, feeds blood to the flangies and lower extremites below the elbow.
facts about the heart
A liquid, blood, to transport
oxygen and carbon dioxide
Two pumps (in a single heart)
one to pump deoxygenated blood to the lungs;
the other to pump oxygenated blood to all the other organs and tissues of the body.
A system of blood vessels to distribute blood throughout the body
Specialized organs for exchange of materials between the blood and the external environment; for example
organs like the lungs and intestine that add materials to the blood and
organs like the lungs and kidneys that remove materials from the blood and deposit them back in the external environment.
From the left atrium,
Blood flows through the mitral valve (also known as the bicuspid valve) into the left ventricle.
Contraction of the ventricle closes the mitral valve and opens the aortic valve at the entrance to the aorta.
The first branches from the aorta occur just beyond the aortic valve still within the heart.
Two openings lead to the right and left coronary arteries, which supply blood to the heart itself.
Although the coronary arteries arise within the heart, they pass directly out to the surface of the heart and extend down across it. They supply blood to the network of capillaries that penetrate every portion of the heart.
The capillaries drain into two coronary veins that empty into the right atrium.
Deoxygenated blood from the body enters the right atrium.
It flows through the tricuspid valve into the right ventricle. The term tricuspid refers to the three flaps of tissue that make up the valve.
Contraction of the ventricle then closes the tricuspid valve and forces open the pulmonary valve.
Blood flows into the pulmonary artery.
This branches immediately, carrying blood to the right and left lungs.
Here the blood gives up carbon dioxide and takes on a fresh supply of oxygen [More].
The capillary beds of the lungs are drained by venules that are the tributaries of the pulmonary veins.
Four pulmonary veins, two draining each lung, carry oxygenated blood to the left atrium of the heart
function of veins
Veins bring deoxygenated blood into the heart from the rest of the body, except for the pulmonary vein, which brings oxygenated blood from the lungs to the heart.
The vein has small one way valves, it carries the blood to heart.
These are wide lumen, thin wall, superficial.
Deoxygenated blood should not miconcepted with completely impure blood. Veins do not carry nitrogenous wastes and other wastes of body other than CO2
the superior vena cava (a large vein to collect oxygen poor blood from chest and above)
the inferior vena cava (a large vein to collect oxygen poor blood from all parts of body below the chest)
pulmonary vein - one of two pairs of vessels carrying oxygenated blood from the lungs to the left atrium of the heart
condition in which fatty deposits called plaque build up on the inner walls of the arteries
There are three basic ways for things to cross the capillary wall:filtration diffusion diapedesis, exchanges between the tissue cells and blood occur here, semi permeable membranes contains pores that let small substances pass through but keep in blood cells and larger molecules like proteins.
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