Healthcare test #4 Flashcards
The cardiovascular system
The organ system that is made up of the heart, the blood, and the blood vessels
The circulatory system connects all parts of the body.
left and right
Oxygenated blood is shown in red (left side of body). Deoxygenated blood is shown in blue (right side of body).
Function of the circulatory system
To transport substances around the body
To move nutrients to all of the body’s cells
Regulation of body temperature
Transport of disease-fighting white blood cells to areas of the body where they are needed (i.e. viruses/bacteria)
How is this done?
Blood flows through lungs, picks up oxygen, then flows to heart to pump to body to deliver it to active cells
Parts of the Cardiovascular (circulatory) system
4 parts of the circulatory system: blood, heart, and blood vessels, lungs
Heart pumps blood through large vessels (arteries) AWAY from heart to body
Blood exchanges substances, in smallest vessels (capillaries), with surrounding tissues
Blood then flows into larger vessels (veins) and returns TO the heart
Blood then goes to lungs for more oxygen, back to heart and cycle continues
The Heart
Located slightly left of middle of the chest -about the size of your fist (weighs 9 oz)
Protected by sternum
Surrounded by pericardium
Muscular part is myocardium (cardiac muscle) coronary artery supplies heart with O2, cardiac vein removes CO2
Has 4 chambers – 2 atria and 2 ventricles
3 Layers of the Heart
pericardium, myocardium, endocardium
Chambers of the Heart
Atria (atrium)– 2 top chambers;
-right atrium gets deoxygenated blood from the vena cava from body
-left atrium gets oxygenated blood from the pulmonary vein from the lungs
Ventricles – 2 lower chambers receive blood from atria
-right ventricle pumps deoxygenated blood to the pulmonary artery to lungs for oxygen
- left ventricle (thicker) pumps oxygenated blood to the aorta to send to the body and cells
Myocardium
Specialized muscle tissue (cardiac muscle) that forms the heart. The heart is considered a “double pump” that is divided into right and left sides.
Pulmonary Circulation
The main function of the right side of the heart is to pump deoxygenated blood, which has just returned from the body, and is going to the lungs.
Systemic Circulation
The role of the left side of the heart is to pump oxygenated blood, which has just returned from the lungs, and is going to the rest of the body.
Blood Flow Through the Heart
Blood is delivered to the right atrium from the superior and inferior vena cava.
It passes through the tricuspid valve and enters the right ventricle.
From there, the blood is pumped through the pulmonary semilunar valve and out through the pulmonary arteries to the lungs
The blood returns from the lungs through the pulmonary veins to the left atrium.
It then passes through the bicuspid valve and enters into the left ventricle.
The blood is then pumped out through the aortic semilunar valve into the aorta and throughout the systemic circulation.
Arteries
Blood vessel
Elastic blood vessels that carry blood AWAY from the heart
Artery expands with surge of blood during contraction of ventricles, then snaps back during relaxation of ventricles
Under a great amount of pressure
Have thicker walls to withstand pressure; will spurt when cut
Can vary in size
Veins
Blood vessels
Elastic blood vessels that carry blood TOWARD the heart
Can’t contract to help move blood back to heart
Have one-way valves to prevent blood from flowing backward
Blood is at a lower pressure
Thinner wall than arteries
Can vary in size
Capillaries
Blood vessel
Extremely small blood vessels located within the tissues of the body
Fine network
Transports blood from arteries to veins
Exchange O2 with CO2 and nutrients with waste
Thin walled
Allow substances to diffuse between the blood and other body fluids and tissues
Artioles
Arterioles are small vessels in the blood circulation system that branch out from arteries (that came from lungs) and lead to capillaries, where gas exchange eventually occurs. Surrounded by smooth muscle, arterioles are the primary site of vascular resistance.
Venules
Small blood vessels that branch out from capillaries and lead to veins with deoxygenated blood used by cells that are sent to lung for oxygen.
Pulmonary arteries
One of the main vessels of the heart
transport deoxygenated blood out of heart to the lungs to pick up oxygen
Pulmonary veins
One of the main vessels of the heart
bring oxygenated blood back to the heart to be pumped out to the body
Aorta
One of the main vessels of the heart
largest blood vessel (artery) in body; where all blood going to the body tissues leaves the heart (brachiocephalic, common carotid, subclavian)
Vena cava
One of the main vessels of the heart
largest vein in the body carrying blood back to heart from body (superior vena cava from top half of body and inferior vena cava from bottom half)
Valves of the Heart
Valves control the flow of blood through the heart in the correct direction
4 valves of the heart:
2 Atrioventricular valves (AV valves)
1.Tricuspid valve (3 flaps)- between the right atrium and right ventricle
2. Bicuspid valve (2 flaps and called mitral valve) between the left atrium and left ventricle
2 Semi-Lunar valves
Pulmonary valve- between the right ventricle and the pulmonary artery
Aortic valve -between the left ventricle and the aorta
Varicose Veins
Varicose Veins occur when valves become faulty and blood begins to pool in areas of the veins.
If the walls of the vein become stretched and less flexible (elastic), the valves can weaken. A weakened valve can allow blood to leak backward and eventually flow in the opposite direction. When this occurs, blood can accumulate in the vein(s), which then become enlarged and swollen.
Compression socks and clothes
help blood flow
Blood
A type of connective tissue that circulates throughout body (about 9 pints at a time)
Both fluid and solid portion
It consists of four components:
Plasma 🡪 55% of blood volume
red blood cells (erythrocytes) 🡪 44% of blood
white blood cells (leukocytes) 🡪1%
Platelets (thrombocytes) 🡪0.5%
Red Blood Cells
Erythrocytes
perform the most important
blood duty
Specialized for oxygen transport
A single drop of blood contains
millions of red blood cells which are
constantly traveling through your body delivering oxygen/nutrients and removing waste/CO2
Contain hemoglobin (protein) which allows cells to pick up oxygen and also transports some of the carbon dioxide waste (iron helps hemoglobin)
RBCs are the most plentiful of the body’s blood cells.
White Blood Cells
Leukocytes
Part of the body’s response to infection
5 types of WBCs
Make up about 1% of blood
volume but this can increase more
than double when your body is
fighting infection
white blood cells are continually
on the lookout for signs of disease.
When a germ does appear, WBCs have
a variety of ways by which they can attack.
Some will produce protective antibodies that will overpower the germ.
Others will surround and devour the bacteria.
Platelets
Thrombocytes
Third major substance (clotting cells) in formed portion of blood
irregularly-shaped, colorless bodies present in blood
Their sticky surface lets them, along with other substances, form clots to stop bleeding.
Human body does not handle excessive blood (hemorrhage) loss well. Therefore, the body has ways of protecting itself. When sudden blood loss occurs, the blood platelets kick into action.
When bleeding from a wound suddenly occurs, the platelets gather at the wound and attempt to block the blood flow. The mineral calcium, vitamin K, and a protein called fibrinogen help the platelets form a clot.
A clot begins to form when the blood is exposed to air.
The platelets sense the presence of air and begin to break apart.
They react with the fibrinogen to begin forming fibrin (an insoluble protein) which resembles tiny threads.
The fibrin threads then begin to form a web-like mesh that traps the blood cells within it. This mesh of blood cells hardens as it dries, forming a clot, or “scab”.
Plasma
protein-rich, yellowish, clear liquid
90% water and essential ingredient for human survival.
It might seem like plasma is less important than the blood cells it carries, but you can’t have one without the other.
contains dissolved salts and minerals like calcium, sodium, magnesium, and potassium.
Also contains proteins called albumin, globulins and fibrinogen
Microbe-fighting antibodies travel to the battlefields of disease by hitching a ride in the plasma.
Pulse
a rhythmic beating felt at an artery as the heart pumps blood
Heart rate
Average adult should have 60-80 beats/min
Bradycardia- very slow heart rate <50 bpm
Tachycardia- fast heart rate >100 bpm
Pulse can easily be felt (palpated) on radial or carotid artery usually ( or femoral, popliteal, temporal, brachial)
Stethoscope- used to hear heart rate
A healthy heart will have 60-100 bpm. Highly conditioned athletes can have a heart rate of 40-60 bpm.
Your heart is a muscle that can be trained. The more you exercise, the stronger and more efficiently it can pump oxygenated blood to your tissues.
Note: Factors that will affect “resting HR” – exercise within 2hrs of measurement, caffeine, sitting or standing for long periods of time.
Blood Pressure
pressure exerted by the circulating volume of blood on the walls of the arteries
Systolic- maximum pressure of the blood exerted against the artery; ventricles contract; top number of reading (120);”lub” sound,
Diastolic- minimum pressure exerted on artery; ventricles relax and refill; bottom number(80).”dub” sound
Average blood pressure reading for an adult is 120/80 mmHg (systole/diastole)
Sphygmomanometer- instrument used to measure blood pressure
Hypertension
High blood pressure is considered anything over 140/90 mmHg.
-causes include obesity, smoking, lack of physical activity, stress, too much salt in diet, genetics
-can have serious risks which include risk of heart attack or stroke, aneurysm, heart failure
Hypotension
refers to low blood pressure which is considered anything less than 90/60 mmHg.
-causes include hormones, pregnancy, medications
-can cause dizziness and lightheadedness, which is an indication that there is not a great deal of blood flow to the heart or brain.
-low blood pressure ultimately isn’t a problem unless it’s causing serious symptoms or is occurring in the elderly.
Vasodilation
widening of arteries when muscle contract
Vasoconstriction
narrowing of arteries when muscle relaxes
Certain conditions or drugs can cause vasodilation or vasoconstriction
Pacemakers
Pacemakers are machines required for people who require the rhythm of their heart to be monitored. When necessary, the pacemaker will generate an electrical impulse in order to trigger a regular heartbeat.
Cardiac Muscle Tissue
Tissue of the heart
Unique tissue found only in the heart
Arranged in a network to allow contractions
Contracts at the same time, which moves blood around the body
Nerve Tissue
Tissue of the heart
Nerve tissue is made up of nerve cells (neurons) and is used to carry “messages” to and from various parts of the body.
Connective tissue
Tissue of the heart
Muscles and nerves are covered by a smooth layer of epithelial tissues.
This layer prevents friction, protects the heart from damage, and allows blood to flow freely.
Connective tissue supports other tissues and binds them together (bone, blood, and lymph tissues). Epithelial tissue provides a covering (skin, the linings of the various passages inside the body).
Coronary Artery Disease
Coronary artery disease is a condition in which plaque builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood.
Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis.
Coronary artery disease (also known as atherosclerosis) involves a gradual narrowing of the coronary arteries resulting from the accumulation of hard deposits of cholesterol (plaque), on the lining of the blood vessels.
Heart Attack
occur most often as a result of a condition called coronary artery disease where plaque builds up over many years on the inside walls of the coronary arteries (the arteries that supply blood and oxygen to your heart). Eventually, an area of plaque can rupture, causing a blood clot to form on the surface of the plaque. If the clot becomes large enough, it can mostly or completely block the flow of oxygen-rich blood to the part of the heart muscle fed by the artery. Called an INFARCT.
Dead heart muscle cannot regenerate
Coronary Circulation
Like all tissues in the body, the heart also needs to be supplied with O2.
There is a misconception that the blood that is flowing through the heart is what is providing the heart with the O2 it’s tissues needs. This is false!
The right & left coronary arteries nourish the myocardium of the heart.
The left & right cardiac veins remove waste from the myocardium.
-system of vessels that supply essential materials via blood to the heart muscle itself is called the coronary circulation.
-Serious health repercussions and even death can occur if a narrowing or blockage of blood vessels restricts the flow of blood to the heart muscle.
Eg. a heart attack (a myocardial infarction) can result when blood flow to a section of the heart muscle becomes blocked due to a plaque buildup or some other reason.
Symptoms of a Heart Attack
Chest pain/pressure (angina pectoris)
Shortness of breath
Nausea
Anxiety
Upper body pain
Abdominal or stomach pain
Sweating
Dizziness
Unusual fatigue
Heart Attack Risks
Age
Gender
Unhealthy diet, high blood pressure or high cholesterol and obesity
Past heart or health conditions like blood clots or diabetes
Stress
Drugs (like smoking)
Lack of exercise
Genetics
Blockage in the heart
angina pectoris-infarct-heart attack
