The Circulatory, Immune, and Respiratory Systems

Objectives : • Explain the function/purpose of the cardiovascular, immune, and respiratory systems.

• Compare/contrast arteries to veins and atria to ventricles.

• Trace the flow of blood through the body and the pulmonary loop.

• Identify and describe the structures and functions of the heart, circulatory, immune, and respiratory systems.

• Recognize normal pulse, blood pressure and respiratory rates.

• Describe illnesses/disorders of the circulatory, immune, and respiratory systems, the tests done, and their causes, treatments or preventatives.

• Accurately perform cardiopulmonary resuscitation, take blood pressure, and count respirations.

• Explain the role of certain nutrients and/or toxins in health.

Vocabulary

:

cardiovascular *

ECG myocardium

* sinoatrial node * * pericardium

AV node

*

atria

* pacemaker * * ventricle *

atrioventricular valves and node

* semilunar valves * valves *

artery/arteriole mitral/bicuspid

* vein/venuole *

capillary

and tricuspid * arrhythmia *

marrow

*

erythrocyte

hemoglobin *

platelets

* pneumonia * *

pulmonary

plasma *

leukocyte

* anemia * coronary/coronary arteries *

pulmonary artery/vein

* aorta *

carotid artery

* femoral artery *

inferior and superior vena cava

brachial artery * * jugular vein *

systolic infarction

* bronchi * diastolic *

pulse

* plaque *

stroke

* myocardial * congestive heart failure *

valve prolapse

* alveoli *

asthma

* pleurisy *

CPR homocysteine

* sphygmomanometer * * C-Reactive Protein *

PAD

* hypertension *

histamine

hypotension *

atherosclerosis vasoconstriction/vasodilation

hypoxia *

edema

* * sublingual * * angina pectoris * aneurysm *

lymph embolism

* * stroke *

thrombosis

angioplasty * *

B-cells

*

AIDS

* T-cells *

lymphocytes

* leukemia *

antigen

* * neutrophils * allergen *

macrophages epiglottis

* * HIV trachea

The Circulatory System The circulatory system is also known as the cardiovascular system . It consists of the heart, arteries, arterioles, capillaries, venuoles, and veins. The purpose of the circulatory system is to deliver oxygen and nutrients to the tissues, etc. and remove carbon dioxide and wastes . Numerous, simpler animals do not require a circulatory system. For example, a planarian (flatworm) is so thin that oxygen and carbon dioxide simply diffuse through its epidermis and its digestive tract branches throughout its body to deliver nutrients.

The muscular portion of the heart is called the myocardium . The heart is surrounded by a tough, protective, connective tissue covering called the pericardium . Swelling of the pericardium is called pericarditis . Swelling of the heart muscle is called myocarditis . Either condition can cause chest pain and shortness of breath. Either condition can be caused by an infection .

In humans, the heart consists of 2 upper chambers, called atria (atrium = singular) and 2 lower ventricles . The atria are not lined with as much muscle tissue as the ventricles because they don’t have to pump the blood as far. The left ventricle has the thickest muscular wall because it pumps blood throughout the entire body. The valves preventing backflow of blood are called the atrioventricular valves (tricuspid and bicuspid or mitral valves) and the semilunar valves (between the ventricles and the arteries).

The right atrium receives de-oxygenated blood returning from the body. It pumps the blood to the right ventricle. When the right ventricle contracts to pump blood to the lungs , the tricuspid valve (has 3 flaps) prevents backflow of blood from the right ventricle back into the right atrium. A semilunar valve prevents backflow of blood from the pulmonary artery as it carries blood from the right ventricle to the lungs. Like all arteries, the pulmonary artery leaves the heart . However, it is the only artery that carries de-oxygenated blood . The pulmonary artery branches into smaller arterioles and finally down to capillaries. Capillaries are networks of tiny blood vessels that often can allow only one cell through at a time. ALL oxygen and carbon dioxide exchange with the blood occurs at the capillaries . In the lungs, the capillaries interface with alveoli. Alveoli are tiny air sacs throughout the lungs where oxygen leaves the lungs to the capillaries and carbon dioxide enters the lungs. A simple pressure gradient movement from high to low pressure drives the exchange. However, the iron in hemoglobin (a blood protein) must carry the oxygen in the blood. Some substances, like carbon monoxide , bind tightly to hemoglobin and will not allow oxygen or carbon dioxide to enter the blood.

So, the pulmonary circulation, or pulmonary loop , begins when blood leaves the right ventricle and enters the pulmonary artery. (“ Pulmonary ” always refers to the lung/respiratory system.) It continues with gas exchange between the circulatory system’s capillaries respiratory system’s alveoli and then proceeds as and the oxygenated blood returns to the left atrium of the heart via the pulmonary vein . The pulmonary vein, like all veins, returns to the heart . However, it is the only vein carrying highly oxygenated blood .

The left atrium pumps the oxygenated blood to the very muscular left ventricle. The mitral valve , or bicuspid (2 flaps) valve prevents backflow of blood when the ventricle contracts. However, a valve prolapse can occur. This is when the valve is forced backward into the atrium and allows blood to backflow. This can cause the heart to enlarge and weaken over time. Certain illnesses, like scarlet fever, a deficiency of magnesium, or valve deformities can cause a prolapse . If the prolapse is severe enough, it can be heard as a murmur through a stethoscope. It is the atrioventricular valves closing, followed by the close of the semilunar valves, that makes the lub-dup heart sound.

The hearts rhythmic beat starts with an electrical jolt over the right atrium by the sinoatrial node (SA node). This is also known as the “ pacemaker ”. People with artificial pacemakers need these to either stimulate the heart rhythm or to keep the rhythm steady. A second region, called the atrioventricular (AV) node , is located between the 2 atria and picks up the electrical signal slightly after the SA node makes the atria contract . Therefore, there is a slight delay between atrial contractions and the AV node’s stimulation for ventricular contractions . An electrocardiogram ( ECG or EKG) is used to detect irregular heart rhythms. An arrhythmia is an irregular heartbeat. It can be caused by a mineral imbalance - usually too little magnesium or potassium . A 24 hour or longer record of the heart’s rhythm can be recorded by wearing a halter monitor .

A normal resting adult heart rate falls somewhere between 60 and 80 beats per minute. It can be measured by taking a pulse reading, usually on the radial side of the middle of the back of the wrist. It is also easy to take in the neck by the carotid artery .

Blood pressure can be taken using a sphygmomanometer . This includes an inflatable cuff with a pressure valve/release and a gauge. The systolic pressure is recorded when the first heart beat is heard as the inflated cuff’s pressure is released. To hear the heart sounds, a stethoscope must be placed over the artery on the inside bend of the elbow (assuming the cuff has been wrapped around the upper arm). The systolic pressure is the pressure felt in the arteries when the muscular ventricles contract. This is usually between 110 and 150 in adults . The diastolic pressure is measured when the last heart beat is heard as pressure is released from the cuff. This is the lowest pressure felt by the arteries. This is usually between 60 and 80 millimeters of mercury (mmHg) pressure. So, a blood pressure of 134/70 indicates a systolic pressure of 134 mmHg and a diastolic pressure of 70 mmHg. A fever can make blood pressure and heart rate (pulse) increase as can other stressors. Also, blood pressure can vary from one side of the body to the next AND can drop DRAMATICALLY upon standing . A dizzy spell from standing up too quickly and a resultant drop in blood pressure is called orthostatic hypotension (low blood pressure).

As blood leaves the left ventricle, it enters the aorta , our biggest artery. The aorta branches into many other arteries including, the carotid artery (to the head), the brachial arteries (to the arms), and the femoral arteries (to the legs). Although very small compared to the aorta, coronary arteries are some of the most important arteries because they supply blood to the myocardium (heart muscle).

Like all arteries, the aorta has a layer of smooth muscle . Vein walls are much thinner than arteries due to their lack of, or very limited amount of, smooth muscle. They are not under as much pressure as the arteries are so do not require thick walls. The smooth muscle layer within artery walls lets them expand when the heart contracts, keeping blood pressure relatively low during ventricular contraction. The muscle can spring back after ventricular contractions to help force blood along. If the smooth muscle layer contracts and stays tense, vasoconstriction , it can cause high blood pressure , also known as hypertension . Increasing magnesium and/or potassium can often help the muscle relax and drop the blood pressure. If plaque (calcium, cholesterol, etc mix) covers the inside of arteries, it’s called atherosclerosis . This too can raise blood pressure.

The aorta first rises toward the head, arches over (the aortic arch ), and then travels downward (the descending aorta). Peripheral artery disease ( PAD ) can be caused by plaque in the descending aorta or the femoral arteries, etc. Symptoms can include numbness. Unfortunately, it is often assumed that numbness in the extremities of the elderly is due to PAD. However, it is often a vitamin B

12

deficiency due to low intrinsic factor needed to absorb B

12

. Sublingual (under the tongue)B

12

or B

12

injections can often stop the progression of this numbing. Gastrointestinal symptoms such as intermittent diarrhea or constipation, etc. can also be a sign of B

12

deficiency. If the symptoms are truly due to plaque build-up on the arteries, it is believed that vitamin D 3 , K 2 , C and the amino acid lysine can help remove the plaque. Digestive enzymes on an empty stomach can also help.

Arteries branch into smaller arterioles and eventually into capillaries for gas exchange with the tissues. Blood begins its return to the heart via small venuoles that join to form veins . Some of our most important veins are the jugular vein (draining the head and neck), superior vena cava (upper body blood flow back to heart), and the inferior vena cava (lower body blood returned to heart). The superior and inferior vena cava join together at the right atrium .

Veins in the legs are working against gravity. To prevent backflow of blood, they contain valves . If the valves weaken and allow backflow and pooling of blood, varicose veins are likely. Certain infections, like campylobacter , can increase the likelihood of varicose veins - probably due to a damaging effect on the valves.

Other complications of the cardiovascular system include angina pectoris (chest pain), congestive heart failure , stroke , myocardial infarction (heart attack), thrombosis , anemia , hypoxia (too little oxygen), and aneurysms .

Angina pectoris is a squeezing, gripping chest pain usually caused by lack of oxygen to the heart muscle due to poor blood flow (atherosclerosis is often the problem). But, angina can also be caused by an almost cramping action of the heart due to a calcium and magnesium imbalance . Either way, magnesium can usually help because it helps dilate the blood vessels for more oxygenated blood to reach the heart and it relaxes cramping of the heart muscle itself. It used to be standard practice to give large amounts of magnesium through an I.V. when a person was suspected of having a heart attack. Many people suffering from angina are given sublingual nitroglycerin tablets to dissolve under their tongue to relieve the chest pain. Nitro helps dilate blood vessels to increase the oxygen delivery to the heart. Nitrous oxide naturally made by the body can do the same thing. Naturopaths recommend the amino acid arginine to help the body dilate the blood vessels by increasing nitrous oxide production .

Congestive heart failure is when the heart becomes very weak. This can allow fluid to build up ( edema ) in the tissues, including around the lungs. People with congestive heart failure become very weak, have a hard time catching their breath ( short of breath ), and get fatigued easily. One sign of congestive heart failure can be a type of heavy breathing while talking or quickly out of breath after short, easy activities like walking. Often, the person allows their mouth to hang open slightly while breathing as they try to catch their breath. C ongestive heart failure can be caused by cigarette smoking because toxins from cigarettes, particularly the cadmium, can accumulate in the heart and damage/weaken it . It can also be caused by enlargement of the heart whether it is from an infection (like Chagas disease in Brazil), or valve prolapses , or atherosclerosis .

The amino acid carnitine acts very much like the B vitamins, helping to restore the heart muscle’s energy. Carnitine helps move fatty acids into the mitochondria to burn as energy. Coenzyme Q-10, at high doses, can also restore the heart’s strength. Also, correcting poor kidney function can help relieve some of the stress on the heart.

Thrombosis , or the formation of a clot, can block blood flow. If a clot occurs in the brain, it is called an ischemic stroke . However, some strokes are not due to a clot but rather to blood too easily flowing out of the blood vessels, leaking into the surrounding tissue (think of a bruise). When blood flows too easily, it may be due to a deficiency in vitamin C or K , or calcium . Signs of a stroke include weakness on 1 side, slurred or irrational speech, vision disturbances , etc. depending on where in the brain it occurs.

An embolism , is a clot that has moved to a new location. Embolisms are more likely to occur in bedridden people when the blood tends to pool in the legs. If the clots that sometimes form in the leg move to the head or heart, this too can cause a stroke or heart attack. A myocardial infarction is a heart attack. During a heart attack, the clot blocks blood flow, depriving the heart of oxygen (needed for ATP synthesis). This causes tissue death. If enough tissue dies or dies in an especially important area of the heart, death can occur. Angina can be a sign that a heart attack is in progress . Pain radiating down the left arm or up to the jaw, or sometimes just plain abdominal pressure, can also indicate a heart attack is in progress .

Medical help should be sought immediately. The faster a clot busting drug (similar to digestive type enzymes) is administered, the less severe the damage from an ischemic stroke or heart attack will be.

When atherosclerosis (plaque build-up on the artery walls) is detected, doctors often recommend balloon angioplasty to open up severely blocked arteries. A tube is inserted in an artery and then fed up into the heart. A small balloon is inflated and a wire-type device is used to scrape the plaque build-up off the artery wall. This can cause severe problems such as a “ cholesterol storm ” (really a “plaque storm”) where pieces of plaque travel in large numbers throughout the body sometimes CAUSING a heart attack, stroke, or kidney failure (sometimes dialysis is then required indefinitely). In addition, the artery wall can become very inflamed from the plaque removal. Inflammation attracts plaque (remember, plaque is like a band-aid for our blood vessels, it usually doesn’t stick unless inflammation is there in the first place). Often periodontal (gum) disease is associated with increased likelihood of heart attack. This is because the same bacteria that irritates the gums can get into the bloodstream and cause inflammation. That’s why there is sometimes a decrease in heart associated problems when antibiotics are taken ( Valve prolapse can also occur due to bacterial infection). In fact, C-reactive protein levels in the blood are considered better indicators of the chance of having a heart attack than cholesterol levels. These proteins measure inflammation.

Cholesterol lowering drugs such as Lipitor may actually reduce heart attacks more because they reduce inflammation. In fact, a 2002 study

in The New England Journal of Medicine

revealed that inflammation in the blood vessels was twice as likely as high cholesterol to lead to ischemic stroke and death from cardiovascular causes .” And, aspirin is likely to also work primarily because of its anti-inflammatory effects rather than its blood thinning properties. The blood thinning properties of aspirin could actually cause more health problems by increasing one type of stroke and causing gastric bleeding. If someone does collapse, possibly due to a heart attack, CPR ( cardiopulmonary resuscitation ) should begin immediately. The newest guidelines for CPR recommend 30 compressions for every 2 breaths. And, they recommend CPR continues even if the heart resumes beating because the heart is weak and could use some help or it’s likely to stop again.

An aneurysm is a ballooning out and sometimes the rupturing of an arterial wall. There is a correlation between low copper levels and aneurysms . Remember, copper is also needed to make red blood cells. If copper, iron, vitamin B12, etc. are low, different types of anemia can occur . Anemia can be due to too few red blood cells, immaturity of red blood cells released, etc. But, no matter what the initial cause, less oxygen is going to be transported in the blood. Therefore, anemia can cause fatigue. Often, if hospitalized, a clothespin-like device is placed on a fingertip to measure oxygen levels in the blood. When levels are too low, it is called “ hypoxia ”.

A fetus and young infant has a special type of hemoglobin, called hemoglobin F (“F” for fetus). Hemoglobin F has a better oxygen binding capacity than normal adult hemoglobin. This increases the fetus’s chances of normal growth and survival.

The blood itself consists of plasma (fluid containing dissolved proteins and minerals ), leukocytes (white blood cells involved in our immune response ), erythrocytes (red blood cells containing hemoglobin - the protein with oxygen binding iron ), and platelets (involved in wound repair/clotting). The erythrocytes (RBC’s) form in the bone marrow . Originally they have a nucleus and the usual cell organelles but they lose these as they mature. Therefore, mature RBC’s cannot divide by mitosis like most other cells. Finding immature, nucleated RBC’s in the blood is not a good sign.

The biconcave shape of a normal RBC increases its surface area. This aids in gas exchange. Each RBC has about 250 million hemoglobin molecules. Each hemoglobin molecule contains 4 heme groups. Each heme group has 1 iron atom and each iron atom carries 1 oxygen molecule. Therefore, each RBC carries close to a billion oxygen molecules! And, RBC’s far outnumber the other blood components by almost 1000 to 1 or more. However, carbon monoxide and many other substances can disrupt the oxygen carrying capacity of blood.

The platelets are cell fragments broken from a large megakaryocyte, formed in the marrow. Platelets normally stick to injured blood vessels to begin the clotting process. There are numerous steps to blood clotting. Vitamin K, C , and calcium are also essential to blood clotting. Easy bruising is a sign of poor clotting ability. Often this occurs after antibiotic use because the natural vitamin K producing flora of the intestines have been destroyed. Hemophilia is an X-linked inherited disorder where clotting is very poor.

The leukocytes (white blood cells) are also part of our immune system and, like RBC’s, they originate in the bone marrow . However, they might mature elsewhere. For example, while our B-cells mature in the bone marrow , our T-cells mature in the thymus . Both of these are a type of WBC called lymphocytes . The B-cells produce our antibodies to bacteria, etc. Unfortunately, mononucleosis (Epstein-Barr virus), a herpes family virus, infects B-cells. This can leave us very susceptible to other infections, such as strep throat.

The T-cells are the big-wigs of the immune system. Depending on what type of T-cell, they can initiate the immune system’s response to a foreign body and activate B-cells, they can suppress the response, they can “remember ” a former invader for a faster response (which is why we get vaccines), etc. Unfortunately, Human Immunodeficiency Virus ( HIV ) infects the T-cells which can then shut down the whole immune system leaving the host susceptible to a lot of very rare and unusual illnesses as well as the common ones. The full blown symptoms of AIDS ( Acquired Immune Deficiency Syndrome ) don’t usually show up until the person becomes deficient in selenium . So, high selenium intake can ward off symptoms. This is probably because the HIV virus depletes our selenium when it makes its unusual selenium dependent amino acid.

Besides the lymphocytes (B and T-cells), we also have 4 other types of leukocytes which include: neutrophils , monocytes , eosinophils , basophils . Neutrophils and macrophages (big eaters) can engulf 20 (neutrophils) to 100 (macrophages) bacteria and destroy them before the phagocyte itself dies. Pus is made of dead phagocytes and bacteria. The fever that often accompanies an infection makes phagocytes more active, decreases iron in the body and increases the need for iron in bacteria and fungi ( bacteria and fungi FEED ON IRON don’t take iron when sick. In fact, some viruses like EBV {mono} can bring iron levels up to a toxic level in our bodies as they try to grab up all we ingest) An increase in any type of leukocyte (WBC) usually indicates an infection. The type of WBC elevated can give a clue as to what type of infection is bothering us (bacterial, viral, fungal, etc).

Any antigen (particle that causes an immune response) can stir up the immune system. If the antigen is non-proliferating, harmless substance, such as pollen, it is called an allergen . (Stinging nettle and mullein are good for many respiratory ailments, including allergies.)

The antibody response may be one of 5 types of immunoglobulins : IgA (in milk, saliva, tears, the digestive tract, and respiratory organs), IgD (stimulates B-cells in blood), IgE (increases when allergens are present), IgG (helps macrophages do their job and helps protect a fetus from invading organisms, but it is also what can kill a fetus if the mother is Rh- and the baby is her second Rh+ child), and IgM.

Leukemia is considered a cancer. Here white blood cells get extremely high and RBC’s decrease in number . The patient becomes extremely fatigued , may need transfusions to increase the RBC, and sometimes require a bone marrow transplant.

Normally RBC’s live about 120 days (4 months), WBC’s about a year (but most of this time they are not in the blood stream) and platelets live about a week. When you take an aspirin it affects the cyclo-oxygenase in platelets, preventing them from sticking. This affect lasts the entire life time of each platelet that was present at the time of aspirin ingestion. So, that effect of aspirin isn’t 100% gone from your body for about a week, but each day, more platelets are being made so the effect does decrease each day.

The plasma is 90% or more water, the rest is dissolved nutrients (vitamins, minerals, proteins, sugars), hormones, gases, wastes, etc. The plasma nourishes most cells directly at the capillary beds, however, not all tissues are serviced by the capillaries. Therefore, some plasma leaks out of the blood vessels to nourish and remove wastes from these tissues. Once plasma leaves the blood vessels, it becomes lymph . Lymph can also be considered part of the immune system. Lymph has its own set of vessels to collect it and carry it throughout the body. It returns to the blood vessels just under the clavicles . Lymph and the WBC’s it carries can accumulate in the lymph glands when war is being waged on bacteria, etc. Swollen lymph glands are a sign of infection .

Antibiotics are often prescribed for bacterial infections. These won’t work on viruses, fungi, or other parasites. In fact, antibiotic treatment can allow fungi, like

Candida albicans

, to proliferate. Natural substances can help. Astragalus can help support the immune system. Elderberry can block the respiratory flu virus from entering cells. Lemon Balm (

Melissa officianalis

) blocks herpes viruses cells. Pau D’Arco , Olive leaf , and Uva Ursi from entering help fend off bacteria, viruses, and fungi.

The Respiratory System Starting at the throat ( pharynx ), the epiglottis , a flap of tissue, covers the trachea (windpipe) when we swallow so that food does not get into the lungs. The trachea is ringed with cartilage to prevent its collapse. The trachea branches into 2 large bronchi , one leading to each lung, which are also ringed with cartilage and have a smooth muscle layer in their walls. The bronchi each branch into bronchioles . These have no cartilage but do have smooth muscle in their walls. The bronchioles terminate as they connect with millions of alveoli (tiny air sacs that interact with the capillaries for gas exchange). Most of the respiratory tract has cilia and mucus lining it. The mucus sticks to bacteria, dust, etc. and the hair-like cilia sweep it up and away from the lungs. Histamine , produced in response to an irritant, like an allergen, can cause increased mucus flow, watery eyes, and sneezing as the body attempts to cleanse itself of the foreign substance.

An asthma attack occurs when the body over reacts to an allergen or exercise and the smooth muscle surrounding the airways constricts. Magnesium can help relax the smooth muscles . Inhalers often contain adrenalin to relax the muscles. But this can leave a person jittery and tired. An imbalance in the blood’s pH can trigger an asthma attack . Sometimes, simply drinking baking soda in water will help soothe the attack.

It is the amount of CO

2

in the blood that triggers breathing . It can form carbonic acid. If this is not kept balanced, the blood pH can drop (acidify). Furthermore, if enough oxygen is not present, cellular respiration will convert from aerobic respiration to lactic acid fermentation. This will cause heavy breathing. Remember, the whole purpose of oxygen/carbon dioxide exchange is for cellular respiration to provide ATP energy to maintain the cells’ and body’s functions.

The smooth muscles lining the bronchi, etc. are NOT what causes the lungs to expand . The lungs have no muscles of their own. They inflate when a vacuum is created as the intercostal (between the ribs) muscles relax and the diaphragm contracts , expanding the chest cavity. The lungs deflate as the diaphragm relaxes and rises again and the intercostals squeeze the ribs inward when they contract. Sitting on someone’s ribs to hold them down has killed many people by suffocating them!

The lungs are surrounded by a double sac that helps maintain the vacuum cavity for breathing. This is the pleura . The pleura reduce friction during breathing. If it gets ruptured, the lung collapses. If it gets inflamed, or fills with fluid between the layers, it’s called pleurisy and can make breathing very difficult, almost like pneumonia (an infection in the lungs where fluid can build-up).