Circulatory system

The circulatory system is responsible for transporting blood, nutrients, and oxygen throughout the body, playing a crucial role in maintaining homeostasis.

Layers of veins: Thin less elastic walls with valves. Thin wall, endothelium, large lumen, valve.

Role of valves in blood vessels: Controls the flow of blood between the chambers and prevent “backflow”

Coronary arteries and veins: Serves the heart muscle itself with blood, first branch off the aorta.

• Aorta: The largest artery in the body that distributes oxygen-rich blood from the heart to the rest of the body.

Chambers of the heart: There are four main chambers: the left atrium, right atrium, left ventricle, and right ventricle, which work together to circulate blood throughout the body. Right side is deoxygenated blood into the pulmonary circuit , where it travels to the lungs for oxygenation before returning to the left side of the heart. Left side is oxygenated blood into the systematic circuit , where it is distributed to the rest of the body to supply organs and tissues with essential oxygen and nutrients.

Pulmonary circuit/Systemic circuit: Pulmonary circuit circulates blood through lungs and systematic circuit circulates blood through body tissues.

3 layers of the heart tissue: The heart is composed of three distinct layers of tissue: the pericardium (epithelial, the outer layer that protects the heart), the myocardium (the thick middle layer of cardiac muscle), and the endocardium (the inner layer that lines the chambers and valves of the heart).

Major veins and arteries in the body:

• Aorta: The largest artery in the body, it distributes oxygenated blood from the left ventricle to the systemic circuit.

• Superior Vena Cava: A large vein that carries deoxygenated blood from the upper body to the right atrium.

• Inferior Vena Cava: A large vein that carries deoxygenated blood from the lower body to the right atrium.

• Pulmonary Arteries: These arteries carry deoxygenated blood from the right ventricle to the lungs for oxygenation.

• Pulmonary Veins: These veins carry oxygenated blood from the lungs back to the left atrium.

Deoxygenated versus oxygenated blood in the pulmonary and systemic circuits:

• Deoxygenated blood travels through the pulmonary circuit from the heart to the lungs, while oxygenated blood returns to the heart to be distributed throughout the body via the systemic circuit.

4 valves of the heart – location and function:

• Tricuspid Valve: Located between the right atrium and right ventricle, it prevents backflow of blood into the atrium during ventricular contraction.

• Pulmonary Semilunar Valve: Found between the right ventricle and the pulmonary artery, pumps blood out through the pulmonary artery.

• Mitral(bicuspid) Valve: Situated between the left atrium and left ventricle, it ensures that oxygenated blood flows into the ventricle without regurgitating into the atrium.

• Aortic Semilunar Valve: Located between the left ventricle and aorta, it opens to allow oxygen-rich blood to be pumped into the aorta and prevents backflow into the ventricle after contraction, pumps blood out through the aorta.

• Semilunar Valves: These valves, which include the pulmonary and aortic valves, are essential for controlling blood flow out of the heart and maintaining pressure within the chambers.

Explain the heartbeat – parts involved and how it works: SA NODE and AV NODE. SA NODE initiates the heartbeat by sending a signal automatically about every 0.85 seconds to make the atria contract, it keeps the beat regular. SA NODE sends its signal along fibers to the atria and also to the AV NODE. When the pulse sent out by the SA NODE reaches the AV NODE, the AV NODE itself then sends out a signal along special conducting fibers called purkinje fibers. Ventricles contract to pump blood to body.

Lub is when the atria contract and atrioventricular valves close, the Dub is when the ventricles contract and semilunar valves close. The sound is caused by vibrations of the heart when the valves close.

AV NODE is located near the central area of the heart, SA NODE is located in upper part of right atrium.

Trace blood throughout the body, naming all parts involved and whether the blood is deoxygenated or oxygenated – YES, the whole thing!! Draw a picture or write it down in a linear sequence!

Body tissues → Vena cavae → Right atrium → Tricuspid valve → Right ventricle → Pulmonary valve → Pulmonary artery → Lungs (gas exchange) → Pulmonary veins → Left atrium → Mitral valve → Left ventricle → Aortic valve → Aorta → Body tissues again

Septum is a muscular wall separating the left and right sides of the heart.

Thrombus is a blood clot that forms inside a blood vessel or the heart and stays attached to the site where it formed.

Embolus is when a thrombus travels through the bloodstream and gets stuck in a blood vessel.

Diastole is the phase of cardiac cycle when the heart muscle relaxes and chambers are filled with blood.

Systole is the phase of cardiac cycle when the heart muscle contracts and pumps blood out of the chambers.

Hypotension: Low blood pressure

Hypertension: High blood pressure

The blood vessels that serve the heart muscle: Coronary veins and arteries.

Blood vessels carrying the least amount of oxygenated: Pulmonary arteries, then vena cavae

Where blood enters/exits the heart and whether it is deoxygenated/oxygenated: Enters through the superior/inferior vena cavae if deoxygenated, leaves through pulmonary artery and enters through pulmonary vein once oxygenated.

Names and locations of the 4 valves: Tricuspid valve is between right atrium and ventricle, bicuspid/mitral valve is between left atrium and ventricle. Pulmonary semilunar valve is between right ventricle and pulmonary artery, aortic semilunar valve is between left ventricle and aorta.

Contraction and relaxation of the chambers: Deoxygenated: Right atrium contracts to force blood through the tricuspid valve and the right ventricle contracts to send blood through the pulmonary semilunar valve into the pulmonary trunk. Oxygenated: The left atrium contracts to force the blood through the bicuspid valve and the left ventricle contracts to force blood through the aortic semilunar valve into the aorta.

Atria contract simultaneously and ventricles also contract simultaneously.

While the ventricles are contracted, the atria relaxed to fill with blood again.

Role of Arteries and veins of the systemic circuit: Arteries bring blood to the lungs and veins bring blood back to the heart. Aorta distributes oxygen-rich blood to the rest of the body. Veins carry deoxygenated blood back to the heart.

How the systemic circulates blood – from here to there of the heart: Left side, oxygenated blood from the lungs enter the heart through the pulmonary vein to the left atrium. The blood then goes through the bicuspid valve and into the left ventricle which then it passes through the aortic semilunar valve into the aorta. From the aorta, oxygenated blood is distributed through the entire body.

Solutes found in blood: Parts of blood? White blood cells, plasma, red blood cells, platelets.

What cells fight infection: White blood cells(neutrophils)

What cells fight allergies: White blood cells(basophils)

What cells fight fungal/bacteria: White blood cells(eosinophils)

Blood type: which antigens are present, which antibodies are present for each blood type: A type has antigen A and antibodies B. B type has antigen B and antibodies A. AB type has antigen AB and no antibodies. O type has no antigens and antibodies AB.

What part of the blood carries antigens and antibodies: Antigens are attached to the surface of a red blood cell. Antibodies are found in the plasma.

Which blood type can donate to which blood type: O is universal donor and AB is universal recipient. A can receive blood from A and O. B can receive blood from B and O. AB all and O is only from O.

Hemoglobin is: An iron-rich protein that carry oxygen to body cells, used by the red blood cells. It buffers blood.

Thrombus traveling through the pulmonary artery will lodge in the small vessels.

Atherosclerosis: Hardening of the arteries caused by cholesterol plaque deposits. Affects the larger arteries and can lead to a heart attack or a stroke. Atherosclerosis reduces the circulation of blood.

Stroke is when a portion of the brain dies while heart attack is when a portion of the heart dies. Both are caused by lack of oxygen.

Complete the chart of the 3 types of blood vessels (structures/layers, function and diagram)

Explain chordae tendinae role and function: Chordae tendinae are very strong, fibrous strings that support the valves and prevent them from inverting. They are attached to muscular projections of the ventricular wall.

Urinalysis – given a set of results, you give a diagnosis, explaining ALL tests

Urinalysis testing:

Dark yellow: Dehydration

Pale light yellow: Hydrated

Orange/red: Blood in urine(hematuria) or caused by damage top kidneys or parasitic infection

Fruity odor: Presence of ketones from diabetes or starvation

Foul odor: Presence of bacteria

Clear: Normal

Cloudy: Old sample or UTI

Sugar: High amounts of sugar in diet or diabetes

Protein: Proteinuria caused by damage to kidneys, diabetes, or high blood pressure

HCG: Pregnancy is female, testicular cancer in males

Ketones: High protein diet, starvation, or diabetes

Leukocytes: Infection or inflammation, certain blood cancers

Iron: Hemoglobin present for sickle cell disease or extraneous exercise