Cardiovascular and Lymphatic Infections

Cardiovascular System

• The cardiovascular system's main function is to transport blood, which carries essential substances like gases, nutrients, and immune cells, throughout the body.
• The heart and its valves are prime targets for cardiac infections.
• Blood is normally sterile, but infections can introduce microbes into the bloodstream, leading to their travel to the heart and other organs.
• Microbes can attach to the heart valves and walls, causing damage.

Septicemia and Endocarditis

• Septicemia occurs when bacteria or their toxins enter the bloodstream.
• Common causes of septicemia are hospital-acquired infections, often from invasive medical procedures.
• Bacteria from the skin and digestive tract can enter the bloodstream, with species from the Staphylococcus and Streptococcus genera being most common.
• Septicemia can lead to sepsis, a serious complication characterized by widespread inflammation.
• Endotoxic shock, a particularly dangerous form of septicemia, is caused by Gram-negative bacteria releasing endotoxins into the bloodstream.
• Endotoxins cause a severe drop in blood pressure, which can be fatal.

Endocarditis:

• Acute Bacterial Endocarditis: Occurs when bacteria from septicemia reach the heart and grow on the heart valves.
• Vegetations: Bacterial growth on the valves, which can inhibit proper valve function.
• Symptoms: Include fever, anemia, abnormal heartbeat, and symptoms resembling a heart attack like chest pain and petechiae.
• Causative agent: Most commonly Staphylococcus aureus.
• Subacute Bacterial Endocarditis (SBE): A slower-progressing form of endocarditis.
• Symptoms: Include fever, weakness, dizziness, and possibly a heart murmur.
• Causative agent: Usually species from the Streptococcus genus.
• Risk factors: History of heart murmur, endocarditis, Rheumatic fever, or other conditions.
• Prevention: Taking antibiotics before dental work to prevent bacteria from entering the bloodstream.

Lymphatic System

• The lymphatic system plays a crucial role in fluid collection and circulation and immune defense.
• It collects excess fluid from tissues, transporting it through lymphatic vessels.
• Lymph fluid eventually returns to the cardiovascular system, emptying into the subclavian/jugular veins.
• This system allows cells, fluids, proteins, and pathogens to circulate throughout the body.
• Lymph nodes, along the lymphatic vessels, filter lymph fluid and house B and T lymphocytes.
• B and T cells actively monitor the lymph fluid for potential pathogens, providing an important line of defense against infection.
• Anything that enters the body through inhalation, ingestion, or cuts eventually reaches the lymph fluid, making it a key site for immune system surveillance.

Cardiovascular System

• Transports blood throughout the body.
• Delivers gases, nutrients, and immune cells.
• Blood is normally sterile.
• Microbes can enter the blood during infection.
• Microbes can attach to heart valves and walls causing damage.

Septicemia

• Bacteria or their toxins in the bloodstream.
• Can be caused by various bacteria, most commonly from hospital-acquired infections (nosocomial).
• Common causes are Staphylococcus and Streptococcus genera.
• Can lead to sepsis, a serious complication with inflammation throughout the body.
• Endotoxic shock is a severe form caused by Gram-negative bacteria in the blood.
• Endotoxin (lipopolysaccharide) from dying Gram-negative bacteria causes a dangerous drop in blood pressure.

Endocarditis

• Infection of the inner heart lining and/or valves.
• Acute Bacterial Endocarditis is caused by septicemia with bacteria colonizing heart valves.
• Vegetations formed by bacteria can impair valve function leading to heart malfunction, stroke, and death.
• Staphylococcus aureus is the most common cause of acute endocarditis.
• Symptoms include fever, anemia, abnormal heartbeat, chest pain, and petechiae.
• Subacute Bacterial Endocarditis (SBE) is a slower-progressing form.
• Usually caused by Streptococcus species, particularly those from the Streptococcus viridans group.
• Can develop after dental procedures allowing oral bacteria into the bloodstream.
• People with a history of heart problems should take antibiotics before dental work to prevent SBE.

Lymphatic System

• Collects and circulates lymph fluid.
• Removes excess fluid from tissues.
• Transports cells, fluids, proteins, and pathogens.
• Lymph fluid eventually returns to the cardiovascular system via subclavian/jugular veins.
• Lymph nodes filter lymph fluid and house B and T lymphocytes.
• Immune cells in lymph nodes monitor for pathogens and defend the body.

Heart Function

• The heart is essential for life, pumping blood throughout the body to deliver oxygen and nutrients.
• The heart is protected by the pericardium, a thin outer layer.
• The endocardium lines the interior of the heart.
• The four chambers of the heart are: two atria (upper) and two ventricles (lower).
• Atria receive blood entering the heart.
• Ventricles pump blood out of the heart.
• Valves between the heart chambers: tricuspid, mitral, pulmonary, and aortic.
• Oxygen-rich blood returns to the heart through the right atrium.
• Blood flows from the right atrium to the right ventricle.
• The right ventricle pumps blood to the lungs via pulmonary arteries.
• Oxygenation occurs in the lungs through inhaled air.
• Oxygen-rich blood returns to the heart through the left atrium.
• Blood flows from the left atrium to the left ventricle.
• The left ventricle pumps oxygenated blood to the body via the aorta artery.
• The heart beats 100,000 times per day, 40 million per year, and up to 3 billion times over a lifetime.
• Heart attacks, heart disease, and hypertension can disrupt heartbeat.
• Exercise and emotions can also influence heartbeat.

Circulatory System

• The circulatory system is a vast network of veins, arteries, and capillaries, totaling over 60,000 miles in the body.
• The heart is the central pump of the circulatory system.

Heart Function

• The heart is a muscular organ responsible for circulating blood throughout the body, delivering oxygen and nutrients to cells.
• The heart has three layers: the pericardium (outer), myocardium (middle), and endocardium (inner).
• It has four chambers: two atria (upper) receive blood, and two ventricles (lower) pump blood out.
• Valves control blood flow between chambers: the tricuspid, mitral, pulmonary, and aortic valves.

Blood Circulation

• The heart pumps deoxygenated blood from the body through the right atrium and ventricle.
• Pulmonary arteries carry this blood to the lungs for oxygenation.
• Oxygenated blood returns to the heart through the left atrium and ventricle.
• The aorta then pumps oxygenated blood throughout the body.

Heart Rate

• The heart beats around 100,000 times daily, 40 million times annually, and approximately 3 billion times over a normal lifespan.

Heart Health

• Conditions affecting heartbeat include myocardial infarction (heart attack), heart disease, and hypertension.
• External factors such as exercise and emotional excitement can influence heart rate.

Circulatory System

• The circulatory system is a vast network consisting of veins, arteries, and capillaries.
• This network spans over 60,000 miles throughout the body.
• The heart serves as the central pump for this system.

Lymphatic System

• Transports lymph fluid throughout the body
• Lymph fluid is a plasma liquid collected from the interstitial fluid surrounding tissue cells
• Lymph fluid moves in one direction, from tissue cells towards the neck
• Lymph nodes filter and enhance lymph fluid by storing white cells and fighting antigens
• Lymph nodes are located throughout the body in clusters near veins
• Organs of the lymphatic system enhance lymph and assist with immune function

Lymphatic Organs

• Tonsils provide a local defense against respiratory infections by producing antigens and trapping them for immune cell destruction
• The thymus stores and matures lymphocytes into T-cells
• The spleen breaks down red blood cells, removes cells coated with antibodies and antigens, and stores immune cells like monocytes, B-cells, T-cells, and natural killer cells

Lymphocytes

• Three primary types of lymphocytes circulate in lymph fluid and migrate into the bloodstream: B-cells, T-cells, and natural killer cells

Explore the key functions of the cardiovascular system, focusing on the implications of septicemia and endocarditis. This quiz covers how infections can affect the heart and bloodstream, highlighting the role of various bacteria. Assess your understanding of these crucial medical concepts and their potential consequences.