Umme Aimen Tailor - Chapter 9: Cardiology

What are the two functions of the circulatory system?

To distribute oxygen gas and carbon dioxide; nutrients/waste products; hormones; and heat to and from the body tissues.

Defense against foreign agents

What are the two divisions of the circulatory system?

Cardiovascular system and the lymphatic system

What organs make up the cardiovascular system?

The heart and blood vessels

What organs make up the lymphatic system?

Lymphatic vessels and associated organs

What are lymphatic capillaries?

Small vessels that absorb excess fluid and return it back to the bloodstream

Anastomotic

interconnecting

Artery

carries blood away from the heart

Vein

Carries blood to the heart

Capillary bed

An anastomotic network of capillaries where the exchange of substances between the bloodstream and tissue fluid occurs

Arteriole

little arteries

Venule

little veins

Pulmonary circuit

The right side pumps blood through the pulmonary circuit/lungs

Systemic circuit

The left side pumps blood through the systemic circuit/all body systems

Heart rate

When both pumps normally contract at the same time. Heart rate is measured in BPM; the normal range is 60-100 BPM

Cardiac output

When both pumps normally pump the same volume of blood; the average cardiac output is 5L/min

Mediastinum

A membranous partition between two body cavities. The heart is located between the anterior sternocostal surface and the inferior diaphragmatic surface

Axis of the heart

An imaginary line drawn from the center of the base down to the apex

Endocardium

The inside tissue of the heart, another name for it is endothelium; makes up the wall of the heart

Myocardium

Muscles of the heart; makes up the wall of the heart

Epicardium

The outside tissue of the heart, a serous membrane that covers the surface of the heart

Pericardium

A two layered sac that encloses the heart

Serous membrane

A tissue that lines the internal cavities of the body, forms a smooth, transparent, two-layered membrane, lubricated by a fluid derived from serum.

Interatrial septum

The wall between the atrium, splits the right and left atria

Foramen ovale

A hole in the interatrial septum

Fossa ovalis

A depression in the interatrial septum

Atria

Receiving chambers

Ventricles

Ejecting chambers

Superior vena cava

Part of the right atrium, found in the upper part of the body

Inferior vena cava

Part of the right atrium, found in the lower part of the body

Coronary sinus

Part of the right atrium, the heart’s largest vein

Tricuspid valve

Prevents backflow of blood from the pulmonary artery trunk, consisting of three semi-lunar cusps

Pulmonary valve

A valve between the right ventricle and pulmonary artery

Mitral valve

Controls the blood flow from the left atrium to the left ventricle

Chordae tendineae

Strong, fibrous cords that connect the atrioventricular valves to the papillary muscles in the ventricles.

Aortic valve

The valve that lets oxygen rich blood flow from the left ventricle to the aorta.

SA node

A collection of specialized heart muscle cells designed to generate an electrical impulse.

How does the heart conduct electricity?

Specialized cardiac muscle fibers generate and conduct electrical impulses (action potential)

AV node

Delays the electrical impulses from the SA node, allowing the atria to fully contract and fill the ventricles with blood. It also acts as a backup pacemaker in case the SA node fails.

Bundle of His

Transmits electrical impulses from the AV node, delaying them slightly to allow the atria to empty the blood into the ventricles. The electrical impulses are distributed via the left and right bundle branches to the Purkinje fibers.

Rt and Lt Bundle branch

Pathways into the heart’s electrical system, carries signals from the AV node into the ventricles to make them contract together.

Purkinje fibers

Specialized cells in the heart’s electrical conduction system that spreads electrical signals throughout the ventricles, causing them to contract at the same time.

Intercalated discs

Specialized junctions between cardiac muscle cells that provide strong mechanical connections and fast electrical coupling.

Coronary Arteries

The blood vessels that encircle the heart along the atrioventricular sulcus

How are the heart muscles joined together?

They form anastomoses with each other

What is the purpose of the coronary arteries

To supply the heart muscle with oxygen and nutrients, enabling it to pump blood effectively

Collateral circulation

The natural backup system of smaller blood vessels that create alternative pathways to supply blood, oxygen, and nutrients to tissues when a main artery or vein is blocked or damaged.

How do you increase collateral circulation?

Cardivascular exercise

Coronary sinus

Located in the atrioventricular sulcus on the posterior surface. It receives blood from the cardiac veins and empties it into the right atrium

Rheumatic heart disease

An autoimmune heart disease triggered by a streptococcus viridans infection.

Endocarditis

Inflammation of the endocardium

Streptococcus viridans

Strep throat

Valvular disease

A disease that affects the valves of the heart, leading to blood back flow

Coronary Artery Disease

Caused by atherosclerosis (hardening of the blood vessels) of the coronary arteries

Angina Pectoris

Chest pain due to the heart muscle not getting enough oxygen-rich blood

Coronary thrombosis

a blood clot formed in the heart artery, leads to a heart attack

Conduction blocks

SA nodal block, AV nodal block, Bundle Branch block

SA nodal block

A heart rhythm problem where electrical signals from the SA node are delayed or blocked from reaching the atria, causing missed heartbeats or pauses in the heart’s rhythm.

AV nodal block

A delay or interruption in the heart’s electrical signals travelling from the atria to ventricle chambers, causing a slow or abnormal heart rate.

Bundle Branch block

A delay or blockage in the heart’s electrical pathways (bundle branches) that control ventricle contraction, causing the heart’s ventricles to beat out of sync.

Arrhythmia

abnormal heartbeat

Myocardial Infarction

heart attack

Stenosis of the lumen

Narrowing of the inside of a blood vessel

Heart murmur

an abnormal recurring sound in the heart

Lumen

A hole or opening inside a cavity

Tunica Intima

Innermost layer of blood vessels

Tunica Media

Middle layer of blood vessels, made of connective tissue and smooth muscle

Tunica Externa

Outermost layer of blood vessels, made of fibrous connective tissue

Vasa vasorum

“Vessel of the vessel” small blood vessels that supply arteries and veins

Elastic arteries

Large arteries, contain more elastic connective tissue in the walls, act to smooth out blood flow

Muscular arterioles

Small Arteries, contain more smooth muscle, innervated by autonomic motor neurons, act to divert blood flow from inactive tissues to active tissues

Capillary bed

Nutrients diffuse out of capillaries, while tissue waste products diffuse into capillaries.

Venules

small veins

Veins

Thinner walls than arteries, no elastic connective tissue in the walls, innervated by autonomic motor neurons, possess semilunar valves to prevent blood back flow

Venous sinus

Veins with no elastic connective tissue or smooth muscle. Found in cranial venous sinuses, coronary sinus, and hepatic sinuses

Aneurysm

A weak spot in the wall of a blood vessel

Hypertension

High blood pressure

Phlebitis

Inflammation of the veins

Embolism

Dislodged blood clot

Varicose veins

Veins distended with blood due to deficient valves