Heart Anatomy and Physiology Lecture Flashcards

Comprehensive vocabulary flashcards covering heart wall layers, chambers, fetal modifications, valves, circulation circuits, coronary blood supply, and the electrical conduction system based on lecture notes.

Heart

Central organ of the cardiovascular system

Heart location

Medium stinum (pericardial cavity with thorasic cavity)

Heart pumps

5 liters each minute

Pericardium

Loose fitting sack surrounding and protecting the heart

Fibrous pericardium

Outer most layer with fibrous connective tissue and anchors the heart in place

Parietal pericardium

Underneath the fibrous pericardium; has pericardial fluid

Visceral pericardium

Adheres to the surface of the heart; coronary arteries located here

Parietal pericardium and visceral pericardium

Serous membrane; produce serous fluid (blood plasma)

Epicardium

Outermost tissue containing the coronary arteries; connective tissue and epithelial (surface of the heart)

Myocardium

The middle, muscle layer of the heart composed of involuntary, intercalated discs containing branched fibers. The “pump”

Anchoring desmosomes

Prevents separation of cardiac cells

Gap junctions

Allows ions to pass from cell to cell

Functional syncytium

A term describing how cardiac cells work as a single unit; when one cell contracts, they all must contract.

Endocardium

The innermost layer of the heart wall composed of connective tissue and epithelial tissue (simple squamous) that lines the chambers and covers the valves.

Fibrous skeleton of the heart

A framework of fibrous connective tissue located in the spaces between cardiac muscle fibers that reinforces the myocardium.

Mitochondria in cardiac cells

Large organelles that take up approximately 25% to 30% of the volume of a cardiac cell, providing energy through aerobic respiration.

Atria (Atrium)

Entryway

Right atrium

A receiving chamber that takes deoxygenated blood from the superior vena cava, inferior vena cava, and coronary sinus.

Coronary sinus

A vessel that delivers deoxygenated blood from the cardiac muscle tissue itself back to the right atrium.

Left atrium

A receiving chamber that takes oxygenated blood from the lungs via four pulmonary veins.

Interatrial septum

The dividing wall or septum that separates the right and left atria from each other.

Foramen ovale

A fetal modification consisting of a hole in the interatrial septum; soon after birth becomes fossa ovalis

Ventricles

The two lower, hollow chambers of the heart that act as the main pumps; the word translates to 'belly.'

Right ventricle

Receives deoxygenated blood from right atrium; takes up most of the anterior surface; pumps deoxygenated blood to the lungs

Left ventricle

Recieves oxygenated blood from, left atrium; thicker myocardium; it forms the apex of the heart and pumps blood to systemic circulation (body cells)

Atria (auricles)

Scalloped extensions of the atria that allow them to hold additional blood volume if necessary.

Pectinate muscle

Smooth muscle found mostly in the right atrium and the auricles of the left atrium that provides an extra squeeze to empty the chambers.

Trabeculae

Columns of cardiac muscle tissue found within the ventricles that give the inner surface a rough appearance.

Papillary muscles

Finger-like projections of cardiac muscle tissue located in the ventricles that anchor the chordae tendineae.

Heart valves

Dense irregular connective tissue covered by simple squamous

Atrio-ventricular valve (AV valves)

Includes the tricuspid valve and bicuspid valve (prevents back flow of blood)

Chordae tendinal

Prevents eversion of the AV valves

Semilunar valves

Pocket-like cusps includes the pulmonic semilunar valve and aortic semilunar valve

Ductus arteriosus

A fetal passageway connecting the pulmonary artery to the aorta; it becomes the ligamentum arteriosum (scar tissue) after birth.

Pulmonary circuit

A low-pressure closed circuit that carries blood from the right ventricle to the lungs for gas exchange.

Systemic circuit

A high-pressure closed circuit that carries blood from the left ventricle to the body tissues.

Arteries

Oxygenated blood away from heart

Veins

carries deoxygenated blood towards the heart

Arterioles

Microscopic arteries that lead from the medium muscular arteries into the capillaries.

Capillaries

Microscopic vessels one cell thick (simple squamous) where exchange of gases and nutrients occurs; they connect the arterial side to the venous side.

Left coronary artery branches

The two major vessels branching from the left side are the anterior descending (anterior interventricular) artery and the circumflex artery.

Right coronary artery branches

The two major vessels branching from the right side are the posterior descending (posterior interventricular) artery and the marginal artery.

Anastomosis

Also known as collateral circulation, these are alternative pathways that allow blood to reach the same destination if a major vessel is blocked.

Intermittent, pulsating blood flow

The manner in which blood reaches the myocardium; blood flow only occurs when the heart is in a relaxed state.

SA (Sinoatrial) node

The pacemaker of the heart, located in the right atrium, which initiates impulses at a rate of 70 to 80 beats per minute.

AV (Atrioventricular) node

A part of the conduction system that slows the impulse from the SA node to allow the atria to fully contract; it can initiate impulses at 40 to 50 beats per minute if the SA node fails.

All 3 needed for proper ventricular contractions

Bundle of HIS, R&L bundle branches, purkinje fibers

Moderator band

Cardiac muscle connecting the interventricular septum to the papillary muscles; it contains conduction fibers to ensure the ventricle fully contracts.

Tachycardia

A resting heart rate that is too fast, typically defined as 100 beats per minute or higher.

Bradycardia

A resting heart rate that is slower than normal, typically less than 60 beats per minute.

Ventricular fibrillation (V-fib)

A medical emergency where cardiac cells are not in sync, causing the heart to act like a 'squirming bag of worms' rather than an efficient pump.

Defibrillation

The use of electrical paddles to depolarize the entire myocardium in hopes of resetting the SA node to a normal sinus rhythm.

Cardiac cycle

The sequence of all events taking place during one heartbeat, measuring approximately 0.8 seconds in a normal cycle.