HEART — QUIZ REVIEWER Chapter 12: Heart | Quiz-focused reviewer using the terms from the uploaded material

SECTION 12.1 — Functions of the Heart

• Generates Blood Pressure — Contractions of the heart generate the blood pressure needed to force blood through the

vascular network.

• Routes Blood — Separates systemic and pulmonary circulations and directs oxygenated/deoxygenated blood

appropriately.

• Ensures One-Way Flow — Heart valves prevent backflow and ensure unidirectional flow of blood.

• Regulates Blood Supply — Adjusts rate and force of contraction to meet changing metabolic demands.

Memory: G-R-E-R = Generates Blood Pressure, Routes Blood, Ensures One-Way Flow, Regulates Blood Supply

SECTION 12.2 — External Heart Anatomy

• Coronary Sulcus — Groove encircling the heart that externally separates atria from ventricles.

• Interventricular Sulci — Anterior and posterior grooves extending from the coronary sulcus toward the apex.

• Superior & Inferior Vena Cava — Return venous blood to the Right Atrium.

• Pulmonary Trunk — Arises from the Right Ventricle and carries blood toward the lungs.

• Aorta — Arises from the Left Ventricle and supplies systemic organs.

• Pulmonary Veins — Return oxygenated blood to the Left Atrium.

PERICARDIUM

• Fibrous pericardium — Tough, fibrous outer connective tissue layer; anchors the heart.

• Parietal layer of serous pericardium — Lines the outer fibrous sac.

• Pericardial cavity — Fluid-filled space that reduces friction during heart beats.

• Epicardium (visceral layer of serous pericardium) — Covers the heart surface.

Outside → inside: Fibrous pericardium → Parietal layer of serous pericardium → Pericardial cavity → Epicardium

SIZE, FORM, AND LOCATION

• Approximately the size of a closed fist.

• Located in the thoracic cavity, within the mediastinum.

• Base — Broad superior portion; site of attachment for great vessels.

• Apex — Blunt, rounded inferior tip; points anteriorly, inferiorly, and to the left.

SECTION 12.3 — Internal Heart Anatomy

• Atria — Receiving chambers: Right Atrium and Left Atrium.

• Ventricles — Pumping chambers: Right Ventricle and Left Ventricle.

• Interatrial septum — Separates the atria.

• Interventricular septum — Separates the ventricles.

HEART VALVES

• Atrioventricular (AV) Valves — Located between the atria and ventricles.

• Tricuspid valve — Right side; 3 cusps.

• Bicuspid (mitral) valve — Left side; 2 cusps.

• Chordae tendineae — Anchor AV valves to the papillary muscles.

• Semilunar (SL) Valves — Pulmonary Valve and Aortic Valve.

• Pulmonary Valve — Between Right Ventricle and Pulmonary Trunk.

• Aortic Valve — Between Left Ventricle and Aorta.

SECTION 12.4 — Histology of the Heart

• Epicardium — Visceral serous pericardium; smooth outer protective layer.

• Myocardium — Thick middle layer made of specialized cardiac muscle cells; responsible for contraction.

• Endocardium — Smooth inner endothelial lining covering chambers and valves.

• Intercalated Discs — Special cell junctions that hold cardiac cells mechanically together.

• Gap Junctions — Allow rapid ion flow and synchronous electrical depolarization.

Order: Epicardium → Myocardium → Endocardium

Don't confuse: Intercalated Discs = mechanical connection; Gap Junctions = electrical communication

HEART CONDUCTION SYSTEM

• Sinoatrial (SA) Node — Located in the superior right atrium; primary pacemaker; approximately 70–80 bpm.

• Atrioventricular (AV) Node — Located in the lower interatrial septum; delays impulse transmission.

• AV Bundle (Bundle of His) — Passes the electrical signal through the fibrous heart skeleton to the interventricular septum.

• Bundle Branches — Right and left branches convey impulses toward the apex.

• Purkinje Fibers — Rapidly spread depolarization through ventricular myocardium.

Sequence: SA Node → AV Node → AV Bundle (Bundle of His) → Bundle Branches → Purkinje Fibers