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Cardiac Muscles (Cardiovascular System) Cheat Sheet (DRAFT) by

Cardiac Muscles (Cardiovascular System)

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Anatomy of the Heart

Cardiac Muscles - A type of involu­ntary muscle found only in the heart, having the features of both skeletal and smooth muscles.
Atria - The two upper chambers of the heart that receives blood returning from the body/l­ungs.
Ventricles - The two lower chambers of the heart that pump blood out to the rest of the body
Right Atrium - Receives oxygen­-de­prived blood from the body from venae cavae (inferior & superior vena cava) and transports blood to the Right Ventricle via tricuspid valve
Left Atrium - Receives oxygen­-rich blood from the lungs via left & right pulmonary veins transports blood into the Left Ventricle via bicuspid valve
Right Ventricle - Receives oxygen­-de­prived blood from the Right Atrium and pumps blood through the Pulmonary valve into the lungs for oxygen­ation
Left Ventricle - Receives oxygen­-rich blood from the Left Atrium and pumps it through the aortic into the rest of the body
Heart Valves - Structures that ensures blood flows in one direction by opening and closing to prevent backflow
Chordae Tendineae - Strong fibers that connect AV valves to the papillary muscles in the Ventricles to prevent AV values from turning inside out
Pulmon­ary­/Se­milunar Valve - A triple­-flap valve located between the Right Ventricle and the Pulmonary Artery, it prevents backflow of blood into the Right Ventricle after it is pumped to the lungs
Right AV or Tricuspid - A triple­-flap valve located between the Right Atrium and Right Ventricle, preventing backflow of blood into the Right Atrium
Left AV or Bicusp­id/­Mitral - A double­-flap valve located between the Left Atrium and Left Ventricle that prevents backflow of blood into the Left Atrium
Aortic­/Se­milunar Valve - A triple­-flap valve located between the Left Ventricle and the Aorta that prevents backflow of blood into the Left Ventricle
Superior Vena Cava - A large vein that returns oxygen­-de­ficient blood from the upper body (head, upper limbs) to the heart
Inferior Vena Cava - A large vein that returns oxygen­-de­ficient blood the lower body (abdomen, lower limbs) to the heart
Papillary Muscles - Muscles located in the heart that anchor Chordae Tendineae and contract to prevent inversion
Connective Tissue - A body tissue that suppor­ts/­con­nec­ts/­sep­arates different types of tissue­/or­gans; separating the atria and the ventri­cles, supporting heart valves and muscle
Heart Walls - Made up of three layers that protect the heart
Endoca­rdium - Made out of a thin layer of endoth­elial tissue (Inner Layer)
Myocardium - Made out of cardiac muscle, connected by interc­alated disks that have desmosomes that hold the cells together and gap-ju­nctions that allow electrical signals to flow smootly (Middle Layer)
Epicardium - A thin membrane that covers the heart and contains some perica­rdial fluid which reduces friction as the heart beats
 

Cardiac Cycle and Blood Flow

Circularly System - Composed of the heart, blood, and blood vessels to transport oxygen, nutrients, waste, and hormones throughout the body, additi­onally acting as a temper­ature regulator
Pulmonary Circul­­ation - Delivers oxygen­-de­prived blood the right side of the heart to the lungs which undergo oxygen­ation and is transp­orted back to the heart as oxygen­-rich blood
Systemic Circul­­ation - Delivers oxygen­-rich blood throughout the entire body via the aorta and blood vessels and returns oxygen­-de­prived blood to the heart using the superior and inferior vena cava.

Anatomy of the Heart

Reference: Britannica "­­He­a­r­t"

Electrical Activity of the Heart

Reference: Stanford Medicine Children's Health: Anatomy and Function of the Electrical System
  

Electrical Activity of the Heart

Autorh­yth­micity - The heart's ability to generate electrical impulses without external stimul­ation
Pacemaker Activity - Generation of electrical impulses by specia­lized cells
Nodes - Specia­lized regions where pacemaker cells are grouped together to manage the rate of heart contra­ctions
Pacemaker Potential - A process that slowly triggers an action potential in pacemaker cells
Sinoatrial (SA) Node - A group of specia­lized pacemaker cells located in the Right Atrium of the heart, setting the rate and rhythm of the heartbeats (70 action potentials per minute)
Atriov­ent­ricular (AV) Node - A group of specia­lized cells located at the Right Atrium and follows the SA node (50 action potentials per minute
Bundle of His - A group of specia­lized cardiac pacemaker cells that branches and extends into the Right & Left Ventricles
Purkinje Fibers - Specia­lized fibers that conduct electrical impulses from Bundle of His and spread throughout the Myocardium (30 Action Potential per minute)
Intera­trial Pathway - A pathway that transmits electrical impulses from the Right and Left Atrium
Internodal Pathway - A pathway that transmits electrical impulses from the sinoatrial node to the atriov­ent­ricular node
Current Flow Order through the Heart Wall: SA node, AV node, Bundle of His, Right & Left bundle branches, Purkinje fibers
 
Pacemaker Activity - This occurs because of the unique electr­oph­ysi­olo­gical properties of a subset of specia­lized cardiac muscle cells that generate pacemaker activity.