Circulatory System

Notes from APLab4 & 01/21 Lecture

Heart

Pump that forces blood through the vessels

Heart and its surrounding blood vessels

Components of the circulatory system

O2, CO2, nutrients, and waste

Blood transports…

Base

The superior portion of the heart, slightly flat

Apex

Inferior portion of the heart, slightly pointy

Parietal pericardium

Thick membrane surrounding the heart

Visceral Pericardium

The layer of membrane that is contiguous with the heart

Atrium

2 thin walled chambers in the superior portion of the heart, collects blood from the body

Septum

Divides the heart longitudinally

Interatrial septum

Separates the atria

Interventricular septum

Separates the ventricles

Myocardium

The heart wall, cardiac muscle. “The muscular part of the heart”

Endocardium

Layer that covers the interior part of the chambers, smooth in texture to prevent formation of clots

Coronary vessels

Nutrition of the heart comes from:

Right and Left coronary arteries

These branches (arteries) come directly from the aorta and rest in the grooves (sulci) around the heart

Sulci

Grooves (seen around the heart)

Coronary sulcus

Encircles the heart between atria and ventricles

Anterior interventricular sulcus

Runs vertically between ventricles on the anterior side

Posterior interventricular sulcus

Runs between ventricles on the posterior side

Left coronary artery

Travels to the left side within the coronary sulcus

Anterior interventricular branch

Travels to the anterior side between the ventricles through the anterior interventricular sulcus. Supplies oxygen to the interventricular septum and the anterior walls of the ventricles

Right Coronary artery

Travels to the right side within the coronary sulcus

Circumflex Branch

Travels via the coronary sulcus on the posterior side

Marginal branch

Given rise from the right coronary arteries. Travels down the left anterior lateral part of the heart

Posterior interventricular branch

Goes to the posterior part and travels via the coronary sulcus and resides in the posterior intraventricular sulcus. Supplies oxygen to the interventricular septum and the posterior walls of the ventricles

Blood collected from the heart tissues —> coronary veins —> coronary sinus —> right atrium

Path of blood from heart tissues…

Superior/Inferior Vena Cava —> Right Atrium —> Tricuspid valve —> Right Ventricle —> Pulmonary Trunk —> Pulmonary Semiulnar Valve —> Pulmonary Arteries —> Lungs —> Pulmonary Veins —> Left Atrium —> Bicuspid Valve —> Left Ventricle —> Aortic Semiulnar Valve —> Aorta —> Tissues —> Veins —> Coronary Sinus

Circulation of blood through the heart…

Tricuspid Valve

Located on the right side, prevents back flow of blood during contraction (V)

Biscupid/Mitral Valve

Valve located on the left side

Chordae tendineae

Holds down valves by the inferior portion. Prevents atrial ventricular valves from inverting, embedded into papillary muscles (wall of the heart)

Pulmonary semilunar valve

Prevents backflow during relaxation on the side of the right ventricle

Aortic semilunar valve

Prevents backflow during relaxation on the side of the left ventricle

Pulmonary Trunk

Exits the right valve and branches into Right & Left pulmonary arteries

Artery

Blood vessel leaving the heart

Vein

Blood vessel entering the heart

Pulmonary veins

Set of 4 veins (two from each lung) located superiorly to left atrium

Left Ventricle

Thickest portion of the myocardium is in this location due to this portion pushing blood to every part of the body through the Aorta

Capillaries

Smallest blood vessels, where the tissues are located

Aorta —> Arteries —> Arterioles —> Capillaries (tissues) —> Venules —> Veins —> Vena Cava

Blood flow cycle to the body

Heart murmur

Caused by back flow of blood through the ventricular valves

Valves slamming shut

Heartbeat is the sound of…

Tamponade

Accumulation of fluid in the pericardial space, prevents heart from expanding and contracting normally

Left Subclavian Branch

Branch on the left side of the aortic arch, going under the clavicle

Left common carotid

Branch of the aortic arch giving rise to the left external and internal carotid

Left external carotid

Goes to the left side of the head and face

Left internal carotid

Goes to the left side of the brain

Innominate Artery/Brachio-cephalic

Asymmetrical branch of the aortic arch, gives rise to the right subclavian and right common carotid (which gives rise to the right external and internal carotid)

Right external carotid

Goes to right side of head and face

Right internal carotid

Goes to right side of brain