Circulatory System Lecture 2

Stopped before 4 chambers of the heart

Red blood cells

erythrocytes

White blood cells

leukocytes

Platelets

need for clotting

Blood

only fluid tissue in the body, comprised of living cells (formed elements) suspended in nonliving fluid (plasma)

Formed elements

erythrocytes, leukocytes, and platelets

Hematocrit

concentration of red blood cells in a sample (45%)

Plasma

straw-colored liquid that makes up about 55% of blood

Atherosclerosis

the accumulation of fatty plaques on arteriole walls that narrows the lumen making it difficult for blood to flow, can lead to ischemia

Arteriosclerosis

when calcium deposits on the fatty plaques and causes the artery to harden

Where is the heart located

in the mediastinum

Apex

the bottom of the heart, rests on the diaphragm

Base

top of the heart where major blood vessels enter and exit

Fibrous pericardium

the outer layer of the pericardium that protects the heart and anchors it to surrounding structures

Serous pericardium

the inner layer of the pericardium consisting of two layers that secrete fluid to reduce friction around the heart during contraction

Two layers of serous pericardium

parietal and visceral pericardium

Parietal pericardium

the outer layer of the serous pericardium that lines the fibrous pericardium

Visceral pericardium

the inner layer of the serous pericardium that lines the myocardium and is also known as the epicardium

Endocardium

lines the inside of the right and left ventricles

Endocarditis

inflammation of the endocardium

Myocarditis

inflammation of the myocardium

Epicarditis

inflammation of the epicardium

Myocardium

the middle layer of the heart wall, composed of cardiac muscle tissue responsible for contraction and pumping blood

Cardiac fibers form two large networks

atrial and ventricular

Intercalated discs

transverse thickening of the sarcolemma that connects cardiac fibers in a network