Chapter 19 and 20: Blood and Cardiovascular System

KIN 267

Functions of blood

transports O2, CO2, nutrients, hormones, heat, waste; regulates homeostasis of fluids, pH, temp, and water; protects by clotting and WBCs

Properties of blood

liquid connective tissue consisting of cells surrounded by a liquid matrix (plasma)

Erythropoiesis

production of RBCs; in red bone marrow; stimulated by erythropoietin hormone from kidneys

Hemoglobin

protein in RBCs; carry O2 to cells and some CO2 dioxide to lungs

Erythrocytes

no nucleus, mitochondria or organelles; biconcave discs; release O2 into interstitial fluid then cell for aerobic respiration (mitochondria); live 120 days

Nitric oxide

vasodilator; improve blood flow and enhances O2 delivery; regulate blood flow and BP

Hematocrit (Hct)

percent of total blood volume composed of red blood cells; ≥60% is dangerous; caused by dehydration and EPO injection

Leukocytes

contains nucleus and organelles but no Hb; leave bloodstream and collect at invasion or inflammation; platelets clot

Pulmonary

right side of the heart; carries deoxygenated blood to lungs for gas exchange

Systemic

left side of the heart; supplies oxygenated blood to all body tissues

Atria

receive blood and pump blood to ventricles

Ventricles

pump blood throughout the body; left is larger with walls 4x stronger than right

Cardiac output

volume of blood ejected from the left or right ventricle into the aorta or pulmonary trunk each minute; CO (mL/min) = SV (mL/beat) × HR (beats/min)

Stroke volume

amount of blood pumped out of the ventricle in one beat (mL/beat)

SA node

primary pacemaker (60-100 times/min), initiates and set heartrate

AV node

secondary pacemaker (40-60 times/min); electrical gateway to ventricles

Right and left bundle branches

carry AP

Purkinje fibers

spread AP throughout ventricles

Electrocardiogram

recording of the electrical changes that accompany each heart beat