Cardiovascular System Study Guide

Vocabulary flashcards for Cardiovascular System Study Guide

Location of Heart

Located between the lungs, with apex pointed toward the left hip

Heart Rate

Contracts about 72 times per minute

Primary Functions of Cardiovascular System

Transportation of oxygen, nutrients, hormones, and waste products; Regulation of body temperature; Fluid volume regulation; Infection prevention through immune components

Plasma

~55% (primarily water - 90% water, 10% dissolved substances)

Erythrocytes (RBCs)

~44%

Leukocytes (WBCs) & Thrombocytes (platelets)

~1% (together form the "buffy coat" when centrifuged)

Viscosity of Blood

Five times more viscous than water

Color of Blood

Ranges from bright red (oxygenated) to dark red/purplish (deoxygenated)

pH Range of Blood

7.35-7.45

Average Blood Volume in Adult Human

5-6 liters

Water content of Plasma

90%

Proteins in Plasma

Albumin, globulins, fibrinogen

Gases in Plasma

Oxygen, carbon dioxide

Structure of Erythrocytes (Red Blood Cells)

Biconcave discs without nucleus; No organelles; Approximately 5 million per milliliter of blood; Lifespan: 100-120 days

Function of Erythrocytes

Oxygen transport via hemoglobin

Production Site of Erythrocytes

Red bone marrow

Biconcave Shape Adaptation for Erythrocytes

Increases surface area for gas exchange

Hemoglobin

Protein composed of four subunits (globins)

Subunit Composition of Hemoglobin

Globin protein and Heme group with iron (Fe²⁺) that binds oxygen

Neutrophils

Most common leukocyte; Phagocytize bacteria; Two-lobed nuclei

Eosinophils

Fight parasitic infections; Lessen allergic responses

Basophils

Release histamine during allergic reactions; Dilate blood vessels

Lymphocytes

Produce antibodies (B cells) or destroy infected cells (T cells)

Monocytes

Kidney-shaped nucleus; Develop into macrophages; Attack viruses, parasites, and bacteria

Key Difference Between RBCs and WBCs 1

Lack a nucleus (RBCs) vs. have a nucleus (WBCs)

Key Difference Between RBCs and WBCs 2

Contain hemoglobin (RBCs) vs. do not (WBCs)

Key Difference Between RBCs and WBCs 3

More numerous (RBCs) (1000:1 ratio)

Key Difference Between RBCs and WBCs 4

Confined to bloodstream (RBCs) vs. can leave via diapedesis (WBCs)

Key Difference Between RBCs and WBCs 5

Remains constant (RBCs) vs. fluctuates with infection (WBCs)

Thrombocytes (Platelets)

Cell fragments (not complete cells); Essential for blood clotting

Hematopoiesis

Blood cell formation in red bone marrow

Differentiation of Hematopoietic Stem Cells

Lymphoid stem cells → produce lymphocytes; Myeloid stem cells → produce all other blood cells

Hormone Stimulating RBC Production

Erythropoietin - stimulates red blood cell production

Antigen

Substance recognized as foreign by the body

Antibody

Protein produced by the immune system to bind to antigens

Type A Blood

Has A antigens on RBCs and anti-B antibodies in plasma

Type B Blood

Has B antigens on RBCs and anti-A antibodies in plasma

Type AB Blood

Has both A and B antigens on RBCs and no antibodies

Type O Blood

Has no antigens on RBCs and both anti-A and anti-B antibodies

Rh+

Has Rh antigens on RBCs (85% of Americans)

Rh-

Lacks Rh antigens (15% of Americans)

Genotype of Type A Blood

I^A I^A or I^A i

Genotype of Type B Blood

I^B I^B or I^B i

Genotype of Type AB Blood

I^A I^B

Genotype of Type O Blood

ii

Pericardium

Protective layer surrounding the heart

Fibrous Pericardium

Provides protection and anchors heart in place

Serous Pericardium

Produces lubricating fluid to reduce friction

Parietal Pericardium

Outer layer of serous pericardium

Visceral Pericardium

Inner layer of serous pericardium (also called epicardium)

Pericardial Cavity

Space between parietal and visceral pericardium filled with fluid

Myocardium

Cardiac muscle tissue - performs contractions

Endocardium

Thin layer lining the heart chambers

Atria

Upper chambers that receive blood

Right Atrium

Receives deoxygenated blood from body

Left Atrium

Receives oxygenated blood from lungs

Ventricles

Lower chambers that pump blood

Right Ventricle

Pumps deoxygenated blood to lungs

Left Ventricle

Pumps oxygenated blood to body

Function of Heart Valves

Prevent backflow of blood

Atrioventricular (AV) Valves

Between atria and ventricles

Tricuspid Valve

Between right atrium and right ventricle (3 flaps)

Mitral (Bicuspid) Valve

Between left atrium and left ventricle (2 flaps)

Semilunar Valves

Between ventricles and great vessels

Pulmonary Valve

Between right ventricle and pulmonary artery

Aortic Valve

Between left ventricle and aorta

Septum

Divides the heart into right (deoxygenated) and left (oxygenated) sides

Pulmonary Loop

Right ventricle → pulmonary artery → lungs → pulmonary veins → left atrium

Systemic Loop

Left ventricle → aorta → body tissues → venae cavae → right atrium

Deoxygenated Blood Pathway

From body tissues → superior/inferior vena cava → right atrium → right ventricle → pulmonary arteries → lungs

Cardiac Conduction Pathway

SA node → AV node → AV bundles → Bundle branches → Purkinje fibers

Sinoatrial (SA) Node

Initiates electrical impulse; Causes contraction of atria

Atrioventricular (AV) Node

Receives impulse from SA node; Delays impulse to allow atria to empty into ventricles

Cardiac Output Definition

Amount of blood pumped by each ventricle in one minute

Cardiac Output Formula

Cardiac Output = Stroke Volume × Heart Rate

Arteries

Carry blood away from heart

Veins

Carry blood toward heart

Capillaries

Single-cell thick walls; Site of material exchange

Mechanisms to Maintain Venous Return

Muscular pumping, Respiratory pumping, Valves

True Capillaries

Sites of gas and nutrient exchange

Capillary Sphincters

Control blood flow into true capillaries

Vascular Contraction

Blood vessel contracts to reduce blood flow

Platelet Activation

Platelets adhere to damaged vessel wall

Negative Feedback Loop

System that maintains homeostasis

tachy-

fast

brady-

slow

athero-

fatty plaque, fatty substance

angio-

blood vessel

hemo-/hemato-

blood

erythro-

red (refers to red blood cells)

leuko-

white (refers to white blood cells)

thrombo-

clot

-cyte

cell

-poietin

producing substance

-emia

blood condition

-penia

deficiency

-osis

condition, usually abnormal

-sclerosis

hardening

-stenosis

narrowing

-cardia

heart condition