Phlebotomy Chapter 6 Review

Layers of heart

Epicardium: thin outer layer ▪ Myocardium: middle muscle layer ▪ Endocardium: thin inner layer

Blood type

Inherited o Determined by presence or absence of antigens on surface of red blood cells o A person's blood either contains or has the ability to develop antibodies directed at the opposite blood type

Intrinsic

Inside bloodstream ▪ Produces thrombin on the surface of activated platelets

Lumen

Internal space of a blood vessel, through which blood flows

Electrical conduction system

Specialized cells that initiate & distribute electrical impulses throughout the myocardium to coordinate cardiac cycle

tunica media

middle; smooth muscle & elastic fibers

pulmonaries take

deoxygenated blood to the lungs and to the veins

Thrombocytes (platelets):

essential to coagulation

Hemostasis

o Arrest or stoppage of bleeding after injury as a body response o Requires coordinated interaction of endothelial cells lining blood vessels, platelets, other blood cells, plasma proteins, & clotting o Is ongoing daily, in conjunction with vessel repair

Lymph

excess tissue fluid that filters into lymphatic capillaries

M-Shaped pattern of antecubital veins

o Cephalic vein o Median vein ▪ First choice o Median cephalic vein ▪ Second choice o Median basilic vein ▪ Third choice o Basilic vein

In Vivo/Cell-Based Coagulation

o Initiation o Amplification o Propagation

structure of lymphatic system

o Lymph (fluid) o Lymphatic vessels, ducts, & nodes

two ducts empty into large veins in upper body

o Lymph is moved by skeletal muscle contraction o Lymph passes through lymph nodes that filter out impurities

H-shapes pattern of antecubital veins

o Median cubital vein ▪ Located near center of AC ▪ Preferred vein/first choice o Cephalic vein ▪ Located in the lateral aspect of AC ▪ Second choice o Basilic vein ▪ Located in the medial aspect of AC ▪ Last choice o Displayed by approximately 70% of population

lymphatic system functions

o Returns tissue fluid to bloodstream o Protects body by removing microorganisms & impurities o Processes lymphocytes o Delivers fats absorbed from small intestine to bloodstream

The Role of the Liver in Hemostasis

o Synthesizes many coagulation factors: V, VIII, prothrombin, & fibrinogen o Produces bile salts needed for synthesis of some factors o Produces heparin

pulmonary

pertaining to the lungs

Which formed element is the first to play a role in sealing an injury to a blood vessel?

platelet

Cardiac output

volume of blood pumped by heart in 1 minute.

Secondary hemostatic plug formation

▪ Amplification ▪ Propagation

Rh blood group system

▪ Based on the "D" antigen (also called Rh factor) ▪ Rh positive (Rh+): RBCs have the D antigen ▪ Rh negative (Rh-): RBCs lack the D antigen

plasma

▪ Contains fibrinogen ▪ Specimen must be collected in an anticoagulant tube ▪ Used in cases when serum cannot be used ▪ Fluid portion of whole blood separated from the RBCs, WBCs, & platelets by centrifugation

serum

▪ Fluid portion of blood remaining after clotting ▪ Can be separated from clot by centrifugation ▪ Does not contain fibrinogen (used up in clotting)

Septa: partitions separating right & left sides of heart

▪ Interatrial ▪ Interventricular

Capillaries

▪ Microscopic, one-cell--thick vessels that connect arterioles & veins ▪ Site of gas exchange between blood & body tissues

Cardiac cycle

▪ One complete contraction (systole) & relaxation (diastole) of heart ▪ Lasts about 0.8 seconds

Fibrinolysis

▪ Process by which fibrin is dissolved ▪ Ongoing process: ➢ Dissolves clots that form in intact vessels, reopening them ➢ Removes hemostatic clots from tissue as healing occurs

Vasoconstriction

▪ Reduction in diameter of blood vessel ▪ Caused by contraction of smooth muscle fibers in vessel ▪ Decreases blood flow past injured area & limits blood loss

Capillaries join to form larger vessels that empty into terminal vessels:

▪ Right lymphatic duct ▪ Thoracic duct

ABO blood group system

▪ Two antigens (A & B) ▪ Four blood types (A, B, AB, & O)

Leukocytes (white blood cells)

➢Formed in bone marrow & lymphatic tissue ➢Neutralize or destroy pathogens ➢Types: granulocytes & agranulocytes

Erythrocytes (red blood cells)

➢Most numerous cells in body ➢ Carry O2 & CO2 ➢ Produced in bone marrow

Coagulation Pathways

extrinsic and intrinsic

Main components of the cardiovascular system

heart, blood vessels, blood

tunica externa

inner; single layer endothelial cells, basement membrane, connective tissue, & elastic internal membrane

aorta

largest artery

The basilic vein is the last choice for venipuncture because it is:

located near a major nerve

Main components of the lymphatic system

lymph, lymph vessels, lymph node

Two commonly used blood group systems

ABO blood group system Rh blood group system

veins

Return deoxygenated blood from tissues to heart ▪ Thin walls, low pressure

Antecubital fossa

Shallow depression in arm anterior to & below bend of elbow ▪ Site of major veins, & thus first choice for venipuncture

size and surrounding of heart

Size of a man's fist Surrounded by pericardium (thin, fluid-filled sac)

arteries always take blood

away from the heart

Second heart sound

"dupp" (ventricles relax, semilunar valves close)

Describe the first heart sound

"lubb" (ventricles contract, AV valves close)

Coronary circulation

: flow of blood through arteries and veins within the heart muscle, also called cardiac circulation

Heart Attack components

-Myocardial ischemia: partial obstruction of coronary artery OR ➢Myocardial infarction: complete obstruction or prolonged ischemia

Functions of the circulatory system

1. Transport to cells 2. Protection away from cells 3. Regulation aids in coagulation and defense

Process of hemostasis

1. Vasoconstriction 2. Formation of a primary platelet plug 3. Progression to a stable blood clot 4. Fibrinolysis (dissolving of clot)

Separated whole-blood specimen

55 liquid to 45 blood

The normal composition of blood is approximately

55% plasma, 45% formed elements

How large is a normal erythrocyte

7-8 microns

average heart rate

72 beats per minute

Plasma

90% water ▪ Gases (O2, CO2, N) ▪ Minerals (Na, K, Ca, Mg) ▪ Carbs & lipids ▪ Proteins ▪ Waste products ▪ Vitamins, hormones, drugs

Diastolic

: arterial pressure during relaxation of ventricles

Electrocardiogram (ECG)

A graphic record of heart's electrical activity during cardiac cycle

Chambers of the heart

Atria, right & left ▪ Ventricles, right & left

Valves of the heart

Atrioventricular (AV), right (tricuspid) & left (bicuspid) ▪ Semilunar, right (pulmonary) & left (aortic)

whole blood

Blood in the same form as it is in the bloodstream ▪ Not allowed to clot or separate ▪ Specimen must be collected in an anticoagulant tube ▪ Must be mixed a minimum of 2 minutes just prior to test

Pulmonary circulation

Carries blood from right ventricle of heart to lungs ▪ Carbon dioxide is removed; oxygen is picked up ▪ Oxygenated blood returns to left atrium of heart

Systemic circulation

Carries oxygenated blood & nutrients from left ventricle to body cells ▪ Returns deoxygenated blood with carbon dioxide & wastes from cells to right atrium

Arteries

Carry oxygenated blood away from heart to tissues ▪ Thick walls to withstand high pressure

diagnostic tests for vascular system

Diagnostic Tests o DIC screen o Lipoproteins o Prothrombin time o Partial thromboplastin time o Triglycerides

Structure of the heart

Four-chambered, hollow, muscular organ

Leg, ankle, and foot veins

High risk for phlebitis or thrombosis, only used with physician permission

Arm and leg arteries

Not routinely used for blood collection

Extrinsic

Outside bloodstream ▪ Initiates the coagulation process

pulse of the heart

Palpable rhythmic throbbing caused by alternating expansion & contraction of an artery as blood passes through

Bicipital aponeurosis

The median vein and the lateral aspect of the median cubital vein overlie this fibrous membrane ▪ An attempt should be made to locate one of these veins on either arm before an alternate AC vein is considered

valves

Thin, membranous leaflets in veins prevent backflow of blood

Dorsal forearm, hand, and wrist veins

Veins on lateral wrist above thumb to mid-forearm must not be used due to risk of nerve injury

Blood transfusion of the wrong type can

agglutinate and hemolyze red blood cells (transfusion reaction)

veins always take blood

back to the heart

aorta goes to

body

Atherosclerosis

buildup of plaque causing narrowing of coronary arteries and reduced blood flow to the heart

Angina (pectoris)

chest pain due to reduced blood flow to the heart

vein blood is moved by

skeletal muscle movement, valves that prevent backflow, & pressure changes in cavities in breathing

Arterioles

small branches of arteries that join capillaries

Venules

small veins that join capillaries

puloamr

take oxygen blood

which part initiates electrical impulse

the Sinoatrial (SA) node (pacemaker)

tunica intima

the innermost layer of a blood vessel

systolic blood pressure

the pressure created in the arteries when the left ventricle contracts and forces blood out into circulation

Which is the medical term for a blood clot circulating in the bloodstream?

thrombus

Layers of blood vessels

tunica intima, tunica media, tunica externa

The greatest chance of nerve injury is

venipuncture in the most medial and lateral portions of the antecubital fossa.