bio lab test

blood

oxygen rich blood is bright red.

average amount of blood

the average amount of blood in the body is about

• 4-5 L in adult females

• 5-6 in adult males

classification of blood

blood is classified as a type of connective tissue because it consists of cells within a matrix

• the nonliving fluid matrix is the PLASMA

• the cells and cell fragments are the FORMED ELEMENTS. The fibers typical of a connective tissue matrix become visible in blood only when clotting occurs. Then they appear as fibrin threads

• formed elements normally make up for 45% of whole blood, plasma is the remaining 55%

amount of substances in plasma

more than 100 different substances are dissolved or suspended in plasma, which is over 90% of water.

• include nutrients, gases, hormones, various wastes and metabolites, many types of proteins and electrolytes

• the composition of plasma varies continuously as cells remove or add substances to the blood

formed elements: erythrocytes

sacs of hemoglobin molecules that transport the bulk of the oxygen carried in the blood (and a small percentage of the carbon dioxide)

leukocytes

part of the body’s nonspecific defenses and the immune system

platelets

function in hemostasis (blood clot formation) together they make up less than one percent of whole blood.

erythrocytes

description: biconcave; anucleate disc; orange-pink color; 7-8μm

function: transport oxygen and carbon dioxide

leukocytes

spherical, nucleated cells 4800-10,800

neutrophil

description: nucleus multilobed; pale red and blue cytoplasmic granules; diameter 10-12 μm

function: phagocytize pathogens or debris

eosinophils

description: nucleus bilobed; red cytoplasmic granules; diameter 10-14 μm

function: kill parasitic worms; slightly phagocytic; complex role in allergy and asthma

basophil

description: nucleus lobed; large blue-purple cytoplasmic granules; diameter 10-14 μm

function: release histamine and other mediators of inflammation; contain heparin an anticoagulant

lymphocyte

description: nucleus spherical or indented; pale blue cytoplasm; diameter 5-17 μm

function: mount immune response by direct cell attack or via antibody production

monocyte

description: nucleus U or kidney shaped, gray blue cytoplasm; diameter 12-24 μm

function: in tissues, develop into macrophages that phagocytize pathogens or debris

platelets

description: cytoplasmic fragments containing granules; stain deep purple; diameter 2-4 μm

function: seal small tears in blood vessels; instrumental in blood clotting

leukocytosis

a white blood cell count over 11,000 cells/mm³, may indicate bacterial or viral infection, metabolic disease, hemorrhage, or poisoning by drugs or chemicals

leukopenia

a decrease in the white cell number below 4000/mm³ is usually due to exposure to certain chemicals or toxins

-lacks the usual protective mechanisms

leukemia

a malignant disorder of the lymphoid tissues characterized by uncontrolled proliferation of abnormal white blood cells accompanied by reduction in the number of red blood cells and platelets. it is detectable not only by a total white blood cell count but also by a DIFFERENTIAL WHITE BLOOD CELL COUNT

polycythemia

increase in the number of red blood cells, may result from bone marrow cancer or from living in high altitudes where less oxygen is available

anemia

a decrease in the number of red blood cells.

a decreased oxygen carrying capacity of blood that may result from a decrease in red blood cell number or size or a decreased hemoglobin content in red blood cells

differential white blood cell count

100 white blood cells are counted and classified according to type

hematocrit

routinely determined when anemia is suspected. centrifuging whole blood spins the formed elements to the bottom of the tube, with plasma forming the top layer, AND BUFFY coat. since the blood cell population is primarily red blood cells, the hematocrit is generally considered equivalent to the red blood cell volume, and this is the only value reported

-however the relative percentage of white blood cells can be differentiated and both white blood cell and plasma volume will be reported here

anemia

a person can be anemic even with a normal red blood cell count. since hemoglobin is the red blood cell protein responsible for oxygen transport, perhaps the most accurate way of measuring the oxygen carrying capacity of blood is to determine its hemoglobin content.

the more hemoglobin molecules the red blood cells contain, the more oxygen they will be able to transport. normal blood contains 12 to 18g of hemoglobin per 100 ml of blood

hemostasis

protective mechanism that is set into motion when a blood vessel break. hemostasis responds rapidly to stop bleeding.

three events occur:

-vascular spasm

-platelet plug formation

-coagulation (blood clotting)

blood clotting or coagulation

process that requires the interaction of many substances normally present in the plasma (clotting factors or procoagulants) as well as some released by platelets and injured tissues

blood typing

a system of blood classification based on the presence of specific glycoproteins on the outer surface of the red blood cell plasma membrane. such proteins are called ANTIGENS or agglutinogens and are genetically determined

several blood typing systems exist, based on the various possible antigens, but the factors routinely typed for are antigens of the ABO and Rh blood groups

antibodies

antigens are accompanied by plasma proteins called antibodies. these antibodies act against red blood cell carrying antigens that are not present on the person’s own red blood cells

if the donor blood type doesn’t match, the recipient’s antibodies react with the donor’s blood antigens, causing the red blood cells to clump, aggulinate, and eventually hemolyze. it is because of this phenomenon that a person’s blood must be carefully typed before a whole blood or packed cell transfusion

Rh blood

individual whose red blood cells carry the Rh antigen are Rh positive. those lacking the antigen are Rh negative. however Rh- negative persons who receive transfusions of Rh- positive blood become synthesized by the Rh antigens of the donor RBCs and their systems begin to product anti Rh- antibodies

atherosclerosis

disease process in which the body’s blood vessels become increasingly occluded or blocked by plaques. by narrowing the arteries, the plaques can contribute to hypertensive heart disease. they also serve as starting points for the formation of blood clots (thrombi) which may break away and block smaller vessels farther downstream in the circulatory pathway and cause heart attacks and strokes

• cholesterol is a major component of the smooth muscle plaques formed during atherosclerosis

• a normal for total plasma cholesterol in adults ranges from 130 to 200 mg per 100 ml of plasma; you will use blood to make such a determination

• although the total plasma cholesterol concentration is valuable information, it may be misleading, particularly if a person’s high-density lipoprotein (HDL) level is high- and low-density lipoprotein level is relatively low

• LDL bad cholesterol: HDL good cholesterol the LDL is traveling to body’s tissue cells, when LDL levels are excessive, cholesterol is deposited in the blood vessel walls

• HDL is destined to be degraded by the liver and then eliminated from the body.

cardiovascular system

major function of the cardiovascular system is TRANSPORTATION. using blood as the transport vehicle, the system carries oxygen, nutrients, cell wastes, electrolytes, and many other substances vital to the body’s homeostasis to and from the body cells. the system’s propulsive force is the contracting heart, which can be compared to a muscular pump equipped with one way valves

heart

a cone shaped organ approximately the size of a fist, is located within the mediastinum of the thorax.

pericardium

the heart is enclosed within a double walled sac

fibrous pericardium

the loose fitting superficial part of the sac

parietal layer

deep to it is the serous pericardium which lines the internal surface of the fibrous pericardium

visceral layer or epicardium

at the base of the heart, the parietal layer reflects back to cover the external surface of the heart

• the outer layer

myocardium

the middle layer and thickest layer, which is composed mainly of cardiac muscle. it is reinforced with dense fibrous connective tissue (cardiac skeleton) which is thicker around the heart valves and at the base of the great vessels leaving the heart

endocardium

the inner lining of the heart, which covers the heart valves, and it is continuous with the inner lining of the great vessels

interatrial septum

the septum that divides the heart longitudinally where it separates the atria

interventricular septum

separates the ventricles

tricuspid and bicuspid

anchored to the papillary muscles by chordae tendineae

pulmonary circuit

the function of the pulmonary circuit is to strictly provide for gas exchange

• the right side of the heart pumps oxygen poor blood entering its chambers to the lungs to unload carbon dioxide and to pick up oxygen. the blood vessels that carry blood to and from the lungs form the PULMONARY CIRCUIT

systemic circuit

the blood vessels that carry blood to and from all body tissues form the systemic circuit

• the left side of the heart pumps oxygenated blood returning from the lungs to the body tissues.

anterior interventricular artery

located in the anterior interventricular sulcus and supplies the anterior portion of the interventricular septum and the anterior walls of both ventricles

coronary sinus

drains into the right atrium, the entire heart; the great, middle and small cardiac veins all drain into the coronary sinus

capillaries

connect the arterioles and venules and branch throughout the tissues directly serve the needs of the body’s cells. it is through the capillary walls that exchanges are made between the tissue cells and blood

three layers of vessels: tunica interna

lines the lumen of a vessel and is composed of the endothelium, subendothelial layer, and internal elastic membrane

tunica media

middle coat, composed primarily of smooth muscle and elastin. plays active role in regulating the diameter of blood vessels which in turn alters blood flow and blood pressure

tunica externa

outermost tunic, composed of areolar or fibrous connective tissue. its function is basically supportive and protective

are walls of veins or arteries thicker

walls of arteries are thicker than veins.

arteries, are closer to the pumping action of the heart must be able to expand as in increased volume of blood is propelled into them during SYSTOLE and then recoil passively as the blood flows off into the circulation during DIASTOLE

arterioles

smallest arteries: blood flows from arterioles into a capillary bed

capillaries

provide for the exchange of materials between the blood and tissue cells

venules

smallest veins: drain capillary beds and merge to form veins

thoracic aorta

courses downward as descending aorta through the thoracic cavity, called the thoracic aorta from T5 to T12, the descending aorta penetrates the diaphragm to enter the abdominal cavity just anterior to the vertebral column. as it enters the abdominal cavity, it becomes the abdominal aorta

healthy heart

in a healthy heart, the two atria contract simultaneously. as they begin to relax, the ventricles contract simultaneously.

systole and diastole

refer to events of ventricular contraction and relaxation respectively

cardiac cycle

equivalent to one complete heartbeat—during which both atria and ventricles contract and then relax

quiescent period

of this time period, atrial contraction occupies the first 0.1 second, which is followed by atrial relaxation and ventricular contraction for the next 0.3 second, the meaning 0.4 second is a period of total heart relaxation

first heart sound

the first heart sound (lub) is referred to as S1 and is associated with closure of the atrioventricular valves at the beginning of ventricular systole

second heart sound

the second heart sound (dup) called S2, occurs as the semilunar valves close and corresponds with the end of systole

murmurs

abnormal heart sounds, and often indicate valvular problems. in valves that do not close tightly, closure is followed by a swishing sound due to the backflow of blood (regurgitation)

pulse

alternating surges of pressure (expansion and recoil) in an artery that occur with each contraction and relaxation of the left ventricle

pulse

this difference between systolic and diastolic pressure

apical pulse

(actually counting of heartbeats) may be slightly faster than the radial because of a slight lag in time as the blood rushes, from the heart into the large arteries where it can be palpated

pulse deficit

a difference between the values observed

blood pressure

defined as the pressure the blood exerts against any unit area of the blood vessel walls, and it generally measured in the arteries. because the heart alternately contracts and relaxes, the resulting rhythmic flow of blood into the arteries causes the blood pressure to rise and fall during each beat, thus you must take two blood pressure readings

systolic pressure

the pressure in the arteries at the peak of ventricular contraction

diastolic pressure

which reflects teh pressure during ventricular relaxation.

what is the name of the instrument used to compress the artery and record pressures in the auscultatory method of determining blood pressure?

sphygmomanometer

sounds of korotkoff

sounds which indicate the resumption of blood flow into the forearm

what causes the systolic sound

when ventricles contract to pump blood into arteries, rapid closure of atrioventricular valves

• disappear of the sound is caused when the artery is constricted. blood is flowing and is relaxed now

explain why pulse pressure is different from pulse rate:

pulse pressure is calculated, measures the difference between systolic and diastolic blood pressure, while pulse rate measures the number of pulses per minute

how do venous pressures compare to arterial pressures and why

Venous pressures are significantly lower than arterial pressures. Venous walls are so thin, pressure within them is readily affected by external factors. arteries have thicker walls because it is closer to the heart and needs more pumping power

what happens to blood pressure in increased diameter of arterioles

decrease

what happens to blood pressure in increased blood viscosity

increase

what happens to blood pressure in increased cardiac output

increase