Test Flashcards
. Why would an excess of albumin in the blood cause problems?
Albumin is a plasma protein that would increase the osmotic potential of the blood. More albumin in the plasma would draw more water from the tissues and increase blood volume.
Why is hemoglobin packed into red blood cells rather than suspended in blood plasma?
The amount of hemoglobin need to transport sufficient oxygen to the tissues would dramatically increase the viscosity of the blood if it were suspended in plasma. This would require tremendous pumping force to circulate the blood and blood pressure would rise.
Why is it a bad idea for someone with O+ blood to receive AB- blood?
An O+ recipient contains anti-A and anti-B antibodies in his/her plasma. An AB- donor contains both A and B antigens on his/her erythrocytes. Thus, the recipient’s antibodies would attack the donor’s antigens and trigger a transfusion reaction leading to major clumping of the donor’s blood.
You locate a formed element on a microscope slide with an “s-shaped” nucleus that is barely visible because of the dark blue granules. Identify the formed element.
Basophil
Which formed element is the primary defender against cancer cells?
Lymphocyte
How does a platelet plug form?
Damage to a blood vessel will expose collagen fibers in the vessel wall. Circulating platelets will stick to these collagen fibers as they pass through the vessel. The platelets that have adhered to the vessel wall will release chemicals that attract additional platelets. This positive feedback loop will eventually create a sticky mass that allows the damaged vessel to begin healing.
- What impact would the inability to form prothrombinase have on an individual?
Without prothrombinase, prothrombin cannot be converted into thrombin and the clotting cascade comes to a halt before fibrin gets formed.
What type of anemia could occur as a result of a snakebite?
Hemolytic anemia.
What type of anemia might occur among those who follow a vegan diet? Why?
Pernicious anemia. Meat-free diets are low in vitamin B-12, which is essential in the formation of erythrocytes.
What is the difference between a thrombus and an embolus?
A thrombus is a clot that becomes large enough to block a blood vessel. If a piece of that clot breaks free, it becomes an embolus that travels through the bloodstream.
- Which heart valve regulates blood flow into the lungs?
Pulmonary semilunar valve
Which chamber of the heart receives oxygen-rich blood from the lungs?
Left Atrium
Factors of blood transportation
Carries oxygen from lungs to cells and carbon dioxide from cells to lungs. 2.)Nutrients from gastrointestinal tract to cells and metabolic heat and wastes away from cells. 3.)hormones from endocrine glands to target cells.
Factors of blood protection
Clotting mechanism protects body against loss of blood. 2.)Phagocytic white blood cells engulf and destroy invading microorganisms and toxins. 3.) antibodies neutralize and/or destroy pathogens. 3.) inflammation limits the spread of an infection.
Factors of blood regulation
Blood buffers maintain constant pH levels. 2.) blood flow maintains normal body temp. 3.) blood volume maintains water balance.
Plasma
55% of blood. Straw colored fluid consisting of 92% water and 8% solutes. Blood serum remains after clotting proteins are removed from blood plasma.
Albumins
(60%) Plasma protein contributes to viscosity and osmolarity. Blood flow, BP, and water balance
Globulins
(36%) Plasma protein that transports lipids, fat-soluble vitamins, minerals, hormones, iron and lipids.
Immunoglobulins
antibodies that combat pathogens
Fibrinogen
(4%) Plasma protein that becomes fibrin which is the main component of a blood clot.
Plasma’s dissolved solutes include:
Nitrogenous wastes(urea)/ Nutrients(glucose,amino acids, fats, cholesterol)/ CO2 & O2/ electrolytes(sodium ions, chloride and bicarbonate ions)
Blood is what % of one’s total weight? How many liters does the average female and male have?
8% of total. Average female has 4 to 5 liters. Average male has 5 to 6 liters.
What % of total blood consists of formed elements and what are they?
45%. Erythrocytes, Leukocytes, and Thrombocytes(platelets)
Is blood more viscous than water? Why?
It is 4.5 to 5.5 more viscous due to formed elements and plasma proteins. This affects its flow through blood vessels.
What is blood’s pH?
Blood is slightly alkaline(basic) with a range between 7.35 and 7.45
How is blood osmolarity determined and why is it important?
Determined by # of RBC’s, sodium ions, and proteins. Its important in maintaining fluid balance with the tissues.
BCOP?
proteins establish Blood Colloid Osmotic Pressure
Blood osmolarity too high?
too much water absorbed results in blood volume and blood pressure rising.
Blood osmolarity too low?
too much water remaining in tissues causes edema.
Erythrocyte structure?
Biconcave disks that lack nuclei and organelles. Plasma membrane is permeable and flexible allowing cells to change shape as they squeeze through capillaries.
what do RBCs carry out? and what cant they?
anaerobic respiration(no O2). Cant carry out protein synthesis and mitosis.
what does Hemoglobin do?
gives blood its red color an transports gases. 1/3 of weight of RBC. Each molecule consists of 4 protein globin chains .
non protein heme group?
contains iron ion that can transport one molecule of O2
Each erythrocyte contains ___ million hemoglobin molecules and can transport up to ___ billion O2 molecules.
280 and 1
Oxyhemoglobin
when O2 is bound to hemoglobin
Deoxyhemoglobin
Hemoglobin lacking O2
What is Hematocrit?
% of whole blood volume that comes from erythrocytes.
Average hematocrit for males and females? Why is it different?
Female(37-48%) Male(42-52%). Lower hematocrit in females is due to androgen( testosterone) levels, higher % body fat, and menstruation.
What do erythrocytes arise from in bone marrow that undergo erythropoiesis?
hemocytoblasts
Kidneys and liver release ___ to stimulate___ to differentiate and become mature over __ days?
hormone erythropoiten/ proerythroblasts/ 15
What does the erythrocyte process require?
dietary iron, transfer & binding proteins, vitamin B12, and folic acid.
Reduction in blood O2 levels causes…
Kidneys to increase the output of Erythropoiten(EPO) to stimulate production of more RBCs
Life span of erythrocyte and why
120 days because of wear and tear on its plasma membrane.
How are old erythrocytes removed?
from circulation by liver and spleen
___ releases the hemoglobin and separates it into __and __ groups
hemolysis/globins/heme
Globins are broken down into ___? Iron is removed from the heme group to___?
amino acids which get recycled./ be reused. rest of heme group is converted into waste biliruben.
What determines a human’s blood type?
The presence or absence of proteins on the surface of an erythrocyte determined by the alleles. EX: individuals with genotype AA or Ai produce only antigen A and have type A blood.
Most common blood type among whites and least common
Type O=most common/ Type AB=least
Agglutinins
naturally occurring antibodies that will react with A or B antigens and cause clumping among RBCs
what antibodies will individuals with antigen A have? With type B? individuals without antigens? Individuals with both?
Type A antigens will have anti-B antibodies/ Type B will have anti-A antibodies/ without antigens (type O) will have anti-A and anti-B./ with both(type AB) will have none
Donor antibodies are usually what?
too dilute to cause clumping in the recipient.
Universal recipients and why
Type AB because they have no antibodies in their plasma.
Universal donors and why
Type O because it doesn’t have A or B antigens
When was the Rh group first identified?
in the blood of a Rhesus monkey
What does Rh+ mean
individuals who have D antigens on their RBC’s. Only appear if sensitized.
Are anti-D antibodies naturally present in blood plasma?
No, they will only appear if an Rh- individual who has been sensitized or exposed to D antigens.
Neutrophil
(60-70%) of WBC count. cytoplasm appears light purple and Granules stain pink to red. nucleus may exhibit 2-5 lobes.phagocytize bacteria and release antimicrobial substances
Eosinophil
(2-4%) of WBC. granules stain bright red to orange. nucleus exhibits 2 distinct lobes. release enzymes to combat inflammation during allergic reactions. protect against parasitic worms
polymorphonuclear leukocytes
many shaped nuclei
Basophil
less than 1%. granules stain dark blue to purple. nucleus is bilobed or “s” shaped and often obscured by cytoplasmic granules. secretes histamine to increase blood flow. secretes heparin to reduce blood clotting.
what do agranular leukocytes lack
cytoplasmic granules
lymphocytes
(25-30%) nucleus is dark violet and surrounded by thin ring of blue-stained cytoplasm. destroy cancer cells, cells infected with viruses, and foreign cells. secrete antibodies during immune responses.
monocytes
(3-8%) nucleus is kidney shaped and cytoplasm is blue-gray. differentiate into macrophages that leave the blood to phagocytize pathogens, dead neutrophils, and tissue debris. activate the immune response.
leukopoiesis
production of white blood cells which is stimulated by various chemical messengers such as interleukins or colony-stimulating factors.
myeloblasts
differentiate into different types of granulocytes. stored in red bone marrow
monoblasts
differentiate into monocytes. stored in red bone marrow
lymphoblasts
differentiate into lymphocytes. mature in thymus gland
how many WBCs are there there per micro liter of blood
5000-10000
differential WBC count
compares % of each type of leukocyte to total WBC count. monitors blood disorders or effects of drugs.
platelet
membrane-enclosed cytoplasmic fragments of larger cells that lack nuclei. Produced by thrombopoiesis. Megakaryoblasts grow larger until cytoplasm breaks into fragments. circulate freely in blood for 10 days
platelet functions
secrete chemicals to stop bleeding and promote blood clotting. phagocytize bacteria. attract neutrophils and monocytes to site of inflammation
normal platelet count
130,000-400,000
hemostasis
stoppage of bleeding in damaged blood vessels
vascular spasm
triggered by chemicals released from local pain receptors that cause smooth muscle in walls of blood vessels to contract and constrict the vessels for a few minutes until other hemostatic mechanism begins
platelet plug
damage to a blood vessel exposes collagen fibers in the wall of the vessel so circulating platelets can adhere to the fibers and form plug.
platelets release chemicals causing
additional platelets to form a sticky mass that acti ates positive feedback loop to prevent blood loss from small vessels.
coagulation
conversion of blood from a liquid to a sticky gel.
clotting cascade
converts clotting factors into enzymes in a sequence to act as amplifying mechanism to ensure clotting
extrinsic pathway
initiated by clotting factors released from a damaged blood vessel or tissues around it. tissue thromboplastin combines with a clotting factor in the presence of calcium ions to activate factor X.
intrinsic pathway
initiated by substances in blood plasma that cause aggregated platelets to release PF3. Activate a cascade of reactions that activate factor X. slower than extrinsic
common pathway
begins when factor X combines with other factors and calcium ions produce the enzyme prothrombinase. prothrombinase catalyzes conversion of prothrombin to thrombin. thrombin converts soluble fibrinogen to fibrin.
normal blood clotting requires
vitamin K to synthesize several clotting factors in the liver
clot retraction
within 30 mins of clot formation it tightens fibrin threads and pulls edges of damaged vessel together so permanent repair can occur.
fibrinolysis
dissolves clot following repair of blood vessel
plasminogen
(t-PA) converts plasminogen into plasmin. plasmin digests fibrin threads and breaks up blood clot. this can help people after strokes
prostacyclin
produced by endothelial cells in undamaged vessels to prevent platelets from adhering to walls of vessel.
anticoagulants
antithrombin deactivates thrombin before it can convert fibrinogen to fibrin. heparin interferes with the formation of prothrombinase. aspirin interferes with enzymes that catalyze the synthesis of prostaglandins. slows clot formation
polycythemia
high RBC count and hematocrit. increases blood volume, viscosity, and pressure. Reduces circulation. primary is caused by cancer in red bone marrow, creates hematocrit of 80. secondary can be caused by dehydration or hypoxemia(reduction in O2)
Anemia
low number of RBC or hemoglobin. iron-deficiency is most common.
hemorrhagic anemia
excessive blood loss through injury, ulcers, or heavy menstruation.
aplastic anemia
red bone marrow is destroyed and erythropoesis halts
thalassemia
group of hereditary anemia’s among Mediterranean people that causes a deficiency or absence of hemoglobin
Sickle-cell
hereditary defect in structure of hemoglobin molecules. RBC become sickled and sticky. reducton in circulation. carriers have resistance to malaria
hemolytic disease of newborn
only occurs if an Rh- woman becomes pregnant with an Rh+ fetus.
leukopenia
abnormally low WBC count. lead or mercury poisoning. symptom of radiation or anti-cancer drugs
infectious mononucleosis
caused by Epstein-Barr virus invading B lymphocytes. transmitted by exchanging saliva. syptoms include sore throat and swollen lymph glands.
leukemia
hemopoietic cancer that produces too many leukocytes
thrombocytopenia
very low platelet count that results in a tendency to bleed from the capillaries.
hemophilia
group of hereditary diseases that are caused by an X-linked recessive gene that produces random bleeding and reduced clotting. lack of factor VIII or IX
thrombus
clot formation that grows large enough to block a small blood vessel. if it breaks loose and travels through bloodstream it becomes an embolus
emboli
common in veins in arms and legs. they tend to break loose and travel to lungs where they can cause pulmonary embolism and death from hypoxia
coarctation of the aorta
involves a segment that is too low
septal defects
involve holes in the interatrial or interventricular septum
tetralogy of Fallot
interventricular septal defect lets O2 poor blood travel from right ventricle to left and into systemic circulation. aorta emerges from both ventricles which reduces cardiopulmonary circulation. narrowing of pulmonary valve. right ventricle is enlarged.
congenital defects
present at birth. most common birth defect in US. 30,000 infants each year
rheumatic fever
caused by bacterial infection that triggers the immune system to produce antibodies that can damage bicuspid and aortic valves.
cardiac tamponade
occurs if pericardial cavity fills with fluid and compresses the heart
cardiomyopathy
any disease that results in deterioration of the heart wall or abnormal thickening of interventricular septum
valvular insufficiency
any valve disorder that may lead to a heart murmur.
aortic steinosis
narrowing of aortic valve.
mitral valve prolapse
occurs when portion of mitral valve is pushed back into left atrium during ventricular systole.
myocardial infarction
sudden death of heart muscle and its replacement with scar tissue because of ischemia. blood supply to an area of the heart wall is interrupted. plaque is deposited along wall of coronary artery. platelets aggregate and release chemicals that trigger vasospasm. common pathway is activated. coronary artery gets blocked
angina pectoris
severe pain tightness or pressure in the chest that accompanies ischemia of the myocardium. pain is constricting or squeezing. anaerobic respiration produces lactic acid. nitroglycerin is used to treat it.
congestive heart failure
failure of ventricles to pump blood effectively. blood backs up in the lungs causing pulmonary edema or blood backs up in the systemic vessels causing peripheral edema.
how long does it take for permanent damage to the heart to occur? death of myocardium
2-4 hours/ within 6 hours
arrhythmia
abnormal or irregular heartbeat due to faulty production of electrical impulses or poor conduction of impulses through heart.
SA node(sinoatrial)
establishes rhythm of ones heart rate. 70-80 beats per minute
ectopic focus
random generation of action potentials outside of SA node
AV node
if SA becomes damaged it takes over and establishes a nodal rhythm at a slower rate. 40-50 beats per minute.
heart block
failure of the cardiac conduction system to transmit signals along the right and left bundle branches which results in missed heart beats or reduced rate. total heart block damages AV node and reduces ventricular contraction to 20-4o BPM
bradycardia
resting heart rate of less than 60 beats per minute
atrioventricular block
prolonged or missing conduction of nerve signals between atria and ventricles
atrial flutter
ectopic foci in the atria cause atrial rhythm to reach 240-360 BPM
tachycardia
resting heart rate over 100 BPM
premature ventricular contractions
occur when action potentials are initiated independent of the SA node and cause occasional abnormal heart beats
Why does extrasystole occur
the impulse is generated more quickly from the SA node and heart has longer time for ventricular filling. can be triggered if the heart is irritated by certain drugs or lack of sleep EX: caffeine or nicotine
ventricular fibrillation
life-threatening condition caused by nerve signals arriving at different parts of the myocardium at different times. blood isn’t pumped so it doesn’t flow to the myocardium and a heart attack occurs. strong and brief electric defibrillation depolarizes the entire heart so the SA node can resume its normal rhythm
where is the heart located?
in the thoracic cavity beneath the sternum in the mediastinum between the lungs with its apex pointed down and toward left hip
how big is the heart
size of a closed fist. 250 to 350 grams depending on body size.
pericardium
sac that surrounds the heart. parietal forms sac and consist of tough fibrous layer of dense irregular connective tissue. visceral covers surface of heart and anchors heart in mediastinum and prevents overstretching.
pericardial cavity
between visceral and parietal layers. filled with pericardial fluid. lubricates membrane and reduces friction
pericarditis
inflamed pericardium due to infection. membranes may stick together and interfere with pumping ability
outer epicardium
(visceral pericardium) is a thin serous membrane composed of mesothelium and areolar connective tissue
middle myocardium
thick layer of cardiac muscle bound together with collagen and elastic fibers.
inner endocardium
thin layer of endothelium and connective tissue. lines chambers of the heart, covers valves, and is continuous with inner ling of large blood vessels associated with heart
two superior heart chambers(atria)
receive blood from veins. each has a small flap-like auricle that increases its capacity to hold blood. they have thin walls and are separated from each other by an interatrial septum
two inferior heart chambers(ventricles)
pump blood into arteries. they have thick walls and are separated by a muscular interventricular septum.
Heart valves
passively control the direction of blood flow through the heart. consist of 2-3 cusps.
AV valves(atrioventricular)
are composed of dense connective tissue and they separate an atrium from its corresponding ventricle. anchored to walls of ventricle by chordae tendineae that attach to papillary muscles
Right AV valve
is tricuspid valve (3 cusps)
left Av valve
is bicuspid(mitral) 2 cusps
Semilunar valves
found at base of each large artery that emerges from the heart. pulmonary semilunar valve opens into pulmonary trunk. aortic semilunar valve opens into the aorta. they consist of three cusps of dense connective tissue that are attached directly to wall of artery
What is the pathway of blood
Blood enters the right atrium from the superior and inferior venae cavae and the coronary sinus.From right atrium, it goes through the tricuspid valve to the right ventricle. From the right ventricle, it goes through the pulmonary semi lunar valves to the pulmonary trunk
From the pulmonary trunk it moves into the right and left pulmonary arteries to the lungs.From the lungs, oxygenated blood is returned to the heart through the
pulmonary veins.From the pulmonary veins, blood flows
into the left atrium.From the left atrium, blood flows through the bicuspid (mitral) valve into the left ventricle. From the left ventricle it goes through the aortic semilunar valves into the ascending aorta.Blood is distributed to the rest of the body(systemic circulation)from the aorta
when left ventricle is full
bicuspid is forced shut
cardiac muscle must receive what?
a constant supply of blood
what does the ascending aorta give rise to?
left and right coronary arteries which branch to supply blood to myocardium
how does blood return to the cardiopulmonary circulation?
20% empties into the right ventricle while remaining blood passes through cardiac veins to coronary sinus and into right atrium
Purkinje fibers
large diameter myofibers conduct the nerve signal from the bundle branches into the ventricular myocardium
Cardiac muscle
short, thick fibers with nucleus. sarcoplasmic reticulum contains big T-tubules to admit more calcium ions. joined by intercalated discs. desmosomes hold muscle fibers together. contains more myoglobin and mitochondria than skeletal muscle . uses aerobic respiration. autorhythmic and can depolarize automatically
cardiac action potential spreads from…
SA node throughout both atria by gap junction.
atrioventricular bundle(bundle of His)
tract of conducting fibers that is only electrical connection between the atria and the ventricles.
pacemaker potential
slow inflow of calcium ions and minimal outflow of potassium ions. threshold of -40mV coltage regulated calcium ion channels open and ions rush in triggering action potential.
how long does it take a nerve signal to reach the AV node
50 milliseconds where it is delayed for the ventricles to fill
electrocardiogram (EKG,ECG)
graphic recording of the electrical changes that accompany a heartbeat
P wave
small upward wave produced by depolarization of the atria following random initiation of action potential in SA node
QRS complex
produced when the AV node fires and ventricles depolarize as the impulse travels through purkinje fibers.
when does ventricular contraction occur
during the S-T segment when ventricular myocytes are in plateau phase
T wave
produced when ventricles re-polarize before relaxing
how much does each cardiac cycle produce
pumps out 70 mL of blood
atrial systole
both atria contract
ventricular diastole
both ventricles relax
ventricular systole
both ventricles contract
atrial diastole
both atria relax
lubb sound of heartbeat
occurs when AV valves are closing as ventricular systole begins
dupp sound of heartbeat
occurs when semilunar valves snap shut at beginning of ventricular diastole
End diastolic volume (EDV)
is 130mL but only 30% is due to atrial systole
isovolumetric contraction
occurs when ventricles start to contract but dont eject any blood because all 4 valves are closed
ventricular ejection
occurs when ventricular pressure increases enough to open semilunar valve and force blood into aorta and pulmonary trunk
end-systolic volume (ESV)
after ventricular ejection is about 60mL
cardiac output
volume of blood ejected from each ventricle each minute and is calculated from stroke volume and heart rate. average cardiac output is about 5.25 liters per minute
Stroke volume
amount of blood ejected from each ventricle during ventricular systole.
preload
degree cardiac muscle cells stretch before they contract . increasing preload increases volume of blood or speed with which blood gets to the heart
Frank-Starling law of heat
greater EDV causes cardiac muscle fibers to stretch more and generate greater contractile force
increasing contractility…
increases stroke volume
positive inotropic agents
increase contractility by making more Ca available increases length of plateau and allows more contractile force to develop. EX: epinephrine, digitalis
negative inotropic agents
reduce contractility by reducing amount of Ca being released EX: potassium, Ca channel blockers
afterload
pressure needed to open semilunar valves. increasing it decreases stroke volume
how is heart rate regulated
by the cintrol center in the medulla oblongata
autonomic nervous system
modulates heart rate. impulses transmitted along vagus nerve to heart release acetylcholine which binds to cholinergic receptors to decrease HR
proprioceptors
in muscles and joints. detect changes in physical activity
baroreceptors
in aorta and carotid arteries monitor changes in BP
chemoreceptors
in aorta, carotid arteries, and medulla oblongata. monitor changes in blood pH, CO2, and O2
norepinephrine
allows threshold to be reached more quickly to allow pacemaker to fire rapidly and heart to beat faster. enhances Ca entry into contractile cells causing them to contract with more force
vagal tone
limits number of beats SA node can generate
