Lesson 5 - Circulatory System: Blood Flashcards
the circulatory system consists of (3)
- the heart - muscular pump
- blood vessels - conducting system
- blood - fluid connective tissue medium
cardiovascular system
refers only to the heart and blood vessels
hematology
study of blood
fundamental purpose of the circulatory stsem
transport substances
blood
liquid transport medium
blood vessels ensure…
proper routing of blood
the heart is the…
pump that keeps blood flowing
three specific functions of the circulatory system
- transport
- protection
- regulation
functions of the circulatory system: transport
carry O2, CO2, nutrient, wastes, hormones, and stem cells
functions of the circulatory system: protection (5)
inflammation, limiting the spread of infection, destroy microorganisms and cancer cells , neutralize toxins, and initiate clotting
functions of the circulatory system: regulation (3)
fluid balance, stabilizes pH of ECF, and temperature control
blood consists of two parts
plasma and formed elements
plasma
matrix of blood; mostly water and has a clear, light, yellow appearance
formed elements (3)
erythrocytes, platelets, and leukocytes
erythrocytes
RBCs
platelets
fragments of certain bone marrow cells
leukocytes
WBCs
granulocytes (3)
neutrophils, eosinophils, basophils
agranulocytes (2)
lymphocytes, monocytes
five important functions of blood
- transportation of dissolved substances
- regulation of pH and ions
- restriction of fluid losses at injury sites
- defense against toxins and pathogens
- stabilization of body temperature
substances transported by blood: gases (2)
O2 and CO2
substances transported by blood: nutrients (3)
glucose, amino acids, fatty acids, etc.
substances transported by blood: hormones (3)
ACTH, TH, GH, etc.
substances transported by blood: immune system components
antibodies, etc
substances transported by blood: waste products
nitrogenous wastes
blood fractionation
separation of blood into basic components based on centrifugation and coagulation
which blood cells are the heaviest?
RBCs, they settle first
hematocrit (packed cell value)
total volume of whole blood that is RBCs, typically 45%
what do WBCs and platelets look like in a centrifuged vial of blood?
a narrow cream colored zone (buffy coat) that is less than 1% of total blood volume
where is plasma in a centrifuged vial of blood?
at the top of the tube and is usually about 55% of blood volume
blood serum
plasma without the clotting proteins (mainly fibrin) and calcium
plasma is a complex mixture of (7)
water, proteins, nutrients, electrolytes, nitrogenous wastes, hormones, and gases
what are the most abundant solute by weight?
plasma proteins
three major plasma protein categories
albumins, globulins, fibrinogen
the liver produces all of the major proteins except _____ _____ produced by plasma cells
gamma globulins
albumins
smallest and most abundant protein
what do albumins contribute to? (2)
viscosity and osmotic pressure
what do albumins do? (4)
what do they transport?
transport fatty acids, TH, steroid hormones, and buffer plasma pH
globulins (4)
what kinds?
h.m.a.i.
hormone-binding proteins, metalloproteins, apolipoproteins, immunoglobulins
what do globulins contribute to? (3)
roles in solute transport, clotting, and immunity
fibrinogen
soluble precursor of fibrin, a stick protein that forms the framework of a blood clot
where are most plasma proteins produced?
the liver
what does the remaining 1% of plasma proteins include?
changing amounts of proteins like peptide hormones and others secreted by the endocrine system
nitrogenous wastes
toxic end products of catabolism
urea
product of amino acids catabolism, the most abundant nitrogenous waste normally removed by the kidneys
the formed elements and plasma composition give rise to the _____ and _____ of blood
viscosity, osmolarity
what are the major contributors to blood viscosity? (2)
RBCs and albumin
osmolarity
total concentration of solute particles
how is optimum osmolarity achieved?
the body’s regulation of sodium ions, proteins, and RBCs
colloid osmotic pressure (COP)
contribution of protein on blood osmotic pressure; plays an important role in water balance
hypoproteinemia
deficiency of plasma proteins
what does hypoproteinemia cause? (4)
- extreme starvation
- liver of kidney disease
- severe burns
- tissues well, pool of fluid in the abdomen may accumulate
Kwashiorkor
children with severe protein deficiency
ascites
fluid accumulation in the abdomen
how do Kwashiorkor children develop?
they are fed on rice and cereals once they are no longer breast-fed leading to a protein deficiency in their diet
how can you identify a Kwashiorkor child?
thin arms and legs, and a swollen abdomen
hematopoiesis =
production of blood, especially formed elements
hematopoietic tissues produce
blood cells
the yolk sac produces what for a fetus?
stem cells for first blood cells that eventually colonize fetal bone marrow, liver, spleen, and thymus
the _____ stops producing blood cells at birth, but the _____ remains involved with lymphocyte production for life
liver, spleen
myeloid hematopoiesis
blood formation in the red bone marrow
lymphoid hematopoiesis
blood formation in the lymphoid organs; beyond infancy this only involved lymphocytes
hematopoietic stem cells (HSCs)
multipotent stem cells in the bone marrow that give rise to all formed elements
what do some HSCs go on to become?
specialized colony forming units (CFUs)
colony-forming units (CFUs)
destine to produce a specific class of formed element
structure of a RBC
disc-shaped cell that is biconcave; a thick rim and thin sunken cente
rouleaux
stacks of RBCs used to move through small blood vessels
how do RBCs produce ATP?
glycolysis/anaerobic fermentation
LACK MITOCHONDRIA
what does it entail that RBCs don’t have a nucleus or DNA?
they cannot synthesize protein or perform mitosis, so they only last about 120 befores being recycled by the body
33% of RBC cytoplasm is _____
hemoglobin
hemoglobin
functions in O2 and CO2 transport, and buffering of blood pH
carbonic anhydrase (CAH)
produced carbonic acid from CO2 and water
where is carbonic anhydrase?
RBC cytoplasm
what role does carbonic anhydrase play?
important in CO2 transport and pH balance
what determine a person’s blood type?
the glycolipids on the outer surface of mature RBCs
what provides RBC membrane resilience and durability?
inner membrane surface has cytoskeletal proteins spectrin and actin that help RBCs stretch, bend, and fold
hemoglobin structure (3)
two alpha chains and two beta chains each associated with a heme group
what do 2.5% of adults have in place of their hemoglobin beta chains?
delta chains
fetal hemoglobin has two _____ chains in place of beta chains
gamma
how many molecules of oxygen can a heme group carry?
one
how are fetal gamma chains different than adult beta chains?
they bind O2 more tightly than adult hemoglobin
where does CO2 bind hemoglobin?
on the globin chains rather than the heme group
heme
a nonprotein moiety that binds O2 with ferrous ion (Fe2+) at its center
hematocrit is _____ proportional to body fat percentage
inversely
why are hematocrit levels lower for women? (2)
- androgens stimulate RBC production
- females have periodic menstrual losses
erythropoiesis
RBC production
development of erythrocytes includes (4)
- reduction in cell size
- increase in cell number
- synthesis of hemoglobin
- loss of the nucleus
when does erythrocyte production begin?
when hematopoietic stem cells become erythrocyte colony-forming units which have receptors of erythropoietin
erythropoietin
stimulates colony-forming units to become an erythroblast
where is erythropoietin made?
the kidneys
erythroblasts multiple, synthesize hemoglobin, and after four days it becomes a _____
normoblast
when the nucleus is discarded from the normoblast, the cell becomes a _____
reticulocyte
what reticulocytes named for?
the fine network of polyribosomes
when reticulocytes leave the bone marrow and enter the bloodstream, what happens?
polyribosomes disintegrate and the cell is then fully matured as an erythrocyte
how it RBC count maintained?
negative feedback;
what could happen if RBC count drops?
hypoxemia
hypoxemia
oxygen deficiency in blood
what happens when hypoxia is detected?
the kidneys increase EPO output, increasing RBC count in 3-4 days to reverse it
causes of hypoxemia include (4)
- blood loss/low RBC count
- high altitude
- increased exercise
- loss of lung tissue in emphysema
_____ is a key nutritional requirement for erythropoiesis
iron
how is iron lost? (3)
urine, feces, and bleeding
how is iron absorbed? (2)
by the small intestine into the blood where is binds transferrin for transport to bone marrow, liver, etc.
bone marrow needs iron for _____
hemoglobin
muscles need iron for _____
myoglobin
all cells need iron to create…
cytochromes in mitochondria
how is iron stored?
liver apoferritin binds iron to form the complex ferritin for storage
additional nutrients required for erythropoiesis (4)
vitamin B12, folic acid, vitamin C, and copper
why do we need vitamin B12 for erythropoiesis?
lack of it reduced stem cell division causing low RBC production (pernicious anemia)
why do we need vitamin C and copper for erythropoiesis?
they are cofactors for enzymes synthesizing hemoglobin
Iron Metabolism (8)
- mix of Fe2+/Fe3+ is ingested
- stomach acid converts Fe3+ to Fe2+
- Fe2+ binds gastroferritin
- gastroferritin transports it to small intestine and releases it for absorption
- in blood plasma, Fe2+ binds to transferrin
- in the liver, some transferring release iron for storage
- Fe2+ binds to apoferritin to be stores as ferritin
- remaining transferrin is distributed to other organs
hemolysis
RBCs rupture in the narrow channels of the spleen and liver
why do RBCs rupture in the spleen/liver?
their membranes become more fragile and less flexible
what do macrophages do to digest ruptured RBCs?
they digest membrane bits to separate heme from globin
what happens to globin during RBC digestion?
it is hydrolyzed into amino acids
what happens to the heme group during RBC digestion?
the iron is removed from the heme pigment
what happens to the heme pigment during RBC digestion?
it is converted into biliverdin (green)
what happens to biliverdin during RBC digestion? (3)
it is converted into bilirubin (yellow-green) by the macrophage and is released into the blood, binding albumin
what makes your urine yellow?
bilirubin
what does the liver do with bilirubin? (2)
removes bilirubin from albumin and secretes into the bile
bile pigments
collective term for biliverdin and bilirubin
iron recycling
iron is removed heme to produce biliverdin
what does iron bind to to be delivered to red bone marrow to synthesize new Hb?
transferrin
what happens to excess trasnferrin?
transferred to storage proteins
T/F: large quantities of free iron is not toxic to cells
false, it is
primary polycythemia (2)
polycythemia vera
RBC excess due to cancer of erythropoietic line in bone marrow
secondary polycythemia
polycythemia from all other causes, including dehydration, emphysema, high altitude, and physical condition
dangers of polycythemia (2)
- increased blood volume, pressure, and viscosity
- can lead to embolism, stroke, heart failure
anemia
deficiency of either RBCs or hemoglobin
causes of anemia (5)
- inadequate erythropoiesis or hemoglobin synthesis
- nutritional deficiencies
- kidney insufficiency
- destruction of myeloid tissue
- aging
hemorrhagic anemia
anemia from bleeding; trauma and bleeding disorders
hemolytic anemia (4)
from RBC destruction from drug reactions, poisoning, infections, hereditary defects, blood type incompatibilities
iron-deficiency anemia
lack of iron uptake/metabolism that affects RBC production
what is excessive iron uptake linked to?
heart disease
inadequate erythropoiesis anemias (2)
iron-deficiency and pernicious
pernicious anemia (2)
autoimmune attack of stomach tissues that leads to inadequate intrinsic factor production, which is needed of rB12 absorption
hypoplastic anemia
decline in erythropoiesis
aplastic anemia
complete cessation of erythropoiesis; failure or destruction of myeloid tissue
three potential consequences of anemia
- tissue hypoxia
- reduced blood osmolarity producing tissue edema
- low blood viscosity
effects of tissue hypoxia (3)
- patient is lethargic
- shortness of breath upon exertion
- life threatening necrosis of the brain, heart, or kidney
what happens with low blood viscosity? (2)
- heart races and pressure drops
- cardiac failure may ensue
sickle-cell disease
a hereditary hemoglobin defect
who is sick-cell disease most commonly found in? (4)
people of sub-Saharan Africa, Mediterranean basin, Middle East, and Indian descent
is sickle-cell recessive or dominant?
recessive
how does sickle-cell hemoglobin (HbS) differ from normal Hb?
only on the sixth amino acid of the beta chain
what is special about sickle-cell heterozygotes?
the are resistant to malaria
what can sickle-cell disease lead to? (5)
- kidney or heart failure
- stroke
- joint pain
- paralysis
how do HbS red blood cells behave different? (2)
- they become rigid, sticky, and pointed at the ends
- the agglutinate and block small blood vessels
how well does HbS bind O2?
not well
antigens
complex molecules on surface of cell membranes
antigens include (3)
proteins, glycoproteins, glycolipids
how are antigens useful?
they are used to distinguish self from foreign matter, foreign matter generates an immune response
agglutinogens
antigens on the surface of the RBC that triggers agglutination (clumping)
antibodies
proteins that bind to antigens to mark them for destructions
agglutination
antibodies bind multiple foreign cells and sticks them together, large clumps may result
agglutinins
antibodies that bind algutinogens
RBC antigens (2)
agglutinogens
glycolipids on RBC surface
blood type A has what antigen? (2)
antigen A/anti-B
blood type B has what antigen? (2)
antigen B/anti-A
blood type AB has what antigen? (2)
both A and B antigens/no anti-antigens
blood type O has what antigen? (2)
neither A or B/anti-A and anti-B
a mismatch during a blood transfusion causes a _____ _____
trasnfusion reaction
transfusion reaction (2)
(1) agglutinated RBCs block small blood vessels, hemolyze, and release their hemoglobin over hours/days (2) where hemoglobin blocks kidney tubes and causes acute renal failure
Charles Drew
first black person to pursue an advanced degree in medicine to study transfusion and blood banking
what special thing did Charles Drew do?
used plasma rather than whole blood, which caused less transfusion reactions
Rh blood group
includes numerous antigens like C, D, and E
which Rh antigen is the most reactive?
antigen D
what antigen makes a person Rh+?
antigen D
are anti-D antibodies normally present?
no, they only form in Rh- individuals exposed to RH+ blood
will an Rh- female with and Rh+ fetus or transfusion of Rh+ blood cause any problems?
no; they do not naturally have anti-D antibodies
hemolytic disease of the newborn (HDN)
erythroblastosis fetalis
may occur when a woman has a baby with mismatched blood type
What causes hemolytic disease of the newborn?
if an Rh- mother has more than one Rh+ child, the anti-D antibodies formed during the first pregnancy can cross the placenta and agglutinate fetal RBCs, cause hemolysis, and result in the baby having severe anemia
how do you prevent hemolytic disease of the newborn?
Rh immune globulin (RhoGAM) is given during the 28 to 32 weeks gestation and during birth to prevent the mother from forming anti-D antibodies
