Exam 3: Circulatory System - Blood

Question 1

functions of blood (6)

Answer 1

• transportation of dissolved substances
• defense against infection
• pH regulation
• fluid balance
• thermoregulation
• clotting

Question 2

what is blood?

Answer 2

specialized connective tissue

Question 3

formed elements of blood

Answer 3

suspended in plasma matrix

-erythrocytes, leukocytes, thrombocytes

Question 4

plasma composition (5)

Answer 4

albumin: maintains oncotic P, some transport
alpha and beta globulins: transport proteins and coagulation factors
gamma globulins: immunoglobulins
complement proteins: defense
fibrinogen: clot structural proteins

Question 5

serum

Answer 5

plasma without the clotting factors

Question 6

what is the origin of hematopoietic stem cells (HSC)

Answer 6

mesenchymal

Question 7

where do HSC develop during late gastrulation

Answer 7

extraembryonic, yolk sac membrane

Question 8

initial hematopoiesis is transient with

Answer 8

stem cells migrating to the fetal liver

Question 9

in early through mid-gestation what is the primary site of hematopoeisis

Answer 9

liver

Question 10

from the liver stem cells migrate through the circulatory system to ___ and ___

Answer 10

spleen and bone marrow

Question 11

at birth spleen production declines and what becomes the main hematopoietic site

Answer 11

bone marrow

Question 12

what happens at 4-5yrs old - bone marrow development

Answer 12

adipose tissue infiltrates marrow cavity at diaphysis and spreads toward the epiphysis replacing hematopoietic tissue

Question 12

what happens at 4-5yrs old - bone marrow development

Answer 12

adipose tissue infiltrates marrow cavity at diaphysis and spreads toward the epiphysis replacing hematopoietic tissue

Question 13

by adulthood where is hametopoietic marrow limited to

Answer 13

flat bones, vertebrae, epiphyses of humerus and femur

Question 14

hematopoiesis

Answer 14

production of blood cells
begins with multi-potent stem cell - hemocytoblast
hemocytoblasts go through mitosis - one stays behind and remains hemocytoblast and the other is sensitized in 2 ways

Question 14

2 ways hemocytoblast is sensitized

Answer 14

become lymphoid stem cell: only gives lymphocytes (b cells, t cells, natural killer)
myoloid stem cell: can become all of the others (platelets, macrophages, other WBC)

Question 14

precursor cells for erythropoiesis contain receptors for…

Answer 14

EPO
transferrin
fibronectin

Question 14

EPO

Answer 14

directs maturation with receptors increasing in proerythroblasts

Question 14

what happens when our oxygen level goes down (erythropoiesis)

Answer 14

kidney interstitial cells release EPO which circulates to bone marrow and binds to receptor on stem cell

this triggers the stem cel to start increasing transferrin receptors - once this happens NO going back - determined to differentiate into mature erythrocyte

Question 14

transferrin

Answer 14

transport molecule for iron

circulates to bone marrow and takes in iron which is the raw material for hemoglobin

Question 14

reticulocytes

Answer 14

show a decrease in fibronectin receptors - correlating with their release from marrow stoma into circulation

they eject nuclei prior to release

Question 15

what is high reticulocytes a sign of

Answer 15

red flag!!

something is happening to cause them the up the production of RBC

Question 16

what happens to reticulocytes that are still expressing fibronectin receptors

Answer 16

they are sequestered in the spleen until the “stickiness” is lost

Question 17

what happens to the erythrocyte after the expulsion of the nucleus as a reticulocyte

Answer 17

it becomes a biconcave disc which the shape causes an increased surface area for more gas exchange

Question 18

as erythrocyte ages what happens?

Answer 18

dec in enzyme activity, membrane, water, and ability to bend and deform under stress ones that lose flexibility cannot navigate through the stresses of spleen and are destroyed

Question 19

composition of hemoglobin

Answer 19

``` 4 subunits (2 alpha, 2 beta) - each subunit has a heme group ```

Question 20

heme group

Answer 20

porphyrin ring with a central iron | - the iron attracts and binds oxygen forming oxyhemoglobin

Question 21

carbon monoxide

Answer 21

irreversibly binds hemoglobin lowering the cell's oxygen carrying capacity - it ruins the cooperativity since each subunit influences the binding of another

Question 22

hemoglobin dissociation curve

Answer 22

sigmoidal so cooperative binding - when partial pressure of O2 high, loading is favored - when partial pressure of O2 low, unloading is favored

Question 23

shifting left vs right on hemoglobin dissociation curve

Answer 23

left: produces hyperbolic curve, increasing affinity for oxygen favors loading right: release more O2 into the tissues affinity decreased

Question 24

2,3-DPG

Answer 24

used to help hemoglobin give sigmoidal curve, favor unloading - shelf life of blood bank - as it goes down you go to the left, hyperbolic, will not be good at delivering oxygen bc affinity is so high

Question 25

what is a shift left characteristic of

Answer 25

dec T, dec 2,3-DPG, dec hydrogen level, inc carbon monoxide - favor loading

Question 26

what is a shift right characteristic of

Answer 26

inc T, inc 2,3-DPG, inc acid level | - caused by lots of exercise

Question 27

fetal vs adult hemoglobin

Answer 27

fetal: no beta chains - it has 2 gamma instead - gamma dos not interact with 2,3-DPG which shifts curve to left - this allows fetal Hb to load while the mother Hb unloads shift fom fetal to adult Hb is at 6 months old

Question 28

main buffering system in the body

Answer 28

bicarbonate system

Question 29

erythrocytes and buffering

Answer 29

CO2 diffuses into erythrocyte and small amounts bind to Hb and are transported as carbaminoHb most CO2 tho is converted by carbonic anhydrase into carbonic acid and then bicarbonate and H+ H+ can be buffered vy Hb and other cytoplasmic proteins

Question 30

what protein is in erythrocyte membranes that acts as the chloride exchanger?

Answer 30

band 3 protein

Question 31

why would you expect band 3 protein to be in the kidney

Answer 31

homeostasis | - the kidney exchanges carbonate and chloride

Question 32

erythrocyte breakdown

Answer 32

- erythrocytes removed from circulation by macrophages in spleen, liver, bone marrow - iron salvaged; transported by transferrin to bone marrow for new cell production or liver for storage - proteins broken down into AA and can be recycled or used - bilirubin excreted via bile through GI tract - microbial activity converts bilirubin to urobilinogen and stercobilins - some urobilins diffuse into bloodstream and eliminated by kidneys

Question 33

most common blood type for transfusion

Answer 33

ABO

Question 34

bombay O phenotype

Answer 34

homozygous recessive do not make any antigens difficult for these people to receive blood

Question 35

have antibodies opposite glycosylation

Answer 35

if type A you have antibodies to B

Question 36

second most important antigen for transfusions

Answer 36

Rh factor if antigen D present = Rh+ if antigen D absent = Rh -

Question 37

leukocytes

Answer 37

involved in defense/immune response once released in bone marrow they migrate to tissues to be functional granulocytes or agranulocytes

Question 38

shape of leukocytes in bloodstream vs tissue

Answer 38

blood: spherical tissue: amoeboid (dendritic cells)

Question 39

what do granulocytes include

Answer 39

neutrophils, eosinophils, basophils

Question 40

what do agranulocytes include

Answer 40

lymphocytes | monocytes

Question 41

production of granulocytes

Answer 41

cytokine known as granulocyte-monocyte colony stimulating factor (GM-CSF) triggers determination of precursor myeloid cell into granulocyte or monocyte developmental pathway

Question 42

secretion of GM-CSF comes from

Answer 42

endothelium, mesenchymal tissue, fibroblasts, macrophages, and lymphocytes

Question 43

what indicates an upregulation in response to immune activity

Answer 43

the fact that activated macrophages and lymphocytes can secrete these growth factors

Question 44

neutrophils

Answer 44

60-70% of the circulating leukocytes first to respond to infection/injury engulf bacteria into vacuoles called - phagosomes granules and lysosomes fuse with vacuoles (lower pH and release enzymes) lactoferrin binds to iron depriving bacteria leads to bacterial death if no iron available

Question 45

apoptotic neutrophils, bacteria, cell debris, and ECF form...

Answer 45

pus

Question 46

eosinophils

Answer 46

2-4% leukocytes phagocytize antigen-antibody complexes modulates inflammatory responses - cells produce substances that inactivate leukotrienes and histamines - have toxins and enzymes with cytotoxic effect on parasites (protozoa, helminths) - found in connective tissue of bronchi, GI, female reproductive tract

Question 47

what inc eosinophils? | what dec eosinophils?

Answer 47

inc: helminthic infection and allergic reaction dec: corticosteroids

Question 48

why are you inactivating histamines wih eosinophils if you are increasing inflammation?

Answer 48

there are other ways to get inflammation they have interplay with worms: worms release histamine which slows down response of eosinophils to counteract the eosinophils inactivate histamines

Question 49

basophils

Answer 49

less than 1% of circulating leukocytes | mediate inflammation

Question 50

what do basophils contain

Answer 50

histamine, leukotrienes, platelet activating factor, eosinophil and neutrophil chemotaxic factors and heparin

Question 51

what do basophils express on surface

Answer 51

IgE | secrete in response to certain antigens

Question 52

mast cells

Answer 52

nearly identical to basopohils | - share common progenitor but have different development

Question 53

what can occur from repeat exposure to basophils

Answer 53

inc in IgE which could result in hypersensitivity reaction - allergic response anaphylactic shock