Study Guide F (test 2)

What are formed elements?

erythrocytes, leukocytes, and plateles

Why are they called “formed elements” instead of cells?

b/c mature erythrocytes contain neither nuceli nor organelles and platelets are merely fragments broken off from a larger cell

The production of blood is known as _____________________________ and takes place in the _________________ ____________________ __________________

hematopoiesis

embryonic period of development

ALL blood cells arise from a stem cell known as the _________________

hemocytoblasts

Production of RBC is known as ______________________ and it is stimulated by the hormone __________________

erythropoiesis and is stimulated by EPO (erythropoietin

Note that there are several precursor cells and that the ________ is ejected

nucleus

What cell is the immediate precursor to the RBC that completes maturation while circulating in blood vessels?

reticulocytes

The production of WBC is known as ___________

leukopoiesis

The production of platelets is known as _________________

thrombopoiesis

Small pieces break off the ____________________ to form platelets

megakaryocytes as they stretch they are called proplatelets

Why is a RBC not technically considered to be a cell?

b/c mature RBC lack nucleus and organelles

Describe the shape of erythrocytes

biconcave disc

What is hemoglobin?

red-pigmented proteins that transports O2 and CO2

Describe the structure of hemoglobin

consists of 4 protein molecules called globins

2: alpha

2: beta

contain 4 heme group: organic compound ring w/ 4 Fe2+ as center

Where does oxygen bind on hemoglobin?

binds to the Fe2+

Where does carbon dioxide bind on hemoglobin?

binds to globin proteins as blood moves through systemic capillaries and is release as blood moves through capillaries of the lungs

What organ produces the majority of EPO in erythopoiesis?

kidney

What stimulates EPO production (primary stim.)?

decrease in blood O2 levels

What is the life span of erythrocyte? Why is is fairly short?

~120 days, b/c as they lack a nucleus and organelles cannot sythen proteins or repair it self

What happens to the globin portion when hemoglobin is destroyed?

globin: broken down into free aa to be used to form new proteins

Most of the Iron is __________ for future RBC production

recycled

Describe what happens to the heme group and pigments involved in erythrocyte destruction

heme group: iron is removed from heme and transported into stroage. Heme is converted by macrophages into biliverdin → bilirubin and causes a chain reaction:

bilirubin released into blood and taken out of the blood by the liver. the liver then transports bilirubin into the small intestine as a components of bile to facilitate digestion. The small intestine also converts bilirubin into urobilinogen which either creates the brown pigment in feces or absorbed back into blood converted into urobilin that is exerted by the kidneys

What are the 2 groups of surface antigens that determine blood type?

ABO group and Rh protein

What are the 2 antigens that determine ABO group?

A and B

Which antigen are found on each ABO blood type?

Type A: surface antigen A only

Type B: surface antigen B only

Type AB: both surface antigen AB

Type O: neither surface antigen

What are the 2 types of antibodies that recognize A and B antigens?

anti-B and anti-A

Which antibodies are found in the blood of individuals with each ABO blood type?

type A: anti-B in plasma

Type B: anti-A in plasma

Type AB: neither in plasma

Type O: both anti-A/B in plasma

Note that a person does not have an _________ that binds to the antigens on their RBC. Why?

antibody

why: b/c the antibody react with the surface antigen A and B

What is the antigen that determines the Rh factor?

antigen D

What is Rh postive

antigen D is present

What is Rh negative

no antigen D is present

What is required for anti-D antibody production in Rh neg. individuals?

when exposed to Rh positive blood

What can occur if incompatible blood is given during a blood transfusion? What is the result?

antibodies in the plasma bind to surface antigens of transfused erythrocytes causing clumps = agglutination

clumped erythrocytes can block blood vessels which prevents normal circulation of blood. eventually some rupture = hemolysis

What is hemolytic disease of newborn (HDN)?

when the mother has been exposed to anti-D and the antibodies cross the placenta

When does (HDN) occur?

during pregnancy when the mother has been previously exposed to Rh + blood

How can HDN be prevented?

giving Rh - special immunoglobins btwn 28-32 weeks b/c the immunoglobinds bind to fetal erythrocyte surface antigens to prevent the mother’s immune system from recognizing anti-D and stimulating to produce anti-D antibodies

What are the 2 classes of leukocytes?

granulocytes: neutrophils, eosinophil, basophil

agranulocytes: lymphocyte, monocyte

What distinguishes the 2 classes of leukocytes?

presence or absence of secretory vesicles in the cytosol

What are granulocytes?

contains secretory vesicles (specific granules)

Describe the cytosol and nucleus of neutrophils

cytosol: contain specific granules

nucles: multilobed

What is the primary function of neutrophils?

phagocytize bacteria

Describe the granules and nucleus of eosinophils

granules: reddish/pink-orange

nucles: bilobed

What are important functions of eosinophils

phagocytize antigen-antibody complexes and allergens

release chemical mediators to destroy parasitic worms

Describe the appearance of basophils

blue purple circle

nucleus: bilobed

cytosol: deep blue/violet specific granules

What 2 chemicals are released by basophils and what is the function of each?

histamine: vasodilator and increases capillary permeability

heparin: anticoagulant

Describe agranulocytes

absent specific granules

Describe the appearance of lymphocytes

round or slightly indented

nucleus: usually darkly stained

What are 3 types of lymphocytes?

T/B lymphocytes and NK cells

What is the function of T-lymphocytes

manage/direct immune response

What is the function of B-lymphocytes

stimulated to become plasma cells and produces antibodies

What is the function of NK cells

attack!

Which WBC’s are most abundant?

Neutrophil

What WBC is least abundant?

basophil

Never Let Monkeys Eat Bananas

Neutrophil (most abundant)

Lymphocyte

Monocyte

Eosinophil

Basophil (least abundant)

What is leukopenia?

reduced # of leukocytes

What is leukocytosis?

slightly elevated leukocyte count

What is a differential WBC count? How is it helpful clinically?

measures the amount of each type of leukocyte in the body to see if any are immature

this can help diagnose disease

What is the general function of platelets?

aid in hemostasis

What is hemostasis?

stoppage of bleeding

What are the three stages of hemostasis?

1. vascular spasm from trauma

2. platelet plug formation

3. coagulation (fibrin strands)

Describe vascular spasm and its benefits

the constriction of a blood vessel to limit blood loss

What do the platelets stick to in a damaged blood vessel?

platelets stick to the exposed collagen fibers

The plateles release chemicals that attract other platelets. Is the neg or positive feedback?

positive feedback

Platelets also release chemicals that ___________ _________ spams and initiate ___________ and are thus involved in all stages of hemostasis

prolong vascular

clotting

What substances prevents platelets from sticking to healthy portions of blood vessels?

prostacyclin

What is the 3rd stage of coagulation?

the clot is formed

A network of which protein composes a blood clot?

fibrin

What is the precursor to fibrin ?

derived from soluble fibrinogen

Which ion is necessary for blood clot formation?

Ca

What triggers the intrinsic pathway?

damage to inside of vessel

What triggers the extrinsic pathway?

damage to tissue outside vessel

he intrinsic pathway and extrinsic pathway merge into the ________________ pathway

common pathway

What is the name of the enzyme that converts fibrinogen into fibrin?

thrombin

What is the precursor to thrombin?

prothrombin

How does the sympathetic NS help to compensate for blood losses over 10%?

bringing increase vasoconstriction of blood vessels, increased heart rate/force of contraction

What is clot retraction?

when actinomyosin contracts and squeezes the serum out of the developing clot making the clot smaller as the vessel walls are pulled together

What is fibrinolysis?

the destruction of fibrin framework

Where is blood produced in young children?

more bones in the body

long bones

Where is blood produced in adults?

spine, hips, ribs, skull, sternum

What is anemia?

percentage of erythrocytes is lower than normal or O2 carrying capacity of blood is reduced

Why are older individuals more prone to anemia?

because the red bone marrow is placed with fat as individuals continue to age causing the decrease in the ability to deliver O2 to body cells

less erythrocytes circulating

A: anti-b

B: anti-a

C: neither

D: both

E: type A

F: type B

G: type AB

H: type O

a: erythrocyte

b: proplatelets

c: platelets

d: endothelial cells

e: megakaryocyte

A: hemocytoblast

b: myeloid stem cells

c: lymphoid stem cell

d: erythrocyte

e: platelets

f: granulocytes and monocyte

g: lymphocytes and NK cell

Which cells are Granulocytes?

eosinophil, neutrophil, basophil

Which cells are agrnulocytes?

plasma cell, macrophage, monocyte, T/B-lymphocytes

Neutrophil

eosinophil

lymphocyte

basophil

Coagulation is described as

“clotting”

includes intrinsic and extrinsic mechanisms

includes a vast enzymatic cascade of proteins produced by the liver

LAST STAGE OF HEMOSTASIS

conversion of fibrinogen to fibrin

Platelet plug formation is described as

involves endothelial collagen exposure and disruption of prostacyclin

2nd stage in hemostasis

degranulation and serotonin, thromboxane A2, and ADP

Vascular spasm is describes as

the first stage in hemostasis and involves vasoconstriction

What leukocyte:

releases histamine, which promotes inflammation

basophil

What leukocyte":

the cytoplasm is a thin ring around the nucleus

lymphocytes

What leukocyte:

contain cytoplamsic granules that stain bright red with eosin

esoinophils

What leukocyte:

most common type of WBC

Neutrophils

What leukocyte:

Nuclei have up to 5 lobes

neutrophils

What leukocyte:

enlarge and become macrophages which engulf foreign substances

monocytes

What leukocyte:

contain large cytoplasmic granules that stain dark blue or purple with basic dyes

basophils