Introduction to Blood, Erythrocytes and Anemia

Clinical PathologyMs. Canga

Introduction to Blood, RBCs, and Anemia

Topics for discussion:

• Function of blood and various components• Composition– Fluid– Cellular (Specific to erythrocytes)

• Anemia• Staining

The Function of Blood

• Classified as a _____________________ tissue– Fun Fact: Approximately ___% of animals body wt.

is blood.

• _________________________• _________________________• _________________________

Function: Transportation

• Carries _______, nutrients, etc…– To every living cell in the body.– Carried by _______ in erythrocytes– Nutrients, etc. are dissolved and delivered via

____________

• Carries waste products of cellular metabolism– Primary waste product is ___________– Carried to disposal organs that excrete from body• __________________&____________

Transportation continued• Transports _______________________– From ______________ glands to target _________

• Transports _______________________– From _______________________ in to circulation – Final destination is the _____________ as needed

• Transports _______________________– To site of ______________ within

_________________– Clump together to prevent further escape.

Function: Defense• Leukocytes (Will be covered in more detail later) – Defense from foreign invaders

• _______________________• _______________________

• Platelets (Will be covered in more detail later)– Work along side 13 clotting factors in the blood

• Are activated when a _______________________wall is damaged.

• Very complex process in which ALL factors must be activated in ____________ and __________________ in order for clot to form.

• Each factor depends on the _____________ factor to activate it.

Function: Regulation• Regulatory system– _______________________– _______________________– _______________________

Regulation• Acid-base balance– Regulation of blood ______.– Normal range is ________________(IDEAL = _____)• Higher pH = _______________________• Lower pH = _______________________

– Required for _______________________– Assists with neutralizing acidic waste products of

cellular metabolism.• Which blood is MORE alkaline? Arterial or venous?• Why?

Regulation continued• Body temperature– Regulators located in the _____________are influenced

by temperature of the blood that passes over them.• Most dogs and cats average 101.0 – 102.5oF

• Homeostasis– Body tissue fluid is maintained as __________________

as possible.– If fluid is lost in large amounts, fluid moves from

________________________ into tissues to compensate.• Leaves less plasma in bloodstream, causing

_______________________. – If fluids are given or excessive fluids are present, fluid

moves from ______________________ into bloodstream.• Excessive fluid in bloodstream causes

_______________________.

Composition of Blood• _______________________ tissue• Composed of ____________and __________– Cellular portion is composed of:• _____________– Responsible for gas exchange• _____________– Responsible for defense and immunity• _____________– Prevent leakage of blood from vessels

– Liquid portion of whole blood is called __________• Whole Blood: Blood in cardiovascular system, OR blood

that contains plasma and all other components.• Plasma is ~90% water.

“Recipe” for an RBC• __________• __________ (for the synthesis of heme-)– __________ is also important in release of iron from

tissues into plasma• ____________________ (formation of -globin)• Essential ______________ (phospholipid bilayer)• __________________: helps form RBC• __________________: also helps in RBC

formation• ____________________: works with B12 to help

form RBC.

Formation of RBCs• Formerly known as ‘__________’• Process of formation is called

_______________.– Erythropoiesis takes place in __________________

and is initiated by the cytokine called __________________ (EPO).

– EPO: produced by __________, is released when kidney cells detect __________in blood.

– EPO acts on __________ ______and causes it to begin undergoing __________divisions, developing into several RBC precursors.

Maturation Cycle of an Erythrocyte

Morphological Changes during Maturation

• Rubriblast:– Is very large, with royal blue __________. – Contains a large purple nucleus in a loose __________

pattern.• Prorubricyte:– Is slightly smaller, with a __________ cytoplasm. – The __________ composing the nucleus is slightly

smaller and __________ and stains __________.• Rubricyte:– Is smaller still, with either a __________or slightly

__________ cytoplasm as it begins to acquire the __________molecules.

Morphological Changes during Maturation

• Metarubricyte: – Cytoplasm is similar in color to __________ RBC. – Nucleus is now considered __________ (becoming more

dense) and stains dark blue. – (____________________ may be seen here)

• Reticulocyte: – __________is “pushed out” of cell leaving behind

____________________ composed of RNA. – Cytoplasm stains slightly blue, and

____________________ may be seen if stained with Wright’s stain. (Deff-Quick is a modified Wright’s stain)

– Mature RBC is seen after all ____________________ is lost from reticulocyte.

Morphological Changes During RBC Maturation

The End Result: Erythrocytes

Erythrocytes• Mature RBC is ____________________ sac.– Contains ~ _____ % water and _____ % solids

(mainly __________)

• Canines have __________RBCs; ~__________ in diameter– μ = a micron. One micron is one millionth of a

meter (VERY TINY)

• Cats, horses, cows, sheep and goats are smaller; ~__________ in diameter.

Erythrocytes - Morphology• Membrane is “____________________”• Can change shape, but is not __________.• _______________ shape provides more

____________________ to allow for gas exchange to take place.

• Disk shape allows for shorter __________ distance in and out of cell compared to a sphere.– Animals with __________ biconcave shape usually

have __________ number of RBCs on average.

Erythrocytes & Hemoglobin

• Carry __________ to all tissues of the body.• O2 carried through hemoglobin, which binds

to the oxygen.• __________ = pigment portion– produced in __________

• __________ = protein portion– Produced by __________

Hemoglobin - structure

• For every heme group, there is one __________ molecule

• Four __________ groups attach to each globin molecule.– This means that each hemoglobin molecule can

carry __________ molecules of oxygen.

Hemoglobin molecule

Hemoglobin Types

• __________ hemoglobin (HbE)• __________ hemoglobin (HbF)• __________ hemoglobin (Hb)• Each type of hemoglobin is found during

different stages of development in the animal.

Embryonic and Fetal hemoglobin

• Embryonic hemoglobin (HbE): is found in early developing __________.

• Fetal hemoglobin (HbF): is present in fetal blood during mid to late __________. – Is also present up to a couple of months after

birth. – Highest concentration of HbF is at __________.

Adult Hemoglobin (Hb)

• Found in the RBCs of all animals beginning a couple of weeks to months after birth.

• Gradually replaces __________ as primary type being produced by the body.

• Inside normal RBCs, Hb is ___________________.

Function of (Adult) Hemoglobin

• Transports __________to the tissues• Exists in two normal physiological states.• ____________________: Carrying oxygen– One oxygen molecule is associated with each iron

molecule.– pH, temperature, and O2 and CO2 levels influence

ability of Hb to carry O2

• ____________________: Has given up oxygen.– Also known as __________ hemoglobin.– CO2 is transported directly and indirectly in the RBC

and is dissolved in the __________.

RBC Life Span and Destruction

• Average in dogs is ~____ days• Average in cats is ~____ days• As an RBC ages, they are replaced by young,

but mature RBCs from __________ in constant ______________________ cycle.

• Process of aging is called ____________________.

Senescence• The process of cellular __________• Enzyme activity __________• Cell loses ____________________ and becomes

__________ as its volume decreases.• 90% of destruction of senescent RBCs occurs

through ____________________.– Takes place __________ the cardiovascular system

via macrophage ____________________.– Macrophages of __________ are especially active in

removal of senescent RBCs

Extravascular Hemolysis• Once inside a macrophage, the

__________________ of the RBC is destroyed.• Contents are recovered from the macrophages

and ________is transported back to red bone marrow.

• Heme is eliminated from the body by being converted to ____________. Bilirubin binds to ___________ (plasma protein) and is carried to the liver.

• Because it is not ____ soluble, it is called ________________________ or free bilirubin.

Extravascular Hemolysis, cont’d.

• Once in the liver, bilirubin is _________________ to ________________________, making the combination water soluble.

• Conjugated bilirubin is excreted as a ______ pigment into the intestines.

• Some conjugated bilirubin is converted into _____________________ by bacteria and eliminated in the ____________ as urobilin.

• Other conjugated bilirubin is converted into ______________________ and excreted in the __________ as stercobilin.

Senescence• ____% of RBC destruction takes place through

_________________________ hemolysis– Takes place within _____________________________.– Results in blood cell fragmentation and/or destruction

• When RBC membrane ruptures in blood vessel, _____ is released directly into the blood. – ____________________ Hb is picked up by transport

protein called __________.– __________carries unconjugated Hb to macrophages in

the __________ for breakdown. – Once in liver, ____________________hemolysis

continues.

Senescence• When ____________________is filled with

____________________ hemoglobin, the excess unconjugated Hb has nothing to bind to.

• Excess Hb is carried to __________ for excretion in urine.– _________________ ____hemolysis results in

plasma that is pink, red, or brownish.– C/S will be ____________________.– Urine will be pink, red, or brownish in color.

Anemia• Anemia: a pathological condition resulting in

decreased oxygen-carrying capacity of the blood.• May be caused by:– Low number of circulating mature RBCs• Increased __________ (RBC parasites/radiation therapy)• Decrease __________ (Bone marrow suppression)• Inappropriate __________ (hemorrhage)

– Not enough ____________________being produced for normal RBCs present. (Iron deficiency)• Appropriate # of RBCs are present• Insufficient Hb to fill each cell.

Classifying Anemia

• Anemia may be classified as either:

–Regenerative: Usually caused by hemorrhage or hemolysis.–Non-regenerative: Involves the bone marrow

(More on Anemia in next presentation)

Polycythemia

• An __________ above normal in the number of RBCs.

• Three common types:– _______________________________________– _______________________________________– _______________________________________

Relative Polycythemia

• Seen in ____________________• Common in __________ animals due to

sensible and insensible losses such as:– Excessive __________, __________,

__________or reduced __________intake.– You will learn more about sensible and insensible

losses in Special Topics.

Treatment of Relative Polycythemia

• Correction of cause of _____________________• Use of ____________________• Managing __________ intake is critical

Compensatory Polycythemia• Also known as __________ Polycythemia• Result of __________• Bone marrow is stimulated to produce more RBCs

because tissues aren’t getting enough oxygen.• Animals living in ____________________ often

develop this type of polycythemia.• Patient in heart failure may develop this type of

polycythemia because heart isn’t pumping enough blood to tissues, resulting in __________.

Treatment of Compensatory Polycythemia

• ____________________may be required if no inappropriate physiological cause

• If there is an underlying __________, surgical correction, followed by __________ treatment is required. (phlebotomy to normalize PCV may also be required)

Polycythemia Rubra Vera

• Rare ____________________ disorder• Characterized by increased _______________

of RBCs• EPO levels are __________. Bone marrow is

producing __________ stimulation from EPO.

Treatment of Polycythemia Rubra Vera

• __________is required– ~__________mLs/kg

• Simultaneous __________therapy to maintain overall blood __________.

• Treatment with Rx: Hydroxyurea will help to suppress the production of RBCs.

Staining of Blood• Different __________ within cell stain specific

colors.• Many different hematology stains – Different names but similar staining characteristics.– Many are _________________-_________stains

(Wright’s stain, Giemsa, Leishman’s, Wright-Giemsa, and May-Grunwald are all Romanovsky-type stains)• Also called ____________________ stains because they

stain more than one color.• Combination of basic blue and acidic red dyes dissolved

in __________alcohol.• Allows ____________________ structures to stain blue• Allows ____________________ structures to stain red.

Staining Blood• Stain depends on ________ you are performing.– Each test we do in here will have specific stain

instructions.

• ____________________stain is the most widely used hematology stain. – Alkaline part is ____________________ blue– Acidic part is __________

• Modified Wright’s stains offer faster staining times but don’t stain some cellular structures as effectively.– ____________________ is a Modified Wright’s stain.

Sources• http://compepid.tuskegee.edu/syllabi/pathobio

logy/pathology/clinpath/chapter2.html• Clinical Anatomy and Physiology for Veterinary

Technicians: Colville and Bassert. Second Edition• Merckvetmanuals.com