NURS 210/211 Exam 3

Blood is a liquid connective tissue consisting of

cells surrounded by a liquid matrix (plasma)

Composition of blood post centrifuge (%)

Blood plasma (55%)

Red blood cells (45%)

Buffy coat in the middle composed of white blood cells and platelets

What is the name of the three layers formed from centrifuged blood

Erythrocytes on the bottom (~45% of the whole blood)

Hematocrit: percent of blood volume that is RBCs

◼ Normal values:

❑ Males: 47% ± 5%

❑ Females: 42% ± 5%

❑ WBCs and platelets in Buffy coat (< 1%)

◼ Thin, whitish layer between RBCs and plasma

layers

Plasma on top (~55%)

The cellular components (formed elements) of blood

include red blood cells, white blood cells, and platelets

The plasma portion of blood consists of...

water (91.5%)

proteins (7%)

-Albumins (54%)

-Globulins (38%), immunoglobulin, aka "Antibodies."

-Fibrinogen (7%) blood clot factors

-all others (1%)

and other solutes (1.5%)

Formed elements consist of

red blood cells 4.8-5.4 million

platelets 150,000-400,000

white blood cells 5,000-10,000

-Neutrophils (60-70%)

-Lymphocytes (20-25%)

-Monocytes (3-8%)

-Eosinophils (2-4%)

-Basophils (.5-1%)

Blood transports...

oxygen, carbon dioxide, nutrients, hormones, heat, and waste products

Blood regulates...

homeostasis of all body fluids, pH, body temperature, and water content of cells

Blood protects...

against excessive loss by clotting, and uses white blood cells to protect against infections

The process of producing blood cells is

hemopoiesis (hematopoiesis)

What differentiates into each of the different types of blood cells

Pluripotent stem cells

Colony-stimulating factors (CSFs) are...

secreted glycoproteins that bind to receptor proteins on the

surfaces of hemopoietic stem cells, causing the cells to

proliferate and differentiate into a specific kind of blood

cell

Administration of exogenous colony-stimulating factors stimulates...

bone marrow to produce more of the particular white blood cells

Red blood cells (erythrocytes) contain the protein

hemoglobin that is used to carry oxygen to all cells and

to carry some carbon dioxide to the lungs

Each hemoglobin molecule contains (how many _____Ions) which allows each molecule to bind four oxygen molecules

4 iron ions

Red blood cells have no nucleus or other organelles and

are

biconcave discs

❑ This allows them to carry oxygen more efficiently

RBCs contain plasma membrane protein___which proveds flexibilyt to change shape

Spectrin

Hemoglobin is involved in regulating blood flow and

blood pressure via the release of____

Nitric Oxide (NO)

Nitric oxide causes_____, which improves blood flow and enhances oxygen delivery

vasodilation

Red blood cells also contain______, which catalyzes the conversion of carbon dioxide and water to carbonic acid

carbonic anhydrase

Red blood cells live for only about_____

120 days

Dead cells are removed from the circulation by the

spleen and liver

Erythropoiesis

(production of red blood cells) begins in the red bone marrow

Erythropoietin, a hormone released by the kidneys in response to______(lowered oxygen concentration) stimulates differentiation of hematopoietic stem cells into erythrocytes

hypoxia

Reticulocytes

(immature red blood cells) enter the circulation and mature in 1 to 2 days

Some athletes abuse artificial EPO (erythropoietin)

Use of EPO increases hematocrit, which allows athletes to increase stamina and performance (thicker blood viscosity = more oxygen)

EPO consequences

❑ EPO can increase hematocrit from 45% up to even

65%, with dehydration concentrating the blood even more

❑ Blood becomes like sludge and can cause clotting,

stroke, or heart failure

Anemia:

blood has abnormally low O2-carrying capacity due to a low count of RBC and decreased hemoglobin

Sickle cell disease

It is a genetic anemia. The RBC in this disease contains hemoglobin-S (Hb-S), which causes red blood cells to bend into a sickle shape when they release oxygen to the interstitial fluid.

Iron-deficiency

Anemia is the most common type, caused by blood loss, but also by low iron intake or impaired absorption

Erythropoietin (EPO) was first isolated from the urine of

anemic patients who had high circulating levels of the

hormone. Despite the presence of the hormone that

stimulates red cell production, however, these patients

were unable to produce adequate amounts of

hemoglobin or red cells. Give some possible reasons

why the patients' own EPO was unable to correct their

anemia.

Missing materials (iron, B12, folate)

Bone marrow not responding (damage/disease)

Chronic inflammation blocking effect

Defective RBC production

Ongoing blood loss or hemolysis

EPO resistance

Sue is fatigued, and some blood tests have been done. Her

results include Hct 40%; Hgb 8g/dL; RBC 3.7million; and

platelets 175,000. The nurse should interpret Sue's

blood work as indicative of:

This is anemia — specifically a low hemoglobin and low RBC count

White blood cells (leukocytes) contain a

nucleus and organelles, but no hemoglobin

Leukocytes (white blood cells) are classified as:

Granular (containing vesicles that appear when the cells are stained)

◼ Granular leukocytes: neutrophils, eosinophils, basophils

❑ Agranular (containing no granules)

◼ Agranular leukocytes: lymphocytes, monocytes

Neutrophil (60-70%)

Granular

The most abundant type of white blood cell acts as the immune system's first line of defense against bacterial infections and acute inflammation. Phagocytes

Lymphocyte (20-25%)

Agranular

(B cells, T cells, NK cells) produces antibodies

-Viral infections, some leukemias, and infectious mononucleosis

-"lymph" associated lymphoid tissues (lymph nodes, spleen, etc.)

Monocytes (3-8%)

Agranular

Largest WBC

Kidney-shaped nucleus

Can leave blood and enter the surrounding tissue (becoming macrophages)

produced in the bone marrow

Viral or fungal infections

Eosinophils (2-4%)

Granular

Elevated in parasitic infection

Increase during allergic reactions

Stains orange/red

Basophils (.5-1%)

Granular

secretes histamine

promote vasodilation and enhance the migration of leukocytes to inflammatory sites

White blood cells may live for several months or years; their main function is to

combat invading microbes

During an invasion, many white blood cells are able to

leave the bloodstream and collect at sites of invasion

❑ The process is called emigration (diapedesis)

An elevation in the white blood count usually indicates an

infection or inflammation

Meghan thinks she has an abscessed tooth (a bacterial

infection). If she does, what type of white blood cell

would you expect to see in elevated numbers in a

differential count?

Neutrophil

________, ________, and ________ are called

granulocytes because ________.

Neutrophil, Basophil, and Eosinophil

-contain granuales

What is a differential white cell count, and when is it used?

% of specific WBCs

Megakaryocytes

In red bone marrow, splinter into 2000-3000 fragments to create the platelets that contain many vesicles but no nucleus

Under the influence of the hormone______, hemopoietic stem cells differentiate into megakaryocytes and form platelets

thrombopoietin

Platelets are used to

Clot the blood

Hemostasis is a sequence of responses to stop

Bleeding

The process of Hemostasis involves

❑ Vascular spasm

❑ Platelet plug formation

❑ Blood clotting (coagulation)

When activated, platelets swell, become spiked, sticky

and release chemical messengers:

❑ ADP causes more platelets to stick

❑ Serotonin and thromboxane A2 enhance vascular spasm and platelet aggregation

Positive feedback cycle:

As more platelets stick, they release more chemicals, which cause more platelets to stick

Blood clotting can be activated in one of 2 ways:

❑ Extrinsic pathway

❑ Intrinsic pathway

Intrinsic pathway

clotting factors are activated within the blood

Extrinsic pathway

clotting factors are activated in tissues located outside blood

❑ Triggered by exposure to tissue factor (TF)

Both of these pathways lead to the formation of_____and, from there, the common pathway continues

Prothrombinase

Phase 2: Pathway to thrombin

Prothrombinase catalyzes the transformation of prothrombin to the active enzyme thrombin

Phase 3: Common pathway to the fibrin mesh

Thrombin converts soluble fibrinogen to fibrin

◼ Fibrin strands form the structural basis of the clot

◼ Fibrin causes plasma to become a gel-like trap, catching formed elements

Once the clot forms

It retracts (tightens) to pull the edges of the damaged vessel together

What is fibrinolysis?

A process whereby clots are removed after repair is completed.

What is plasminogen?

A plasma protein that is trapped in a clot.

What is plasmin?

A fibrin-digesting enzyme.

What converts plasminogen to plasmin?

Plasminogen is converted to plasmin during fibrinolysis via tPA (Tissue Plasminogen Activator)

Thrombus

A clot that develops and persists in an unbroken blood vessel

◼ May block circulation, leading to tissue death

Embolus

A thrombus freely floating in the bloodstream

◼ Embolism: embolus obstructing a vessel. Example:

pulmonary or cerebral embol

Bleeding disorders. Thrombocytopenia:

deficient number of circulating platelets, cause spontaneous hemorrhage

Blood Groups and Blood Types

◼ At least 100 known blood groups

◼ Groups: ABO and Rh: cause the most vigorous transfusion reactions

Rh blood groups

❑ Named Rh agglutinogens (Rh factors)

❑ Rh+ indicates the presence of the D antigen

❑ 85% Americans are Rh+

Rh positive (+)

Do have D antigens present on surface of RBCs

Rh negative (-)

Do not have D antigens present

❑ Anti−Rh antibodies form if Rh- individual receives

Rh+ blood, or Rh- mom is carrying Rh+ fetus

Blood type is determined by ______--molecules

on the surface of RBCs.

Antigens

Antigens stimulate production of:

Antibodies -- proteins in plasma that attack foreign antigens

resulting in agglutination(clumping) and hemolysis (rupture) of RBCs

Blood plasma usually contains __________

that react with A or B antigens

antibodies (agglutinins)

IMPORTANT

◼ An individual will not have agglutinins against his or her

own blood type

◼ Mismatched transfused blood is perceived as foreign

and may be agglutinated and destroyed

◼ Potentially fatal reaction

Blood Types

A drop of blood is mixed with an antiserum that will

agglutinate blood cells that possess agglutinogens that

react with it

Why is O- universal donor

no antigens

Why is AB the universal recipient?

No A or B antibodies

True or False: Type A blood would have anti-A antibodies in the plasma

False (type B would)

If a person has AB type blood, which of the ABO blood types can they receive as a transfusion?

All of them are "universal recipients" with no antibodies

Hemolytic Disease of the Newborn

❑ If the baby is Rh+ and the mother is Rh-, she will

develop antibodies to the Rh factor

❑ During next pregnancy with an Rh+ baby, when

mother transfers antibodies to the fetus (a normal

occurrence), transferred anti Rh antibodies will

attack some of the fetal red blood cells causing

agglutination and hemolysis- erythroblastosis fetalis

(hemolytic disease of the newborn)

❑ *Prevention- RhoGam injection: inhibit anti-Rh

antibodies*

Bill wants to determine his blood type, so he takes a few

drops of blood from a puncture wound in his finger and

mixes it with various antisera. His blood cells agglutinate

when mixed with the anti-A sera but not with the anti-B

or anti-D sera. What does this mean?

◼ A) Bill could receive type B-negative blood in a

transfusion.

◼ B) Bill could donate blood to an individual with type O

blood.

◼ C) Bill is Rh positive.

◼ D) Bill's plasma contains B antibodies.

◼ D) Bill's plasma contains B antibodies.

Bill's blood type is A negative.

John and Laura are expecting their first child. John is Rh- and Laura is Rh+. Do they have to worry about Rh compatibility?

No, only when Laura is negative and John is positive

The heart is located in the

mediastinum

The heart is enclosed and held in place by the

percardium

The pericardium consists of an

outer fibrous pericardium and an inner serous pericardium

The serous pericardium has 2 layers:

1. Visceral (innermost)

2. Parietal (outermost)

The wall of the heart has 3 layers

1. Epicardium

2. Myocardium

3. Endocardium

Gross Anatomy of the Heart

Gross anatomy of the heart

The right atrium receives blood from the

superior and inferior vena cava and the coronary sinus

The right ventricle receives blood from

The right atrium and sends blood to the lungs via the pulmonary trunk

The left atrium receives oxygenated blood from the

pulmonary veins

The left ventricle receives blood from the left atrium and sends blood

All over the body via the Aorta

Note that the wall of the left ventricle is much thicker than that of the right ventricle - why?

It must generate significantly higher pressure to pump blood throughout the entire body

Heart Valves

◼ Ensure unidirectional blood flow through heart

◼ Open and close in response to pressure changes

Two major types of valves: Atrioventricular valves (right and left)

located between atria and ventricles

◼ Prevent backflow from the ventricles into the atria

Two major types of valves: Semilunar valves (right and left)

located between ventricles and major arteries

◼ Prevent back flow from the arteries into the ventricles

Two atrioventricular (AV) valves: Tricuspid

(right AV valve): Made up of three cusps and lies between the right atrium and ventricle

Two atrioventricular (AV) valves: Mitral (bicuspid) valve

(left AV valve, bicuspid valve): made up of two cusps and lies between the left atrium and the ventricle