Cardiovascular system

RBC, WBC , platlets , Blood groups

What is blood?

Blood is a fluid connective tissue containing erythrocytes leukocytes and platelets suspended in plasma.

What are the general functions of blood?

-Blood transports dissolved gases, nutrients, hormones and metabolic wastes;

.

-regulates pH and ion composition of interstitial fluids;

.

- restricts fluid loss at injury sites;

.

-defends against toxins and pathogens;

.

-stabilizes body temperature.

constituents of plasma

What are the major plasma proteins?

The major plasma proteins are albumins, globulins and fibrinogen.

What percentage of plasma proteins is made up of albumin globulins and fibrinogen?

-Albumins make up about 55–60%;

.

-globulins about 35–38%; and

.

- fibrinogen about 4–7% of plasma proteins.

What is albumin and where is it produced?

Albumin is the most abundant circulating plasma protein and is synthesized by liver hepatocytes.

What are the functions of albumin?

Albumin maintains plasma osmotic pressure

.

-transports fatty acids thyroid hormones, some steroid hormones and other substances.

,

-most of blood vol

Why does albumin contribute to osmotic pressure?

most abundant

What is hydrostatic pressure?

Hydrostatic pressure is the pushing force on water caused by the presence of more fluid in one region than another; larger fluid volumes generally produce higher hydrostatic pressure.

How are osmotic pressure and hydrostatic pressure different?

Osmotic pressure is the pulling force on water caused by solutes and hydrostatic pushing force due to presence of more fluid in one region

Indication of diff albumin levels

-If lower albumin level:

may have malnutrition or liver disease, kidney disease, or an inflammatory disease

.

-If higher albumin level:

may be caused by acute infections, burns, and stress

from surgery or a heart attack

.

-Higher than normal

albumin levels:

may be a sign of dehydration, which may be caused by severe diarrhea or other conditions.

What are globulins and categories

-Globulins are plasma proteins that include enzymes [Immunoglobulin m (IgM) , (IgA)antibodies] and fibrous or contractile proteins

.

- and are divided into alpha beta and gamma globulins.

What are the functions of globulins?

Globulins contribute to immune defense through antibodies

What substances can transport globulins carry and ie?

Transport globulins can bind small ions ,hormones and compounds that may be lost at the kidneys or have very low solubility in water;

.

examples include thyroid-binding proteins transferrin apolipoproteins and steroid-binding proteins.

What are antibodies and which plasma protein group contains them?

Antibodies are immune proteins found among the globulins; examples include IgM IgG and IgA.

Globulin test

Used to diagnose kidney,

liver, or immune disorders.

Different levels of globulin indication

-High/Low Levels?

High levels may indicate

autoimmune disease, infections

or cancer.

.

-Low globulin reading may be a

sign of liver or kidney disease.

What is fibrinogen?

Fibrinogen is a plasma protein synthesized by the liver that is converted into fibrin during blood clotting.

How would reduced fibrinogen affect blood clotting?

Reduced fibrinogen would impair clot formation because fibrinogen must be converted into fibrin to form the structural framework of a blood clot.

Low fibrinogen symptoms

-Bleeding gums

.

-Bleeding in your

gastrointestinal tract

.

-Blood in your urine or stool

.

-Coughing up blood

.

-Excessive bruising

.

- Frequent nosebleeds.

- Ruptured spleen

Types of Fibrinogen Deficiency

Afibrinogenemia: no fibrinogen in

your blood; extremely rare (1 in 1mil)

.

 Hypofibrinogenemia: low fibrinogen

levels; more common than

afibrinogenemia.

.

 Dysfibrinogenemia:

typical fibrinogen levels, but fibrinogen

doesn’t function properly; a large

number of people without

symptoms - but more common than

afibrinogenemia.

High vs low fibrinogen

High

> 700 mg/dL may mean

danger of forming clots

that could harm heart or

brain

.

Low

< 50 mg/dL: may mean

danger of bleeding

after surgery.

How to get rid of excess fibrinogen

-smoking cessation most

effective

.

-weight or stress

reduction or an increase

in regular physical

activity may have less

pronounced effects

What are erythrocytes?

Erythrocytes are red blood cells that contain hemoglobin and primarily transport oxygen.

What are the main functions of erythrocytes?

-Erythrocytes transport oxygen through hemoglobin and

,

-transport carbon dioxide on a smaller scale; (CO2 is transported by binding to the protein portion of hemoglobin.)

What is the structure of an erythrocyte?

An erythrocyte is thin and biconcave

How does erythrocyte flexibility help circulation?

Flexibility allows RBCs to squeeze through very narrow capillaries

What are rouleaux and why can they be useful?

Rouleaux are stacks of RBCs that can form in small capillaries; they help prevent individual cells from bumping into vessel walls and each other and forming blockages that could restrict blood flow.

What is the hematocrit?

Hematocrit is the percentage of whole blood volume contributed by formed elements

.

-percentage of whole blood volume consisting of RBC (bk0

packed cell vol

percentage of all formed elements within a sample of whole blood

process formed elements are produced

Hemopoiesis or hematopoiesis

Which formed element contributes almost all of the hematocrit?

Erythrocytes contribute approximately 99.9% of the hematocrit value.

Describe various conditions due to varying hematocrit levels

Dehydration: increase in hemocrit due to decreases plasma volume of stimulation of hormone erythropoietin.
.

-decrease due to internal bleeding or RBC formation problems

How do the structural features of erythrocytes relate to their oxygen-transport function?

Their biconcave shape increases surface area for oxygen diffusion

Hemopoiesis and site

Formation of blood cells (formed elements)

.

occurs in red bone marrow

Erythropoiesis

Formation of red blood cells in red bone marrow/ myeloid tissue stimulated directly by erythropoietin; indirectly androgen, thyroxine and growth hormones

What gives urine its yellow color

Urobilins

What gives faces its brown color

urobilins

.

stercobilins

structure of hemoglobin

-Quaternary structure: 2 alpha and 2 beta-chains

.

-Each HB chain contains a heme group

.

-Each Heme unit holds Fe2+ so it can interact with O2

Agglutinogen

Specific surface antigens on RBC plasma membranes

.

They are integral membrane glycoproteins or

glycolipids

List the 4 diff blood types

Difference btwn antibodies and antigens

• Antigens are present on RBC and in the plasma membrane used to determine blood type

• .

• -Antibodies detect the presence of foreign RBC and attach to those antigens causing agglutination and lysis of RBC

what is the Rhesus blood typing system

Blood group based on the presence or absence of a Rh surface antigen

.

Rh pos (Rh+) presence of RH factor / Rh neg (Rh-) no Rh factor

.

( term RH usually emitted ie : O+ , A- etc

Rhesus System Antibodies

Only the Anti-Rhesus

Antibody exists in the

Rhesus System

Characteristics of WBC

• lack hemoglobin

• Migrate out of the blood stream

• Capable of Amoeboid movement ( gliding motion due to the flow of cytoplasm )

• Attracted to specific chemical stimuli ( positive chemotaxis) guides WBC to invading pathogens , damaged tissues and other WBC

• Defends body against pathogens removing toxins , waste and abnormal or damaged cells

Explain the migration of WBC out of the bloodstream and another name

Diapedesis

.

WBC are activated and adhere to the vessel walls in a process called margination

.

WBC then squeeze btwn adjacent endothelial cells and enter the surrounding tissue ( emigration ) leaping motion

What are the general functions of leukocytes?

Leukocytes help remove toxins wastes abnormal cells and damaged cells and participate in immune defense.

What are the two major categories of leukocytes and how they’re identified ?

Granulocytes and agranulocytes.

.

Appearance after Wright’s stain or Giemsa stain

Which leukocytes are granulocytes?

Neutrophils eosinophils and basophils are granulocytes.

Which leukocytes are agranulocytes?

Monocytes and lymphocytes are agranulocytes.

A: Monocyte

B: RBC

C: lymphocyte

D: platelet

E: neutrophil

f: Eosinophil

g: Basophil

What distinguishes granulocytes from agranulocytes?

Granulocytes contain azurophilic primary granules and specific secondary granules while agranulocytes only have primary granules

What are the main structural features of neutrophils?

-Neutrophils are about 12 µm in diameter

.

-2 – 5 lobed nucleus

.

-Granules not stained well by either acidic or basic dyes

.

-Granules contain lysosomal

enzymes and bactericidal agents

What are the main functions of neutrophils?

Neutrophils are usually first at injury sites and attack engulf and digest bacteria

.

they can produce H2O2 and O2 to kill bacteria and release prostaglandins: capillary permeability and leukotrienes : attract phagocytes and coordinate

immune response

What are the main structural features and functions of eosinophils?

-Eosinophils have a bilobed nucleus

.

- large reddish granules;

.

-They engulf antibody-coated bacteria protozoa and cellular debris

.

-releases cytotoxic substances

destroying parasites (flukes, parasitic roundworms)

.

-Increase during allergic reactions

.

-Attracted to injury sites; release enzymes to

reduce inflammation

What are the main structural features and functions of basophils?

-Rare cells with large purple-blue granules takes up basic stain

,

- obscured bilobed nucleus

Function of Basophils

Migrate to injury sites and intensify inflammation

.

-Histamine: dilates blood vessels, increase capillary

permeability resulting in edema/swelling

.

-Heparin: prevents clotting

.

-Chemicals: that attract eosinophils and other

basophils

What are the main structural features of monocytes?

-Spherical

.

may exceed 15 um

.

-Large oval or kidney-bean shaped nucleus

.

-bluish-gray cytoplasm.

Functions of monocytes

they remain in circulation for about 24 hours before entering tissues and becoming macrophages

.

-engulfs debris and pathogens release chemicals that attract and stimulate

neutrophils, monocytes and fibroblasts

What are the main structural features of lymphocytes?

-spherical cells

.

-small lymphocyte : 6-9 μm in dia., thin rim of cytoplasm , round nuclei

(densely stained heterochromatin)

.

-Large : – 9-15 μm in dia., more cytoplasm than sml lymphocytes; nuclei

contain euchromatin and heterochromatin.

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- thin layer of cytoplasm surrounding the nucleus

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-slightly larger than RBC

.

-Continuously move between bloodstream and peripheral tissues

What are macrophages?

Macrophages are cells formed when monocytes enter peripheral tissues; they are aggressive phagocytes that can engulf particles as large as or larger than themselves.

Explain

Origin and Differentiation:

Macrophages originate in the bone marrow from stem cells that differentiate into monoblasts, which then develop into monocytes circulating in the blood.

.

 * Tissue Migration:

Monocytes migrate from the bloodstream into various body tissues, where they mature into resident macrophages.

 * Specialized Tissues:

Depending on their destination tissue, resident macrophages take on specialized forms and names, including:

   * Microglia in the central nervous system (CNS)

   * Kupffer cells in the liver

   * Alveolar macrophages in the lungs

   * Osteoclasts in bone

.

 *Activation:

Upon encountering pathogens or inflammatory signals, tissue macrophages can transform into activated macrophages

3 types of Lymphocytes

T Cells (T-lymphocytes):

-cell-mediated immunity specific defense against invading foreign cells and tissues

-attack peripheral tissues invading foreign cells & directly control activity of other lymphocytes

.

B cells (B-lymphocytes):

-humoral immunity (antibody-mediated) involves production of antibodies for defense

-Attack foreign antigens; Activated B-cells Differentiate into Plasma cells which produce antibodies

.

Natural Killer cells:

-Detect and destroy abnormal tissue cells

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-Helps prevent cancer

How do the functions of neutrophils eosinophils basophils monocytes and lymphocytes differ?

Neutrophils mainly attack bacteria

.

-eosinophils defend against parasites and participate in allergic reactions;

.

-basophils intensify inflammation; monocytes become macrophages that perform phagocytosis

.

- lymphocytes provide specific and immune-surveillance functions.

What are platelets?

Platelets are cytoplasmic fragments of megakaryocytes that lack a nucleus.

What are the structural features of platelets?

Platelets are flattened discs that appear spindle-shaped in a blood smear

Where do platelets come from?

Platelets are cytoplasmic fragments produced from megakaryocytes.

What are the main functions of platelets?

Platelets release chemicals important to clotting

What is hemostasis?

Hemostasis is the process of stopping bleeding from a broken blood vessel and establishing a framework for tissue repair.

What are the three phases of hemostasis?

The vascular phase

What happens during the vascular phase of hemostasis?

Smooth muscle in the damaged blood vessel contracts

What happens during platelet adhesion?

Platelets stick to the endothelium

What happens during platelet aggregation?

Platelets accumulate at the injury site and stick to one another

What happens during platelet activation?

Platelets become spherical and develop cytoplasmic processes

What chemicals are released by activated platelets and what are their functions?

ADP promotes platelet aggregation and secretion; thromboxane A2 and serotonin promote vascular spasm; clotting factors aid blood clotting; platelet-derived growth factors promote vessel repair; and calcium ions assist platelet aggregation and clotting.

What happens during the coagulation phase?

Fibrinogen is converted into fibrin

What are the three coagulation pathways?

The extrinsic pathway

How does the extrinsic pathway begin and what does it ultimately activate?

Damaged endothelial cells or peripheral tissues release tissue factor Factor III; tissue factor combines with Ca2+ and Factor VII and activates Factor X in the common pathway.

Why is the extrinsic pathway described as short and fast?

It begins with tissue factor released from damaged tissues and rapidly leads to activation of Factor X.

How does the intrinsic pathway begin?

Factor XII in the blood becomes activated when exposed to collagen fibers.

How does the intrinsic pathway lead to activation of Factor X?

Factor XII is activated by collagen exposure; platelets release factors; Ca2+ aids activation of Factor IX; activated Factor IX combines with Factor VIII and activates Factor X.

What happens once Factor X is activated?

Factor X forms the enzyme prothrombinase; prothrombinase converts prothrombin to thrombin; thrombin converts fibrinogen to fibrin.

How do the extrinsic and intrinsic pathways relate to the common pathway?

Both pathways ultimately activate Factor X

What is the sequence of the major events in the common pathway?

Factor X activation → formation of prothrombinase → conversion of prothrombin to thrombin → conversion of fibrinogen to fibrin → formation of the blood clot.