Lab 5 –Blood, Lymphatics and the Immune Response

Gilbert Pitts, Ph.D., Joseph Schiller, Ph.D., James F. Thompson, Ph.D.

Objectives

Examine: Lymph node slide Lymphatic vessels on charts and models

Blood slides Differentiate red blood cells, platelets,

neutrophils, lymphocytes, monocytes, eosinophils, and basophils

Perform 2 differential WBC counts Identify leukemia Identify sickle cell anemia

Understand blood typing (ABO and Rh systems)

Calculate and interpret hematocrit/packed cell volume

The Lymphatic System

Basic organization Lymph fluid in lymph vessels Lymphatic organs (red bone marrow, thymus,

spleen, lymph nodes, tonsils) with smaller collections of lymphatic tissue in other organs

Functions Return interstitial fluid and proteins to the blood Transport dietary fats to adipose tissue Protect against cancer & infection

Lymph Flow from smallest to largest: Capillaries vessels trunks ducts

Lymph vessels anastomose and supply and drain lymph nodes along their course

Lymph Flow Follows Venous Circulation

Right head, arm, and thorax drained by the right lymphatic duct into right subclavian vein

Left head, arm, thorax, most of the abdominal cavity and both legs drained by the thoracic duct into the left subclavian vein

R

L

Connective tissue capsule with trabeculae extending from cortex to medulla

Stroma – the supportive connective tissue network of reticular fibers and fibroblasts

The Lymph Node

capsule

trabeculae

Lymph Node Parenchyma Cortex - filled with

lymphocytes and macrophages in follicles Outer edge of

follicle contains more T cells

Inner germinal center is the site of B-cell proliferation

Medulla - medullary cords of lymphocytes, macrophages, plasma cells (activated B cells)

Cortex

Medulla

Lymph Node Micrograph

Cortex

Medulla

Lymph Node Germinal Centers

germinal centers

Leukocytes = White Blood Cells

Granular leukocytes (granulocytes)

neutrophils eosinophils basophils

Agranular leukocytes (agranulocytes)

lymphocytes - T cells, B cells

monocytes tissue macrophages

The Formed Elements of the Blood:

Granular Leukocytes

Neutrophil60-70%

Eosinophil2-4%

Basophil0.5-1%

Agranular Leukocytes

Lymphocyte20-25%

Monocyte3-8%

Leukocyte Life Span and Number 5,000 - 10,000 WBC’s/mm3 blood

RBC/WBC ratio 700/1

Differential WBC count (a standard clinical lab report) Neutrophils 60-70% Lymphocytes 20-25% Monocytes 3-8% Eosinophils 2-4% Basophils 0.5-1%

Abnormal proportions are correlated with different types of disease processes

Differential WBC Count

20-25%

3-8%

l2-4%

l60-70%

0.5-1%

Leukocyte IdentificationAgranular

Lymphocyte

Granular

SmallSpherical nucleus

DarkHidden nuc.

Large2+ lobes

Neutrophil

Eosinophil

Basophil

Monocyte

Red gran.

Faint gran.no largegranules incytoplasm

All have many largegranules in cytoplasm &multilobed nuclei

Composition of Blood

Blood sample separates into 2 parts plasma - straw colored

liquid on top ~55% of the volume

formed elements ~45% of the volume

• red blood cells• buffy coat: white

blood cells and platelets

Hematocrit (Hct) Packed Cell Volume is

the % of the blood which is RBC’s Males: 40-54% (47%) Females: 38-46%

(42%)

Hct indicates the status of RBC production, the state of hydration, or various disease states

Hematocrit Procedure

Blood Typing Antigen – any

substance which provokes specific immune responses

Antigenic determinants Antigen parts which

trigger the specific immune response

An antigen may be an entire microbe or only small structures such as subregions of large molecules

RBC antigens (agglutinogens) are membrane glycoproteins

Most “antigens” are complex and express

multiple types of antigenic

determinants.

ABO Blood Types 2 glycoprotein agglutinogens, A & B One gene from each parent, A, B or O 6 combinations - AA, AB, AO, BB, BO, OO (no agglutinogens)

ABO Blood Types

Agglutinins Naturally occurring antibodies produced in response to

the agglutinogens not present in your blood React in antigen-antibody response to blood not of your

type blood type AB = universal recipients blood type O = universal donors

ABO System

Rh System Rh typing - Rhesus monkey

Those expressing Rh antigens are Rh+

Those without Rh agglutinogens are Rh-

Normally, blood does not contain Rh agglutinins

Immune system only makes agglutinins in response to specific exposure to Rh antigens

Rh sensitivity does not occur until second transfusion

Hemolytic disease of the newborn (erythroblastosis fetalis)• many “blue babies” prior to WWII

Hemolytic Disease of the Newborn =

Erythroblastosis Fetalis

Perform Fingerstick and Transfer Blood

Slide Appearance

Blood Type

                          A

                          B

                          AB

                          O

Please Clean Up Your Work Area Place only lancet and capillary tubes in

designated sharps containers

Place all other blood contaminated materials (gloves, alcohol wipes, paper towels, etc.) in the large red biohazard bucket at the front of the room

Place all other discards in regular trash receptacles

Disinfect your work area with the spray solution after you have concluded your blood work.

Homework

o Complete and turn in the questions on pages 5-13 to 5-15

o Complete Assignment 5 on MasteringAandP.

End Lab 5