Chapt. 9: Hematopoietic System

-poietic

production/formation of

Hemato-

Blood

Consists of…

blood, lymphatic tissue, bone marrow, and spleen

Plasma

55% of total blood volume

Water (90%) and plasma proteins (10%)

Blood Cells 

45% of total blood volume 

Erythrocytes - red blood cell 

Leukocytes - white blood cells 

Thrombocytes - clotting cells 

Formed Elements

Erythrocytes

red blood cell (RBCs)

Biconcave disks 

Live about 120days 

Most numerous cells in body

• Average: 4.5-5million cells per cubic mm of blood

Carry O2 and CO2

Produced in bone marrow

Blood types ; Antigens, Rh factor 

Formed Elements

Leukocytes

white blood cells (WBCs)

Immune support / body’s defense

changes in number indicate presence of disease

5,000 - 9,000 - per cubic mm of blood

Neutralize or destroy pathogens

Formed in bone marrow and lymphatic tissue

Types: neutrophils, eosinophils, basophils, monocytes, and lymphocytes

Formed Elements

Thrombocytes

Platelets 

clotting cells

140,000 - 340,000 per cubic mm of blood

Essential to coagulation (clotting)

Formed in red bone marrow 

Live for 10 days 

• clotted trauma area and then done

Blood tranfusion of the wrong type can…

agglutinate and hemolyze red blood cells (transfusion reaction - can be fatal)

Blood type need to be checked during…

cross match or compatibility testing

2 commonly used blood group systems..

ABO blood group system

Rh blood group system ( + / - ) 

Hemaglobin (Erythrocytes)

Bloods measure potential of transporting O2 and CO2

Anemia if lower than 12g / 100mL 

Hematocrit (Erythrocytes) 

The total % of RBCs in the blood

Erythrocytes is formed by…

Hemocytoblasts

Reticuloendothelial system

the recycling process of RBCs into bile or new RBCs

Erythrocytes function…

Transport gases

Universal Recipient

AB+

Universal Donor

O-

Granular (Leukocytes)

Formed in Red Bone Marrow

Live for about 2 weeks 

Basophils - inflammatory process

Neutrophils - fast, first to site 

Eosinophils - allergies 

Nongranular (Leukocytes)

Formed in the lymphatic tissues

live for years 

Lymphocytes - antigen specific 

Monocytes - slow - lazy WBC

CBC

Complete Blood Count

Lymphatic System

Subsystem of circulatory system

Function - immunity (lymphocytes and antibodies), absorbing fat 

Composed of lymphatic vessels and nodes 

Nodes 

Linked in chains along the vessels 

• concentrated in Neck, mediastinum, axillary, retroperitoneal, pelvic, and inguinal regions

Spleen 

Largest lymphoid organ, produces lymphocytes and plasma cells 

MOST radiosensitive cell in the body =

Lymphocyte

• whole body dose of 0.5 Gy - 0.75 Gy would damage the lymphatic system 

Myeloid Tissue 

Bone marrow 

Predominantly found in flat bones and proximal ends of long bones 

Red 

• still actively producing RBCs 

Yellow 

• in active 

• composed of fatty tissue 

Imaging considerations

Radiography 

of limited value in hemopoietic disorders 

Skeletal survey - multiple myeloma, leukemia 

Chest radiography for lymph nodes 

Acute Respiratory Infections 

HIV 

Imaging considerations

CT

Is of great assessment value 

head and chest for HIV - associated pathologies

Imaging considerations

PET

Choice of modality for Hodgkin’s lymphoma

Imaging considerations

MRI

Useful for bone marrow imaging

Imaging considerations

Nuclear Medicine

bone scans for metastatic bone disease

Multiple myeloma 

Patient care considerations

standard precautions for blood and body fluids

Gloves

Handwashing 

Needles 

• never recap needles

• correct disposal of needles

  • Puncture - proof, non - recyclable sharps containers