L1 Blood as a Tissue

What type of tissue is blood?

• Specialized connective tissue

• Cell suspended within tissue specific extracellular matrix: plasma

What are the components of blood?

1. ~50% plasma

• 90% water, 10% dissolved substance (protein, waste, etc)

2. 45% RBC

3. 1% buffy coat 

• White blood cell

• platelets

What is serum?

The remaining liquid when the clotting factors moves to the blood which clots naturally,

What is plasma?

• Contains clotting factors (fibrinogen) 

• Anticoagulant is added to it to prevent clotting

RBC

What?

Function?

Appearance?

• Red blood cell aka erythrocytes

• Mature in bone marrow, starts out as reticulocytes (immature RBC, larger than RBC and contains less hemoglobin)

Function:

• Contains hemoglobin (Hb) 

  • Protein that carries molecules of oxygen

Appearance: 

• Central pallor: dived in the center 

• Anucleate: no nucleus 

  • Due to evolution reasons 

  • Also means they cannot replicate bc they have nowhere to store DNA/RNA

Biconcave disc (shaped)

What are reticulocytes?

Immature RBC in the bone marrow (less hemoglobin but bigger)

What is central pallor?

Dip center of RBC

RBC

What are the increase and decrease of RBC?

Erythrocytosis (increase): can be caused by 2 things

• Overproduction in the bone marrow 

• Compensation such as chronic hypoxia (low oxygen levels), high altitudes

Anemia (decrease): Making of new red blood cells

1. Regenerative anemia:

• Bone marrow is intact: not due to its inability to make enough/malfunctioning in its production 

• Can see the reticulocytes (to overcompensate the lost somewhere)

• Usually bc of blood lost

2. Non-regenerative anemia: 

• issue with the bone marrow

• Does not have enough, and cannot make new ones

What are white blood cells?

• Leukocytes 

Classified into granulocytes and agranulocytes

What is the increase and decrease of white blood cells?

Leukocytosis (increase)

Leukopenia (decrease)

What are the Granulocytes

• 3 types

• “BEN”

• Basophil

• Eosinophil

• Neutrophil (most abundant)

What is a neutrophil?

Function?

Appearance?

Increase decrease?

• Most abundant leukocytes 

• First responders (cuts invasion) 

Function: 

• Fight diseases by migrating into blood vessels and perform phagocytosis: engulfing the invading bacteria, cellular debris etc. 

Appearance: 

• Lobulated nucleus

  • Mature: segmented neutrophil

  • Immature: band neutrophil, more unified 

    
    

Neutrophilia (increase)

Neutropenia (decrease)

Increase in band neutrophil: left shift

neutrophils

What are eosinophils? 

Function?

Appearance?

Increase decrease?

Function:

• Defend against parasites

• Regulate w allergic reactions 

• Enzymes that will inactivate histamine 

Appearance: (like a raspberry) 

• Lobulated nucleus 

• Eosinophilic (pink) granules 

Eosinophilia (increase)

Eosinopenia (decrease)

• Eosinophil

What are basophils? 

Function?

Appearance?

Increase decrease?

Function:

• Parasite defense

• Regulate allergic reactions 

• Release histamine (responsible for allergic reactions: runny nose, itchy eyes, hives)

  • Proinflammatory/signals inflammatory cells to go to sites of inflammatory 

Appearance: 

• Lobulated nucleus 

• Granules are much more purple/blue 

Basophilia (increase)

Basopenia (decrease)

• basophils

What the the types of agranulocytes?

• 2 types

• Monocyte (largest of all leukocytes)

• Lymphocyte (2nd most common of all leukocytes)

What are monocytes?

Function?

Appearance?

Increase decrease?

Function:

• Phagocytic, kills anything that’s too big, kills microorganism, ingests foreign material, remove dead cells

Appearance: 

• BIGGEST leukocytes 

• Variable morphology (shape) 

  • Dog: horseshoe shape 

• Can sometimes see vacuoles like bubbles in cytoplasm 

• When they migrate into tissues, they mature into macrophages or dendritic cells 

Monocytosis (increase)

Monocytopenia (decrease)

• monocyte

What are Lymphocytes?

Function?

Appearance?

Increase decrease?

• Second most common leukocytes 

Function:

• Main cell type of immune system (B and T cells)

  • B cell: mature into plasma cells and produces antibodies (protein that tags bacteria, virus)

  • T cell:

    • Cytotoxic T cell: kill infected cells

    • Helper T cells: antibodies that recognize infected cells & recruitment of inflammatory

Appearance: 

• Overmall small, round nucleus, little cytoplasm 

Lymphocytosis (increase): sometimes just mean its stressed 

Lymphopenia (decrease)

Lymphocyte

What are the types of lymphocytes?

• B cell: mature into plasma cells and produces antibodies (protein that tags bacteria, virus)

• T cell:

  • Cytotoxic T cell: kill infected cells

Helper T cells: antibodies that recognize infected cells & recruitment of inflammatory

What are Platelets?

Function?

Appearance?

Increase decrease?

• Aka thrombocytes 

• Produced in bone marrow (fragments of cells)

Function:

• Forming blood clots

• Prevents bleeding after vessel injury

• Form “platelet plug” at site of injury 

Appearance: 

• Very small compared to red blood cells 

• Disc shape

• Anucleate (like RBC) 

Thrombocytosis (increase)

Thrombocytopenia (decrease)

• Can lead to increased bleeding and bruising

What are thrombocytes?

• Platelets!

• Blood clot

• Platelets (thrombocytes)

Identify sites of blood collection:

• Jugular vein (neck): catheter and site with good blood pressure 

• Cephalic vein (front limb): catheters mainly done for dog and cat 

• Lateral saphenous vein/Medial saphenous vein: used for smaller animals/sacred animal 

Purple blood tube:

• Contains EDTA (anticoagulant: prevent blood clot)

• Used for CBC (complete blood count)  

  • Analyse the # & type of blood cell

Green blood tube:

• Contains Heparin (anticoagulant) 

• Chemistry panel 

  • analyze the non-cellular components (plasma, serum: protein, electrolyte, minerals)

Blue blood tube:

• Citrate (anticoagulant) 

• Coagulation panels

Red blood tube:

• No additives

• Clot and form serum

• Used for chem panel

What is a blood smear?

morphology(form) of blood cells

What is the anticoagulant?

Substance that prevents blood from clotting