PHRM 542 Blood Overview

What are the two major components of blood?

Liquid (plasma) and solid (RBCs, WBCs, platelets) components

What are the three major functions of blood?

Transport

Protection

Regulation

How much blood do adults have?

4-6 L

If osmolarity is high, what happens to fluid?

Fluid will be absorbed into blood, increasing BP

If osmolarity is low, what happens to fluid?

Fluid will flow into tissues, causing edema

What does plasma include?

Clotting factors

What are the two major components of plasma?

Non-protein

Protein

What are the non-protein components of plasma?

Nitrogenous

Nutrients

Gases

Electrolytes

What are the protein components of plasma?

Albumins

Globulins

Fibrinogen

Define hemopoiesis

The production of blood cells and platelets in bone marrow/hemopoietic tissues

What cell lines do IL-1 and IL-3 stimulate?

Erythrocyte

Granulocyte

Megakaryocyte

Monocyte

What cell line does IL-4 stimulate?

Basophil

What cell lines does IL-5 stimulate?

Eosinophil

Erythrocyte

Granulocyte

What cell lines does IL-6 stimulate?

Granulocyte

Megakaryocyte

Monocyte

What cell lines does IL-11 stimulate?

Erythrocyte

Granulocyte

Megakaryocyte

What cell line does EPO stimulate?

Erythrocyte

What cell lines does SCF stimulate?

Erythrocyte

Granulocyte

Megakaryocyte

Monocyte

What cell line does G-CSF stimulate?

Granulocyte

What cell lines does GM-CSF stimulate?

Erythrocyte

Granulocyte

Megakaryocyte

What cell lines does M-CSF stimulate?

Monocyte

What cell line does TPO stimulate?

Megakaryocyte

Define erythropoiesis

The process that forms RBCs, stimulated by erythropoietin (EPO)

Where is EPO formed?

In the kidneys

What is notable about the shape of RBCs?

Biconcave disk shape

How long do RBCs function before being removed from circulation?

3-4 months

What is a major function of RBCs?

Filled with hemoglobin, allowing them to carry O2

What organelle is notably missing from RBCs?

At maturity, RBCs do NOT have a nucleus

What are nutritional needs for RBC formation?

Iron (Hb)

Vitamin B12 and folic acid for rapid cellular division

Vitamin C and copper = enzyme cofactors

How long does development of RBCs take?

3-5 days

How do RBCs transport gas?

1/3 of cytoplasm is Hb which carries O2 from lungs to tissue and CO2 in reverse

Shape has increased surface area/volume ratio which increases the diffusion rate of substances

What is the function of carbonic anhydrase in RBCs?

Produces carbonic acid from CO2 and water which is important in gas transport and pH balance

Describe hemoglobin

Tetramer with quaternary structure involving two alpha and two beta chains

What is the major difference between fetal hemoglobin and regular hemoglobin?

Fetal Hb has gamma chains instead of beta chains = better with O2 for better respiration

How many oxygens can each hemoglobin carry and how does it do this?

Four oxygens

Each oxygen binds ferrous ions (true binder of oxygen)

Define hematocrit

Percent of blood composed of cells

Describe erythrocyte homeostasis

Negative feedback control

Drop in RBC count causes kidney hypoxemia

EPO production stimulates bone marrow

RBC count increases in 3-4 days

What are stimuli for erythropoiesis?

Low levels of O2

Increase in exercise

Loss of lung tissue in emphysema

Define megakaryoblasts

A precursor cell to megakaryocytes

Define megakaryocytes

Gigantic cells that remain in the bone marrow

In-foldings of cytoplasm splits off cell fragments that enter bloodstream as platelets

Define platelets

Small fragments of megakaryocyte cytoplasm

What are the functions of platelets?

Secrete clotting factors and growth factors for vessel repair

Initiate formation of clot-dissolving enzyme

Phagocytize bacteria

Chemically attract neutrophils and monocytes to sites of inflammation

Define leukopoiesis

The process that forms leukocytes (WBCs)

What are the three pluripotent stem cells that develop into WBCs?

Myeloblasts = form neutrophils, eosinophils, basophils

Monoblasts = form monocytes

Lymphoblasts = form B and T lymphocytes and NK cells

What are the two types of WBCs?

Granulocytes

Agranulocytes

What are the three types of granulocytes?

Neutrophils

Eosinophils

Basophils

What are the functions of neutrophils?

Increase in bacterial infections

Phagocytosis of bacteria

Release antimicrobial chemicals

What are the functions of eosinophils?

Increase in parasitic infections of allergies

Phagocytosis of antigen-antibody complexes, allergens and inflammatory chemicals

Release enzymes to destroy parasites

What are the functions of basophils?

Increase in chicken pox, sinusitis, diabetes

Secrete histamine and heparin

What are the two types of agranulocytes?

Lymphocytes

Monocytes

What are the functions of lymphocytes?

Increase in diverse infections and immune responses

Destroy cells

"Present" antigens to activate other immune cells

Coordinate actions of other immune cells

Secrete antibodies and provide immune memory

What are the functions of monocytes?

Increase in viral infections and inflammation

Differentiate into macrophages

Phagocytize pathogens and debris

"Present" antigens to activate other immune cells

Define anemia

Too little RBCs

Define polycythemia

Too much RBCs

Define immune deficiency

Too little WBCs

Define leukemia and lymphoma

Too much WBCs

Define hemophilia

Too little platelets

Define thrombosis

Too much platelets