FHS Hematology Notes 1

Role of Blood

  • Moves oxygen

  • Nutrients

  • hormones

  • eliminate metabolic waste

  • regulate pH and temp

  • body fluid volume

  • defend against infection


Blood pH is 7.35-7.45

Temperature of blood is around 38 celcius


Components of Blood

  • Plasma

    • liquid portion

    • About 55%

    • Made of water, proteins like albumin, globulins, fibrinogen

    • electrolyte, nutrient, hormones, and waste products

    • Helps regulate osmotic pressure, coagulation, transport, and immune function

  • Formed elements

    • RBCs, WBCs, and platelets

      • RBCs lack a nucleus and contain hemoglobin, which hold on to both O2 and CO2

      • RBCs survive for 120 days

    • WBCs combat pathogens

    • Platelets are cell fragments that clump to start blood clotting when vessels are injured to prevent blood loss


Red Blood Cells

  • Anucleus

    • allows for extra flexibility and space to pack more hemoglobin, increase O2

  • Maturation stage: enucleation


Platelets

  • never had a nucleus

  • small cell fragments derived from megakaryocytes


Hematopoiesis

  • blood cell production process making all WBCs, RBCs, and platelets


Reconversion

  • if the body faces severe blood loss or chronic anemia, yellow marrow in long bones can turn back to red marrow to help make more blood cells


Main producers of Blood

  • Tibial and femur (stop mid 20s)

  • Vertebra and pelvis

  • Sternum

  • Ribs

  • Lymph nodes


Red Bone Marrow- make blood cells

Yellow Bone Marrow- reconversion, stores fat


Totipotent stem cell

  • originator of all cells, give rise to cells committeed to specific development


Committed: pluripotent hematopoietic SC have self-maintainging ability

Committed cells differentiate continuously- no reverse flow


In Heme SC transplants, stem cells replace cells damaged by chemo, disease, or serve as a way for immune system to fight types of cancer and blood-related diseases

  • leukemia, lymphoma, neuroblastoma, multiple myeloma


Blood Marrow Stem Cell → makes different kinds of cells and they continue to make other cells


Take blood marrow from pt, grow in petri, differentiate between healthy and diseased bone marrow stem cell, healthy SC can detect other SC and stop, the healthy SC are grown and then injected back into the pt to reestablish their immune system


Confluence- when there are enough SC they stop dividing


Cancer cells have no stopping point, and will grow upwards in petri


Totipotent vs Committed Stem Cells


Requirements for Hematopoiesis

  • bone marrow stem cell

  • Growth Factor

  • microenvironment


Bone marrow SC are multipotent cells found in the spongy tissue inside bones.


Hematopoietic Stem Cells

  • create RBC, WBC, and platelets


Mesenchymal SC

  • Can become bone, cartilage, fat, and muscle tissue

  • Cell regeneration, immunity, tissue repair, making them central to health and needed for bone marrow transplants


What are mesenchymal cells?

  • Multipotent stem cells

    • Turn into bone, cartilage, and fat

  • Muscle potential

    • have ability to differentiate into skeletal and cardiac muscle


How They Help Muscle

  • DIrect repair

    • differentiate into muscle-like cells to help repair damaged tissue

  • Support Signals

    • release helpful chemicals that reduce inflammation and wake up local muscle stem cells to help with repair


Core Mesodermal Lineages

  • Osteoblasts: bone-forming

  • Chondrocytes

  • Adipocytes

  • Myocytes

  • Tenocytes/Fibroblasts: tendon and stromal connective tissue cells


Extended and Non-Traditional Lineages

  • Neurons and glial-like cells under specific inducing cues

  • Cardiomyocytes

  • Endothelial cells

  • Hepatocytes


Hematopoietic System

  • blood, spleen, bone marrow, liver, and kidneys


Cytokines

  • small proteins that are crucial in controlling growth and activity of other immune system cells and blood cells

  • effect the growth of all blood cells and other cells that help with the immune system

  • Stimulate or inhibit, prevent apoptosis, colony-stimulating factors are produced by many different cells, interleukins


Interleukin

  • family of cytokines mainly secreted by leukocytes, primary goal is to facilitate communication among immune cells for growth, differentiation, and immune regulation

  • specialized cytokines that mediate communication among immune cells, but not all cytokines are interleukins


Classes of Cytokines

  • pro-inflammatory

  • chemokines (makes a chemical attractant)

  • regulatory (anti-inflammatory)


Chemokines

  • specialized subgroup responisble for inducing chemotaxis, directing immune cells to site of infection


Growth Factors

  • extracellular messengers that stimulate cell growth, differentiation, survival, inflammation, and tissue repair

  • secreted by neighbring cells, distant tissues and glands, tumor cells

  • VEGF


Plasma

  • all plasma proteins except gamma-globulins are synthesized in liver

    • Human serum albumin

      • Absorbs water, keeps osmotic pressure constant

    • Alpha-fetoprotein

      • fetal counterpart of serum albumin

    • Soluble plasma fibronectin    

      • help in forming a blood clot to stop bleeding

    • C-Reactive protein

      • opsonin on microbes, acute phase proteins


Opsonization

  • marks pathogens for elimination by phagocytes which are immune cells that eat foreign particles. Involves molecules called opsonins that cover pathogen. Act as handles for phagocytes to grab and ingest


Megakaryocytes are giant bone marrow cells tha produce platelets

They come from hematopoietic stem cells through endomitosis


Pulmonary circulation moves blood between the heart and lungs. It transports deoxygenated blood ot lungs to absorb oxygen and release CO2. Oxygenated blood then flows back to heart. Systemic circulation moves blood between heart and rest of body


Hemoglobin Alpha and Beta Globin Chains

  • most of RBC is hemoglobin, two alpha and two beta with a heme and iron in each

  • Hydrophilic on outside, hyprophobic on inside

  • High CO2 in tissue, O2 is kicked off for CO2 to hitch a ride

  • High O2 in tissue, CO2 is kicked off, O2 hitches a ride


Hemoglobin binds oxygen to become oxygemoglobin

Hemoglobin releases oxygen, converting it to deoxyhemoglobin


When pH is low, hemoglobin can be a buffer by binding free H+ to increase pH

This prevents blood from becoming acidic


Nitric Oxide

  • Hemoglobin binds NO to iron in heme group and to specific thiol groups on the globin protein

  • HMG acts as an NO scavenger and transporter

  

Hydrogen Sulfide

  • produced by metabolic pathways in various tissues, H2S is a gasotransmitter


Gasotransmitter

  • a small molecule of gas produced inside the body that acts as a chemical messenger

  • nitric oxide, carbon monoxide, hydrogen sulfide




White Blood Cells

  • help fight infection

  • Neutrophils, eosinophils, basophils, lymphocytes, monocytes


Natural Killer Cells

  • WBCs that destroy infected and diseased cells


Mast Cells

  • IgE


Coagulation

  • vascular spasm

    • contraction of tunica media

  • platelet plug

    • platelet aggregation

  • coagulation

  • formation of fibrin clot


Blood Products and Typing



Pregnancy with positive baby, negative mom

2nd pregnancy the neg mom will have antibodies against positive baby




Anemia

  • do not have enough RBCs or they are not working properly, not enough gas exchange

  • inherited or acquired

  • less RBCs or less Hg


Anemia Causes:

  • microcytic

  • normocytic

  • macrocytic


Inherited Anemias

  • Diamond-Blackfin: keeps bone marrow from making enough RBCs

  • Fanconi Anemia: rare blood disorder, causes proteins to fix crosslinks in DNA to be dysfunctional

  • Sickle Cell: condition changes shape of BC

  • Thalassemia: body produces less Hg, small RBC and anemia


Polycythemia

  • overproduction of RBCs