Histology Flashcards
(34 cards)
What are the 3 main functions of blood?
Transport and Distribute gases, immune response, hormones.
Homeostatic regulation of temp and osmotic balance
Clotting and Healing vascular wall.
What is the composition of plasma?
92% water
7% Protein
1% other solutes (nutrients, electrolytes)
What is the difference between plasma and serum?
Serum is coagulated plasma and so the values found from both are technically different.
What is the Plasmalemma?
The membrane of a red blood cell. Peripheral and Integral membranes anchor and organize the cytoskeletal proteins.
Peripheral on inside. Integral in membrane
What is the function of the peripheral protein spectrin?
They are cytoskeleton that can attach and reconnect to allow the membrane to change shape in small capillaries.
Thalassemias?
Hemoglobinopathies?
Genetic disorders related to the underproduction of hemoglobin
Genetic disorders related to dysfunctional hemoglobin
What is Polycythemia?
Erythrocytosis
Increase in RBC count, caused by a variety of factors: environmental adaptation (decrease in atmospheric pO2) physiological or pathological.
Describe Platelets (Thrombocytes)
Membrane bound cell fragments
A nuclear with sparse mitochondria
Have Glycocalyx that lines the extracellular membrane to allow sticking.
Filled with different granules
Outer cytoplasm has complex intracellular arrangement to facilitate rapid degranulation.
What is the process of platelet clotting?
Primary aggregation: Glycogcalyx allows platelets to adhere to substrate or damage
Secondary aggregation: release of glycoproteins and ADP to induce more aggregation
Blood coagulation: Released granules
Clot retraction: clot contracts due to activity of platelet actin and myosin
Clot removal: growth of new tissue repairs damage.
Thrombocytopenia purpura?
Hemophilia?
Thrombophilia?
Circulating platelet function is compromised (causes pitichiae)
Genetic disorders in the function of clotting factors
Disorder that increases the risk of thrombosis.
Which WBC are granulocytes and which are Agranulocytes?
Granulocytes: Neurtrophil, Eosinophil, Basophils
Lymphocyte, Monocytes
How do you differentiate Neutrophils
Eosinophils
Basophils Histologically?
3-5 lobes: Granules are less dense and stain lightly pink
Bi-lobed nucleus: granules stain pink/red and there are more than neutrophils
Bi-lobed or S-shaped nuclei: with dark purple granule- have heparin, GAGs, Histamines
(Involved in allergic reactions with mast cells in type 1 hypersensitivity)
What are the histological Characteristics of:
Lymphocytes
Monocytes
Lymphocytes: Smallest diameter, spherical nucleus, maybe slight indentation. Thin ring of basophilic cytoplasm.
(T, B and NK cells) (Need to be presented antigen for T and B cells)
Monocytes: Indented or C-shaped nucleus with basophilic cytoplasm. Granules are present but very small.
(Many become antigen presenting cells)
Explain Leukocyte Extravasion
- Macrophage releases PROINFLAMMATORY CYTOKINES IL-1 and TNF-a. Signals selectins
- Neutrophils bind to selectins to loosely adhere
- Other cytokines express integrins on the neutrophil and ICAM-1 on the endothelial surface
- Integrins provide firm adhesion
- Attracted by local injury factors neutrophils become motile and migrate by DIAPEDESIS between loosened cells.
What is Anaphylaxis?
Rapid degranulation of mast cells and basophils regulating in vasodilation in many organs that drop blood pressure.
Explain the embryology of the sites of hemopoiesis
Yolk Sac first
Liver and Spleen from 3 to 6 months gestation
Bone marrow: tibia and femur as kid. Ribs sternum and vertebrae later on.
What is the make up of Red Marrow?
hematopoietic cords: Cell lines, maturing cells, and more hematopoietic cells
Reticular tissue to support mesh work of hematopoietic cords
Sinusoid also capillaries- lined by discontinuous endothelium (the holes let cells easily leave to mature)
Adipocytes (increases with age)
What are pluripotent stem cells?
Stem cell that can give rise to any of the 7 blood cells.
First differentiate to CMP (common myeloid cell) or CLP for lymphoid stem cells
CMPs become Erythrocytes or Thrombocytes
CLP for Lymphoid or grulocytes
What is cellularity?
Percentage of marrow that is comprised of active hemopoietic tissue vs. adipose tissue.
Erythropoiesis?
Go over this in the notes
Differentiation of proerythroblast from CMP (or MEP from research) driven by erythropoietin
Nucleus is ejected making a reticulocyte that still has some ribosomal bundles. Within a few hours that become mature erythrocytes.
RBCs are pushed into the sinusoidal capillaries because of the holes in them.
Explain Thrombopoiesis
Differentiation of megakaryoblasts from the CMP (MEP) driven by thrombopoietin
Large cells with endomitosis rounds that divide DNA without dividing the membrane.
They then bud off those pieces of DNA that are dropped into the bloods using proplatelets that extend into sinusoidal capillaries
Explain Granulopoiesis
Differentiation of Granulocytic progenitors (myeloblasts) driven by G-CSF
Promyelocyte have Golgi and RER with small granules
Myelocyte — Metamyelocyte have the specific granules of the granulocytes
Band Stage — an intermediate stage in which the nucleus has not completely formed its polymorphic shape.
Explain how neutrophil numbers can rise so quickly?
Marginating cells that are on the endothelium but not in the blood that are ready to go. There are also many in storage or ready to differentiate.
Explain Monocytopoiesis.
Differentiation of monocytes progenitor cell and monoblasts driven by M-CSF
Promonocyte have slight indentation and stains slightly basophilic.
