Basic Blood Flashcards
Components of blood (3)
- Erythrocytes
- Leukocytes
- Thrombocytes
Hematocrit
Volume of RBCs in a sample of blood (packed cell volume, PCV).
Blood plasma
> 90% water by weight. Serves as a solvent for proteins, nutrients, and wastes.
Interstitial fluid
Fluid found surrounding tissue cells. Derived from blood plasma. Electrolyte composition derived from blood plasma.
Serum
Blood plasma without clotting factors.
Albumin
Main protein made in the liver. Responsible for exerting the concentration gradient between blood and EC tissue fluid. Major source of colloid osmotic pressure.
What does albumin carry?
Thyroxine, bilirubin, barbiturates.
Colloid osmotic pressure
Osmotic pressure on vessel walls.
Non-immune (alpha and beta globulins)
Maintains osmotic pressure within the vascular system and serve as carrier proteins.
Examples of non-immune globulins (a and b)
Fibronectin, lipoproteins, coagulation factors.
Fibrinogen
Soluble form of fibrin. Thrombin acts to activate to fibrin which forms blood clots.
Erythromycin lifespan
120 days. Approx. 1% of RBCs are removed each day. Phagocytosed in spleen, bone marrow and liver.
Reticulocytes
Immature RBCs released from bone marrow. Have not yet shed nuclear material and still have organelles. Wll mature in 24-48 hrs.
Glycophorin
Attaches underlying cytoskeleton protein network to cell membrane.
Band 3 protein
Binds hemoglobin and acts as an anchoring site for cytoskeletal proteins. More abundant.
Hereditary spherocytosis
Autosomal dominant mutation. Affects ankyrin complex. Defective anchor points, causing membrane to detach and peel off, causing spherical erythrocytes.
a-spectrin and b-spectrin
Make up the lattice network inside the RBC. Form a heterodimer that then forms long, flexible tetramers.
Spectrin filaments are anchored by (2):
Band 4.1 protein complex - interacts with glycophorin C.
Ankyrin protein complex - interact with band 3.
Hereditary elliptocytosis
Autosomal dominant mutation. Spectrin-to-spectrin lateral bonds bonds and spectrin-ankyrin-band 4.1 protein junctions are defective. Membrane doesn’t rebound and progressively elongates (elliptical RBCs).
Granulocytes (3)
Neutrophils
Eosinophils
Basophils
Agranulocytes (2)
Lymphocytes
Monocytes
Neutrophils
“Polymorphonuclear nuetrophils”
Lack of cytoplasmic staining.
Function in acute inflammation and tissue injury.
Recognize and bind bacteria and other foreign agents.
Neutrophil granulocytes (3)
- Azurophilic granules (primary granules): lysosomes with MPO (myeloperoxidase).
- Specific granules (secondary granules): secretory vessels containing enzymes.
- Tertiary granules: Phosphatases and metalloproteinases (facilitate migration through CT).
Eosinophils
Nuclei are bilobed.
Contain large specific and azurophilic granules.
Release arylsulfatase and histaminase.
Concentration increases in people with allergies or parasitic infections (eosinophilia).
Basophils
Least numerous.
Functionally related to mast cells.
Responsible for severe vascular disturbances associated with hypersensitivity reactions and anaphylaxis.
Lyphmocytes
Various sizes.
Not terminally differentiated (can differentiate into other effector cells).
Types of Lymphocytes (3)
- T cells
- B cells
- NK cells
T cells
Differentiate in the thymus. Have a long life span and are involved in cell-mediated immunity.
B cells
Form and differentiate in bone marrow. Transform into plasma cells, which make Abs.
NK cells
Programmed to kill virus-infected cells or tumor cells.
How are leukocytes differentiated?
T and B cells can’t be distinguished. NK cells can be determined based on size, nuclear shape and cytoplasmic granules.
Monocytes
Largest WBC.
Contain small azurophilic granules.
Differentiate into phagocytes in tissues.
Monocytes differentiate into (3):
- Mononuclear phagocytotic system
- Osteoclasts
- Macrophages of connective tissues
Thrombocytes
Membrane-bound.
Derived from megakaryocyte.
Small bits of cytoplasm break off and circulate to control hemostasis.
Thrombocytes release _______ to promote adhesion (2):
- Serotonin: vasoconstriction –> smooth muscle contraction –> reduces blood flow.
- ADP and thromboxane A2: increase aggregation of platelets to form primary hemostatic plug.
Conversion of fibrinogen to fibrin
Platelets provide a surface for soluble fibrinogen to become fibrin. Fibrin forms a mesh over initial plug, trapping platelets. This is the secondary hemostatic plug.
