Basic Blood Flashcards
function of blood
• Delivery of nutrients & oxygen AND transport of wastes & CO2
• Delivery of hormones, regulatory substances, immune system cells
• Maintenance of homeostasis: acts as a buffer, participates in
coagulation, thermoregulation
packed cell volume (PCV)
Volume of RBCs in a
sample of blood
Buffy coat
Leukocytes & platelets
constitute only 1% of the
blood volume
blood plasma
- Liquid extracellular material, >90% H2O by weight
- Solvent for a variety of solutes:
- Proteins, regulatory substances
- Nutrients, electrolytes, dissolved gases
- Wastes
Interstitial fluid:
fluid found surrounding tissue cells, derived
from blood plasma
-ulfiltrate of blood
plasma proteins
albumin, globulins, fibrinogen
serum
blood plasma without clotting factors
albumin
main protein constituent (50%) of plasma
- made in liver
-Responsible for exerting the concentration gradient btwn blood & EC
tissue fluid
-Carrier protein for thyroxine, bilirubin, barbiturates
what is a major source of colloid osmotic pressure
albumin
immunoglobulins (γ-globulins)
largest component, functional immune-
system molecules
Non-immune globulins (α-globulin & β-globulin):
-Maintain the osmotic pressure within the vascular system & serve as carrier proteins
• Includes fibronectin, lipoproteins, & coagulation factors
fibrinogen
largest plasma protein (340 kDa), is made in the liver
conversion of fibrinogen to fibrin
• In conversion, fibrinogen chains → monomers → polymerize forming long
fibers
• Become cross-linked → form an impermeable net preventing further blood
loss
functional components of blood cells
- Erythrocytes
- Leukocytes
- Platelets
where are blood cells formed
• All formed in bone marrow
erythrocytes
• Anucleate cells devoid of typical organelles • Biconcave disc, extremely flexible • Bind O2 for delivery to tissues & bind CO2 for removal from tissues
lifespan of erythrocytes
• Lifespan = 120 days • ~1% of RBCs are removed each day • Phagocytosed in spleen, bone marrow, & liver
reticulocytes
• Immature RBCs released into circulation
from bone marrow
• Have not yet shed all of their nuclear
material & still have organelles
• Will mature into erythrocytes in 24-48hrs
what are the integral membrane proteins in erythrocyte cytoskeleton
- glycophorin C
- Band 3 protein
glycophorin C
-integral membrane protein (erythrocyte cytoskeleton)
-attaches
underlying cytoskeletal protein
network to cell membrane
band 3 protein
-integral membrane protein (erythrocyte cytoskeleton)
-binds
hemoglobin & acts as an
anchoring site for the
cytoskeletal proteins (most
abundant)
what are the peripheral membrane erythrocyte cytoskeleton proteins
-Lattice is composed α-spectrin & β-
spectrin molecules
what are spectrin filaments anchored by
• Band 4.1 protein complex
• Ankyrin protein complex (ankyrin &
band 4.2 protein
what % of whole blood are erythrocytes
44%
what % of whole blood is Buffy coat
1%
what percent of whole blood is plasma
55%
what does band 4.1 protein complex interact with
glycophorin C
what does ankyrin protein complex interact with?
band 3
Anemia
decreased Hb levels
what are most anemias caused by?
reduction in number of RBCS
hemolytic anemia
accelerated destruction of RBCS
what can lead to decreased RBC production?
Insufficient dietary Fe, vitamin B12, or folic acid
clinical symptoms of anemia
- Weakness, fatigue, & loss of energy
* Frequent headaches, difficulty concentrating, dizziness, pale skin
Hereditary spherocytosis:
- autosomal dominant
- affects ankyrin complex
- defective anchor points (membrane detaches and peels off)
Hereditary elliptocytosis:
• Autosomal dominant mutation
- Spectrin-to-spectrin lateral bonds & spectrin-ankyrin-band 4.1 protein junctions are defective
- Membrane fails to rebound & progressively elongates
jaundice
Can be caused by the destruction of circulating erythrocytes
• Characteristic in a variety of hemolytic anemias that result from:
• Inherited RBC defects (hereditary spherocytosis)
• Pathogenic microorganisms, animal venoms, chemicals, & drugs
sickle cell anemia
-changes glutamic acid for valine
-• HbS molecules aggregate & grow in length
• Sickle-shaped at ↓O2sat
- more fragile break after ~ 20 days
-pile up
neutrophils
• Multi-lobed nucleus, polymorphonuclear neutrophils or polymorphs • General lack of cytoplasmic staining • Function in acute inflammation & tissue injury
- Azurophilic granules
-type of neutrophil granule
-(primary granules): lysosomes
containing myeloperoxidase (MPO)
- Specific granules (secondary granules):
-type of neutrophil granule
-various enzymes,
complement activators, & antimicrobial peptides
Tertiary granules (two types):
- Phosphatases
* Metalloproteinases - facilitate migration of through CT
eosinophils
• About same size as neutrophils
• Nuclei are typically bi-lobed
• Contain large & elongated specific & azurophilic granules
• Release arylsulfatase & histaminase
• Phagocytose antigen–Ab complexes
• Increase counts w/ allergies and/or parasitic
infections (worms) → eosinophilia
• May mediate chronic inflammation (i.e., lung
tissues in asthmatics)
basophils
• About the same size as neutrophils
• Least numerous < 0.5%
• Lobed nucleus is usually obscured by the granules
• Functionally related to mast cells (connective tissue)
• Bind an antigen-IgE antibody complex (plasma cells) triggers activation
• Release of vasoactive agents from granules
• Responsible for the severe vascular
disturbances associated with hypersensitivity reactions and anaphylaxis
lymphocytes
Functionally distinct : T lymphocytes, B lymphocytes, & Natural
Killer (NK) cells
T & B cells are indistinguishable in blood smears & sections
• NK cells can be identified by size, nuclear shape, & cytoplasmic
granules
T lymphocytes (T cells):
undergo differentiation in the thymus; long
life span & are involved in cell-mediated immunity
B lymphocytes (B cells):
form & differentiate in bone marrow;
transform into plasma cells → antibodies
NK cells
programmed to kill virus-infected and/or tumor cells
monocytes
• Largest of the WBCs (~18 μm)
• Indented, heart-shaped nucleus
• Contain small, azurophilic granules
• Differentiate into phagocytes in tissues
• Mononuclear phagocytotic system
• Osteoclasts, Kupffer cells (liver)
• Macrophages of connective tissue, lymph
nodes, spleen, & bone marrow
• Inflammation: monocyte leaves vasculature
→ macrophage → phagocytosis
thrombocytes
• Small, membrane-bound, cytoplasmic fragments • Derived from megakaryocyte: large polyploid cells in bone marrow • Involved in hemostasis, control of bleeding -platelets
platelet release of serotonin causes
potent vasoconstrictor → smooth muscle
contraction → reduces blood flow at injury
platelet release of ADP & thromboxane A2:
increase aggregation of platelets
to form primary hemostatic plug
what kind of plug does platelet conversion of fibrinogen to fibrin cause
→ secondary hemostatic plug
diapedesis
- Neutrophils leave the circulation & migrate to their site of action in tissues
- Controlled by adhesion molecules that interact with ligands on endothelial cells
- Further directed to injury site by chemotaxis
