Blood Flashcards
What is blood made up of?
55% plasma
45% cells=99% RBC less than 1% WBCs and platelets.
What is blood?
Specialized connective tissue
Cells: erythrocytes, leukocytes, thrombocytes
Ground substance: plasma (protein rich)
Forms approx. 7-8% of total body weight
What are the functions of blood?
Functions to
-deliver nutrients and oxygen to the tissues
- transport waste and carbon dioxide away from tissues
- Serves as medium to transport hormones and other regulatory substances to and from tissues
- Maintains homeostasis by acting as a buffer, thermoregulation, participates in coagulation
- Transports humoral agents and cells of the immune system
How is for,action 9f blood different at different stages of life?
Embryonic: umbilical vesicle (yolk sac)
Fetal: liver and bone marrow
Adult: bone marrow
What is a hematocrit?
Volume of packed erythrocytes
What is Serum?
Plasma without clotting factor
What are the components of blood plasma?
- Provides optimal pH and osmolarity for cellular mechanism
- Contains and transports the cells and elements to the various tissues
- 91-92% water
- 7-8% protein
- Albumin, globulins, fibrinogen
- 1-2% other
- electrolytes~ sodium, potassium, calcium etc
- Non protein nitrogen substances~ urea, uric acid, creatine etc.
- nutrients~ glucose, lipids and amino acids
- blood gases~ oxygen, carbon dioxide, and nitrogen
- Regulatory substances~ hormones and enzymes
Except for the cells and plasma proteins most of these components can easily travel through the blood vessel wall
Assist in formation of interstitial fluid
-connective tissue most similar to plasma
Where are plasma proteins made?
In the liver
What are the plasma proteins?
Albumin (most abundant)
Globulins
Fibrinogen
What is the function of albumin?
Most abundant plasma protein
- responsible for exerting the concentration gradient between blood and the extracellular tissue fluid
- colloid osmotic pressure (osmotic pressure on vessel wall) maintains the correct proportion 9f blood to tissue fluid volume
If a significant amount of albumin leaks out into the tissues (or is lost through the kidneys) fluid accumulates in the tissues (swollen ankles by end of the day)
-Act as a carrier protein for horm9nes, metabolites and drugs
What is the function of globulins?
Immunoglobins -antibodies
No immune globulins-helps. Maintain osmotic pressure in the blood vessels and serve as carrier proteins fir various substances including hemoglobin
What is the function of fibrinogen?
Largest of the plasma proteins and converted to fibrin as needed
What are the formed elements of blood?
Erythrocytes -99%
Leukocytes-1%
granulocytes= neutrophils, eosinophils, basophils
Agranulocytes=
-lymphocytes= T cells, B cells and natural killer cells
-monocytes
Thrombocytes(platelets)= special cell fragments
What is the lifespan of an erythrocytes?
120 days
Describe the shape of erythrocytes
Cells with no nucleus or organelles
7-8 um in diameter(histological ruler)
Biconcave dusk
- maximizes cell surface area for gas exchange
- flexible shape for narrow spaces
- shape is maintained by membrane proteins
Contain hemoglobin (gives blood it’s red color) approx. 1/3 of cell’s weight it’s hemoglobin
How are erythrocytes stained?
Eosin
What is the function of Band 3?
Binds hemoglobin in erythrocyte cytoskeleton
What is the function of glycoprotein C?
Attached the underlying cytoskeleton network to the membrane in erythrocyte cytoskeleton
What is the function of glycosylated proteins in erythrocytes ?
Displays specific antigens(A,B,O)
How is the erythrocyte cytoskeleton organized?
Undergoes continual rearrangement as required
Organized into a 2-d hexagonal lattice network that gives it its unique shape and flexibility
band 4.1 or band 4.1 protein complex
Tropomyosin
Actin
Adducin
Dematin
Tropomodulin
Describe hemoglobin
4 polype0tide chains of globin a, B, d, y- structure varies
Each have iron containing heme group
The combination of chains that form the hemoglobin determines its type
Describe hemoglobin A(a2B2)
- further divided into subtypes
- HbA1c binds irreversibly to glucose
Describe HbA2(a2d2) Population
1.5-3%
Describe HbF(a2y2)
Less than 1%
Most abundant in the fetus
Binds oxygen more strongly
Found in higher number in individuals with sickle cell and thalassemia
What are the main blood sampling techniques?
Venipuncture
Finger or heel prick
How is venipuncture done?
- sample taken from vein with hypodermic needle & syringe
- median cubical vein
Why not stick an artery?
-veins less pressure.
-veins are closer to surface
How is a finger or heel prick?
- common technique for diabetics to monitor daily blood sugar
- method used for infants
How is preparation of a blood smear for visualization done?
-Drop of blood on a slide, smeared with another slide, dried and stained
- Wright’s stain
- use of eosin/methylene blue (Romanovsky)
- red (acidic), blue (basic) for staining
- specific granules (azurophilic )(lysosomes)
What is anemia?
A lack of sufficient numbers of healthy RBC to accommodate bodily needs
May be temporary e.g., in females once a month or chronic due to an underlying condition
What are the symptoms of anemia?
- fatigue
- weakness
- pale skin
- shortness of breath
- dizziness or lightheadedness
- cold hands and feet
What is polycythemia?
High numbers of red blood cells in the blood
Two main causes
Primary: polycythemia Vera, a type of blood cancer
Secondary: due to an altitude or diseases that cause reduced oxygen levels
What are the symptoms of polycythemia?
- dizziness or vertigo
- headaches
- excessive sweating
- itchy skin
- ringing of the ears
- blurred vision
- fatigue
- reddish or purplish skin on the palms, earlobes, and nose
- bleeding or bruising
what is poikilocytosis?
Refers to the presence of poikilocytosis in blood
Poikilocytosis are RBCs of distorted shape (can be entirely of a different shape)
When these abnormal cells make up 10% or more of the total population, it is refferred to as poikilocytosis
What causes poikilocytosis?
The various shapes can due to membrane abnormalities or due to traumatic conditions
What is anisocytosis?
A blood abnormality where the red blood cells are of unequal sizes
Can be detected in peripheral smears
Can signify conditions such as anem8a and thalassemia
What is hereditary spherocytosis?
Caused by a variety of molecular defects in the genes that code for spectrin, ankyrin, band 3 and band 4 proteins
These proteins which are essential for the normal shape of an erythrocyte, when deformed, results in a spherical shape of RBC than the biconcave nature of it
What is thalassemia ?
Hereitary hypochromic anemia resulting from decreased a or B chains
B thalassemia-indicates decreased or absent B chains. Excessive a chains produced in compensation are unable to form tetramers
Instead, they bind to the red blood cell membranes, producing membrane damage, and at high concentrations form toxic aggregates
What is sickle cell anemia ?
Genetic defect in hemoglobin molevule(Hb-S): hydrophilic glutamic acid is replaced by hydrophobic valine at point 6 in B chain
Any condition resulting in reduced oxygen levels will cause the cells with HbS to sickle
What are leukocytes?
Unlike RBCs they contain a nucleus and a few organelles
Generally, have a protective function
Great motility, can move from the blood to other tissues with ease
All have azurophilic (primary) granules
-Large lysosomes containing lysosomal acid hydrolases and other enzymes depending on the type of leukocyte
- Not visible on light microscopy
- Generally function to destroy and foreign body engulfed by the cell
What are the two major types of leukocytes?
Granulocytes: those with both azurophilic and specific (secondary granules) that can be observed that can be observed on light microscopy.
-neutrophils, eosinophils, and basophils
Agranulocytes: those with only azurophilic granules
-lymphocytes and monocytes
How much of circulating leukocytes consist of nutrophils?
60-70%
Describe the physical features of the neutrophils
Diameter is about 10-12 um
Polymorphonuclear (PMN)
- Nucleus - 2 to 4 lobes connected by thin nuclear strands - older cells have more lobes - young cells called band cells. (horseshoe shape) - inactive X chromosome in females forms a Barr body
Contains 3 types of granules
What leukocytes are the first to react en masse to tissue damage?
Nutrophils
What leukocytes are active phagocytes especially for bacteria?
Nutrophils
What are the 3 types of granules contained in neutrophils?
-specific: enzymes, compliment activators and antimicrobial peptides
Azurophilic: myeloperoxidase , acid hydrolases, defensive, and Cathelicidin
Tertiary: phosohatases, metalloproteinases
How does nutrophils treat bacteria ?
Bacterial phagocytosis
-lysosymes destroy/ digest bacteria
- defensin proteins act like antibiotics & poke holes in bacterial cell walls
- strong oxidants (bleach like) that destroy bacteria
What percentage of circulating leukocytes are eosinophils?
2-4%
Describe eosinophils physical structures
Diameter is 10-12 um
Nucleus - bilobed connected by a thin strand
Contains large, uniform-sized specific granules that stain eosinophilic (granule red)
Contains major proteins and enzymes
What are the 4 major proteins in eosinophils?
- Major basic proteins- confined in the crystalloid body, gives the color
- ECP- eosinophil cationic protein
- EPO- eosinophil peroxidase
- EDN-eosinophil derived neurotoxin
What enzymes are contained in eosinophils?
Histaminase
Sulfatase
Collagenase
Cathepsin
What 8s the function of eosinophil?
Leave capillaries to enter tissue fluid
- MBP, ECP & EPO- impart cytotoxic effect on protozoans & helminthic parasites
- EDN causes nervous system dysfunction in parasites
Release histaminase, which neutralizes histamine
-Arylsulphatase neutralizes leukotrienes produced by basophils & mast cells
Antibody-antigen (immune) complexes internalized by eosinophils
How much of circulating leukocytes are basophils?
Less than 1%
What are the physical features 9f the basophils?
Diameter is 10 to 12 um
Nucleus- irregular, s-shaped,bilobed
Cytoplasm- large, variable-sized, granules stain blue/purple with basic dyes- obscure the nucleus
Specific granules contain - heparin (sulphate ), hisstamine & leukotrienes, IL-4 & IL 13
-High levels of sulphate so give rise to basophilia of granules
When are basophils released ?
Heighten inflammatory response and account for hypertensivity (allergic) reaction
What are the functions of the basophils?
Leave capillaries & enter the CT
Release:
Heparin-anticoagulant
Histamine-vasoactive substance causing vasodilation
Leukotrienes- prolonged constriction of smooth muscles in pulmonary airways
Interleukin 4 & 13- promote synthesis of IgE antibodies
What is the percentage of circulating leukocytes are lymphocytes?
20-25%
Describe the physical features of lymphocytes
Diameter can very between 6-30 um
Classified as small, medium and large sized lymphocytes
Nucleus- dark, oval to round
Cytoplasm thin, pale blue rim (of varying size)around nucleus
- contain azurophilic granules - ribosomes
Where are lymlh9cytes found?
Blood as well as lymph
Lymphocytes are capable of…
Recirculation
Lymphocytes are…
Immunicompetent cells (can recognize and respond to antigens)
What are the types of lymphocytes?
T cells
B cells
Natural killers
What Are the characteristics of T cells?
Differentiate in thymus
Cell mediated immunity
Long life span
Attack viruses, fungi, transplanted organs, cancer cells & some bacteria
What are the characteristics of B cells?
First recognized in bone marrow
- production of antibodies
- destroy bacteria and their toxins
- turn into plasma cells that produces antibodies
- Variables life span
What are the characteristics of natural killer cells?
Programmed during development
- attack many different microbes & some tumor cells
- destroy foreign invaders by direct attack
How much of circulating leukocytes are monocytes?
3-8%
Describe the physical structures of monocytes
Diameter- average 18 um
Nucleus appears indented (kidney shaped)
Cytoplasm- foamy blue gray -contains azurophilic granules
Largest WBC in circulating blood
Doesn’t remain blood fir long, (only 3 days) before migrating ti tissues
What do macrophages differentiate into?
- histiocytes in connective tissue
- alveolar macrophages (Dust cells) in lungs
- kupfer cells in liver
What are the functions of monocytes?
Take longer to get to site of inflammation, but arrive in larger numbers
-During inflammation, monocyte leave capillaries to enter that site and transform into tissue macrophage, which function as antigen presenting cells in the immune system
They phagocytose bacteria, dead cells and tissue debris following an infection
Cluster of macrophages—> giant cells at sites of chronic infection
How much thrombocytes(platelets) are in the blood?
Normal blood contains 250,000 to 400,000 platelets /uL
What is the life span of thrombocytes/platelets?
5-9 days
Describe the physical features if thrombocytes/platelets
Measure 2-4 um in diameter
Cytoplasmic fragments from this cell result in platelet formation
Each fragment, enclosed by a pierce of cell membrane, is a platelet (thrombocytes)
Aged and dead platelets are removed by fixed macrophages in the spleen and liver
Where are thrombocytes/platelets formed
In bone marrow from megakaryocytes
What are the functions of granules in thrombocytes /platelets?
- Alpha contains clotting factors and platelet derived growth factor
- cause proliferation of vascular endothelial cells, smooth muscle & fibroblasts to repair damaged vessels
Dense has ADP, ATP Ca2+, serotonin, fibrin stabilizing factor, & enzymes that produce thromboxane A2
What are the functions of thrombocytes/platelets ?
Continuous surveillance of blood vessels
Blood clot formation (hemostasis)
Clot plugs ruptured area of blood vessel
Platelets pull on the fibrin threads causing clot retraction
-trapped platelets release factor XIII stabilizing the fibrin threads
Edges of damaged vessel are pulled together
Fibroblasts & endothelial cells repair the blood vessel
Repair of injured tissues
What causes elevation of neutrophils 60-70% ?
Acute bacterial infection
What causes an increase in lymphocyte in blood?
20-25%, chronic infection/ cancers
What causes an increase in monocytes ?
3-8% increase in fungal /viral infection
What increases eosinophils?
2-4% increases in parasitic infection
What causes an increases in basophils?
Below 1% increases in allergic reactions