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