Lab 2 157 Flashcards
Hematology
Study of blood, blood forming tissues, blood disorders
Erythrocytes =
Red blood cells
List functions of the blood
-nutritive and excretory function
-respiratory function
-transports hormones and enzymes
-regulates water and acid-base balance
-regulates body temp
True or false
Blood is a type of connective tissue where the matrix is the plasma
True
What temperature does blood typically maintain
38°C (1°C higher than oral or rectal temp)
True or false
Blood is denser and 5x more viscous than water
True
What is the average pH of blood
7.4 (7.35-7.45)
Adult volume of blood
Male: 5-6L
Female 4-5L
What type of veins do you want for withdrawing blood
Superficial veins:
-easier to locate
Why do we withdraw blood from veins and not arteries
-vein walls are thinner and easier to penetrate
-blood pressure is lower in venous system
-puncture seals quickly
Two components of blood
Plasma: straw coloured, 92% water 8% solutes (55% whole blood)
Formed elements
Buffy coat
Leukocytes and platelets (<1% of whole blood)
What % of erythrocytes make up whole blood
45%
Serum
Fluid left after plasma coagulates and clotting proteins have been removed
Where are plasma proteins found and produced
Found in the blood produced mostly by the liver
Name 3 plasma proteins
-Albumins (60%)
-globulins (36%)
-fibrogens (4%)
Albumins
Transport proteins for hormones and fatty acids
-has major impact on blood thickness and osmolarity which then impacts blood volume, bp, blood flow
Globulins
1) antibodies (immunoglobulins) that bind to foreign substances and pathogens for immune response
2) transport globulins that transport some hormones, metal ions, lipids, some lipid soluble vitamins
Fibrogens
Plasma protein for blood clotting
Other components to plasma
-electrolytes
-nutrients
-enzymes
-gases
-hormones
-waste products
Hematopoiesis
Production of the blood, especially formed elements
Where do formed elements and lymphocytes get produced
-red bone marrow produces all 7 types of formed elements
-lymphocytes can also be produced in lymphoid tissues
What is the originating cell in hematopoiesis
Hematopoietic stem cell (HSC) or/ hemocytoblast
Two main functions of erythrocytes
1) pick up O2 from lungs and deliver it to tissues
2) pick up C02 from tissues and unload it in the lungs
True or false
Erythrocytes lack most organelles except for the exoskeleton
True
The biconcave shape of RBC’s allows for what functions:
-allows for rapid exchange of oxygen as cells pass through capillaries of lungs or peripheral tissue
-allows RBC’s to temporarily stack to smooth their flow through narrow blood vessels
-flexible membrane allows them to deform without rupturing while squeezing through narrow or tight capillaries
Hematocrit (Hct)
% of blood volume occupied by RBC’s
What is normal Hct
Female: 42%
Male: 46%
True or false
Testosterone stimulates RBC production meanwhile estrogen does not
True
Anemia
-reduction of O2 carrying capacity of RBC
-decrease in hematocrit is present
-different types:
-decrease in absolute number of RBC’s
-insufficient hemoglobin
Polycythemia
-increase in hematocrit (>65%)
—abnormal increase in RBC production or can be due to dehydration
-blood becomes too thick which is harder for heart to pump, increases bp and increases risk for stroke or heart attacks
Hemoglobin (Hb)
Oxygen carrying pigment molecule that gives blood its red colour
True or false
Hb is a protein with 4 identical chains
True
What is the chain of Hb made up of
Each chain of Hb is made up of a polypeptide chain called globin
A chemical group called____, which contains an ___ molecule that can bind to an oxygen molecule
Heme, iron
How many oxygen molecules can a hemoglobin molecule carry
4 oxygen molecules
How many hemoglobin’s does every RBC contain
Approximately 280 million (each RBC can carry over 1 billion O2 molecules)
When do hemoglobin’s become loaded with oxygen
When RBC’s travel through the lungs
When is Hb red?
When oxygen is bound
When is Hb blue?
When it does not have a full oxygen load
Why does blood always appear red
Due to the oxygen in the air
Cyanosis
Blue colouration of mucous membrane, lips, nail beds
-seen when Hb is not carrying enough oxygen
True or false
Hb has some binding sites for C02
True
Erythropoiesis
Erythrocyte production
How long does it take for erythropoiesis to take place
3-5 days
4 major steps involved in Erythropoiesis
1) reduction in cell size
2)increase in cell number
3) synthesis of Hb
4) loss of nucleus and other organelles
Iron metabolism
1) stomach acid converts Fe3+ to Fe2+
2) Fe2+ binds to gastroferritin and is transported to small intestine
3) Fe2+ is released for absorption in bloodstream and binds to transferrin that carries the iron through the blood stream
4) some Fe2+ is stored in the liver
5) Fe2+ will also bind to apoferritin in the liver and will be stored as ferritin
6) iron will be diffused to organs for production of:
Hb
Myoglobin
Hypoxemia
Inadequate O2 transport
Causes of hypoxemia
-blood loss
-high altitude
-increase in bodies consumption of oxygen
-emphysema
Correction of hypoxemia by a negative feedback loop
1) hypoxemia
2) sensed by liver and kidneys
3)secretion of erythropoietin
4) stimulation of red bone marrow
5) increased RBC production and count
Life and death of RBC
1) macrophages in the spleen, liver, red bone marrow phagoctize old RBC’s
2) hemoglobin separates into heme and globin
3) heme is broken down to iron nd biliverdin
4) iron binds to transferrin
5) biliverdin is converted to bilirubin
6) bilirubin is secreted into bile and converted to urobilinogen in feces
Stercobilin
Brown pigment in feces
Transferrin
Transport protein
Ferritin
Storage protein
Jaundice
Condition which develops if bile ducts are blocked or liver cannot process bilirubin
Is sickle cell disease an inherited condition
Yes
Sickle cell disease
Abnormally shaped RBCs due to gene that codes Hb production
-defective Hb (HbS)
-HbS doesn’t bind to oxygen well and causes shape of RBCs to change
-Abnormal RBCs clump together and can get stuck in small blood vessels causing pain and potentially organ failure
How is ABO blood type determined
By the presence or absence of specific surface antigens attached to the RBC plasma membrane
What are the surface antigens
Glycolipids- membrane phospholipids with short carbohydrate chains bonded to them
What antigen is displayed in Type A blood
Antigen A
What antigen is displayed in type B blood
Antigen B
What antigen is displayed in type AB blood
Both antigen A and antigen B
What antigen is displayed in Type O blood
Neither antigen A or antigen B
Agglutination of RBC
Occurs when plasma antibodies bind to the antigens and link RBCs together forming antibody antigen complex
Why do we have the antibodies that we do
We have the antibodies for the antigens that are not present on our own RBC
How is Rh blood type determined
Based on the presence or absence of the Rh antigen (D antigen)
Cross reaction
Transfusion of blood from someone with an incompatible blood group
Effects of a mismatched transfusion
1) distribution of oxygen carrying capacity
2) agglutinated cells block small blood vessels
3)macrophages destro agglutinated RBCs to to immune response releasing large amounts of Hb
5 types of leukocytes
Neutrophils (most common)
Lymphocytes
Monocytes
Eosinophils
Basophils (least common)
Describe WBC
Much larger than RBC,
No hemoglobin,
Characterized based on presence or absence of granules when stained, found mostly in connective tissue and lymphatic organs,
only small number found in blood
Characteristics of all WBC’s
1) emigration via diapedesis
2) ameboid movement
3) positive chemotaxis
Granulocytes
Clearly visible granules in cytoplasm
-neutrophil
-eosinophil
-basophils
Agranulocytes
- unvisible granules
-monocytes
-lymphocytes
Leukopoiesis
WBC production
Platelets
-irregular shaped cell fragments from large cells in bone marrow (megakaryocytes)
-forms platelet plug and promotes clotting in positive feedback loop when blood vessels are damaged
-stains dark
Leukemia
-excessive number of one type of WBC due to mutation and loss of growth control
-cells are often immature
4 types of leukaemia
Chronic vs acute
Lymphocytic vs myeloid
Leukopenia
-decrease in number of WBC
- occurs from prolonged stress, infections, bone marrow depression
Leukocytosis
-high wbc count
- due to inflammation, allergies, infection
