Ch 9 Part 2 Flashcards
Components of Blood
Plasma (55% by volume) - liquid portion. Contains electrolytes, buffers (pH 7.4), sugars, blood proteins, lipoproteins, CO2, O2, and waste.
Formed elements - cellular components.
Principle Sugar in Blood
Glucose
Blood Proteins
Most made in liver.
Include Albumin; immunoglobulins (antibodies); fibrinogen, lipoproteins.
Oncotic Pressure
Osmotic pressure in the capillaries due to plasma proteins ie. alubmin
Fibrinogen
Essential for blood clotting
Lipoproteins
fats, cholesterol, and carrier proteins
Metabolic waste products
Principle = urea
bilirubin - a breakdown product of heme
Hematocrit
Volume of blood occupied by erythrocytes
Males: 40 - 45%
Females: 35 - 40%
White Blood Cells
Leukocytes (and platelets) make up about 1%.
Origin of all formed elements in blood
Bone Marrow Stem cells
Serum
Produced during blood clotting. Same as plasma, but lacks all proteins involved in clotting.
Erythrocytes
Erythropoietin (in Kidney) - stimulates RBC production in bone marrow.
Old erythrocytes are eaten by phagocytes in the spleen and liver.
No nucleus or organelles (including mitochondria).
Requires ATP synthesis, but produces ATP through glycolysis.
Flat biconcave shape helps in transport of O2
Blood Typing
Most important antigens:
ABO blood group and Rh blood group
Rhesus Factor
Classic dominant pattern. RR or Rr leads to expression.
Expression indicated by (+/-)
Hemolytic Disease of the newborn
Result of Rh- mom with Rh+ babies.
First baby is typically fine; however, during birth some of baby Rh+ can enter mother, resulting in the development of anti-Rh antibodies. A process known as SENSITIZATION.
Puts future babies at risk as Rh+ antibodies can cross the placental barrier and cross clumping of the blood in a baby.
Typically resolved by injecting mother with anti-Rh antibodies can assist.
Transfusion reaction
Destruction of red blood cells carrying incorrect antigens
AB+ and O-
AB+ is universal recipient as produces non of the antibodies.
O- produce none of the antigens that another body could react to, so considered universal donor.
**Although O- can sometimes produce anti-A and anti-B antibodies so ideally blood types are matched perfectly.
Leukocytes
White blood cells.
Destroy infection and dispose of waste.
Large cells with all normal eukaryotic features.
Macrophages/neutrophils - can move by amoebid motility.
Some exhibit chemotaxis.
Types of Leukocytes
Monocyte
Lymphocyte
Granulocyte
Monocyte
MACROPHAGE - phagocytose debris and microorganisms; amoebid motility; chemotaxis
Lymphocyte
B - cell: mature into plasma cell and produce anti-bodies
T - cell: kill virus infected cells, tumor cells, reject tissue grafts; control immune response
Granulocytes
Neutrophil: Phagocytose bacteria resulting in pus, amoebid motility and chemotaxis.
Eosinophil: destroy parasites; allergic reactions
Basophil: store and release histamine; allergic reaction
Platlets
No nuclei and limited life span.
Result from fragmentation of large bone marrow cells, MEGAKARYOCYTES (come from same cells that produce RBCs and WBCs)
Platelet Plug
Formed by platelets to stop bleeding
Hemostasis
Mechanism for body to stop bleeding:
Platelets and Fibrin
Fibrin
Threadlike protein that forms mesh to hold platelets together.
When Fibrin dries it becomes a scab.
Fibrinogen —-> Fibrin (mediated by thrombin). Ca and Vitamin K required for many of proteins here.
Thrombus
A blood clot. A scab floating in the blood stream.
Hemophilia
X-linked recessive group of diseases that reflects faults in the hemostatic system.
Oxygen Circulation
O2 is too hydrophobic to dissolve in plasma in significant quantities, requires RBC.
Hb (Hemoglobin)
Composed of 4 polypeptide subunits.
Each subunit has one molecule of heme, which has single atom of iron.
Each Hb can carry 4 molecules of Oxygen.
Binds Oxygen cooperatively. Tense state when no O2 bound. Relaxed after first O2 binds –> increases likelihood that other subunits will bind O2.
At tissues, Hb has low affinity for O2. At lungs has high affinity.
Tense Configuration of Hb
Stabilized by decreased pH;
Increased PCO2
Increased Temperature
*Known as the Bohr Effect, and these conditions perfectly characterize the state of active tissue.
%Saturation
(#O2 molecules bound/#O2 binding sites) *100
Relaxed hemoglobin always has higher %saturation
Represented in the O2-hemoglobin dissociation curve. Characteristic Sigmoidal shape is typical of cooperative enzymes.
*Note, fetal Hb is left shifted on this curve as has to “steal” O2 from the mom.
CO2 Transport in blood
- As Bicarbonate and a proton which is highly soluble (73%):
CO2 + H2O <-> H2CO3 <-> HCO3- + H+
Catalyzed by carbonic anhydrase
- Binding of CO2 to hemoglobin (20%). Not at O2 sites, but stabilizes tense hemoglobin state.
- CO2 dissolved in blood (7%)
Intercellular Clefts
Spaces between endothelial cells in capillary walls that facilitate improved exchange of NUTRIENTS, WASTE, WBCs.
Note O2 and CO2 can simply pass through cells by diffusion.
Nutrients transported by blood through capillaries into tissue.
Amino Acids, Glucose, Lipids.
Hepatic portal vein transports Amino acids and glucose from intestine to liver for storage.
Fats are absorbed from intestine in CHYLOMICRONS (lipoprotein) that can enter lymphatic vessels in intestinal wall called LACTEALS. Lacteals drain into larger lymphatics that drain into a large vein in the neck. ie. bypass the hepatic-portal system.
Chylomicrons are eventually transported to the liver and made into another lipoprotein and then released to move to adipocytes. When needed they are hydrolyzed to be free fatty acids that are released into blood stream.
Lipemia
Blood appears milky after eating a fatty meal as Chylomicrons in blood.
“lipids flowing in blood”
Waste
Passed into blood stream, then to liver, converted into bile in gut and excreted as feces. Other waste is secreted directly by kidneys.
White Blood Cells
Only Neutrophils and Macrophages can move into surrounding tissues using amoebid movement.
Water and Capillaries
Water flows out of capillaries efficiently:
- High hydrostatic pressure from the heart
- High osmolarity of surrounding tissue. (System counterbalances this by giving plasma a high osmolarity, oncotic pressure)
Note that water tends to flow out of capillaries at start (high hydrostatic pressure; high osmolarity of surrounding tissue); and into capillaries at end (plasma more dense due to loss of water; lower hydrostatic pressure).
Inflammation reflects a breakdown of this system though. Capillaries swell, intercellular clefts enlarge, more WBCs can leave blood, decreasing osmolarity of blood plasma.
Edema
water in tissue or swelling
Lymphatic System Overview
One-way flow system. Function to retrieve WBC and proteins from body and return to circulation.
Lymphatic capillaries –> Lymphatic vessels (valves) –> Lymphatic ducts (smooth muscle) –> Thoracic Duct –> Empties into large vein
Fluid is termed Lymph, and is filtered by lymph nodes.
Types of immunity
innate; humoral, and cell-mediated
Innate Immunity
General non-specific immunity to invaders.
Examples:
1. Skin
2. Tears, saliva, blood - contain lysozymes
3. Stomach acidity
4. Macrophages and Neutrophils
5. Complement System - ~20 proteins that can bind surface of foreign cells and lead to destruction
Humoral Immunity
Specific protection by antibodies (Ab) or Immunglobulins (Ig)
All antibodies are composed of two copies of two different polypeptides joined by disulfide bonds: LIGHT CHAIN and HEAVY CHAIN
Additionally, contains a CONSTANT region and a VARIABLE region (responsible for detecting foreign bodies, forms 3-D cleft specific to antigens).
Immunoglobulins differentiated by constant regions: IgG, IgA, IgM, IgD, IgE.
Most antibodies circulating in plasma are IgG.
Note that antibodies can only detect antigen surface proteins. Not cytoplasmic ones.
IgM
Located: Blood and B-cell surface
Function: initial immune response; pentameric in blood; monomeric on B cell as antigen receptor.
IgG
Location: Blood
Function: Ongoing immune response; can cross placental barrier
IgD
Location: B-cell surface
Functions: Antigen receptor on B-cell; with IgM
IgA
Location: Secretions (Saliva, mucus, tears, breast milk)
Functions: protects newborns; dimeric structure
IgE
Location: blood
Function: Allergic Reactions
Antigen
Molecule that an antibody binds
Epitope
Small site that an antibody recognizes on a much larger antigen. There can be multiples on each antigen.
Smaller molecules don’t tend to get their own antibody. Rather, antibodies form to detect the smaller molecules (HAPTEN) when it to a larger antigenic molecule (CARRIER)
Antibody binding Antigen effect
Can:
- Directly innactivate the antigen
- Can induce phagocytosis
- Can activate the complement system of innate immune response.
Antibody Production
Formed by Lymphocyte, B Cells
B Cells are derived from bone marrow stem cells.
Genes that encode antibodies are formed from small fragments by recombination. therefore many B cells have different variable gene regions, resulting in unique combinations of antibodies on surface. This means that B and T Cells are an exception to the rule that all cells contain the same genome.
Immature B cells have different antibodies on surface. If bind Antigen that is recognized. B Cell divides into two types: Plasma cells and memory cells.r
Plasma Cells
Daughter of B-cells that actively produce and release antibody proteins into plasma.
Memory Cells
Daughter of B-cells that remains dormant after activation of an immature B-cell.
If encounters antigen will rapidly start to produce antibodies.
Clonal selection
Selection for cells with a specific antigen binding capacity.
Primary Immune Response
First time that someone experiences an antigen during infection.
Production of antibodies can take up to a week, meaning symptoms are prevalent.
Secondary Immune response
Much faster than primary.
Result of memory cells.
Cell Mediated Immunity
Two types of T-Cells:
T helpers (CD4); activates B Cells, T Killer Cells, and other immunity cells - but can only do this if antigen is presented on MHC II proteins by B Cells or macrophages. Controller of immune response. Also hosts HIV.
T Killers (cytotoxic T cells, CD8 cells)
Lymphokines and interleukins
Hormones released by T helper cells to coordinate the immune response.
T-Killer Cell
Attacks:
- Virus-infected host cells
- Cancer cells
- Foreign cells ex. skin graft
MHC
Major Histocompatibility Complex. Important cell surface proteins on T cells.
All our cells express MHC proteins so that T Cells can inspect them.
MHC I - on all nucleated cells in the body. Pick up peptides from inside cell so T Cells can inspect.
MHC II - only expressed on Antigen-presenting cells (APCs) which includes macrophages and B Cells. Phagocytize cells, chop up, and display for T helper cells to recognize – which will activate B Cells and T killer cells.
Full activation of T Cells requires
T Cell binding to both antigen and the MHC molecule.
Bone Marrow Stem Cell
Gives rise to blood cells
Spleen
Filters blood and is a site of immune cell interaction.
Destroys old RBCs.
Thymus
Site of T-cell maturation.
Shrinks in size in adult as majority of maturation of immune system occurs during childhood.
Tonsils
Masses of Lymphatic tissue that catch pathogens entering the body. (can be removed)
Appendix
Found near beginning of large intestine. Acts similarly to tonsils. (Can be removed)
Autoimmunity
Production of different B and T cells is random and so some of them can become specific to normal cells in the body.
In Bone Marrow:
For B cells that bind normal cell surface proteins, apoptosis is induced. For B cells that bind Soluble proteins, they become unresponsive or ANERGIC.
Only B cells that don’t bind normal cells are released into the blood stream.
In Thymus or Lymphnodes:
T cells that bind surface proteins undergo apoptosis, and because not all cell types exist in thymus, some become ANERGIC when bind outside in the periphery.
Autoimmune Diseases
Type I daibetes mellitus
Rheumatoid arthritis
Graves disease
myasthenia gravis
Celiac Disease
