Exam 2: Blood, lymphatic, and immune system Flashcards
What are the components of blood
plasma (liquid fraction)
(make up 55-65%)
formed elements
(make up 35-45%)
what are the different formed elements in blood
Erythrocytes (Red Blood Cells)
Leukocytes (White Blood Cells)
Thrombocytes (platelets)
what are the functions of blood
-Transport of: gasses, nutrients, regulatory molecules (hormones, enzymes, immune molecules)
-pH balance
-extracellular fluid volume
-body temperature regulation
Describe Plasma
-makes up 55-65% of blood
-mostly water
-colloid (liquid that contains suspended substances)
what are the proteins suspended in plasma colloid
-Albumin (most common)
-Globulins
-Fibrinogen
what is the function of albumin
most common plasma colloid protein:
-regulates: water balance between tissues and blood; osmotic pressure
-Transport of: hormones (T3 & T4) & other molecules
What is the function of globulins
Transport of: hormones (E2, CORT) and other molecules
what is the function of fibrinogen
clotting
What differentiates serum from plasma
2 definitions of plasma:
-referring to blood as whole
-when in clinical setting
definition is based on research/clinical collection technique
how is serum found
-let blood clot in test tube, then centrifuge sample
-liquid fraction (lighter material on top)=SERUM
-Does not contain clotting factors (@ bottom of tube)
how is plasma found
-blood collected in tube w/ anticoagulant (limits clotting), then centrifuged
-liquid fraction=plasma
-Contains clotting factors
Describe the formed elements of blood
Red blood cells/erythrocytes
-O2 transport
White blood cells/leukocytes
-involved with immune function
Platelets/thrombocytes
-cell fragments
-necessary for clot formation
what are the two groups of WBCs (leukocytes)
Granulocytes
Agranulocytes
which WBCs are considered granulocytes
-Neutrophils (most common WBC, 1st responder)
-Eosinophils
-Basophils
which WBCs are considered agranulocytes
-lymphocytes
-monocytes
What do all WBCs have in common
-All are highly motile ( move a lot)
-chemotaxis (movement to a chemical signal) toward injury/foreign material
chemo=chemical taxis=movement
Describe the process of WBC chemotaxis
Chemotaxis is movement of WBCs between circulation & tissue
Occurs in response to:
-toxins
-chemicals released from damaged/infected tissue
what occurs during WBC chemotaxis
Inflammation:
-vasodilation (histamines)
-increased capillary permeability
-neutrophil & macrophage accumulation
what is an effect of inflammation from WBC chemotaxis
Pus=dead WBCs, bacteria, cell debris
-this is leftover from inflammation
Describe Neutrophils
Most common WBC:
(makes up 60-70% of all WBCs)
-have multilobed nuclei
-first responders to infections
-phagocytize (engulf) bacteria, antigen antibody complexes, & other foreign bodies
Describe Eosinophils
Less common WBC
(makes up 2-4% of all WBCs)
- Defense against parasites
-Ex. malaria, blood worms, etc.
-Attach to parasite & release chemicals to kill it
*NO phagocytosis - Regulation of inflammatory response
-Aggregate in tissues during allergic reaction
-Destroy inflammatory chemicals, prevent spread of allergic inflammation
Describe basophils
Rare WBC
(make up 0.5-1% of all WBCs)
-Proliferate (increase) during allergic reactions
-Release heparin (anticoagulant)
-Release histamines
*vasodilation, itching, swelling
Describe lymphocytes
fairly common WBC
(make up 20-25% of all WBCs)
-B lymphocytes
*differentiate into plasma cells (responsible for antibody production) or memory cells (responsible for immunological memory)
-T lymphocytes
*cytotoxic T cells: destroy tumor & virus infected cells
*Helper T cells: activate B cells & cytotoxic T cells
-Natural Killer (NK) cells: destroy tumor & virus infected cells
Describe monocytes
Less common WBC
(makes up 3-8% of all WBCs)
-when they leave blood circulation they are called macrophages
*phagocytize bacteria, debris, etc.
*stimulate chemotaxis of other cells
Describe Erythrocytes (Red Blood Cells)
-Primary function: Oxygen & Carbon dioxide transport
-Anucleated (no nucleus) & biconcave
*increases surface area, creates more space for hemoglobin
*can fold & pass through small capillaries to bring O2 to tissues
What is hemoglobin
a protein with four units found on RBCs
what makes up each subunit of hemoglobin
globin (polypeptide) bound to heme
define heme
red pigment molecule, contains one iron atom
REVIEW ADULT HEMOGLOBIN STRUCTURE IMAGE
what binds to heme at the iron in the center of heme
Oxygen
How many O2 can each adult hemoglobin molecule carry
up to 4 O2 molecules
what other element does hemoglobin transport
CO2 (attaches to globin instead of the iron in heme)
what are the major types of hemoglobin
embryonic
fetal
adult
what differentiates the different types of hemoglobin
the different types/structures of globins
when is embryonic hemoglobin made
at 3 weeks to 3 months of pregnancy
when is fetal hemoglobin made
at 3 months of pregnancy until birth
when is adult hemoglobin made
takes about 2 years to fully transition from fetal to adult hemoglobin
what makes embryonic and fetal hemoglobin unique from adult hemoglobin
These kinds have a high affinity (attraction) for O2
*Beneficial BC the blood coming to fetus from mother’s placenta isn’t a lot, so affinity allows for more O2 to get to fetus easier
Describe Sickle Cell disease
Abnormality of hemoglobin gene
-irregular RBC shape (crescent instead of biconcave)
-cells block blood flow or break
-reduced oxygen delivery to tissues
*sickle cell carries some protection from plasmodium parasites (malaria)
Describe anemia
RBC deficiency
Occurs due to:
-blood loss
*chronic bleeding or Menstruation
-Iron deficiency
-Vitamin B12 and folate deficiency
-Sickle Cell Anemia
*reduced O2 delivery due to sickling of RBCs
Describe Polycythemia
Excess RBCs
Occurs due to:
-Hypoxia
*compensatory polycythemia=Low O2 content due to high altitude
-Polycythemia Vera—cancer of blood
*Rare blood disorder, over production of blood cells (Esp. RBCs)
*Thickening of blood, so poor blood flow
Through what process are the formed elements of the blood formed
hematopoiesis
Define hematopoiesis
Blood cell production
Where does fetal hematopoiesis take place
occurs in:
-yolk sac
-liver
-thymus
-spleen
-lymph nodes
-Red marrow
Where does post natal/adult hematopoiesis take place
Occurs mostly in:
-Red marrow
Describe the process of hematopoiesis
-Hemocytoblasts
*stem cell origin of all formed elements
*blood cell formation
-Hemocytoblast division
*one daughter cell remains as hemocytoblast other becomes either:
- myeloid stem cell: develops in RBCs, platelets, & most WBCs
- Lymphoid stem cell: develops into lymphocytes
Through what process are Erythrocytes (RBCs) produced
Erythropoiesis
Define Erythropoiesis
Specifically red blood cell production
Describe the process of Erythropoiesis
-Hemocytoblast–>
-Myeloid Stem Cell–>
-Proerythroblast
*mature over time
*produce hemoglobin
*organelles then break down
*nucleus condenses & gets ejected from cell–>
-Reticulocyte (immature RBC)
*have reticulum (organelle fragments)
*released into circulation
*reticulum breaks down–>
-Mature into RBCs within ~2 days
What is the process of erythropoiesis regulated by
erythropoietin (EPO)
Describe Erythropoietin (EPO)
-hormone produced by kidneys
-stimulates red marrow to produce RBCs
-stimulus for release=low blood oxygen levels
*Blood doping is when athletes inject themselves with EPO to increase oxygen carrying/delivering abilities for better performance (This is illegal!)
What is hemostasis
The stoppage of bleeding via:
1. Vascular spasm
2. Platelet plug formation
3. Coagulation
Define vascular spasm stage of hemostasis
-immediate, temporary constriction of blood vessel
-damage to vessels activates reflexes
-stops blood flow
Define the platelet plug formation stage of hemostasis
-accumulation of platelets to seal breaks in vessel
-platelet adhesion
*Von Willebrand factor (vWF) helps platelets to bind to damaged vessel
*platelet activation
-Platelet release reaction
*Release of ADP & thromboxanes by activated platelets
*leads to additional platelet activation
(ends up being a positive feedback loop)
-Platelet aggregation
*platelet shape change, fibrinogen bridges platelets, forming plug
Define the coagulation stage of hemostasis
-formation of a clot
-network of fibrin traps blood cells, platelets, and fluid
-clot formation depends on clotting factors (proteins in plasma)
-Activation of clotting factors:
*extrinsic pathway: initiated by chemicals outside the blood
*intrinsic pathway: initiated by chemicals within the blood
*conversion of fibrinogen (from platelet plug) to fibrin (what makes up the clot)
REVIEW COAGULATION PATHWAY
What is ABO blood type based on
which antigen is present on surface of RBCs
what are located in plasma and associated with each blood group
antibodies
why are antigens important
for matching blood donors
What happens if blood is not compatible during a transfusion
Bad antigen and antibody reaction could result in:
agglutination (clumping)
*Rapid hemolysis, coagulation, shock, renal failure, or death
REVIEW ABO BLOOD GROUP TABLE TO KNOW THE ANTIGENS & ANTIBODIES as well as who can donate to who
What is the Rh blood group
Based on D antigen on RBCs
+ if present, - if absent
*Genetically determined
*first studied in rhesus monkeys
What is the Rh blood group
Based on D antigen on RBCs
+ if present, - if absent
*Genetically determined
*first studied in rhesus monkeys
In what scenarios can Rh antigen develop if Rh negative person is exposed to Rh positive blood
-through blood transfusion
-Blood crossing placenta from mother to fetus (& vice versa)
What is hemolytic disease of a newborn
Potential problem if mother is Rh negative and fetus is Rh positive
-if fetal blood leaks through placenta, mother will produce antibodies against Rh antigen
-if these antibodies cross back to fetus–>agglutination and hemolysis can occur
-Prevention of this done through blocking mother’s sensitization
What is an important factor of the lymphatic system
Lymph
what is lymph
fluid within the lymphatic system that stores WBCs
what are functions of the lymphatic system
-body fluid homeostasis
*between tissues and circulation
-fat absorption and transport
-filtration and removal of infectious agents
What is the lymphatic vessels pathway
-lymphatic capillaries (small)
*excess fluid passes through tissue spaces & enters capillaries to become lymph
-lymphatic vessels
*movement of lymph by contraction of skeletal muscle and one way valves
-lymph nodes
*filter lymph
-lymphatic trunks
*connect to large thoracic veins or lymphatic ducts that connect to veins
what is a thoracic duct
largest lymphatic vessel that drains lymph from right and left sides of body
what percentage of arterial blood enters lymphatic capillaries
10%
-returns through lymphatic system
What cells and structural components make up lymphatic tissue
-mostly consists of lymphocytes
-Also includes: macrophages & dendritic cells
Structural components:
-reticulocytes: produce reticular fibers
-fiber network has immune cells attached
*traps microorganisms and other particles & filters lymph
Describe Diffuse lymphatic tissue
-has dispersed immune cells
-no clear boundaries
Describe nodules of lymphatic tissue
-Are slightly denser
-contain the tonsils:
*palatine tonsils
*pharyngeal tonsils
*lingual tonsils
~all of these possess capture cells to alert B & T cells of a pathogen
Describe Lymph nodes of lymphatic tissue
-Superficial vs. deep
*capsule: dense regular connective tissue —->extends inward to form
*Trabeculae
Lymph nodes are only structures that filter lymph
Describe the spleen
-The largest lymphoid organ
*can enlarge with infection & reduces size after
-Arteries and veins supply and drain internal compartments
-Have pulps:
*Red pulp (makes up 75% of spleen)-associated with veins
*white pulp (makes up 25% of spleen)-associated with arteries
what are the functions of the spleen
-Destroys defective RBCs
-responds to foreign substances
-acts as blood reservoir
what is a splenectomy
surgical removal of spleen
Occurs if:
-spleen experiences severe enough rupture
IF splenectomy is done:
-other lymphatic organs & liver must compensate for loss of spleen
Describe the Thymus
-Bilobed structure, superior to heart
-lobes divided into lobules
-made of epithelial cells (instead of reticular fibers)
what occurs in the Thymus
T-cell maturation
Describe components of T-cell maturation
positive selection:
-T-cells that bind appropriately to Major histocompatibility complex (MHC) protein=WILL SURVIVE
Negative Selection:
-T-cells that bind too strongly to Major histocompatibility complex (MHC) protein=DESTROYED
*this minimizes the risk of autoimmune response=the body attacking itself
What are some chemical mediators of the lymphatic and immune system
-Cytokines
-Early induced proteins
-Complement system
What are cytokines
a signaling molecule responsible for induction of chemotaxis
What proteins are considered early induced proteins
-Interferons
-Mannose-binding protein & C-reactive protein
-Complement System
Describe Interferons
-Secreted by virus infected cells
*induce cells/adjacent cells to produce antiviral proteins to inhibit viral replication
Describe Mannose-binding protein & C-reactive protein
-Bind to bacterial cell wall, recognized by phagocytic cells
*opsonization=tagging a pathogen for phagocytosis occurs
Describe complement system
-complements ability of phagocytic cells and antibodies to destroy invaders
Describe Major Histocompatibility Complex (MHC) proteins
MHC Class I Proteins:
-found on every nucleated cell surface
-presentation of antigen
-recognition & destruction of infected cell by cytotoxic T-cells
MHC Class II Proteins:
-on antigen presenting cells (APCs), like dendritic cells & macrophages
-APCs take in & process antigen, present fragment at surface, bound to MHC Class II molecule
-allows for recognition by T-cells
What is barrier immunity
bodies first line of defense
-bypassing barriers including:
*skin
*mucus, etc.
what are the 2 major components of the immune system
- innate immune response
- adaptive immune response
Briefly describe the innate immune response
-fast acting defense mechanism
-NOT specific to certain pathogens
Briefly describe the adaptive immune response
-slower & more complex
-pathogen must be processed and recognized
-provides defense against specific pathogens through:
*Humoral Immunity &
*Cell-mediated immunity
Briefly describe Humoral immunity
antibody production
Briefly describe Cell-mediated immunity
T-cells kill cells infected by pathogen
Describe the different components of the innate immune response
Fast-acting, non specific response:
-Phagocytosis of foreign materials
-Pattern recognition receptors (PRR)
-Surface molecules on pathogens bind to PRRs on phagocytic cell membranes
-Innate response against viral infections
-Inflammatory Response
What are pattern recognition receptors (PRRs) and what do they do
(Innate Immune response)
-found on surfaces of WBCs (neutrophils, macrophages, & others)
-Recognizes characteristics of pathogens or damage
-small number of receptors to recognize a wide variety of pathogens
what happens when surface molecules on pathogens bind to PRRs on phagocytic cell membranes
(Innate immune response)
-engulfing of pathogen
-lysosomes that contain hydrogen peroxide, etc. digest pathogens
Describe the innate response against viral infections
(innate immune response)
-natural killer (NK) cells provide early response against viral infections
*Induce apoptosis (cell death) before viral replication can occur, secretion of interferons
-Recognition: find and attack cells with low concentration of MHC Class I proteins on surface
Describe the purpose and signs of the inflammatory response
(innate immune response)
-purpose: attract immune cells, slow spread of infection, promote tissue repair
-Signs: Redness, swelling, pain, heat
Describe the adaptive immune response
-slower & complex, but provides specific protection
-response is faster at second infection
*primary vs. secondary response & immunological memory
-self-recognition
*distinction between self- & non-self anitgens
Describe the components of cell-mediated immunity
(adaptive immune response)
-T-cells mature in thymus
*Recognize antigens with 2 chain protein receptor which is done by:
-Antigen Processing & presentation
*T-cells only recognize antigens on surface of antigen presenting cells
-Antigen-presenting cells: dendritic cells
*antigens internalized & fragmented
*MHC molecules present fragments at cell surface
*T-Cell binding and recognition occurs, which allows for
-T-cell activation
*Helper T-cells
*Cytotoxic T-cells
*regulatory T-cells
what does CD mean
Cluster of differentiation
*found on T-cell surface, act as identifiers
Function of Helper T-cells
CD4 molecule
-secrete cytokines to activate or enhance other cells or functions
Function of Cytotoxic T-cells
CD8 molecule
-Kills infected cells by inducing apoptosis (cell death)
Function of Regulatory T-cells
CD4 & CD24 molecules
-Recent discovery, poorly understood
-Suppress other T-cell responses (end of response)
Describe Humoral immunity
(Adaptive immune response)
-Clonal expansion
-B-cells formed in Bone marrow
-Recognition of antigen
*B-cell binds to antigen
*proliferation & activation of of B-cell clones
-plasma cell formation: produces antibodies specific to antigen
-Memory B-cell formation: Rapid secondary response at subsequent infection
*differentiation into plasma cells
*Rapid production of Specific antibodies
-Antibodies (immunoglobulins)
*paratope binding to epitope of antigen (lock & key precision)
Describe antibody functions
-neutralization: attacking cell is ineffective
-agglutination: clumping, targets for phagocytosis
-precipitation: force precipitates out of solution, targets for phagocytosis
-complement activation: encourage complement cascade & cell lysis (breakdown)
How to put humoral and cell-mediated together to get adaptive immunity
Primary response (cell-mediated)=slow antibody production
Secondary response (humoral)=fast antibody production
Describe the components of Natural immunological memory
-natural passive immunity:
antibodies passed from mother to child
-natural active immunity:
antibodies produced in response to illness
Describe the components of Artificial immunological memory
-artificial passive immunity: pre-formed antibodies introduced by injection or transfusion
-artificial active immunity: antibodies produced in response to vaccine
Describe the typical vaccine mechanism of action
-Injection of live or killed pathogen (typically into deltoid bc close to lymph node)
-antigen-presenting cell takes in and fragments pathogen
-migration to lymph node
-MHC presents antigen to T-cells
-Information conveyed to B-cells
*antibodies and memory B-cells made against that specific pathogen produced
Why are vaccines recommended even for healthy people
to raise herd immunity!
