Physiology II- Midterm 1 Flashcards
1
Q
What 3 Systems Affect Cardiovascular System?
A
- Endocrine
- Nervous
- Kidneys
2
Q
What type of organ receives the most blood and what are three examples?
A
Reconditioning organs
- Digestive
- Kidneys
- Skin
3
Q
Blood flow is adjusted by _______ according to _____.
A
reconditioning organs, metabolic needs of organs
4
Q
Which organ is least tolerant to blood flow changes?
A
brain
5
Q
Blood flow depends on ____ and ____.
A
- Pressure
2. Resistance
6
Q
Vascular resistance ____ flow rate while pressure gradient ____ flow rate.
A
decreases
increases
7
Q
What is a Pressure Gradient?
A
pressure difference between beginning and end of vessel
8
Q
What is Resistance?
A
measure of opposition to flow
9
Q
What/how effects resistance?
A
- Blood viscosity (doesn’t usually change) as v increases, R increases
- Length (doesn’t change) as L increases, R increases
- Radius (most changed) as R increases R decreases
10
Q
What determines viscosity?
A
number of RBC’s
11
Q
Heart–> ____–>____–>____–>____–>____–>Heart
A
- Arteries
- Arterioles
- Capillaries
- Venules
- Veins
12
Q
2 Functions of Arteries
A
- Rapid Transit from heart to organs
2. Pressure reservoir to provide driving force
13
Q
Collagen provides _____strength, elastic provides ____ strength.
A
Tensile, elastic/stretch
14
Q
What is Blood Pressure?
A
force exerted by blood against a vessel wall that drives blood around body
15
Q
Blood Pressure Depends On…
A
- Volume
2. Compliance of vessel walls
16
Q
Arteries are ___ complient than veins
A
less
17
Q
What is systolic blood pressure?
A
- peak pressure
- exerted by ejected blood against vessel walls during cardiac systole
- around 120mmHg (“normal”)
18
Q
What is diastolic Blood Pressure?
A
- minimum pressure
- when blood is draining into vessels downstream
- around 80mmHg (“normal”)
19
Q
What is Pulse Pressure?
A
- pressure difference between systolic and diastolic pressure
- pulse we can feel close to skin
20
Q
What is Mean Arterial Pressure?
A
- MAP
- average pressure driving blood forward into tissues throughout cardiac cycle
21
Q
Muscular Arteries
A
- deliver blood to specific organs
- thick muscular media
- active in vasoconstriction
- helps regulate blood pressure
22
Q
Radius supplying individual organs can be adjusted to….. How?
A
- distribute CO among organs depending on body’s momentary needs
- dilation increases blood flow
- constriction decreases blood flow
23
Q
Arterioles
A
- major resistance vessels
- exist within organs
- resistance occurs in arterioles primarily
24
Q
What are the two resistance mechanisms?
A
- Vasoconstriction (narrowing)
2. Vasodilation (enlarging)
25
How does vasoconstriction and vasodilation effect resistance and flow?
Vasoconstriction--> decreases flow, increases resistance
| Vasodilation--> increases flow, decreases resistance
26
What is Vascular Tone?
| 2 Factors of Vascular Tone.
degree of constriction experienced by a blood vessel
1. Myogenic activity of smooth muscle
2. Sympathetic fibres continually release norepinephrine
27
What regulates flow?
| Flow is never ___ or _____.
- ANS
- nonexistent/stopped
- organ/tissue dies
28
What are intrinsic and extrinsic factors? Local ___ and ____ influences change arterial radius.
Intrinsic--> local environment
Extrinsic --> neuronal inputs
- chemical (histamine, metabolic changes)
- physical (heat, cold, stretch, stress)
29
What is Active Hyperaemia?
| What are the 4 causes?
- increase in organ blood flow associated with increased metabolic activity of an organ or tissue
1. Increases metabolic activity in organ
2. Decreased O2, increased metabolites in ISF of organ
3. Arteriolar dilation in organ
4. Increased blood flow in organ
30
What are the 7 chemical factors that cause vasodilation of arterioles?
1. decreased O2
2. Increased CO2
3. Increased Acid
4. Increased K+
5. Increased Osmolarity
6. Adenosine release
7. Prostaglandin release
31
Endothelial Cells Are...
They release ___ in response to ___.
An example is ____.
- local vasoactive mediators
- locally acting chemical messengers
- chemical changes in their environment
- NO (nitric oxide)
32
Norepinephrine and epinephrine are ___ controls. NE is a ___ and causes ___. E is a _____ or ______ and causes ____.
Extrinsic
a, vasoconstriction
b, vasodilation
a, vasoconstriction
33
Local controls can _____ sympathetic vasoconstriction.
| There is no ____ innervation to arterioles.
- override
| - parasympathetic
34
The Cardiovascular Control Centre is located in ____ and is the integrating centre for ____.
medulla of brain stem, BP regulation
35
Vasopressin and Angiotensin II control ____.
fluid balance
36
Describe a Capillary
- smallest blood vessel (single file RBCs)
- exchange site for blood and tissues
- thin walled
- small radius
- branched
- slow velocity of blood
- close to target tissues
37
Where does exchange occur in capillaries?
between endothelial cells
38
3 Typesof Capillaries and Example Locations
1. Continuous
- have tight junctions
- e.g. skin, muscles
2. Fenestrated
- more permeable
- e.g. kidneys, intestines, hormone tissues
3. Sinusoidal
- incomplete basement membrane
- e.g. liver, bone marrow, lymphoid
39
What are capillary pores?
- water-filled gaps
- at junctions between cells
- permit water-soluble
- size varies between organs
40
How do lipids and proteins exchange between capillaries and tissues?
Lipids--> pass through lipid bilayer (pass readily)
| Proteins--> vesicular transport too big to diffuse (e.g. hormones)
41
What proteins do not pass through capillaries? Why?
plasma proteins, because no mechanisms of transport
42
Two types of passive exchange
1. Passive Diffusion
| 2. Bulk Flow
43
What is Bulk Flow? What is it for?
-not metabolic (no energy exchange)
-movement of fluid from blood to ISF and back
-through capillary pores
-ultrafiltration and reabsorption
distributes ECF
44
What are the Starling forces?
| What do they influence?
1. Capillary Blood--> hydrostatic pressure
2. Plasma--> colloid osmotic pressure
3. Interstitial Fluid--> hydrostatic pressure and colloid osmotic pressure
- Bulk Flow
45
What is Hydrostatic Pressure?
force exerted by fluid pressing against a wall
46
Where does most filtration occur?
filtration=fluid out
| arterial end because pressure is higher
47
What is Colloid Osmotic Pressure?
- force opposing hydrostatic pressure
- created by plasma proteins
- does not vary across capillaries
48
If BP increases fluid moves ____ via bulk flow. If BP decreases fluid moves ___ via bulk flow.
into interstitial space, into plasma space
49
Define...
1. Lymphatic System
2. Initial Lymphatics
3. Lymph
4. Lymph Vessels
1. Networks of one way vessels allowing fluid to be returned from ISF to blood
2. Small, blind-ended, terminal vessels permeating almost every tissue
3. ISF entering a lymphatic vessel
4. convergence of initial lymphocytes that enter into venous system near entrance to RA. One way
50
4 Functions of the Lymphatic System
1. Return of Lymph
2. Defence against disease
3. Transport absorbed fat
4. Return filtered proteins
51
What is Edema, and what are its four causes?
- swelling of tissues due to accumulation of ISF
1. Decrease in concentration of plasma proteins
2. Increase in permeability of capillary wall
3. Increased venous pressure
4. Block of lymph vessels
52
Veins
- return blood to heart
- large radius and little resistance
- blood reservoir (60% of blood is in veins at any given time)
- walls are thinner
- little smooth and elastic tissue
- more collagen than elastin
53
Five Factors that Increase Venous Return
1. driving pressure around 15mmHg
- sympathetic venous vasoconstriction
- skeletal muscle activity
- respiratory activity
- effect of cardiac suction
54
What is the purpose of venous valves?
mechanically prevent back flow of deoxygenated blood
55
Three Primary Determinants of Blood Pressure
1. Cardiac Pressure
2. Total Peripheral Resistance
3. Mean Arterial Pressure
56
Mechanisms of blood pressure regulation
Baroreceptors- arterial pressure sensors (increased action potentials as MAP increases)
-e.g. carotid sinus, aortic arch
57
How does the ANS effect heart functions?
- changes cardiac output
| - changes blood vessel size (resistance to flow)
58
What does sympathetic drive regulate?
1. Arteriolar diameter (TPR)
| 2. Venular diameter (CO)
59
What does the PNS regulate?
heart rate
60
What are the steps of Baroreceptor Reflex?
1. Baroreceptors monitor BP
2. Action potentials are produced in cardioregulatory/vasomotor centres in medulla oblongata
3. Decreased parasympathetic stimulation of heart, increasing heart rate
4. Increased sympathetic stimulation increases heart rate and stroke volume
5. Increased sympathetic stimulation increases vasoconstriction
61
Describe Baroreceptor Reflex
- short-term adjustments
- occur within seconds (rapid response)
- change made by CO and TPR
- mediated by ANS
- influences HR, veins, arterioles
- if BP deviates for a few days a new set point is in place
62
What is a longterm regulator of blood pressure?
blood volume influenced by salt/water balance
63
What are the three main components of blood?
1. Erythrocytes
2. Leukocytes
3. Platelets
64
What are thrombocytes?
- platelets
- cell fragments
- used in homeostasis
- produced in bone marrow
65
What is Hematocrit?
percentage of cells that are RBCs
66
What makes of the Buffy coat after centrifuging?
platelets
67
What are the three components of Plasma?
1. water
2. proteins
3. organic molecules
68
What are the three groups of plasma proteins?
1. Albumins
- most prevalent
- colloid osmotic pressure
- bind substances
2. Globulins
- transport hormones and cholesterol
- aid in blood-clotting
- immunoglobulins (antibodies)
- inactive before input
3. Fibrinogen
- forms fibrin threads for clotting
69
Constituent of Blood:
| Function of Water
- transport medium
| - carries heat
70
Constituent of Blood:
| Functions of Electrolytes
- membrane excitability
- osmotic distribution of fluid between ECF and ICF
- buffer pH changes
71
Constituent of Blood:
| Functions of Nutrients, Wastes, Gasses, Hormones
- transported in blood
| - blood gas CO2 plays a role in acid-base balance
72
Constituents of Blood:
| Functions of Plasma Proteins
- exert osmotic pressure for distribution of ECF between vascular and interstitial compartments
- buffer pH changes
73
Blood Constituents:
| Function of Albumins
- transport many substances
| - contribute to colloid osmotic pressure
74
Blood Constituents:
| Functions of Alpha and Beta Globulins
- transport water insoluble substances
- clotting factors
- inactive precursor molecules
75
Blood Constituents:
| Functions of Gamma Globulins
-antibodies
76
Blood Constituents:
| Functions of Fibrinogen
inactive precursor for the fibrin meshwork of a clot
77
Describe Erythrocytes
- transport O2 to tissues
- remove CO2 from blood
- thin and biconcave
- large surface area
- very flexible
- no nucleus or organelles
- no DNA or RNA
- have enzymes and hemoglobin
78
Why are Erythrocytes so flexible?
they have to fit into capillaries which are smaller than they are
79
What are the two enzymes in RBCs and what do they do?
1. Glycolytic Enzymes
- anaerobic resp
- need glycolysis for ATP
2. Carbonic Anhydrase
- CO2 transport
- catalyses CO2 into HCO3-
80
Describe Hemoglobin
- Hb
- found only in RBCs
- contain pigment
- ion
- red when oxygenated
- blue when deoxygenated
- carries O2
- combines with CO2, H+ from CO2 rxn, Co, NiO2
81
What are the two components of hemoglobin and what do they do?
1. Globin
- protein
- four folded poly-peptide chains
2. Heme
- four iron groups
- each bound to one poly-peptide
82
What is Erythropoiesis?
erythrocyte production
83
Describe the production sites of erythropoiesis in each stage of life
1. Intrauterine
- yolk sac -developing liver and spleen
- bone marrow when developed
2. Childhood
- bones (RBM)
3. Adults
- sternum (RBM)
- ribs (RBM)
- ends (upper of long bone) (RBM)
84
How does the spleen contribute to erythropoiesis?
removes old RBC's from blood
85
Describe the progression of cell development in erythropoiesis
- -----------------------------BONE MARROW-----------------------------
1. Pluripotential Stem Cell
2. Erythroid
3. Normoblast
4. Reticolocyte
- -------------------------------------Blood-------------------------------------
5. Erythrocyte
86
4 Steps of Control of Erythropoiesis
1. Kidneys detect decreased O2 carrying capacity
2. kidneys secrete erythropoietin hormone
3. Erythropoiesis stimulated
4. Increased O2 carrying capacity relieves initial stimulus through negative feedback
87
Cells committed to become RBCs....
undergo proliferation and maturation causing them to lose their nucleus and organelles and gain Hb
88
What is the life span of a RBC?
120 days
89
Blood types are categorized by...
the type of antigen present on the RBCs
90
Why antigens do A, B, AB, and O blood have?
A-A on RBC, Anti-B in plasma
B-B on RBC, Anti-A in plasma
AB-A&B on RBC, none in plasma
O- none on RBC, Anti-A and Anti-B in plasma
91
What is the universal receiver and why?
AB because it has both A and B antigens on RBC and no antigens in it's plasma
92
What is the universal donor and why?
O, because it doesn't have antigens on RBC, and has both antigens in plasma
93
What is a transfusion reaction?
occurs when blood of incompatible type is given causing kidney failure
94
What is the most dangerous transfusion reaction?
AB in plasma for incoming RBCs
95
Rh Factor
- people with Rh are Rh positive
- people without Rh are Rh negative
- no naturally occurring antibodies develop against Rh factor
- Anti-Rh antibodies are only produced by Rh-negative people if exposed to Rh-positive blood (dangerous second time they are exposed)
96
Describe the process of filtering and destroying RBCs
- spleen filters and removes old RBCs
- liver metabolizes byproducts from breakdown of RBCs
- iron is recycled for new Hb
- iron is stored in ferritin in liver, spleen and small intestine
97
What is Anaemia?
- below normal O2 carrying capacity of blood
| - cab be nutritional
98
Describe Pernicious Anemia
- B12 deficiency (needed for folic acid)
- dietary
- lack intrinsic factor in stomach lining
99
Describe Aplastic Anaemia
- insufficient RBC production
| - bone marrow destruction from radiation, chemo etc.
100
Describe Renal Anaemia
kidney disease/ failure
101
Hommorrhagic Anaemia
- wound
| - menstrual flow
102
Hemolytic Anaemia
- rupture of RBC
- infections
- sickle cell disease
- fragile (destruction of deformed)
- production unable to keep up with removal
103
Primary Polycythaemia
- erythropoiesis at excessive and uncontrolled rate
| - increases viscosity of blood
104
Secondary Polycythaemia
- adaptive mechanism to help decrease O2
- occurs at high altitude
- occurs due to chronic lung disease or heart failure
105
Leukocytes
- white blood cells
- mobile units of immune system
- colourless in real life
- structure and function varies
- larger than RBCs
106
What are the three functions of Leukocytes?
1. defends against invading pathogens
2. Identifies and destroys cancer cells
3. Removes worn-out cells and tissue debris
107
What are Granulocytes? What are the three Granulocytes? Where are they produced?
cytoplasmic granules
1. Neutrophils
2. Eosinophils
3. Basophils
bone marrow
108
What are Agranulocytes? What are the two Agranulocytes? Where are they produced?
no cytoplasmic granules
1. Monocytes
- bone marrow
2. Lymphocytes
- lymphocytes already in lymphoid tissues
109
Leukopoiesis
- chemical messages from damaged or invaded tissues
| - colony-stimulating factors from endothelial cells, marrow, fibroblasts, and activated WBCs
110
What are Neutrophils?
- phagocytic specialists
| - destroy bacteria by phagocytosis by releasing bacteria-killing chemicals
111
What are the four functions of Neutrophils?
1. First defenders on scene of bacterial invasion
2. Importnat in inflammatory responses
3. Scavenge to clean up debris
4. Increased cell count may point to bacterial infection
112
What are Eosinophils?
- increase in circulating associated with allergic reactions (including asthma and hay fever) and internal parasite infestations
- attack and secrete killing substance
113
What are Basophils?
- least numerous
| - synthesize and store histamine and heparin (allergies and anti-clotting)
114
What are Monocytes?
- phagocytic
- migrate to tissue to become macrophages
- for antigen presentation, cytokine production, and cytotoxicity
- emerge from bone marrow
- circulate for day or two before settling in various areas to mature
115
What are Lymphocytes?
- B&T cells
| - immune defence against specifically programmed targets
116
B Lymphocytes
- produce antibodies
| - responsible to antibody mediated or humoral immunity
117
T Lymphocytes
- do not produce antibodies
| - destroy specific target cells by releasing chemicals punch holes in the victim cell (cell-mediated immunity)
118
Platelets
- from megacaryocytes
| - don't leave the blood
119
What is the lifespan of a monocyte?
Several months to a few years
120
What is the lifespan of a lymphocyte?
-100-300 days
121
Where can you find approximately 1/3 of all Platelets?
in blood filled-sacs in the spleen, only released by sympathetically induced splenic contraction when needed
122
What is Thrombopoietin?
a liver hormone that increases the number of megakaryocytes and more platelets/cell
-unknown mechanism
123
What is a Thrombocyte?
-cytoplasmic fragments derived from megakaryocytes
124
What is the lifespan of a platelet?
around 10 days
125
Describe and Throbocyte
- no nuclei
- have some organelles and enzymes
- have granules
- essential for blood clotting
126
What are the three secretary products in thrombocyte granules?
1. ADP
2. Serotonin
3. Epinephrine
127
What is Haemostasis?
stoppage of bleeding from broken blood vessels
128
What is the first step of Haemostasis?
Vascular Spasm
1. when blood vessel is damaged tissue secretes constriction factors
2. vessels constrict to minimize blood loss and maintain BP
3. endothelial layer becomes sticky to start clotting
129
What is the second step of Haemostasis?
Formation of Platelet Plug
1. platelets aggregate on contact with exposed collagen in damaged wall
2. platelets release thromboxane which induces platelet aggregation and arterial constriction
3. platelets release ADP causing other platelets to become sticky
4. Plug results in decreased blood loss
130
What is the third step of Haemostasis?
Blood Coagulation
| 1. blood converted into solid gel called clot or thrombus around platelet plug
131
What is the one cell absolutely required for Haemostasis?
platelets
132
Clotting factors are _____ in blood plasma as an _______.
present, inactive precursor
133
What causes a Clotting Cascade?
12 plasma proteins from liver acting as co-factors/proteolytic enzymes
134
What is the final step in a clotting cascade?
conversion of fibrinogen into a stabilized fibrin mesh
135
What triggers a clotting cascade?
1. Intrinsic pathway
| 2. Extrinsic pathway
136
Describe the Intrinsic Pathway
- all elements present in blood
- 7 steps
- factor XII (Hageman factor) is activated by coming into contact with exposed collagen in injured vessel or foreign surface
137
Describe the Extrinsic Pathway
- 4 steps
- requires contact with tissues external to the blood
- tissue thromboplastin released from traumatized tissue directly activates factor X
138
Describe Clot Retraction
-contraction of platelets shrinks fibrin mesh, squeezing fluid from the clot
139
Describe Clot Dissolution
- enzyme plasmin dissolves clot
- plasmin formed from plasminogen
- Factor XII
- plasminogen converted to plasmi
- fibrinolytic enzyme
- breaks down fibrin meshwork
140
Most ____ is bound to fibrin threads thus ___ systematic clotting.
thrombin, preventing
141
Unbound thrombin is ____.
inactivated
142
What two endothelial cells are clot controllers?
1. Nitric Oxide
| 2. Prostacydin
143
What are two types of inappropriate clotting?
1. Thrombus
| 2. Emboli
144
Describe a Thrombus
- abnormal intravascular clot attached to a vessel wall
- can eventually completely occlude the vessel
- Ischemia and tissue death downstream from the clot
145
Describe an Emboli
- freely floating clots
| can suddenly block blood flow
146
Where does a Pulmonary Embolism occur?
lungs
147
What can a Cerebral Embolism cause?
stroke
148
What are three factors that can cause a thromboembolism?
1. Endothelial cell dysfunction (atherosclerosis)
2. Imbalances in the clotting
3. Slow-moving blood from dehydration
149
How can impaired liver function affect coagulation?
reduced protein production including clotting factors
150
How can vitamin K deficiency affect coagulation?
- decreased synthesis of clotting factors
151
Define Immunity
the body's ability to resist or eliminate potentially harmful foreign materials or abnormal cells
152
Four Functions of Immunity
1. Defends against invading pathogens
2. Removes "worn-out" cells and tissue damaged by trauma
3. Identifies and destroys abnormal or mutant cells that have originated in the body
4. Mounts inappropriate immune response that lead either to allergies or to autoimmune disease
153
What are the Two Major Targets of the Immune System
1. Bacteria
| 2. Viruses
154
Describe Bacteria
- non-nucleated
- single-celled
- causes tissue damage and disease by releasing enzymes or toxins
155
Describe Viruses
- consists of either DNA or RNA enclosed by a protein coat
| - cannot carry out metabolism or reproduce without invading a host cell
156
What are two barriers that act as external defences?
1. Skin
- physical
- produce antimicrobial chemicals
2. Mucous Membrane
- sticky secretions
157
What are the three defences of the digestive system?
1. Saliva
- friendly bacteria convert nitrate into nitrite
2. Nitrite is converted into nitric oxide in the stomach which is toxic
3. Gastric juice kills other bacteria
158
What are the three defences of the respiratory system?
1 .Lymphoid tissues (tonsils, adenoids) provide protection against inhaled pathogens
2. Cilia lining pathway beat upwards and trap inspired debris in mucous
3. Alveolar macrophages scavenge air sacs of the lungs
159
Describe Neutrophils
highly mobile phagocytes that engulf and destroy unwanted materials
160
Describe Eosinophils
- secrete chemicals that fight parasites
| - involved in allergic reactions
161
Describe Basophils
- release histamine and heparin
| - involved in allergic reactions
162
Monocytes
-transformed into macrophages (tissue-bound phagocyte specialists)
163
Lymphocytes (two types and functions)
1. B-Cells
- transformed into plasma cells that secrete antibodies
2. T-Cells
- responsible for cell-mediated immunity
- mainly produced from lymphoid colonies in lymphoid tissues
164
What is a Lymphoid Tissue?
tissues that produce, store, or process lymphocytes
165
What are the eight lymphoid tissues?
1. Bone Marrow (B-cell maturation)
2. Lymph nodes
3. Spleen
4. Thymus (T-cells maturation)
5. Tonsils
6. Adenoids
7. Appendix
8. Peyer's Patches (GALT)
166
What is an Innate Immune Response?
- non-specific
- work immediately when triggered
- non-selective
- rapid but limited responses
- first line of internal defence
167
If Innate Immune Responses are non-selective then how do they not attack everything?
they recognize general molecular properties (e.g. sugars or lipids) and mark invaders as foreign based on this
168
What Lymphocytes are Used in Innate Immune Responses?
1. Neutrophiles
2. Macrophages
3. Some plasma proteins
169
Define Diapedesis
the passage of blood cells through the intact walls of the capillaries, typically accompanying inflammation
170
Define Chemotaxis
chemicals release initiate rolling (margination) and migration
171
What are the effects of Innate Immune Response?
- vasodilation
- increased capillary permeability
- localized edema
- walling off of inflamed area
- emigration of leukocytes
- leukocyte proliferation
- mark bacteria for destruction by opsonins
- leukocyte destruction of bacteria
172
Describe Phagocytosis
- recognize carbs or lipids on bacteria wall after contact
| - aided by opsonins (prepare for eating)
173
What is Pus made up of?
collection of phag cells and dead tissues
174
What is an Opsonin?
action of some agents to help phagocytosis
| -receptors on phagocyte are specific to opsonin
175
What is Histamine?
from mast cells; induces local vasodilation and increases capillary permeability
176
What are Interleukin-1 and 6, and TNF?
- from macrophages
- fever
- promote inflammation
- enhances proliferation and differentiation of B and T lymphocytes
177
Can tissue repair ever be perfect? Why?
Yes
| lost cells are replaced by the same cells
178
Where is Scar Tissue Produced?
non-regenerative tissues
179
Describe the Complement System
- non-specific
- composed of plasma proteins produced in liver
- circulate in inactive form
- cascade sequence of events
180
C5 to C9 assemble to from _________.
Membrane Attack Complex (MAC)
181
Describe the steps of the complement system
1. embeds in surface membrane of nearby microorganisms
2. Resulting hole makes membrane leak
3. Victim cell swells and bursts
* *Kills without phagocytosis
182
What are the __ Components of Innate Immune Response?
1. Complement System
2. Phagocytosis
3. Antiviral Effect of Interneuron
4. Natural Killer Cells
5. Complement System
183
What is the difference between primary mechanisms and alternate pathways?
Primary- activated by antibodies
| Alternate- activated by exposure to carb chain on microorganisms
184
How do Alternate Pathways Work?
- forms membrane attack complex that punch holes in victim cells
185
What are complement proteins in the inflammatory process of alternate pathways?
- opsonins
- promote vasodilation and increased vascular permeability
- stimulate release if histamine from mast cells
- chemotoxins
186
What is the Antiviral Effect of Interneuron?
- inhibits multiplication of viruses in most cells
- triggers the production of virus-blocking enzymes by potential host cells
- released nonspecifically from any cell infected by a virus
- provides general, rapid defence until more specific but slower-responding immune mechanisms can begin
187
What are Natural Killer Cells?
- lymphocyte-like cells
- nonspecifically destroy virus-infected cells and cancer cells
- directly lyse cell membranes upon first exposure to these cells
188
What are the three components of Adaptive Immunity?
1. Antibody -Mediated/ Humoral Immunity
2. Cell-Mediated Immunity
3. B-Lymphocytes
189
Descrive Antibody-Mediated/Humoral Immunity
- produces antibodies using activated B lymphocyte (plasma cells)
190
Describe Cell-Mediated Immunity
- produces activated T lymphocytes
| - directly attack unwanted cells
191
B-Lymphocytes
- each lymphocyte has receptors for one antigen
- one binding with processed and presented antigen
- most B-cells differentiate into active plasma cells
- the rest become dormant (memory cells)
192
Describe Plasma Cells
- secreted into blood or lymph, depending on the location of the activated plasma cell
- produce and secrete IgG antibodies
- combine with antigen and marks it for destruction
- during initial contact antibody response is delayed to form plasma cells
- peak is reached in a few weeks by primary response
- after peak, antibody concentration decreases
193
Do Plama Cells or B Cells have more Er?
Plasma
194
What are the five immunoglobulin subclasses?
1. IgM
2. IgG
3. IgE
4. IgA
5. IgD
195
What is IgM?
- B-cell surface receptor for antigen attachment
| - secreted in early stages of plasma cell response
196
What is IgG?
- most abundant immunoglobin in blood
| - produced in large amounts when body is exposed to same antigen
197
What is IgE?
- protects against parasitic worms
| - antibody mediator for allergic responses
198
What is IgA?
- in secretions of digestive, respiratory, urinary systems
| - in milk and tears
199
What is IgD?
- surface of many B cells
| - unknown function
200
What combination of immunoglobulin subclasses produce the most significant response?
IgM and IgG
201
Describe the Composition of Antibodies
- Y shaped
- four interlinked polypeptide chains (2 long and heavy, two short and light)
- identical unique antibody binding fragments at tip
202
What is significant about the tail of antibodies?
properties of tail determine function of antibody and subclass
203
What is Agglutination?
the clumping of foreign cells and antibodies
204
What are the three functions of antibodies?
1. activated complement system
2. Enhance phagocytosis (opsinization)
3. Stimulating killer (K) cells
205
What is Clonal Selection?
- diverse B lymphocytes are produced during fetal development, each capable of synthesizing an antibody against a particular antigen
206
Memory Cells
- small %
- dormant
- more ready for immediate action upon re-exposure to same antigen than original lymphocyte of clone
207
Describe Secondary Response
- quicker
- more potent
- longer lasting
- induced by disease or vaccine
208
What is Active Immunity?
- self generated
| - from exposure to antigen
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What is Passive Immunity?
- "borrowed immunity"
- from transfer of pre-formed antibodies
- provide immediate protection or bolster resistance
eg. transfer of IgG from mom to fetus, Ab against rabies virus in non-imunized person
210
What is the percentage of contribution of T ad B lymphocytes?
B- 1/2 body's specific immune defence
| T - 50-70% of total lymphocyte number in blood circulation
211
Where do T cells get clonal and specific antigen receptors? Where do clines mature?
thymus
212
What two things must occur for a T cel to be activated?
1. foreign antigens
| 2. Self Antigens (MHC)
213
What is CD8?
- T cell
- killer/cytotoxic
- destroys cancer/virus cells
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What is CD4?
- T cell
- helper
- modulates activities of other immune cells
- secrete chemicals (cytokines) that amplify activity of other cells
(B&T cell growth factor, macrophage migration inhibitor)
215
What are Memory T-Lymphocytes?
- form memory pool
- primary and secondary responses
- primary responses initiated in lymphoid tissue
- most die via apoptosis in a few weeks
- remaining become long-lived memory T
216
Describe Cell-Mediated Immunity
- antigen complexed with another cellular protein
- major histocompatibility complex (MHC)
- "identity tags" for biological self
217
What is MHC?
- plasma membrane bound glycoproteins
- directs synthesis
- exact pattern varies from one individual to another
218
What is Class I MHC?
expressed on surface of all nucleated cells
219
What is Class IIMHC?
- expressed on immune system cells
| - macrophages, dendritic cells, activated B cells
220
What are the mechanisms of killing of CD8 cells?
- perforin molecules
- release granzymes to induce apoptosis (programmed cell death)
- released virus dealt with by phagocytes Ab+compliment
- require Class I MHC
221
CD8 cells require ____ while CD4 cells require _____.
Class I MHC
Class II MHC
222
What causes Immune diseases?
Inappropriate Immune Attacks
| -too much or too little responses or mistargeted response.
223
Describe Autoimmune Disease
- treats part of self as foreigner
| e. g. Diabetes, Arthritis
224
Describe Allergy as anImmune disease
- inappropriate specific immune reactivity to normally harmless environmental substance
- offending against allergen
- immediate and delayed hypersensitivity
- using chemical mediator histamine
