Unit II Review Flashcards
(Chapter 19)
What are the 5 functions of blood?
- Transport gases, nutrients, hormones and waste
- Regulate pH and ion composition of ISF
- Restrict fluid loss at injury sites
- Defend against toxins and pathogens
- Stabilize body temperature
How does blood temperature compare to body temperature?
Blood temperature is slightly higher (100.4F or 38C)
What is the pH of blood?
7.35 - 7.45
What is the viscosity of blood vs water?
Blood is 5x more viscous than water
What is whole blood?
Plasma + formed elements
What is plasma?
92% water, 7% plasma proteins, 1% other solutes
What is the composition of formed elements?
99.9% RBCs, <0.1% WBC, <0.1% platelets
What is hematocrit?
The percentage of formed elements (or RBCs) in whole blood
List the different plasma proteins and their functions
Albumins - 60% - major contributor to osmotic pressure, transport fatty acids, some thyroid/steroid hormones
Globulins - 35% - antibodies and transport globulins
Fibrinogen - 4% - Important in the clotting process
List the different solutes that are found in blood
Nutrients, electrolytes, waste
What is the ratio between RBCs and WBCs
1000:1
What is oxyhemoglobin?
Hemoglobin (Hb) whose iron ion holds O2 –> HbO2
What is deoxyhemoglobin?
Hb molecule whose iron ion does not hold O2 –> Hb
What is carbaminohemoglobin?
Hb bound to CO2
What is the average life span of a red blood cell?
120 days
What type of white blood cell recycles red blood cell components?
Phagocytic macrophage
What is hemoglobinuria?
Abnormally large numbers of RBCs break down in the bloodstream, and may cause urine to turn red or brown
What is hematuria?
The presence of intact RBCs in urine
What is biliverdin?
After RBC breakdown, when a heme is stripped of its iron by a phagocytic cell
Note: Bruises commonly developed a greenish tint when biliverdin forms in the blood-filled tissues
What is bilirubin?
Biliverdin is converted to bilirubin, an orange-yellow pigment, and released into the bloodstream. There, the bilirubin binds to albumin and is transported to the liver for excretion in bile.
What causes jaundice?
Yellowing of the skin and eyes caused by a backup of bilirubin. This may happen if bile ducts are blocked or the liver cannot absorb or excrete bilirubin.
What are urobilins and stercobilins?
Created from bilirubin in the large intestine.
What is transferrin?
A plasma protein which binds and transfers iron ions. (Large quantities of iron by itself are toxic). Absorbed by RBCs in red bone marrow.
What are ferritin and hemosiderin?
Excess transferrin is removed in the liver and spleen and the iron is stored in ferritin and hemosiderin.
Where are RBCs produced in adults?
Red bone marrow exclusively
What are hemocytoblasts?
Produce myeloid and lymphoid stem cells
What nutrients are needed by the red bone marrow for proper erythropoiesis?
Amino acids, iron, and vitamins B6/B12/Folic Acid
What factor in females accounts for the lower hematocrit values when compared to males?
Estrogens do not stimulate erythropoiesis
What is erythropoietin (EPO)?
Formed by kidneys and liver. Released when O2 levels are low, especially at kidneys. Stimulates RBC development.
What determines your blood type?
Surface antigens
What are the three surface antigens of importance when addressing blood types?
A, B, Rh
If a person has type A- blood, what type of antibody would be in their plasma?
Anti-B antibodies (does NOT have Rh antibodies - this occurs only after sensitization)
What are agglutinogens and agglutinins?
Surface antigens
What is sensitization? (In reference to Rh)
Previous exposure to Rh+ RBCs, causing the formation of anti-Rh antibodies.
How are WBCs different from RBCs
Have nuclei and organelles. Lack hemoglobin.
List the four characteristics of WBCs
- Can migrate out of the bloodstream
- Capable of amoeboid movement
- Attracted to specific chemical stimuli
- Neutrophils, Eosinophils, and Monocytes are capable of phagocytosis
How do neutrophils protect the body from bacteria?
Attack and digest bacteria that have been marked with antibodies.
What types of pathogens are the main focus of eosinophils?
Attack objects coated with antibodies.
What is the role of basophils in the inflammatory response?
Release histamine (dilates blood vessels) and heparin (prevent clotting) at injury sites to enhance inflammation (similar to mast cells)
What are the three classes of lymphocytes?
T cells, B cells, NK cells
What is a differential count?
Shows the number of each type of WBC in a sample of 100
What is leukopenia?
Inadequate number of WBCs
What is leukocytosis?
Excessive number of WBCs
Which WBCs are derived from myeloid stem cells?
Neutrophils
Basophils
Eosinophils
Monocytes
What are platelets?
Thrombocytes. Clump together when they recognize blood vessel damage.
What is thrombocytopenia?
Excessive platelet destruction or inadequate platelet production
What is thrombocytosis?
High platelet counts. Usually results in response to infection, inflammation, or cancer.
What is hemostasis?
The stopping of bleeding.
What are the phases of hemostasis?
- Vascular phase
- Platelet phase
- Coagulation phase
What is coagulation time?
The time it takes blood to clot in a fine glass tube (8-18 minutes)
What is bleeding time?
The time it takes a small puncture wound to stop bleeding (1-4 minutes)
What are the naturally occurring anticoagulants found in the body?
Antithrombin-III, Heparin, Thrombomodulin, Protein C
What is the role of calcium ions and vitamin K in the blood clotting
Ca+2 is required for all pathways - intrinsic, extrinsic and common
Vitamin K is required for the liver to synthesize four of the clotting factors, including prothrombin
What is clot retraction?
Pulls the torn edges of the vessel closer together
What is fibrinolysis?
Gradual dissolving of a clot
What is plasmin?
Digests fibrin strands to erode a clot
(Chapter 20)
What are the two types of cardiac muscle cells?
Myocardial contractile and myocardial conducting cells
What causes the SA node to spontaneously depolarize?
Slow inflow of Na+ without a compensating outflow of K+
Before atrial systole begins, how much blood is in each ventricle as a result of passive filling?
70% of 130 mL = 91 mL
What occurs during the 0.1 second delay in action potential propagation at the AV node?
Atrial systole
What is the volume of blood that is in the ventricles at the end of atrial systole called?
End diastolic volume
The fully filled ventricles place a stretch on the walls of the ventricles. What is this called?
Preload
What is the pressure in the wall of the left ventricle during ejection called?
Afterload
What is ejection fraction?
SV divided by EDV = EF %
What is the formula for cardiac output?
Heart rate x SV
(Chapter 21)
Which layer of the blood vessel contains smooth muscle?
Tunica media
What are the main differences between arteries and veins?
- Artery walls are thicker
- Arteries hold their shape better
- Arteries are more resilient
- Veins contain valves
What are elastic arteries?
aka Conducting arteries, they carry large volumes of blood away from the heart. Diameter up to 2.5 cm. Examples are the pulmonary trunk and aorta, as well as their major branches.
What are muscular arteries?
Aka distribution arteries, most vessels of the arterial system are muscular arteries. Some muscular arteries are important pressure points.
What is another name for arterioles and why?
Resistance vessels, because their changing diameter can introduce resistance to the circulatory system.
What are the main characteristics of continuous capillaries?
Permit water, small solutes, and lipid-soluble material to diffuse into the interstitial fluid, but prevent the loss of blood cells and plasma proteins.
What are the main characteristics of fenestrated capillaries?
Contain pores that penetrate the endothelial lining, allowing rapid exchange of water and solutes between blood and ISF. (Found in choroid plexus in the brain, several glands, intestinal tract, and the kidneys)
What are the main characteristics of sinusoidal capillaries?
Resemble fenestrated capillaries. Also commonly have gaps between adjacent endothelial cells, thinner or absent basement membrane.
How is blood flow through capillaries regulated?
Precapillary sphincters
What are collaterals?
Multiple arteries that supply a single capillary bed
What is an arterial anastomosis?
The fusion of two collateral arteries that supply a capillary bed
What is an arteriovenous anastomosis?
Direct connections between arterioles and venules
What is vasomotion?
Precapillary sphincters alternately contract and relax in a rhythmic motion called vasomotion.
Why are the walls of veins thinner than those of corresponding arteries?
They lack a tunica media
What is the role of venules?
They collect blood from capillary beds
Which system contains most of the blood in the body during periods of rest?
The venous system (65-70%)
Why are veins called capacitance vessels?
They expand easily to accommodate large changes in blood volume.
What is the venous reserve?
The amount of blood that can be shifted from liver skin and lungs to the the rest of the circulatory system (about 20% of blood volume) in the event of major blood loss
What is venous pressure?
The pressure in the venous system. Quite low, about 18 mm/Hg.
What is vascular resistance?
The forces that oppose blood flow in the blood vessels
How does vessel length affect vascular resistance?
Increased length = Increased friction (You can blow the water out of a snorkel easily, but you can’t blow the water out of a garden hose)
How does vessel diameter affect vascular resistance?
Smaller diameter = more friction
Which blood vessels are most responsible for providing peripheral resistance?
Most peripheral resistance occurs in arterioles
What is viscosity?
The resistance to flow caused by interactions among molecules and suspended materials in a liquid
What accounts for turbulence in blood vessels?
High flow rates, irregular surfaces, and sudden changes in vessel diameter upset the smooth flow of blood, creating eddies and swirls.
List some local vasodilators
Decreased tissue oxygen levels or increased CO2 levels.
Lactic acid or other acids generated by tissue cells.
Nitric oxide (NO) released from endothelial cells.
Rising concentrations of potassium ions or hydrogen ions in the interstitial fluid.
Chemicals released during local inflammation, including histamine and NO. p. 144
Elevated local temperature.
What is vasomotor tone?
The sympathetic vasoconstrictor nerves are always active, producing a significant vasomotor tone. This vasoconstrictor activity normally keeps the arterioles partially constricted.
Where are the baroreceptors involved in cardiovascular regulation located?
- Walls of the carotid sinuses
- The aortic sinuses
- Wall of the right atrium
Where are the chemoreceptors involved in cardiovascular regulation located?
The carotid bodies and aortic bodies
Describe the steps involved in Angiotensin II production, beginning with the release of renin
- A fall in renal blood pressure causes juxtaglomerular cells to release renin (an enzyme)
- Renin converts Angiotensinogen (a plasma protein) to Angiotensin I
- In the lungs, angiotensin-converting enzyme (ACE) converts Angiotensin I to Angiotensin II (a hormone)
What effects does Angiotensin II produce
- Stimulates release of aldosterone
- Stimulates secretion of ADH
- Stimulates thirst
- Stimulates cardiac output and triggers constriction of arterioles
What is ANP?
Atrial natriuretic peptide, released by the right atrium in response to excessive stretching during diastole and act in various ways to reduce blood pressure.
What hormone is produced by the ventricles which is similar to ANP?
BNP - brain natriuretic peptide
What adaptations account for the lower resting heart rates and stroke volumes seen in trained athletes?
Trained athletes have larger hearts and greater stroke volume
(Chapter 22)
What are pathogens?
A disease-causing organism. Can be a virus, bacteria, fungus, parasite, etc.
What makes up the lymphatic system?
The cells, tissues, and organs responsible for defending the body.
What is immunity?
The ability to resist infection and disease
What are the two forms of immunity that are present in the body?
Innate and adaptive
How is lymph produced?
ISF is collected by lymphatic vessels and cleansed by lymphocytes in the lymph nodes. It is then returned to the blood stream at the R/L subclavian vein.
How are lymphatic capillaries different from blood capillaries?
- Originate as pockets, rather than continuous tubes
- Have larger diameters
- Have thinner walls
- Have a flattened or irregular outline in sectional view
What causes lymphedema?
Blockage of the lymphatic drainage from a limb
What are the three classes of lymphocytes?
T cells, B cells, NK cells
What type of immunity is provided by Cytotoxic T cells?
Cell-mediated immunity
What type of immunity is provided by B cells?
Antibody-mediated immunity
What are antigens?
Antibodies bind to specific chemical targets called ANTIGENS, which stimulate an immune response.
What are the functions of NK cells?
NK cells provide innate (nonspecific) immunity. They attack foreign cells, cells infected with viruses, and cancer cells that appear in normal tissues. Their continuous “policing” of peripheral tissues has been called immune surveillance.
What is the life span of most lymphocytes?
80% survive about 4 years. Some survive 20+ years.
Where are T cells, B cells, and NK cells produced?
- Red bone marrow produces hemocytoblasts, which create Lymphoid Stem Cells
- LSC that remain in red bone marrow become B cells and NK cells
- LSC that migrate to the thymus become T cells
What are lymphoid tissues?
Connective tissues dominated by lymphocytes
List the different structures that are classified as lymphoid tissues
- Lymphoid nodules, such as the tonsils
- MALT (mucosa-associated lymphoid tissue)
List the three lymphoid organs
Lymph nodes, thymus, and spleen
Where are lymph nodes located?
Primarily neck, armpits, and groin.
What happens to antigens that are present in lymph that flows through a lymph node?
At least 99 percent of the antigens in the lymph are removed. Fixed macrophages in the walls of the lymphatic sinuses engulf debris or pathogens in lymph as it flows past. Antigens removed in this way are then processed by the macrophages and “presented” to nearby lymphocytes.
What causes swelling to occur in lymph glands?
An increase in the number of lymphocytes and phagocytes in response to a minor, localized infection.
What is the main function of the thymus in immunity?
Site of maturing T cells
What are the main functions of the spleen?
(1) removing abnormal blood cells and other blood components by phagocytosis
(2) storing iron recycled from red blood cells
(3) initiating immune responses by B cells and T cells in response to antigens in circulating blood
What are physical barriers and how do they protect the body from invading pathogens?
Skin and other epithelial layers, hair, secretions from sebaceous and sweat glands
What are phagocytes?
Serve as janitors and police in peripheral tissue. Provide first line of defense against invading pathogens.
What are microphages and how do they protect the body from invading pathogens?
Microphages - Neutrophils and Eosinophils - Leave the bloodstream and enter peripheral tissues that have been subjected to injury or infection.
What is immunological surveillance?
The constant monitoring of normal tissues by NK cells
What is the difference between NK cells and other lymphocytes?
- NK cells are less selective and can respond to a variety of abnormal antigens that may appear anywhere on the plasma membrane.
- NK cells respond much more rapidly than T or B cells, because it respond immediately on contact
What are interferons
- Small proteins released by activated lymphocytes and macrophages, and by tissue cells infected with viruses
- Binds to surface receptors on the membrane of a normal cell and, by second messengers, triggers the production of antiviral proteins in the cytoplasm
- Antiviral proteins do not prevent viruses from entering the cell, instead they interfere with viral replication inside the cytoplasm
What is the complement system?
It complements the action of antibodies
What are the results of complement activation?
- Pore formation
- Enhanced phagocytosis
- Histamine release
What is inflammation
A localized tissue response to injury
What are the four signs of inflammation
- Swelling
- Redness
- Heat
- Pain
What substances are released by mast cells when they are stimulated by injury?
Histamine, heparin, prostaglandins, and other chemicals into interstitial fluid
What is the effect of histamine release on local blood flow?
Increases the flow of blood (via vasodilation)
What stimulates pain receptors at an injury site?
Histamine stimulates nociceptors
What causes an injured area to redden and have an increase in temperature?
Increased blood flow
How can an increase in temperature at an injury site help in fighting pathogens?
Increases the rate of enzymatic reactions and accelerate the activity of phagocytes. It may also denature foreign proteins.
What is fever
A body temperature greater than 37.2C (99F)
What are pyrogens
Circulating proteins that can raise body temperature
What is the role of fever in the immune response?
The most likely beneficial effect is on body metabolism. For each 1°C rise in body temperature, metabolic rate increases by 10 percent. Cells can move faster, and enzymatic reactions take place more quickly. As a result, tissue defenses can be mobilized more rapidly and the repair process speeds up.
What is the difference between cell-mediated and antibody-mediated immunity?
T cells bring about cell-mediated immunity and B cells bring about antibody-mediated immunity
What is the role of Cytotoxic T cells?
Responsible for cell-mediated immunity. These cells enter peripheral tissues and directly attack antigens physically and chemically
What is the role of Memory T cells?
Respond to antigens they have already encountered by cloning more lymphocytes to ward off the invader
What is the role of Helper T cells?
Stimulate the responses of both T cells and B cells. Helper T cells are absolutely vital to the immune response, because they must activate B cells before the B cells can produce antibodies.
What is the role of Suppressor T cells?
Inhibit T cell and B cell activities and moderate the immune response
What is antigen presentation?
Occurs when an antigen–glycoprotein combination capable of activating T cells appears in a plasma membrane
How do abnormal peptides from invading pathogens get incorporated into Class I MHC proteins?
Class I MHC proteins are continuously synthesized packaged at the Golgi apparatus, and foreign proteins can get incorporated into these proteins and sent to the surface.
What is antigen recognition?
If the MHC protein contains the antigen that the T cell is programmed to detect, binding occurs. This process is called antigen recognition.
What type of CD markers are found on Cytotoxic T cells and Suppressor T cells?
Cytotoxic T cells and Suppressor T cells = CD8
What class of MHC proteins do CD8 T cells bind to?
MHC Class I
What is costimulation?
Costimulation is important only in determining whether a T cell will become activated. Once activation has occurred, the “safety” is off and the T cell will attack any cells that carry the target antigens.
What types of T cells are produced when inactive CD8 T cells are exposed to antigens bound to Class I MHC proteins?
- Cytotoxic T cells (Active Tc)
- Memory T cells
- Suppressor T cells
How do activated Cytotoxic T cells destroy its target antigen bound to Class I MHC proteins?
- Release perforin
- Secrete a poisonous lymphotoxin
- Induce apoptosis (cell suicide)
What is the role of Tc on first exposure and subsequent exposures to its specific antigen?
Cytotoxic Tc: When a cytotoxic T cell encounters its target antigen bound to Class I MHC proteins, it immediately destroys the target cell
Memory cells: These cells do not differentiate further the first time the antigen triggers an immune response. However, if the same antigen appears a second time, memory T cells immediately differentiate into cytotoxic T cells
What is the role of Suppressor T cells?
Suppress the responses of other T and B cells to prevent an over-exaggerated immune response.
What type of CD markers is found on helper T cells?
CD4
Where are Class II MHC proteins found?
Plasma membrane of Antigen-Presenting Cells and B cells
What are antigen-presenting cells?
Specialized cells responsible for activating T cell defenses against foreign cells (including bacteria) and foreign proteins
How do foreign antigens get incorporated into Class II MHC proteins on the cell membranes of antigen-presenting cells?
Phagocytic APCs engulf and break down pathogens or foreign antigens. This antigen processing creates fragments of the antigen, which are then bound to Class II MHC proteins and inserted into the plasma membrane
CD4 T cells or helper T cells respond to antigens presented by what class of MHC proteins?
MHC Class II
What happens when an inactive Th cell binds to its specific antigen bound to Class II MHC proteins on the surface of an antigen-presenting cell?
The Th cells produces Cytotoxic Tc (Active Tc) and Memory Tc
What do activated helper T cells secrete and what are the effects of this secretion?
They secrete cytokines. Cytokines:
- Stimulate production of Th and Tc
- Attract macrophages to enhance nonspecific defenses
- Attract Tc
- Promote the activation of B cells, leading to antibody production
What happens when the antibodies that are present on the surface of a B cell bind to its specific antigen in body fluids?
Sensitization occurs
What class of MHC proteins are found not he surface of B cells?
MHC Class II Proteins
When B cells present foreign antigens incorporated in its Class II MHC proteins, the B cells are now in a state of _______________
Sensitization
What type of helper T cell is capable of activating a sensitized B cell?
An already activated helper T cell
What happens when a B cell is activated? What types of cells are produced?
- Memory B Cells
- Active B Cells, which lead to PLASMA CELLS
List the five classes of antibodies
IgG, IgE, IgD, IgM, IgA
GED My Ass
What is neutralization?
Both viruses and bacterial toxins have specific sites that must bind to target regions on body cells before they can enter or injure those cells. Antibodies may bind to those sites, making the virus or toxin incapable of attaching itself to a cell.
What is precipitation and agglutination?
Antibodies bind to many antigens, creating large “clumps” which cannot remain in solution.
The formation of insoluble immune complexes is called precipitation.
When the target antigen is on the surface of a cell or virus, the formation of large complexes is called agglutination. (Like what makes your blood clump when exposed to anti-A, B, Rh antibodies)
What triggers the activation of the complement system?
When an antibody molecule binds to an antigen, portions of the antibody molecule change shape. This change exposes areas that bind complement proteins.
What is Opsonization?
A coating of antibodies and complement proteins which increases the effectiveness of phagocytosis
How do antibodies stimulate inflammation?
By stimulating basophils and mast cells
How do antibodies prevent bacteria and viruses from adhering to body surfaces?
A covering of antibodies makes it difficult for pathogens to attach to and penetrate body surfaces.
What are the characteristics of the primary response to antigen exposure?
The antibody tither peaks 1-2 weeks after exposure. Molecules of IgM are the first to appear in the blood. IgG rises more slowly, but is more effective.
What are the characteristics of the secondary response to antigen exposure?
Memory B cells do not divide unless exposed to the antigen again, in which case, they react more quickly than the first exposure. Antibody tithers and concentrations rise much more rapidly than they do in the primary response. Additionally, the antibodies are much more effective.
Which type of antibody is able to cross the blood-placenta barrier?
IgG
Why is a fetus affected by anti-Rh antibodies and not anti-A or anti-B antibodies?
Because anti-A and anti-B antibodies are IgM antibodies, and only IgG antibodies can cross the blood-placenta barrier.
What are autoimmune disorders?
When the body attacks self-antigens
