Flashcards in Exam 2 Deck (212):
How does lymphatic system prevent excess accumulation of tissue fluid (edema)?
Absorbs plasma proteins and fluid (2-4 L/day) from tissues and returns it to the bloodstream
How does lymphatic system counteract tissue infections?
Delivers WBCs to the site of infection
How does lymphatic system prevent the spread of malignant cells?
Traps damaged or harmful cells and also can destroy them in lymph glands
How many lymph nodes do we have?
Between 501-700 lymph nodes
-What is it?
-Where does it originate?
Clear, colorless fluid
Similar to plasma but much less protein
Originates as interstitial fluid
Circulation Pathways of Lymph
1. Lymphatic capillaries
2. Collecting vessels
3. Lymphatic trunks
4. Collecting ducts
--Right lymphatic duct and thoracic duct
Right Lymphatic Duct
Drains lymph from upper right limb and the right side of the head and thorax
Receives lymph from the rest of the body
Arises as enlarged sac called the cisterna chyli
Where does lymph end up?
Goes from lymph nodes to right or left subclavian vein, where it mixes back with the blood
--Where are they found?
--What is their function?
Found throughout the body except in avascular tissue
Deliver lymph to the tissues
How do lymph capillaries collect fluid?
Collect fluid from the tissues
How do lymph capillaries differ from blood capillaries?
Blood capillaries carry blood from small arterioles to small venules
Lymphatic capillaries carry lymphatic fluid from tissue to lymphatic venules
--What is their function?
--Where are they located?
--What do they contain?
1. Produce lymphocytes
2. Scattered throughout the body, but concentrated near mammary glands, axillae, and groin
3. B cells and plasma cells
Mucosa-Associated Lymphoid Tissue
Diffuse system of small concentration of lymphoid tissue found in the GI tract, thyroid, breast, lung, salivary glands, eye, and skin
Tonsils and MALT Function
Aggregations of lymphocytes in the connective tissues of mucous membranes and various organs
NOT a lymphatic organ
Filters blood and removes dead RBCs
Location of the Spleen
Between the stomach, diaphragm, and kidney
Upper left quadrant
Sac formed from two lumbar trunks and intestinal trunk that collects a large amount of chyle
On the left
Larger and stronger than right lymphatic duct
Right Lymphatic Duct
Receives drainage from right arm and right side of the thorax and head and empties into the right subclavian vein
Terminal End of the Thoracic Duct
Sometimes called the left lymphatic duct
Final Destination of Lymph Fluid
Why is the lymphatic system a 1-way system?
Lymphatic system is a return system only; removes fluid from the body and carries it to lymphatic ducts and trunks and puts it back into circulation
Condition of localized fluid retention and tissue swelling caused by a compromised lymphatic system
Inflammation of the walls of lymphatic vessels
Inflammation of the lymph nodes
Specific Immune Defenses
Immunity is directed against a particular pathogen
Body reacts when re-exposed to the same pathogen
Nonspecific Immune Defense
Initial immune reaction against foreign antigens via nonspecific antibodies and immune cells
Immunity that is not inherited
Nonspecific defense mechanisms that come into play immediately or within hours of an antigen's appearance in the body
The body makes its own antibodies or T cells against a pathogen
Body acquires antibodies from another person or an animal that has developed immunity to the pathogen
Injection for Passive Immunity
Immune serum from another person or from animals that have antibodies against a certain pathogen
Injection for Active Immunity
Vaccine that contains dead or weakened pathogens to stimulate an immune response
First Line of Defense
Second Line of Defense
Create a killing zone by degranulating and initiating a respiratory burst
Phagocytize antigen-antibody complexes, allergens, and chemicals
Secrete chemicals to attract other leukocytes
Histamine, leukotrienes, heparine
Also produced by mast cells
Large grouping of monocytes
Form outside of the circulatory system
Produced by virally infected cells (lymphocytes and macrophages)
Diffuse to neighboring cells to induce synthesis of antiviral proteins
Inactive proteins in blood plasma
When activated enhance immune, allergic, and inflammatory reactions
Natural Active Immunity
Production of one's own antibodies or T cells as a result of natural exposure to an antigen
Artificial Active Immunity
Production of one's own antibodies or T cells as a result of vaccination
Molecule or bit of foreign material
Which cells have MHC-I?
Found in the cell membrane of all cells except red blood cells
Which cells have MHC-II?
Found only in antigen-presenting cells (macrophages, B cells, thymus cells)
Normal function of MHC-I?
Contains bits of virus marking cell so T cells recognize
Normal function of MHC-II?
If antigen-presenting cells ingest foreign proteins, they will display as part of MHC-II
Encounters an antigen and migrates to the nearest lymph node and displays it to the T cells
Signaling process that helps to ensure that the immune system does not launch an attack in the absence of an enemy
Found on the surface of T cells and is responsible for recognizing fragments of antigen as peptides bound to MHC
Helper T Cells
Necessary for most immune responses
Coordinate humoral and cellular immunity
What happens when a Helper T cell recognizes an Ag-MHC complex?
Secrete interleukins that exert three effects:
1. Attract neutrophils and NK cells
2. Attract macrophages and stimulate phagocytic activity
3. Stimulate T and B cell mitosis and maturation
Any class of glycoproteins produced by leukocytes for regulating immune responses
Activation of Cytotoxic T Cells
Docks on diseased cell with MHC-I protein and delivers a lethal hit of chemicals that will destroy it
Clones of the cell the helper T cell recognized to make sure it is introduced into the system
Antibody-Mediated Immunity is also called...
1. Helper T Cells
3. B-Cell receptors
4. Plasma cells
5. Memory B-cells
Develop from B cells that have been activated by helper T cells
Synthesize and secrete antibodies
Mount a very quick secondary/anamnestic response if exposed to the same antigen
Gamma globulin produced by plasma cells in response to an antigen
Counteract the antigen by means of complement fixation, neutralization of toxins, agglutination, or precipitation
How do T-Cells fight off a pathogen?
Produce perforin, granzymes, interferon, tumor necrosis factor, and other cytokines
How do B-Cells kill off a pathogen?
B-Cells make antigens clump together
Why do we give booster vaccinations?
Immune response "memory" weakens over time
Which cells are involved in cellular immunity?
Which cells are involved in humoral immunity?
Lymphocytes directly attack and destroy foreign cells
Antibodies tag pathogens for destruction
Five Classes of Antibodies
Able to cross the placenta
Found in tears, saliva, mucus
Prevents pathogens from adhering to epithelia and penetrating underlying tissues
Involved in allergies
Produced earlier in an infection
What cells does HIV destroy?
Helper T cells
Short-term immunity that results from the introduction of antibodies from another person or animal
Found in vaccines or serum
Advantages of Passive Immunity
Benefits immunosuppressed patients
Protection is immediate
Disadvantages of Passive Immunity
No immunological memory is generated
Which immunity provides an anamnestic response?
Which immunity has a lag time before an immune response is generated?
Which immunity is immediately effective?
Which immunity provides only short-term, temporary protection?
What kind of molecule are complement proteins?
Where are complement proteins found?
General Action of Complement Proteins
Circulate in the blood in inactive form and are activated with the presence of pathogens
How do complement proteins kill cells?
2. Immune clearance
Located between the sternum and the aortic arch in the superior mediastinum
Function of Thymus
Produces thymopoietin, interleukins, and interferon to stimulate production of white blood cells
Thymus with age?
1. Antigens bind to B cells
2. Interleukins/helper T cells costimulate B cells
3. B cells proliferate and produce plasma cells that contain antibodies against the antigen
4. B cells produce memory cells
1. Antigen-presenting cells display foreign antigens that bind to T cells
2. Interleukins costimulate activation of T cells
3. If MHC-I, cells proliferate and produce cytotoxic T cells that destroy the cell displaying the antigen
4. If MHC-II, cells produce helper T cells that release interleukins that stimulate B cells to produce antibodies to bind to the antigens and nonspecific agents (NK and macrophages) to destroy the antigens
Which immunity is effective against intracellular pathogens?
Which immunity is effective against extracellular pathogens?
Which immunity is effective against transplanted cells?
Which immunity is effective against tumor cells?
A set of undesirable reactions produced by the normal immune system, including allergies and autoimmunity
Type 1 (Acute) Hypersensitivity
Most common allergies
Type 2 (Antibody-Dependent Cytotoxic) Hypersensitivity
Occurs when IgG or IgM attacks antigens bound to cell surface
Type 3 (Immune Complex) Hypersensitivity
Occurs when IgG or IgM forms antigen-antibody complexes that precipitate beneath the endothelium of the blood vessels or in other tissues
Type 4 (Delayed) Hypersensitivity
Cell-mediated reaction in which the signs appear about 12 to 72 hours after exposure
Where are T Cells produced and what activates them?
Produced in the bone marrow
Activated by the thymus
Upper Respiratory System
Respiratory organs in the head and neck
Lower Respiratory System
Respiratory organs of the thorax
2. Bronchial tree
Ventilation of the lungs/breathing
The use of oxygen in cellular metabolism
Bones Forming the Nose
Location of Nasal Cavities
Internal chamber of the nose divided into right and left halves (Nasal Fossae)
Vertical plate dividing the nasal fossae
Formed by vomer and perpendicular plate of the ethmoid bone
Three folds of tissue that project from the lateral walls toward the septum
Support the olfactory mucous membranes and increase the surface area
Nasal passages of the nasal cavity
Facilitates the detection of and response to odor molecules
How does your nose prevent bacteria from entering your lungs?
Mucus membranes trap bacteria
Nasal hairs remove suspended microorganisms from the air
Between pharynx and trachea
Uppermost cartilage within the larynx
Opening between the vocal cords
Located near the middle and center of the neck, slightly below the thyroid cartilage
Trachea and Esophagus
Trachea is posterior, esophagus is anterior
When you swallow, what prevents food from moving from the oropharynx to the nasopharynx?
Valve created by the soft palate
What is contained by the mediastinum?
Heart, aorta, thymus, chest portion of trachea, esophagus, lymph nodes
Outer membrane that attaches to and lines the inner surface of the thoracic cavity
Covers the surface of each lung
Between parietal and visceral pleura
Epithelium of Trachea
Pseudostratified squamous epithelium
Function of Cartilage Rings
Support the trachea while allowing it to move and flex during breathing
Hilus of Lung
Inner side of each lung
Apex of Lung
Rounded upper part of the human lung
Base of Lung
Broad, concave, and rests upon the surface of the diaphragm
What kind of muscle is found in bronchiolar wall?
Alveolar-Capillary Membrane (Respiratory Membrane) Function
Exists to prevent air bubbles from forming in the blood and from blood entering the alveoli
Thickness of Alveolar-Capillary Membrane
Varies from 0.4 to 2 micrometers
Layers of Alveolar-Capillary Membrane that CO2 and O2 Molecules Need to Cross
1. Epithelial alveolar
2. Shared basement membrane
3. Endothelial alveolar
Function of Elastic Fibers
Allow alveoli to stretch as they are filled with air during inhalation
Function of Macrophages in Alveoli
Clear inhaled particles from the alveolar regions of the lung
Purpose of Surfactant
Reduces the surface tension of fluid in the lungs and helps make alveoli in the lungs more stable
Secreted by alveoli
Normal differences in pressure between pleural cavity and atmosphere
Pleural cavity pressure is less than atmospheric pressure
Negative Pressure Breathing
The rib cage expands and the diaphragm contracts, expanding the chest cavity, causing pressure in the chest cavity to decrease and the lungs to expand and fill the space
What muscle produces an intra-pleural pressure change?
1. Diaphragm moves downward
2. Increases vertical dimension of thoracic cavity
3. Lowers air pressure in lungs
4. Air moves into the lungs
Lung volume representing the normal volume of air displaced between normal inhalation and exhalation
Inspiratory Reserve Volume
Maximal amount of air that can be drawn into the lungs by determined effort after normal inspiration
Expiratory Reserve Volume
The additional amount of air that can be expired from the lungs by determined effort after normal expiration
The volume of air still remaining in the lungs after the most forcible expiration possible
The greatest volume of air that can be expelled from the lungs after taking the deepest possible breath
Total Lung Capacity
The volume of air contained in the lungs at the end of maximal expiration
How are pulmonary volumes measured?
In a mixture of non-reacting gases, the total pressure exerted is equal to the sum of partial pressures of the individual gases
Percentage of Nitrogen in the Air
Percentage of Oxygen in the Air
Percentage of Carbon Dioxide in the Air
The pressure that would be exerted by one of the gases in a mixture if it occupied the same value on its own
Partial Pressure of Oxygen
Reflects the amount of oxygen gas dissolved in the blood
Measures the effectiveness of the lungs in pulling oxygen into the bloodstream from the atmosphere
Partial Pressure of Carbon Dioxide
Why can we breathe 79% nitrogen?
Nitrogen is inert and doesn't react with anything; does not get absorbed by the body
Concentration Gradients of CO2 and O2 Across the Respiratory Membrane of the Alveolus
The change in partial pressure from the alveoli (high concentration) to the capillaries (low concentration) drives the oxygen into the tissue and the carbon dioxide in the blood (high concentration) from the tissues (low concentration) where it is returned to the lungs and exhaled
Concentration Gradients of CO2 and O2 Across Capillary Membranes Into and Out of Interstitial Fluid and Cytoplasm
O2 will diffuse from high O2 blood in capillaries to low O2 body cells
CO2 goes from high CO2 to low CO2 capillaries to be carried out of the body
Respiratory Membrane Thickness
0.5-1 micrometer thick
Respiratory Membrane Surface Area
As large as a tennis court
How is CO2 carried?
1. Dissolved in solution
2. Buffered with water as carbonic acid
3. Bound to proteins such as hemoglobin
Systemic Gas Exchange: O2 Loading or Unloading?
Systemic Gas Exchange: CO2 Loading or Unloading?
Carbon Dioxide Unloading
How does blood transport oxygen?
What is normal hemoglobin saturation?
How does pH affect loading/unloading?
Decreased pH: caused by increased CO2 and enhances unloading of O2
Increased pH: caused by decreased CO2 and enhances loading of O2
How does temperature affect loading/unloading?
Increased Temperature: enhances unloading of O2 in the tissues and decreases loading of O2 in the lungs
Decreased Temperature: enhances loading of O2 in the lungs
CO2 source of production in the body?
Mitochondria via aerobic respiration
Bicarbonate Buffer System
Acid-base homeostatic mechanism involving the balance of carbonic acid, bicarbonate ion, and carbon dioxide to maintain pH
Bicarbonate Buffer System Equation
CO2 + H2O H2CO3 HCO3 + H+
What does carbonic anhydrase do?
Aids in conversion of CO2 to carbonic acid and bicarbonate ions
Normal Body pH
How do higher plasma levels decrease body pH?
Cellular buffering elevates plasma bicarbonate, which causes body to be acidic
Cause of Alkalosis
Loss of acid from the blood or low level of CO2 in the blood
Compensation Mechanism of Alkalosis
Breathing into a paper bag
Excessive CO2 in the bloodstream caused by inadequate respiration
State of reduced CO2 in the blood caused by rapid deep breathing or hyperventilation
CNS Centers of Respiration
Detect changes in pH of spinal fluid
Include aortic body
Detect changes in blood O2 and CO2
5. Sleep apnea
Compound of hemoglobin and carbon dioxide and is one of the forms in which carbon dioxide exists in the blood
Bright red substance formed by the combination of hemoglobin with oxygen
Innate Pulmonary Defense Mechanisms
Nose: nasal mucosa
Alveolar Gas Exchange (Lungs)
CO2 + H20
Systemic Gas Exchange (Tissues)
CO2 + H2O ----> H2CO3 ----> HCO3 + H+
The pressure of a given quantity of gas is inversely proportional to its volume (assuming constant pressure)
The volume of a given quantity of gas is directly proportional to its absolute temperature (assuming constant pressure)
At the air-water interface, the amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in the air (assuming constant temperature)
Functions of the Kidney
Eliminates nitrogenous waste
Regulates blood ions
Regulates blood pH, osmolarity, glucose, blood volume
Regulates blood pressure
Releases EPO and calcitrol
Excretes wastes and foreign substances
Site of filtration of blood
Glomerular Capsule/Bowman's Capsule
Performs the first step in the filtration of blood to form urine
Proximal Convoluted Tubule
Lies between Bowman's capsule and the loop of Henle and reabsorbs sugar, sodium, and chloride ions
Descending Loop of Henle
Constitutes the first part of the loop of Henle
Ascending Loop of Henle
Second part of the loop of Henle
Distal Convoluted Tubule
Between the loop of Henle and the collecting duct system
Participates in electrolyte and fluid balance through excretion and reabsorption and is regulated by aldosterone
Blood Supply to the Nephron
Artery--Capillary--Artery--Capillary--Vein Blood Flow
Three Basic Processes Performed by the Nephron
1. Glomerular filtration
2. Tubular secretion
3. Tubular reabsorption
Process by which the kidneys filter the blood, removing excess waste and fluids
The transfer of materials from peritubular capillaries to the renal tubular lumen
The process by which solutes and water are removed from the tubular fluid and transported into the blood
Difference Between Glomerular Filtrate and Blood
GF is solute-rich fluid without blood cells or plasma proteins
Blood has plasma and blood cells
Layers of the Glomerular Filer
1. Fenestrated endothelium
2. Basement Membrane
3. Filtration Slits (pedicels)
Cells in the Bowman's capsule in the kidneys that wrap around the capillaries of the glomerulus
Estimates how much blood passes through the glomeruli each minute
Where is the majority of GF reabsorbed?
Proximal convoluted tubule
Concentration of a substance dissolved in the blood above which the kidneys begin to remove it into urine
What substances are secreted into GF?