What does the Lymphatic system do?
Responsible for filtering extra fluid in tissues through lymphoid tissues and nodules for bacteria, microorganisms, and viruses ie foreign bodies.
Lymphatic mode of passages
- Lymphatic capillaries
- collecting vessels
- lymphatic trunks
- lymphatic ducts
How does fluid get into the lymph vessels?
swelling and high pressure force fluid through flaplike minivalves that allow liquid to move in but not out.
How does the fluid move through lymph vessels?
Name two Lymphoctes and what they do.
- T cells -manage the immune response
- attack and destroy foreign cells
- B cells -produce plasma cells which secrete antibodies
- chemical attack
Name 3 other lymphoid cells
Dendritic Cells -
- help activate t cells
capture antigens and deliver to lymph nodes
-produce stroma that supports other cells in lymphoid organs
What is the role of lymph nodes?
- Activate- ID pathogen
- filter- kill
Discuss the lymph node features
- -more afferent vessels to allow prolonged filtration
- -lymphoid follicle houses T cells
- -Germinal center houses macrophages
- -Subscapsular sinus houses lymphocytes
Discuss importance of the Spleen
- -largest lymphoid organ
- -site of lymphocyte proliferation and immune surveillance and response
- -cleanses the blood of aged cells, platelets, and debris
- -stores break down of RBC material
- -fetal erythrocyte production
Discuss importance of the Thymus
- -lymphoid organ
- -strictly for T-cell maturation
- -t cell immunocompetent
- -vistigual organ. important during youth- disfunctional in old age
Name all lymphoid organs.
- peyer's patches
What are the differences between the innate defenses and adaptive defenses?
innate does not learn or change like adaptation
What are the 3 lines of defense the body has?
- 1st line -skin and muccous
- 2nd line-phagocytes, fever, Natural killer cells, antimicrobial proteins, inflammation
- 3rd line-
- Humoral immunity- B cells (chemical)
- Cellular immunity- T cells (cells defending me)
What is a macrophage?
they attack everything without receptors
What does a fever do to help?
A fever is a neurological response that unwraps proteins and increases metabolism. It unravels pathogens too to make them easier to kill. However temps too high for too long can be irriversible and cause more damage than good
What kind of surface barriers do we have?
Protective chemicals to inhibit or destroy microorganisms
- Skin acidity- keratin
- -lipids in sebum and dermcidin in sweat
- -HCl and protein digestion enzymes in our gut
- -Lysozyme in saliva and lacrimal fluid
Name two kinds of macrophages
- Aleolar- free macrophages wander through tissues spaces
- Kupffer cells (liver) and microglia (brain)- fixed macrophages that are perminate residents
How does phagocytosis operate?
- -phagocyte forms around the microbe
- -lysosomes fuse with phagocytic vesicle
- -microbe is broken down and deposited out of the cell in exocytosis
- -becomes pus
What are natural killer cells?
- -Large granular lymphocytes
- -targets cells that lack self receptors
- -induce apoptosis in cancer and virus infected cells
- -secrete potent chemicals that enhance the -imflammatory response
Describe what happens during the healing process.
- l-eukocytosis- chemical response to increase WBC
- -diapedesis- move from capillary to tissues -chemotaxis
- -pus from macrophages
Primary mechanisms of defense
- 1. Phagocytosis- digest viruses by macrophages
- 2. memory cell activation- recall pathogens we have had previously
- 3. antibody mobilization- neutrilize and stop pathogen from hurting us
What is margination?
rolling along membrane to find signal to leave capillary
What do interferons do?
- -activate macrophages and mobilize NK.
- -virus enters cell
- -interferon genes get switched on
- -cell produces interferon molecules
- -antiviral proteins block viral reproduction
- -interferon binding stimulates cell to turn on geses for antiviral proteins
- -cell dies after interferon
What are complements?
- -about 20 blood proteins that circulate in an inactive form
- -amplifies all aspects of the inflammatory response- helps create chemical trail and clumps pathogens
- -kills bacteria and certain cell types by cell -lysis
- -enhances both non specific and specific defenses
How exactly does a fever start?
leukocytes and macrophages secrete pyrogens which reset the bodies thermostat upwards
Why is a fever dangerous?
It unwinds proteins so we can access protein molecules faster but unprotected and unwound the proteins can fracture or break.
What two organs can sequester Fe/Zn during a fever?
spleen and liver
- Specific, systemic, has memory
- 1. Humoral (antibody-mediated) immunity B cells Dont attack
- 2. Cellular (cell-mediated) immunity T cells attack
Where do they lymphocytes originate and mature?
- -Originate in red bone marrow
- -b cells mature in red bone marrow
- -t cells mature in the thymus
- -Immature cells live in lymph nodes have not yet come in contact with viruses yet
When they mature, cells have...
- Immunocompetence- they are able to recognize and bind to a specific antigen
- self-tolerance- unresponsive to self antigens
What are antigens?
- -markers of things that exist, belong or dont belong
- -bacteria and virus look for specific cells to infect by locating their antigens and our cells attack viruses and bacteria by identifying their antigens
What are antibodies?
- -have and affinity for antigens
- -bind and identify
- -if antigens don't belong- neutralization, agglutination, and precipitation
What is positive selection?
- -T cells must recognize self major histocompatibility proteins
- -matching is good/ no match = cell death
What is negative selection?
-T cells must not recognize self antigens- if it recognizes its own cell apoptosis occurs-if it doesnt match up then it goes to maturation
Explain B cells
- -bind with antigens it identifies
- -replicates to plasma cells and memory cells
- -antibodies are made from plasma cells
- -2nd response is greater and faster
Immunological memory- Primary immune response
- -Occurs in first exposure to a specific antigen
- -lag period is 3-6 days
- -peak levels of plasma antibody are reached in 10 days
- -antibody levels then decline
Immunological memory- secondary immune response
- -Occurs on re-exposure to the same antigen
- -sensitized memory cells respond within hours
- -antibody levels peak in two to three days -at much higher levels
- -antibodies bind with greater affinity
- -antibody level can remain high for two weeks to two months
Name four ways we can acquire immunity.
- Naturally acquired
- Active- infection- contact with pathogen
- Passive- antibodies pass from mother to fetus
- Artificially acquired
- Active- vaccine
- Passive- injection of immune serum -antibiotics
Basic antibody structure
- -IgM- fixes and activates complement
- -IgA- helps prevent entry of pathogen
- -IgD- Function as a B cell receptor
- -IgG- fetus development
- -IgE- causes mast cells and basophils to release histamine
Functions of Antibodies
- Inactivates by:
- -leads to inflammation or phagocytosis
- Activates by:
- -fixes complement- leads to cell lysis or inflammation
Complement proteins do what three things
- -help cells
- -utilized to enhance function
- -used as weapon
Name two types of T Cells
CD8 and CD4
- -memory cells
- -activated cytotoxic cells
- -physical attack
- -memory cells
- -activated helper cells
- -recruits macrophages and NK cells to kill specific cells
- -cytokin can initiate b cell pathway and b cells can activate helper t cells
Name four varieties of Organ Transplants
- Autographs: one body site to another in the same person
- Isografts: between identical twins
- allografts: between human to human
- xenografts: another animal species to human
Prevention of rejection
- -depends on tissue similarity
- -cartilage and cornea and ligament- 0 blood flow
- -more blood flow= higher chance of rejection
- -treated with immunosuppressive therapy, corticosteroid- suppress inflammation, antiproliferative
What does the conducting zone do?
passage of air. Moisten and warm air, filter, resonation chamber, and smell receptors.
Why do we have three concha and meatus?
to increase surface area.
Functions of Nasal Mucosa and Conchae
- -During inhalation, the conchae and nasal mucosa- filter, heat, and moisten air
- -During exhalation these structures
- -reclaim heat and moisture
Name 3 Larynx functions
- 1. Open airway
- 2. route food and air
- 3. vocalization
What is the Valsalva's Maneuver?
- Vocal cords can prevent air passage- intermittent release of air-
- -opens and closes- tense cords-
- -fast vibration and high pitch
What two layers line the lumen of the trachea?
- 1. pseudostratified ciliated columnar epithelium
- 2. seromuccous glands in submucosa
How many segments are in the lung?
10 segments in the right lung9 segments in the left lung
What is the point of avleolar pores?
to relieve pressure in the lungs
Describe the alveoli.
- -small sacs of air
- -300 million alveoli
- -reduce diameter
- -elastic fiber contracts
- - capillaries surround each aveoli
What are two cell types in the Alveoli?
- Type I. squamous epithelium each alevolar is only made up of simple squamous ethithelium for gas exchange
- Type II. Surfactant secreating cell surfactant- weaken surface tension between water molecules
What role does water play in alveoli?
- -water resists helps in exhange
- -water tension puts resistance in alveolus
How do the parasympathetic and sympathetic systems affect the lungs?
- -Parasympathetic fibers constrict air tubes
- -Sympathetic fibers dilate air tubes
Explain the pressure residing in the chest cavity.
- -The visceral tissue lines the organ.
- -The parietal tissue lines the ribs.
- -The serous fluid in the pleural cavity is in between.
Explain how the lungs get blood to function.
- -Systemic circulation (high pressure, low volume)
- -fed by bronchial arteries/ capillaries
- -enter lungs at hilum
- -bronchial veins anastomose with pulmonary veins
What is the Pleurae?
- -A thin, double-layered serosa
- -parietal pleura on thoracic wal and superior face of diaphragm
- - Visceral pleura on external lung surface
- -pleural fluid fills the pleural cavity and provides lubrication and surface tension
Diaphragm contracts, interxostals contract lifting the rib cage, moves sternum and rib cage
passive, intercostals and diaphragm relax, no muscles
Explain what Intrapleural Pressure is
- -Negatice interpleural pressure is caused by opposing forces.
- - Two inward forces promote lung collapse- elastic recoil of lungs decreases lung size and surface tension of alveolar fluid reduces alveolar size
- -one outward force tends to enlarge the lungs, elasticity of the chest wall pulls the thorax outward
Which pressure should always be higher?
Intrapleural pressure should always be less than intrapulmonary pressure.
Intrapulmonary (inside the lung) should be higher
- higher pressure = lower volume
- lungs at rest = 1 atm
- when volume increases= pressure drops
- move from high pressure to low pressure
Explain the relationship between transpulmonary pressure and intrapulmonary pressure.
The difference stays relatively the same throughout breathing.
Explain the four individual volumes the lung contains.
- 1. Tidal volume- vol of air moving in and out normally
- 2. inspiratory volume- amount of air that can be forcibly inhaled
- 3. Expiratory volume- amount of air that can be forcibly exhaled
- 4. Residual volume- remains even after strenous expiration
Explain the four interperted lung volumes.
- 1. Inspiratory volume- inspiratory + tidal
- 2. Functional residual- expiratory reserve + residual volume
- 3. Vital capacity- inspiratory + tidal + exiratory
- 4. Total lung capacity
Composition of Alveolar gas
- - alveoli contain more CO2 and water vapor than atm air due to:
- 1. gas echanges in lungs
- 2. humidification of air
- 3. mixing of alveolar gas that occurs with each breath
Roughly how long does it take for blood to exchange gases in the pulmonary capillary?
- 1/3 of the time the RBC is in the capillary.
- This allows time for gas exchange when exercising and blood pumps faster and when affinity for O2 is down.
What is Henry's Law?
mixture of gas in contact with a liquid, each gas dissolves in the liquid in proportion to its partial pressure.
Name 3 primary things that influence O2 and CO2 movement across respritory membrane.
- 1. pressure gradient and solubility
- 2. matching alveolar ventialtion and blood perfusion
- 3. structurally have thin membranes
What are dead spaces?
less frequently air exchanged, like corners in a lung
What dictates the gas exchange in the lung?
Partial pressures of CO2 and O2
Describe the conditions in the pulmonary capillaries and lung alveoli and the tissue capillries and ateries.
- Pulmonary- low O2 and high CO2
- lung alveoli- high O2 and low CO2
- Ateries- high O2 and low CO2
- tissue- low O2 and high CO2
Define Ventilation and Perfusion.
- -Ventilation- amount of gas reaching the alveoli
- -Perfusion- blood flow reaching the alveoli
- -ventilation and perfusion must be match for efficent gas exchange
Which alveoli are chosen by the capillaries for diffusion?
- -alveoli wih high O2 have large arterioles
- -alveoli with high CO2 have small arterioles
- -circulatory changes in response to gas concentrations
Describe the relationship between O2 and Hb.
- -Loading and unloading of O2 is facilitated by change in shape of Hb
- -As O2 binds Hb affinity for O2 increases and vise versa
- - fully saturated if 4 heme groups carry O2
- partially saturated if 1-3 heme groups carry O2
What is the difference between exercising tissues and resting tissues with regaurd to saturation?
O2 is only partially saturated at 25% during exercise.
Resting tissue are fully saturated
What are some other factors that influence Hemoglobin Saturation?
- -Increases in temp, H+, P of CO2, and BPG
- - modify structure of hemoglobin and decrease its affinity for O2
- -Occur in systemic capillaries
- -enhance O2 unloading
- -Shift the O2 hemoglobin dissociation curve to the right
- -decreases in these factors shift the curve to the left
What ultimately controls and regulates breathing rate?
CO2 levels because the exchange in pressure is much smaller and therefore more sensitive. about 5mm Hg
What gas makes the blood more acidic?
- CO2 makes acidity rise, O2 makes it more basic
- - ranges from 7.2- 7.4 -7.6
Factors that Increase Release of O2 by Hemoglobin
- -As cells metabolize glucose:
- - P CO2 and H+ increase in concentration in capillary blood ( declining pH weakens hemoglobin- O2 bond) aka Bohr Effect
- -Heat production increases, directly and indirectly decreases Hb affinity for O2
Explain affinity and pH in the blood.
- higher acidity = lower O2 binding
- higher basic = higher O2 binding
What is Hypoxia?
- -too low O2 for metabolism
- - inadequate delivery to tissues
What causes hypoxia?
- -too few RBC
- -abnormal or too little Hb
- -blocked circulation
- -metabolic poisons
- -pulmonary disease
- -carbon monoxide
What three forms is CO2 transported in the blood as?
- 1. 7-10% dissolved in plasma
- 2. 20% bound to globin of Hb (carbaminohemoglobin)
- 3. 70% transported as bicarbonate ions in plasma (HCO3-)
- 4. plasma as HCO3-
Explain the chloride shift in exchange of CO2.
-Outrush of HCO3- from RBCs is balances as Cl- moves in from the plasma
What happens in the Cell tissue systemic capillaries?
- - trace amts of O2 diffuses in plasma
- - HbO2= O2+ Hb = deoxyhemoglobin
- -O2 flows into interstitial fluid due to pressure gradient
- -CO2 flows into the plasma and RBC
Why doesnt O2 bind back with the Hb?
the blood is always flowing in the capillaries bringing a fresh supply.
Transport and Exchange of CO2
- In pulmonary capillaries-
- - HCO3- moves into the RBC and binds with H+ and to form H2CO3
- - H2CO3 splits by carbonic anydrase into CO2 and water
- - CO2 diffuses into the alveoli
What is the Haldane effect?
- -the amount of CO2 transported is affected by PO2
- - the lower the PO2 and Hb saturation with O2, the more CO2 can be carried in the blood
- -More CO2 enters the blood the more oxygen dissociates from hemoglobin
- - as HbO2 releases O2, it more readily forms bonds with CO2 to form carbaminohemoglobin
Name the three areas of the Medulla and what their function is.
- Pontine Respriatory Center- overall control and smooths breathing
- Ventral Respiratory Group- Controls Rhythm
- Dorsal Respriratory Group-Modifies VRG with information from receptors
The pontine receptor can be controlled by signals from what to areas of the body?
The brain and the carotid and aortic bodies
What is Hyperventilation?
increased depth and rate of breathing. Exceeds bodies need to expell CO2 (hypocapnia)
What condition occurs when the PCO2 is abnormally low?
When does the body raise alert about dropped O2 levels?
- below 60mm Hg
- - cause respiratory centers to increase ventiliation
Chemical facors that influence respiration
- -pH can modify respiratory rate and rhythm even when O2 and CO2 are normal
- - decreased pH may reflect CO2 retention, accumulation of lactic acid, excess ketone bodies in patients with diabetes mellitus
- - respiratory system controls will attempt to raise the pH by increasing respiration rate and depth
What three features can adjust the body for exercise?
- Psychological stimuli- anticipation
- Simultaneous cortical motor activation of skeletal muscles and respiratory centers
- Excitatory impulses reaching respiratory centers from muscles
- - not driven by O2, CO2 or pH - too late
Acclimatization to high altitude
- -chemoreceptors become more responsive to PCO2 when PO2 declines
- - Substantial decline in PO2 directly stimulates peripheral chemoreceptiors
- -results in minute venilation increases and stabilize in a few days to 2-3 L/min higher than at sea level
- - Decline in blood O2 stimulates the kidneys to accelerate production of EPO
Name and describe three types of obstructive pulmonary diseases.
- Emphysema- enlargement of alveoli, require more muscles to breathe, barrel chest reduces flexibility
- Chronic bronchitis- muccous build up, inflammation, constriction of bronchiols for airway obstruction
- asthma- allergic reaction, often immue system caused, result of inflammation