Exam 3 Study Guide Questions Flashcards
Why is the nose better than the mouth for breathing purposes? Which type of tissue is most responsible for making the nose better?
Filters/cleans air, pseudostratified ciliated columnar epithelium (also found in nasopharynx)
What are the three regions of the pharynx? Into which does the pharyngotympanic/auditory/eustachian tube drain? Which allow both food and air to pass through?
nasopharynx, oropharynx, laryngopharynx
nasopharynx (drain)
oropharynx (food and air passes)
Which two cartilage tissues make up the larynx? Which forms the epiglottis and why is that an important structure/function relationship?
Hyaline cartilage (rigid), elastic cartilage (epiglottis - flexible flap that can open and close)
Describe the mechanism by which you can vocalize and adjust volume and pitch.
Small space between true vocal folds (cords) allows air to be pushed through on exhalation creating vibration and resonance in the chamber emitted out of mouth. Force of exhalation generates stronger amplitude of sound waves (volume) and greater/lesser stretch of vocal cords creates frequency (more stretch, higher pitch).
What are the three tissue layers of the trachea? Which best transports mucous? What structure keeps the trachea from collapsing during negative pressure breathing?
Hyaline cartilage - keeps trachea from collapsing, smooth muscle, pseudostratified ciliated columnar
epithelium - transport mucous
What type of bronchi channels air to individual lobes?
Secondary or lobar bronchi
Which tissue is most responsible for constriction and dilation in bronchioles? What is the last type of bronchiole before entering an alveolar duct?
Smooth muscle
Respiratory bronchiole
What are the 3 general processes of respiration? In which would CO2 be exchanged between blood and the lungs?
Ventilation, internal and external respiration
External respiration
List in order from nose to alveoli the pathway for air entering the body.
Nares ➡️ nasal conchae and meatuses ➡️ nasopharynx ➡️ oropharynx ➡️ laryngopharynx ➡️ larynx ➡️ trachea ➡️ primary bronchi ➡️ secondary and tertiary bronchi ➡️ bronchioles ➡️ terminal bronchioles ➡️ respiratory bronchioles ➡️ alveolar ducts ➡️ alveolar sacs ➡️ alveoli
The simple squamous cells of these two structures create the gas/blood exchange surfaces in respiration.
Alveolus, pulmonary capillary
These cells secrete surfactant. What does the surfactant do to ease breathing?
Type Il pneumocytes, surfactant reduces surface tension (increases ability to inflate alveolus)
Contrast Atmospheric pressure (Patm), Alveolar pressure (Palv), and generally define Pleural pressure (Pip).
Patm = pressure of air outside the body
Palv = air pressure in alveolus (can be changed by inspiration/expiration)
Pip = pressure between inside rib cage and outside of lung
Total lung capacity
5800 mL
Inspiratory lung capacity
3500 mL
Vital capacity
4600 mL
Functional residual capacity
2300 mL
Residual volume
1200 mL
If your diaphragm contracts, why does air enter your lungs?
Diaphragm contracts “down” to increase volume of thoracic cavity and reduces Palv. So Patm > Palu, air moves down pressure gradient (outside air to alveolus).
If your diaphragm relaxes, why does air leave your lungs?
Diaphragm moves up in relaxation to decrease volume of thoracic cavity and increases Palv. So Palv> Patm, air moves down pressure gradient (alveolus to outside air).
If you forced expiration, which additional muscles would participate?
Internal intercostal muscles “squeezes” rib cage/thoracic cavity further increasing Pal
What is left after you have expired all of your respiratory reserve volume?
Residual volume - 1200 ml
What is a normal tidal volume? When might you increase it?
500 ml - resting breathing, exercise
Tidal volume
500 mL
Inspiratory reserve volume
3000 mL
Expiratory reserve volume
1100 mL
Why does O2 move from alveoli to pulmonary capillaries?
PO2 in air sac = 100 mmHg and PO2 in pulmonary capillaries returning to lungs from tissues is = 40 mmHg.
This creates partial pressure gradient and O2 diffuses through epithelial layers of air sac and capillary into bloodstream.
Why does CO2 move from the blood to lungs (or tissues to blood) just as well as O2 even though it has a much smaller partial pressure gradient?
CO2 is more soluble - travels/diffuses better than O2
Why does O2 always move from blood to tissues? How is 98% of O2 delivered in blood?
PO2 blood = 100 mmHg and PO2 tissues = 20-40 mmHg.
Partial pressure gradient from blood to tissues.
98% delivered by Hemoglobin (Hb)
Even though O2 content might be substantially different between sea level and 6,000 ft of elevation, O2 saturation of Hb for people in those two locations is very close. Why?
Hb has high affinity for O2 over wide range of PO2. Flat top of saturation curve.
What does lower pH do to the O2 saturation curve (Bohr effect)?
Lower pH, higher PCO2 and higher temp will each shift O2 saturation curve to right meaning at any given PO2 pressure, Hb will release more O2 at that pressure. Each condition changes the shape of Hb slightly so affinity is decreased. Think exercise and higher demand for O2.
How is most CO2 transported in blood? Which enzyme assists in its temporary conversion? Conversion to what?
CO2 + H20 with help of carbonic anhydrase ➡️ H2C03- (carbonic acid) ➡️ HCO3- and H+ (travels in this
form)
Which part of the medullary respiratory center stimulates the diaphragm?
Dorsal group
What does the pontine respiratory group do to breathing?
Controls switching between inspiration and expiration (rhythm).
Contrast limbic vs cortical respiratory control.
Limbic - primitive emotions (anger, fear, etc) can affect breathing as limbic includes hypothalamus which has “override” regulation of pons and medulla
Remember medulla, pons and limbic are all subconscious control.
Cortical (consciousness/voluntary) - you think/control respiration but there are limits (hold your breath).
Which gas influences breathing most?
CO2 drives breathing the most. Primarily picked up by medullary (central) chemoreceptors. pH and PO2 primarily affect aortic/carotid bodies (peripheral) chemoreceptors.
If you inhaled an irritant to the bronchioles, what would be the response?
Cough reflex - so that it will not move further into airways/alveoli.
What muscles are involved in labored breathing?
Abdominal muscles
Exercise may induce increased respiration. Why?
CO2 builds up in bloodstream as muscle cells are more metabolically active (cell respiration producing
CO2 as byproduct) which also reduces pH. O2 demand as O2 used/depleted by muscles.
Contrast COPD/emphysema and asthma.
Bronchitis - inflammation of airways by irritants (smoke, work chemicals)
Emphysema - destruction of alveolar walls which reduces surface area, gas exchange and ability to exhale forcefully.
Bronchitis + emphysema = COPD chronic obstructive pulmonary disease, chronic = long term
Asthma - hypersensitivity immune reaction to irritants/allergens (most common) causing inflammation and smooth muscle bronchoconstriction, acute/temporary
What is the genetic defect in cystic fibrosis? What does that do to mucous?
Mutation causes synthesis of defective C- transport channels causing mucous to be thicker and more viscous which reduces airflow/exchange and increases risk of infection.
Common pathway
Activated Factor X ➡️ Prothrombinase ➡️ Thrombin ➡️ Activated Factor XIII & Fibrin ➡️ Fibrin clot
The pleural cavity is lined with a _____ membrane.
Serous
Describe the general components of blood as a connective tissue.
Cells in a matrix.
Formed elements are red blood cells (erythrocytes), white blood cells (leukocytes) and platelets
Matrix -liquid plasma with proteins
Which cells of blood make up 99% of total cells?
Red blood cells
ID the three major plasma proteins and their general functions.
Albumins - osmotically active proteins that draw H2O to them
Fibrinogen - precursor to fibrin which is the major clotting protein
Globulins - mostly antibody proteins active in immune function
Air moves from an area of ______ pressure to an area of ______ pressure.
High; low
How would the structural and functional characteristics of erythrocytes and leukocytes differ?
Erythrocytes - ghost cells, without nucleus, chocked full of Hb, biconcave
Leukocytes - full nucleus, some with a lot of lysosomes, agranular /granular
Specifically hemoglobin has ________
which physically attaches/detaches oxygen.
Fe as part of the heme group, 4 per Hb so 4 O2 per Hb
What form does Hb take when holding Oz? How about when it loads CO2? (overlap with Ch 23)
Oxyhemoglobin
Carbaminohemoglobin
Once a hemocytoblast commits to the erythrocyte line, the cell is called a _____
proerythroblast
What stimulates EPO production? What is the primary site of EPO synthesis?
Decreased O2
Kidney
Cite the negative feedback loop for erythropoiesis
Low O2 (ex high altitude) stimulates kidney to increase EPO synthesis which travels through the blood stream and activates red bone marrow to make new RBCs which carry/deliver more O2 in blood
Describe the process whereby hemoglobin is hydrolyzed and most molecules are recycled and reused.
Hb endocytosed by macrophage
Globin (of hemoglobin) amino acids recycled
Heme is broken down to Fe and rest of heme
Fe binds transferrin and carried to red bone marrow to make new RBCs
Non Fe part of here is converted to bilirubin, added to bile and excreted by gut
What two functions make movement out of the capillaries and towards an area of infection possible for leukocytes/WBCs?
Diapedesis - leukocytes escape capillaries, squeeze between endothelial cells of cap wall
Chemotaxis - leukocyte follows chemical “bread crumb” trail
What type of leukocyte makes up the greater number of the 1% of total leukocytes in blood? What is their major function and how do they accomplish it?
Neutrophil
Destroy microbes (lysozymes) and phagocytosis to eat
A WBC count shows elevated eosinophils. What may be the problem?
Allergies, parasitic infection
Functional _____ are similar to mast cells because they release _____ which causes the _____ response.
Basophils
Histamine
Inflammatory
Which type of lymphocyte produces antibodies?
B lymphocytes
Longer term infections would activate monocytes into their phagocytic form known as the ____
macrophage
After the herocytoblast, the cell which would give rise to all the granular leukocytes is the _____
myeloblast
Which molecule is released by damaged endothelial cells of blood vessels resulting in vasospasm?
endothelin
Name two chemicals involved in platelet plug formation. What are their functions?
Von Willebrand Factor - connects exposed “raggedy” collagen to platelets
ADP/thromboxanes - activate more platelets
Fibrinogen - connects platelets
Ultimately, all the chemical reactions for coagulation will wind up in making the protein _____ which will _____
Fibrin
clot
What stimulates activation of prothrombin? Once activated, what two things does thrombin stimulate? Name thrombin’s inorganic helper.
Prothrombinase
Activates factor XIII
Fibrinogen to fibrin
Fibrin and factor XIlI form clot
Ca++
Why and how does fibrinolysis occur? What is the final enzyme that makes it happen?
Repair has occurred, clot dissolves gradually
Plasminogen activated to plasmin which hydrolyzes fibrin
Antigens (aka agglutinogens) occur as surface markers on your erythrocytes. Antibodies (aka agglutinins) float freely in your bloodstream poised to attack surface markers which are considered foreign.
a. How do you know that someone with AB blood can receive blood from almost anyone without a transfusion reaction?
b. How do you know that someone with O blood can donate to almost anyone without a transfusion reaction?
c. Why can a transfusion reaction be fatal?
a. AB antigen on RBC but no Anti A or anti B antibody so no antibodies to react with donors RBC antigen surface marker
b. O has neither A nor B antigen surface marker so recipient antibodies don’t attack
c. Agglutination reaction - cells and antibodies clump together which decreases flow and 02 delivery, potentially fatal
What are the basic functions of the lymphatic system?
Fluid balance (Capillaries “push” approx. 3L into interstitial fluid which becomes lymph).
Lipid absorption via lacteals and chyle.
Filters/cleans fluid as returns to venous circulation.
Describe the general path of lymph as it returns to the venous circulation.
Lymph capillaries ➡️ lymph vessels (and nodes) ➡️ lymph trunks ➡️ lymph ducts ➡️ subclavian veins
How do one-way valves within the lymphatic system help lymph return?
(in lymph capillaries) Because lymph is under very low hydrostatic pressure, one-way valves keep lymph from moving backwards (retrograde) so movement always towards vessels/nodes
Name the lymphocytes found in the lymphatic system. What are their functions?
B and T lymphocytes (part of adaptive immunity - make antibodies and attack antigens respectively)
Macrophage - major phagocytic innate immunity leukocyte (mature version of monocyte)
Dendritic cells - monitor antigens and present to T lymphocytes
Describe the general structure and function of lymph nodes regarding germinal centers, lymph circulation and overall effect on directionally filtering lymph.
Lymph enters node via afferent vessels, node divided into medullary (inner region - cords and sinuses) and cortex (outer region - follicles containing germinal centers)
Dendritic cells around follicles/nodules
Germinal centers grow new B cells
Cords contain working Ts and Bs (plasma cells are type of B)
Sinuses contain macrophage
Lymph exits node via efferent vessels (fewer so slows lymph flow - more time for immune cells to work)
State the red and white pulp functions of the spleen. Where does most of the lymphocyte activity reside?
Red pulp - filters blood of pathogens, recycling of erythrocytes
White pulp - most immune function and lymphocyte production
Other than T-cell maturation, name a function of thymic corpuscles and the cell type involved.
Thymic corpuscles form regulatory T cells (which prevent attack of own cells/autoimmunity)
What MALTs are located in connective tissue surrounding the digestive system? What is their purpose?
Peyer’s patches - MALTs surround areas where environmental exposure to pathogens is increased due to access and proximity so these patches surround the digestive tract to remove pathogens which could be absorbed into body from the Gl tract (especially the small intestine)
What is the “scary place” that bacteria go to be killed within the tonsils?
Tonsillar crypts trap deep in tonsil tissue.
In which two general locations would you find innate defense mechanisms? Name two related mechanical and two chemical defenses.
Skin and mucous membranes
Cilia, vomiting
Lysozyme, gastric juice
How do interferons reduce viral infection?
Produced by infected cells (which will die to stimulate neighbor healthy, yet uninfected cells to produce antiviral proteins.
What are three ways in which the complement system improves immune response?
Opsonization - coat microbes with complement protein which allows for better recognition by phagocytes
Cytolysis- insert complement protein “channel” into microbe which causes fluid to enter and burst microbe
Inflammation - complement protein stimulates mast cell release of histamine which increases vasodilation/capillary permeability to improve delivery of phagocytes.
Describe the process of phagocytosis.
Chemotaxis by neutrophil or macrophage to site of microbe concentration. Microbe engulfed by cell to form pseudopod which has vesicle around it called phagosome. Lysosome binds phagosome to create phagolysosome where hydrolytic enzymes destroy microbe. Residual body contains microbe parts and is usually dumped through exocytosis.
What are the “cardinal” signs of inflammation?
Redness, heat, swelling, pain, (sometimes) loss of function
Which phagocytes will use chemotaxis and phagocytosis as actions to destroy microbes? Define these two actions. Which responds first?
Neutrophils and macrophage
Chemotaxis -follow the “bread crumb” trail of cell debris/chemicals released during damage/death
Phagocytosis - cell eating
Neutrophils respond first.
Which cells lyse tumor and virus-infected cells?
Natural killer (NK) cells
What are the symptoms of local inflammation? What is actually happening to cause these symptoms? Why is this beneficial within limits?
Local inflammation - redness, heat, swelling, pain, sometimes loss of function
Increased vasodilation and capillary permeability increased blood flow and fluid movement to interstitial space
Delivers phagocytes to region.
What are the chemicals which initiate fever called? Name one benefit of moderate fever.
Pyrogens
Improves performance of immune system cells (increased metabolism/activity) and reduces effectiveness of microbe/ pathogens with narrow optimal temperature range
Is oxygen more soluble in blood or carbon dioxide?
Carbon dioxide (20x more soluble than in blood)
