this unit covered a few basic biochemical ideas about the way that oxygen and carbon dioxide are transported by the blood. oxygen is mainly transported in the bound form to hemoglobin, oxyhemoglobin, and thus the uptake and release of oxygen to and from the blood is governed by the oxyhemoglobin saturation curve, a sigmoidal shaped curve which describes the relative saturation of oxygen for a given PO2. this graph ties in with the previous lecture on gas exchange, in which we covered all the PO2 and PCO2s for the atmosphere, arteries, body tissues, and veins. looking at these numbers using the dissociation curve, we find that at the arterial PO2 of 95 mmHg, hemoglobin is ~97% saturated and at the venous PO2 of 40 mmHg, hemoglobin is ~70% saturated -- this difference in saturation represents oxygen's unloading from the blood. we then look at factors that can shift the dissociation curve to the right (essentially saying that for a given partial pressure, hemoglobin affinity for oxygen has decreased). these factors are: increased H+ production, which causes conformational changes in hemoglobin that reduces its affinity to oxygen, increased temperature, and increased 2,3-DPG, which competes for O2 binding sites on Hb.
carbon dioxide is transported as a dissolved gas (7%), bound to hemoglobin (23%), but mainly in the form of bicarbonate ion (70%). this conversion to bicarbonate is facilitated by carbonic anhydrase, which converts dissolved CO2 into carbonic acid, H2CO3, which then dissociates into H+ and bicarbonate ion, HCO3-. this reaction is important because it also is the common pathway which describes the mechanism for both the bohr and the haldane effect. the bohr effect can be summed up as: increased CO2 production in body tissues and uptake into the blood facilitates O2 release into tissues. this occurs when CO2 is converted to carbonic acid, and thus H+ and bicarbonate-- the H+ binds to hemoglobin and as described above decreases its affinity for O2, allowing it to be released into the tissues. the haldane effect is the opposite: increased O2 uptake in the lungs facilitates CO2 release. this happens because O2 binds to hemoglobin and causes the release of H+ protons, which then combine with bicarbonate and form carbonic acid, which is converted back into CO2 via carbonic anhydrase, which is then released into the air.
questions
1. what are the ways in which O2 is transported in the blood and the relative percentage of each?
2. what is the saturation level of hemoglobin in arterial blood?
3. what is the saturation level of hemoglobin in venous blood?
4. what would the saturation level of hemoglobin be if PO2 was at 160mmHg, the atmospheric PO2?
5. what are three factors that can shift the hemoglobin saturation curve to the right?
6. what are the ways in which CO2 is transported in the blood and the relative percentage of each?
7. describe the formation of bicarbonate ion from dissolved CO2.
8. what is the enzyme that catalyzes the formation of carbonic acid?
9. what is the "chloride shift"?
10. describe the bohr effect.
11. describe the haldane effect.
answers
1. 3% as a dissolved gas, 97% bound to hemoglobin.
2. ~97%
3. 70%
4. >99%
5. decreased pH, increased temperature, increased concentration of 2,3-DPG
6. 7% as a dissolved CO2 gas, 23% bound to hemoglobin, 70% as bicarbonate ion.
7. dissolved CO2 + H2O -> H2CO3 (carbonic acid) -> H+ and bicarbonate ion.
8. carbonic anhydrase.
9. Cl- moving into cells to balance the H+ that is being dissociated from carbonic acid.
10. the bohr effect refers to hemoglobin's decreased affinity for O2 in the tissues which is caused by the increase in H+ concentration which binds to hemoglobin and changes its conformation. the increased H+ concentration in the tissues is due to higher CO2 levels from metabolism, which is converted into carbonic acid, which dissociates into H+ and bicarbonate. in short: increased CO2 in the tissues causes decreased hemoglobin affinity for O2.
11. the haldane effect is analogous to the bohr effect except in the reverse order; increased O2 in the lungs causes CO2 to be released from the blood.
Showing posts with label lungs. Show all posts
Showing posts with label lungs. Show all posts
Saturday, December 6, 2008
Tuesday, November 25, 2008
organ systems: pulmonary ventilation
pulmonary ventilation is the first unit in dr. kaminski's guest lecture on the physiology of respiration. it reviews the mechanisms for breathing and introduces a slew of terminology and ideas with which we can analyze the process of respiration. the first part was the review of the mechanics of breathing, which occurs when the pleura is expanded via the lowering of the diaphragm and the raising / expansion of the ribcage. the muscles involved in raising the ribcage are the external intercostals, sternocleidomastoid, scalenes, and serratus anterior while the muscles involved in lowering the ribcage are the rectus abdominis and the internal intercostals. the forces that are at play in the thoracic region are then looked at: the elastin in the alveoli causes it to collapse inward, countered by the elasticity of the ribcage pushing outward. the surface tension of water on the inside of the alveoli draws it inward, countered by the surfactant that is secreted in the alveoli which reduces surface tension. finally, the negative pressure (less than atmospheric) in the pleural cavity draws the lungs outward and the pleura inward.
the idea of respiratory work is then introduced. in mechanics, work = force x distance, and in respiration this is analogous to work = intrapleural pressure x displaced air. the total work of inspiration is the idealized work if all the energy of inspiration is converted directly into air movement. tissue resistance work is the work done to move the ribcage, muscles, bones, cartilage, etc. airway work is the work done to move the air itself and is analogous to the "resistance" of Q=P/R, especially in the sense that increasing or decreasing the radius of brochi has a huge effect on airway resistance and thus work. tissue resistance + airway work represents the deviation from the idealized compliance work-- these two factors create the delay after the pleura expands, before the increasingly negative pressure in the intrapleural cavity causes the lungs to expand.
the free work of expiration is the idealized work from expiration minus the tissue resistance and airway work. maybe the most important term in this section is the total work of breathing, which is the sum of the work from inspiration and expiration (and is graphically represented by the area between the two curves).
next we look at the different terms given to the breakdown of lung capacity. total lung capacity is the total air possible in the lung and is generally ~5500mL. of this, ~1000mL is untouched by respiration and is called the residual volume. what's left is the vital capacity, which is generally 4500mL. the vital capacity is made up of the tidal volume, inspiratory reserve volume, and expiratory reserve volume. the tidal volume represents the volume of air that comes in and out of the lungs during normal breathing, generally 500mL. the inspiratory reserve is the amount you can breathe in after the tidal volume, which is generally 3000mL. the expiratory reserve is the amount you can breathe out after the tidal volume, generally 1000mL. some factors that can influence vital capacity-- anatomy can play a role in that a larger body size or shape can increase VC while abnormalities like scoliosis or lung paralysis can decrease VC. physiology plays a role in that muscle strength or exertion can increase VC while decreased compliance or bronchoconstriction can reduce VC.
the last set of terms that are introduced seem to be more geared toward measurement of respiratory function. forced vital capacity represents the time it takes to exhale the vital capacity, while forced expiratory volume represents the volume or percentage of vital capacity that is exhaled within a unit time, generally 1 or 3 seconds. the FEV (1sec) for a normal, young adult is 80-90% of the vital capacity. forced expiratory flow is a measure of the flow rate during the middle of the exhalation of the vital capacity. minute respiratory volume is the volume of fresh air that is actually being exchanged in the lungs, and is analogous to cardiac output -- represented by breathing rate x tidal volume. minute alveolar volume is the same, except looking at the fresh air that is being exchanged specifically in the alveoli. finally, anatomical dead space is the volume of air from respiration that does not take place in gas exchange.
questions
1. what are the two mechanisms for respiration?
2. what are the muscles that raise the ribcage?
3. what are the muscles that lower the ribcage?
4. restful breathing is mostly ___ while vigorous breathing is mostly ___.
5. describe the force dynamics operating in the thoracic cavity due to elasticity, surface tension, and negative intrapleural pressure.
6. what is compliance, tissue resistance, and airway work?
7. what is the total work of inspiration?
8. what is the free work of expiration?
9. what is the "total work of breathing"?
10. what proportion of total body work is the work of breathing?
11. tidal volume...
12. inspiratory reserve volume...
13. expiratory reserve volume...
14. vital capacity...
15. residual volume...
16. total lung volume...
the factors that influence vital capacity:
17. normal anatomical factors...
18. normal physiological factors...
19. abnormal anatomical factors...
20. abnormal physiological factors...
21. what is forced vital capacity?
22. what is forced expiratory volume?
23. what is a normal value (percentage of vital capacity) of 1 second FEV for healthy, young, people?
24. what is forced expiratory flow?
25. what is minute respiratory volume?
26. what is minute alveolar volume?
27. what is anatomical dead space?
answers
1. diaphragm lowering and raising, ribcage raising and lowering.
2. external intercostals, parasternal internal intercostals, scalenes, sternocleidomastoid, serratus anterior
3. rectus abdominis, internal intercostals.
4. diaphramatic, rib-cage based.
5. elastin in alveolar septa causes inward recoil while elasticity in ribs and chest promotes outward expansion. water on inner surface of alveoli causes inward force, surfactant produced by alveoli counters this surface tension. negative intrapleural pressure causes alveoli to expand and chest/ribs to shrink.
6. in the respiratory system, the W=F x D equation is translated into W=Pressure X air displacement. compliance work represents the ideal work done if all energy is converted into air movement. tissue resistance work is the work done to move the bones, muscles, cartilage, etc. airway work is the work done to move the air itself and is analogous to the "R" in the Q=P/R from hemodynamics.
7. the combination of compliance, tissue resistance, and airway work.
8. the compliance work from expiration minus the tissue and airway work from expiration.
9. the work of the entire breathing cycle (the area inside the inspiration / expiration curves)
10. ~3%, no more than 5% even in heavy exercise.
11. the regular amount of air ventilated per breath, generally ~500mL
12. amount of air that can be inhaled after tidal volume, ~3000mL
13. amount of air that can be exhaled after tidal volume, ~1000mL
14. expiratory reserve + tidal volume + inspiratory reserve ~4500mL
15. amount of air still in lungs after complete exhalation, ~1000mL
16. vital capacity + residual volume, ~5500mL
17. larger body size or type increases VC
18. muscle strength or vigor of effort increases VC
19. kyphosis, scoliosis, respiratory paralysis lowers VC
20. pulmonary congestion, reduced compliance (asthma, bronchitis, etc.) lowers VC
21. time it takes to get the vital capacity out.
22. the amount of vital capacity exhaled in a given unit of time, which includes tissue resistance and airway work.
23. 90-100% of VC
24. average flow during the middle part of the FVC
25. tidal volume X respiratory rate (analagous to cardiac output), generally ~6L/min
26. the amount of fresh air that is reaching the alveoli
27. the air that filled the airways but does not participate in gas exchange, generally ~150mL
the idea of respiratory work is then introduced. in mechanics, work = force x distance, and in respiration this is analogous to work = intrapleural pressure x displaced air. the total work of inspiration is the idealized work if all the energy of inspiration is converted directly into air movement. tissue resistance work is the work done to move the ribcage, muscles, bones, cartilage, etc. airway work is the work done to move the air itself and is analogous to the "resistance" of Q=P/R, especially in the sense that increasing or decreasing the radius of brochi has a huge effect on airway resistance and thus work. tissue resistance + airway work represents the deviation from the idealized compliance work-- these two factors create the delay after the pleura expands, before the increasingly negative pressure in the intrapleural cavity causes the lungs to expand.
the free work of expiration is the idealized work from expiration minus the tissue resistance and airway work. maybe the most important term in this section is the total work of breathing, which is the sum of the work from inspiration and expiration (and is graphically represented by the area between the two curves).
next we look at the different terms given to the breakdown of lung capacity. total lung capacity is the total air possible in the lung and is generally ~5500mL. of this, ~1000mL is untouched by respiration and is called the residual volume. what's left is the vital capacity, which is generally 4500mL. the vital capacity is made up of the tidal volume, inspiratory reserve volume, and expiratory reserve volume. the tidal volume represents the volume of air that comes in and out of the lungs during normal breathing, generally 500mL. the inspiratory reserve is the amount you can breathe in after the tidal volume, which is generally 3000mL. the expiratory reserve is the amount you can breathe out after the tidal volume, generally 1000mL. some factors that can influence vital capacity-- anatomy can play a role in that a larger body size or shape can increase VC while abnormalities like scoliosis or lung paralysis can decrease VC. physiology plays a role in that muscle strength or exertion can increase VC while decreased compliance or bronchoconstriction can reduce VC.
the last set of terms that are introduced seem to be more geared toward measurement of respiratory function. forced vital capacity represents the time it takes to exhale the vital capacity, while forced expiratory volume represents the volume or percentage of vital capacity that is exhaled within a unit time, generally 1 or 3 seconds. the FEV (1sec) for a normal, young adult is 80-90% of the vital capacity. forced expiratory flow is a measure of the flow rate during the middle of the exhalation of the vital capacity. minute respiratory volume is the volume of fresh air that is actually being exchanged in the lungs, and is analogous to cardiac output -- represented by breathing rate x tidal volume. minute alveolar volume is the same, except looking at the fresh air that is being exchanged specifically in the alveoli. finally, anatomical dead space is the volume of air from respiration that does not take place in gas exchange.
questions
1. what are the two mechanisms for respiration?
2. what are the muscles that raise the ribcage?
3. what are the muscles that lower the ribcage?
4. restful breathing is mostly ___ while vigorous breathing is mostly ___.
5. describe the force dynamics operating in the thoracic cavity due to elasticity, surface tension, and negative intrapleural pressure.
6. what is compliance, tissue resistance, and airway work?
7. what is the total work of inspiration?
8. what is the free work of expiration?
9. what is the "total work of breathing"?
10. what proportion of total body work is the work of breathing?
11. tidal volume...
12. inspiratory reserve volume...
13. expiratory reserve volume...
14. vital capacity...
15. residual volume...
16. total lung volume...
the factors that influence vital capacity:
17. normal anatomical factors...
18. normal physiological factors...
19. abnormal anatomical factors...
20. abnormal physiological factors...
21. what is forced vital capacity?
22. what is forced expiratory volume?
23. what is a normal value (percentage of vital capacity) of 1 second FEV for healthy, young, people?
24. what is forced expiratory flow?
25. what is minute respiratory volume?
26. what is minute alveolar volume?
27. what is anatomical dead space?
answers
1. diaphragm lowering and raising, ribcage raising and lowering.
2. external intercostals, parasternal internal intercostals, scalenes, sternocleidomastoid, serratus anterior
3. rectus abdominis, internal intercostals.
4. diaphramatic, rib-cage based.
5. elastin in alveolar septa causes inward recoil while elasticity in ribs and chest promotes outward expansion. water on inner surface of alveoli causes inward force, surfactant produced by alveoli counters this surface tension. negative intrapleural pressure causes alveoli to expand and chest/ribs to shrink.
6. in the respiratory system, the W=F x D equation is translated into W=Pressure X air displacement. compliance work represents the ideal work done if all energy is converted into air movement. tissue resistance work is the work done to move the bones, muscles, cartilage, etc. airway work is the work done to move the air itself and is analogous to the "R" in the Q=P/R from hemodynamics.
7. the combination of compliance, tissue resistance, and airway work.
8. the compliance work from expiration minus the tissue and airway work from expiration.
9. the work of the entire breathing cycle (the area inside the inspiration / expiration curves)
10. ~3%, no more than 5% even in heavy exercise.
11. the regular amount of air ventilated per breath, generally ~500mL
12. amount of air that can be inhaled after tidal volume, ~3000mL
13. amount of air that can be exhaled after tidal volume, ~1000mL
14. expiratory reserve + tidal volume + inspiratory reserve ~4500mL
15. amount of air still in lungs after complete exhalation, ~1000mL
16. vital capacity + residual volume, ~5500mL
17. larger body size or type increases VC
18. muscle strength or vigor of effort increases VC
19. kyphosis, scoliosis, respiratory paralysis lowers VC
20. pulmonary congestion, reduced compliance (asthma, bronchitis, etc.) lowers VC
21. time it takes to get the vital capacity out.
22. the amount of vital capacity exhaled in a given unit of time, which includes tissue resistance and airway work.
23. 90-100% of VC
24. average flow during the middle part of the FVC
25. tidal volume X respiratory rate (analagous to cardiac output), generally ~6L/min
26. the amount of fresh air that is reaching the alveoli
27. the air that filled the airways but does not participate in gas exchange, generally ~150mL
Tuesday, November 18, 2008
organ systems: respiratory system anatomy I
this lecture describes the basic anatomy of the lungs and thoracic area and goes over the basics for the mechanics of breathing. the first part deals with lung anatomy. the right and left lungs are divided into upper and lower lobes by oblique fissures, and the right has a middle lobe that is delineated by the horizontal fissure. in the left lung, the lingula is a protuberance that is homologous to the right middle lobe and is formed by the cardiac notch. the lungs are further divided into 10 "bronchopulmonary" segments, which are functional units that are separated by connective tissue septa. air comes into the lungs first through the trachea, which then branches into primary, secondary, and tertiary bronchi, which branch off into the right and left lungs (primary), individual lobes (secondary), and individual bronchopulmonary segments (tertiary). the root of the lung is called the hilum and contains the pulmonary arteries, veins, nerves, and lymph nodes. within the bronchopulmonary segment, pulmonary arteries snake down the center, supplying oxygenated blood, while the pulmonary veins collect deoxygenated blood and follow the intersegmental CT septa.
next we look at the mechanics of breathing. the pleura is introduced as the bursa that surrounds the lungs and reduces friction. much like the pericardium, it has a parietal and visceral layer and is filled with a lubricating fluid. the visceral layer in this case adheres to the lungs and the parietal layer adheres to the diaphram, pericardium, and thoracic cage. the space between the visceral and parietal pleura is called the pleural cavity and is the space in which the lungs can expand into during inspiration. a couple of pathologies related to the pleura are mentioned: pleurisy is inflammation of the pleura, causing the visceral and parietal layers of the pleura to fuse together and not allow the lung any room to expand. pneumothorax is the filling of the pleura with liquid, which causes the lungs to collapse.
the structure of the ribs is looked at: ribs 1-7 are "true ribs" and insert directly into the sternum, ribs 8-10 are "false ribs" and insert onto the costal margin, and ribs 10-12 are "floating ribs" which do not insert on bone or cartilage. the ribs origin has two types of joints: costovertebral joints, which are the joints between the heads of the ribs and the articular facets of two adjacent vertebras, and costotransverse joints, which are the joints between the transverse processes of the vertebrae and the tubercle of the ribs. these joints allow the ribs to be pulled up and out, allowing the thoracic cage to increase its transverse (from side to side) as well as anterior-posterior diameters, the first step in inspiration. the external intercostal and parasternal intercostal muscles lift the ribs as the diaphram pulls the pleura downward, producing negative (below atmospheric) pressure in the pleura, which expands the lung and begins inspiration. expiration can occur passively, in which the lungs elastically recoil and the inspiration muscles relax, or actively, in which the abdominal muscles pull the ribs back out and the diaphragm pushes back upwards.
questions
1. what is the advantage of the separation of the lungs into lobes via fissures?
2. what are the upper and lower lungs separated by?
3. what is the right middle lobe formed by?
4. what is the lingula formed by and what is it homologous to?
5. what is the apex of the lung called and where does it extend to?
6. what is the root of the lung called and what does it contain?
7. describe the role of the trachea in maintaining an open airway.
8. describe the subdivision of the bronchi in relation to their location/function in the lung.
9. what is one important role of elastic tissue and smooth muscle in the lungs?
10. describe the symmetry of the primary bronchi.
11. what are bronchopulmonary segments and how many are there?
12. describe the locations of the pulmonary arteries, veins, and lymphatics in a bronchopulmonary segment.
13. describe the organization of lymph drainage in the lungs.
14. what does lymph from the lung often contain?
15. describe the location and function of the bronchial arteries and veins.
16. what effects do parasympathetic nerves have on the lungs?
17. what effect do the sympathetic nerves have on the lungs?
18. what is the pleura?
19. what does the parietal pleura adhere to?
20. what is the pleural cavity?
21. what are the costodiaphragmatic and costomediastinal recesses?
22. what is pleurisy?
23. what is pneumothorax?
24. describe the costovertebral joints.
25. describe the costotransverse joints.
26. describe the costosternal joints.
27. what are "true ribs"?
28. what are "false ribs"?
29. what are "floating ribs"?
30. describe the actions required for inspiration.
31. what are the two diameters increased during the movement of the ribs during inspiration?
32. what are the accessory muscles involved in raising of the ribs?
33. what is the diaphram and what goes through it?
34. what is the phrenic nerve and what does it innervate?
35. what is passive vs. active expiration?
origins and insertions for...
36. external oblique
37. internal oblique
38. transversus abdominis
39. rectus abdominis
40. how do the abdominal muscles aid in respiration?
41. how do the abdominal muscles move the vertebral column?
42. what do the intercostal nerves innervate and where do they originate on the spinal column?
answers
1. separation promotes more uniform expansion of the lungs, allows the upper lobes to "expand unimpeded".
2. the oblique fissure
3. the horizontal fissure
4. the cardiac notch, homologous to the right middle lobe.
5. called the cupola, and extends into neck above the 1st rib
6. called the hilum, location of passage of bronchi, pulmonary artery and vein, nerves, and lymph nodes.
7. the trachea contains cartilage rings that maintain patency, and the trachealis muscle maintains wall tension.
8. primary bronchi branch off into each lung, secondary bronchi branch off into each lobe, tertiary bronchi branch off into each bronchopulmonary segment.
9. facilitating passive expiration
10. the right primary bronchi extends down straighter than the left, allowing particulates to flow into right lung more easily.
11. there are 10 bronchopulmonary segments and they are functional units of the lung separated by CT septa and filled with tertiary bronchi.
12. the pulmonary artery flows down the middle of the segment, the pulmonary vein flows near the intersegmental CT septa, and the lymphatics follow the veins.
13. superficial and deep plexuses drain into the bronchopulmonary nodes in the hilum of the lungs.
14. lymph from the lung often contains lung macrophages which have injested carbon particles.
15. the bronchial arteries branch off of the aorta and supply the lung tissue with oxygenated blood. the bronchial veins drain deoxygenated blood from the lung tissue and follow the intercostal veins to the azygos veins.
16. the vagus nerve causes bronchoconstriction and activates mucus glands
17. bronchodilation
18. the bursa that surrounds the lungs that has a parietal and visceral layer.
19. thoracic cage, diaphragm, pericardium
20. the space in between the visceral and parietal layers that is filled with a viscous lubricating fluid.
21. the spaces in between the visceral and parietal layers of pleura into which the lung expands.
22. inflammation of the pleura that may lead to adhesions between pleural layers, limiting lung movements.
23. entry of fluid between the visceral and parietal layers of pleura causes collapse in lung.
24. joints between the head of the ribs and the facets of two adjacent vertebral bodies, with ligaments radiating outward from rib
25. joints between tubercle of the rib and transverse processes of vertebrae, with costotransverse ligaments.
26. ribs that articulate with the sternum via costal cartilage.
27. ribs 1-7, articulate directly onto sternum
28. ribs 8-10, articulate onto costal cartilage of ribs above
29. ribs 11,12, do not attach to sternum or costal cartilage.
30. the external and parasternal internal intercostal muscles raise the ribs, and the diaphragm lowers
31. the anterior poster and the transverse diameters
32. serratus posterior, levator costarum, SCM, scalenes
33. a ring of muscle around a central tendon attached along the costal margin. penetrated by IVC, aorta, esophagus
34. nerve that originates in C3,4,5, innervates fibrous pericardium, diaphragm, pancreas, gall bladder.
35. passive expiration comes from the relaxation of the inspiration muscles and the elastic recoil of the lungs. active expiration comes from abdominal muscles pulling down on the ribs, as well as pushing the diaphram upwards to collapse the lungs.
36. O: lower 8 ribs, I: iliac crest, pubis, linea alba
37. O: iliac crest, I: costal margin, linea alba, symphysis pubis
38. O: costal margin, iliac crest, I: linea alba
39. O: symphysis pubis, I: costal margin, cartilage of ribs 5,6,7
40. the rectus abdominus and obliques depress ribs during expiration
41. the rectus abdominus flexes and the obliques abduct and rotate.
42. they innervate the intercostal muscles (T1-T12) and the abdominal muscles (T6-L1)
next we look at the mechanics of breathing. the pleura is introduced as the bursa that surrounds the lungs and reduces friction. much like the pericardium, it has a parietal and visceral layer and is filled with a lubricating fluid. the visceral layer in this case adheres to the lungs and the parietal layer adheres to the diaphram, pericardium, and thoracic cage. the space between the visceral and parietal pleura is called the pleural cavity and is the space in which the lungs can expand into during inspiration. a couple of pathologies related to the pleura are mentioned: pleurisy is inflammation of the pleura, causing the visceral and parietal layers of the pleura to fuse together and not allow the lung any room to expand. pneumothorax is the filling of the pleura with liquid, which causes the lungs to collapse.
the structure of the ribs is looked at: ribs 1-7 are "true ribs" and insert directly into the sternum, ribs 8-10 are "false ribs" and insert onto the costal margin, and ribs 10-12 are "floating ribs" which do not insert on bone or cartilage. the ribs origin has two types of joints: costovertebral joints, which are the joints between the heads of the ribs and the articular facets of two adjacent vertebras, and costotransverse joints, which are the joints between the transverse processes of the vertebrae and the tubercle of the ribs. these joints allow the ribs to be pulled up and out, allowing the thoracic cage to increase its transverse (from side to side) as well as anterior-posterior diameters, the first step in inspiration. the external intercostal and parasternal intercostal muscles lift the ribs as the diaphram pulls the pleura downward, producing negative (below atmospheric) pressure in the pleura, which expands the lung and begins inspiration. expiration can occur passively, in which the lungs elastically recoil and the inspiration muscles relax, or actively, in which the abdominal muscles pull the ribs back out and the diaphragm pushes back upwards.
questions
1. what is the advantage of the separation of the lungs into lobes via fissures?
2. what are the upper and lower lungs separated by?
3. what is the right middle lobe formed by?
4. what is the lingula formed by and what is it homologous to?
5. what is the apex of the lung called and where does it extend to?
6. what is the root of the lung called and what does it contain?
7. describe the role of the trachea in maintaining an open airway.
8. describe the subdivision of the bronchi in relation to their location/function in the lung.
9. what is one important role of elastic tissue and smooth muscle in the lungs?
10. describe the symmetry of the primary bronchi.
11. what are bronchopulmonary segments and how many are there?
12. describe the locations of the pulmonary arteries, veins, and lymphatics in a bronchopulmonary segment.
13. describe the organization of lymph drainage in the lungs.
14. what does lymph from the lung often contain?
15. describe the location and function of the bronchial arteries and veins.
16. what effects do parasympathetic nerves have on the lungs?
17. what effect do the sympathetic nerves have on the lungs?
18. what is the pleura?
19. what does the parietal pleura adhere to?
20. what is the pleural cavity?
21. what are the costodiaphragmatic and costomediastinal recesses?
22. what is pleurisy?
23. what is pneumothorax?
24. describe the costovertebral joints.
25. describe the costotransverse joints.
26. describe the costosternal joints.
27. what are "true ribs"?
28. what are "false ribs"?
29. what are "floating ribs"?
30. describe the actions required for inspiration.
31. what are the two diameters increased during the movement of the ribs during inspiration?
32. what are the accessory muscles involved in raising of the ribs?
33. what is the diaphram and what goes through it?
34. what is the phrenic nerve and what does it innervate?
35. what is passive vs. active expiration?
origins and insertions for...
36. external oblique
37. internal oblique
38. transversus abdominis
39. rectus abdominis
40. how do the abdominal muscles aid in respiration?
41. how do the abdominal muscles move the vertebral column?
42. what do the intercostal nerves innervate and where do they originate on the spinal column?
answers
1. separation promotes more uniform expansion of the lungs, allows the upper lobes to "expand unimpeded".
2. the oblique fissure
3. the horizontal fissure
4. the cardiac notch, homologous to the right middle lobe.
5. called the cupola, and extends into neck above the 1st rib
6. called the hilum, location of passage of bronchi, pulmonary artery and vein, nerves, and lymph nodes.
7. the trachea contains cartilage rings that maintain patency, and the trachealis muscle maintains wall tension.
8. primary bronchi branch off into each lung, secondary bronchi branch off into each lobe, tertiary bronchi branch off into each bronchopulmonary segment.
9. facilitating passive expiration
10. the right primary bronchi extends down straighter than the left, allowing particulates to flow into right lung more easily.
11. there are 10 bronchopulmonary segments and they are functional units of the lung separated by CT septa and filled with tertiary bronchi.
12. the pulmonary artery flows down the middle of the segment, the pulmonary vein flows near the intersegmental CT septa, and the lymphatics follow the veins.
13. superficial and deep plexuses drain into the bronchopulmonary nodes in the hilum of the lungs.
14. lymph from the lung often contains lung macrophages which have injested carbon particles.
15. the bronchial arteries branch off of the aorta and supply the lung tissue with oxygenated blood. the bronchial veins drain deoxygenated blood from the lung tissue and follow the intercostal veins to the azygos veins.
16. the vagus nerve causes bronchoconstriction and activates mucus glands
17. bronchodilation
18. the bursa that surrounds the lungs that has a parietal and visceral layer.
19. thoracic cage, diaphragm, pericardium
20. the space in between the visceral and parietal layers that is filled with a viscous lubricating fluid.
21. the spaces in between the visceral and parietal layers of pleura into which the lung expands.
22. inflammation of the pleura that may lead to adhesions between pleural layers, limiting lung movements.
23. entry of fluid between the visceral and parietal layers of pleura causes collapse in lung.
24. joints between the head of the ribs and the facets of two adjacent vertebral bodies, with ligaments radiating outward from rib
25. joints between tubercle of the rib and transverse processes of vertebrae, with costotransverse ligaments.
26. ribs that articulate with the sternum via costal cartilage.
27. ribs 1-7, articulate directly onto sternum
28. ribs 8-10, articulate onto costal cartilage of ribs above
29. ribs 11,12, do not attach to sternum or costal cartilage.
30. the external and parasternal internal intercostal muscles raise the ribs, and the diaphragm lowers
31. the anterior poster and the transverse diameters
32. serratus posterior, levator costarum, SCM, scalenes
33. a ring of muscle around a central tendon attached along the costal margin. penetrated by IVC, aorta, esophagus
34. nerve that originates in C3,4,5, innervates fibrous pericardium, diaphragm, pancreas, gall bladder.
35. passive expiration comes from the relaxation of the inspiration muscles and the elastic recoil of the lungs. active expiration comes from abdominal muscles pulling down on the ribs, as well as pushing the diaphram upwards to collapse the lungs.
36. O: lower 8 ribs, I: iliac crest, pubis, linea alba
37. O: iliac crest, I: costal margin, linea alba, symphysis pubis
38. O: costal margin, iliac crest, I: linea alba
39. O: symphysis pubis, I: costal margin, cartilage of ribs 5,6,7
40. the rectus abdominus and obliques depress ribs during expiration
41. the rectus abdominus flexes and the obliques abduct and rotate.
42. they innervate the intercostal muscles (T1-T12) and the abdominal muscles (T6-L1)
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