this lecture talked about various aspects of the pharynx, including muscles, tonsils, and innervation. the first section covered structures of the mouth and teeth: philtrum is the median shallow groove in the upper lip, labia frenulum is the fold of mucosal membrane that attaches the lip to the gums, and lingual frenulum is the fold that connects the tongue to the base of the mouth. there are 32 teeth, 8 in each half of each jaw: 2 incisors, 1 canine, 2 pre-molar, and 3 molars. the crowns of the teeth are made up of dentine and enamel, and the pulp cavity inside contains nerves and blood vessels, which travel through the tooth in root canals and exit via the apical foramen. teeth are anchored to bone via the cementum and peridontium layers.
there are intrinsic muscles inside the tongue and extrinsic muscles of the tongue that attach to various structures in the pharynx and move the tongue in different directions. this includes the genioglossus, which attaches to the mental spine of the mandible and protrudes and depresses the tongue, the hyoglossus, which attaches to the hyoid bone and depresses the tongue, the styloglossus, which attaches to the styloid process of the mandible and retracts the tongue, and the palatoglossus, which attaches to the soft palate and raises the tongue. the first three tongue muscles are innervated by the hypoglossal nerve (CNXII), and the palatoglossus is innervated by the vagal nerve.
the tongue's sensory innervation can be divided into two aspects: somatosensory innervation delivers pain, touch, heat sensation from the filiform papillae of the tongue, while viscerosensory information delivers the taste information from the chemoreceptors from the valate and fungiform papillae on the tongue. on the top 1/3 of the tongue, both somatosensory and viscerosensory innervation is provided by the glossopharyngeal nerve (CNIX) while in the bottom 2/3 of the tongue, viscerosensory innervation is provided by the facial nerve (CNVII) and somatosensory by the lingual nerve (V3).
the next topic in the lecture was the pharyngeal and palatine muscles. there are several pharyngeal constrictor muscles which constrict the pharynx, all originate from the posterior pharyngeal raphe, and are all innervated by the vagus nerve. the superior constrictor attaches to the buccinator by way of the pteromandibular raphe, the middle constrictor attaches to the hyoid, and the inferior constrictor attaches to the cricoid and thyroid cartilage. the palatine muscles include the palatopharyngeus, which attaches the soft palate to the back of the throat and serves to lower the soft palate and the palatoglossus, which was covered above. the tensor veli palatini (innervated by CN V3), which originates on the base of the skull, hooks around the hamulus and tautens the palate while the levator veli palatini (innervated by the vagus nerve) lifts the palate.
tonsils are masses of lymphoid tissue which are present in 4 main places in the pharynx: the pharyngeal tonsils in the upper nasopharynx, the tubular tonsils near that auditory tube, the lingual tonsils on the posterior tongue, and the palatine tonsils, which are between the palatoglossus and the palatopharyngeus. lymph from these nodes ultimately drains into the deep cervical lymph nodes and into the venous system.
questions
lips and tongue...
1. what is the philtrum?
2. what is the labia frenulum?
3. what is the lingual frenulum?
4. what are sublingual veins used for?
teeth...
5. what are the crowns of teeth made up of?
6. what attaches the root of the teeth to the bone?
7. what is the pulp cavity made up of?
8. how many teeth are there? what are the different types?
9. which nerves innervates the teeth?
origins, insertions, actions, innervations:
10. genioglossus
11. hyoglossus
12. styloglossus
13. palatoglossus
tongue innervation...
14. which tongue muscles does the hypoglossal nerve innervate?
15. what are the two categories of sensory innervation of the tongue?
16. which nerves provide somatosensory and viscerosensory innervation to the lower 2/3 of the tongue?
17. which nerves provide somatosensory and viscerosensory innervation to the upper 1/3 of the tongue?
18. which nerves provide somatosensory and viscerosensory innervation to the palate and epiglottis?
19. what is the difference between the filiform, fungiform, and vallate papillae?
pharyngeal muscles...
20. where do the pharyngeal constrictor muscles all originate?
21. what are the pharyngeal constrictor muscles innervated by?
22. where does the superior constrictor insert?
23. where does the middle constrictor insert?
24. where does the inferior constrictor insert?
palate muscles...
25. how does the soft palate help regulate the passage of air and food?
26. how does the epiglottis help regulate the passage of air and food?
27. tensor veli palatini...
28. levator veli palatini...
29. palatopharyngeus...
30. salpingopharyngeus...
31. snoring is associated with...
32. palatopharyngeus and palatoglossus forms a ... space which contains the ...
tonsils...
33. what is waldeyer's ring?
34. what is unique about the nasopharyngeal tonsils?
35. where is the tubal tonsil located?
36. where is the palatine tonsil located?
37. where is the lingual tonsil located?
nerves and lymph nodes...
38. which nerve innervates the upper section of the oral and nasal cavities?
39. what part of the pharynx does the glossopharygeal nerve innervate?
40. what other sensations or reflexes in the pharynx does the glossopharyngeal nerve mediate?
41. which nerve innervates the lower pharynx and larynx?
42. superficial lymph nodes all drain into...
answers
1. the median shallow groove in the upper lip.
2. folds of mucous membrane that connects the lips to the gingiva.
3. folds of mucous membrane that connects tongue to the base of the mouth.
4. ingestion of medicine directly into the blood.
5. enamel and dentine.
6. cementum and peridontial membrane.
7. a root canal that exits through the apical foramen. also contains nerves and blood vessels.
8. 32 total; 8 in each half of each jaw. 2 incisors, 1 canine, 2 premolar, 3 molar.
9. upper teeth: superior alveolar (V2). lower teeth: inferior alveolar (V3).
10. O: mental spine of the mandible, I: body of tongue, N: hypoglossal (CNXII) A: depress and protrude tongue.
11. O: hyoid bone, I: body of tongue, N: hypoglossal nerve, A: depress tongue.
12. O: styloid process of mandible, I:body of tongue, N: hypoglossal nerve, A: retract tongue.
13. O: soft palate, I: body of tongue, N: vagal nerve, A: elevate tongue.
14. the extrinsic muscles of the tongue (except the palatoglossus) and the intrinsic muscles of the tongue.
15. somatosensory includes tactile, pain, temperature sensation and viscerosensory is the taste sensation.
16. SS: lingual nerve (V3), VS: facial nerve (VII)
17. glossopharyngeal (IX)
18. vagus (X)
19. filiform is pain, temperature, touch receptor; valate and fungiform are taste receptors.
20. the posterior pharyngeal raphe.
21. vagus nerve
22. buccinator via the pteromandibular raphe.
23. hyoid bone
24. thyroid and cricoid cartilage.
25. during breathing it lowers down against the tongue and during eating it raises against the pharyngeal wall.
26. ascends against the tongue during breathing and folds down over larynx during eating.
27. O: pterygoid plates, I: palatine aponeurosis, N: V3, A: tauten palate, open auditory tube.
28. O: base of skull I: pterygoid processes, N: vagus A: raise soft palate and open auditory tubes.
29. O: thyroid cartilage, I: soft palate, N: vagus, A: depress soft palate
30. O: auditory tube, I: pharynx, N: vagus, A: open auditory tubes.
31. obstructions in the soft palate region.
32. triangular space which contains the palatine tonsil.
33. the ring of lymphoid tissue that contains: pharyngeal, tubal, palatine, lingual tonsils.
34. they are the uppermost part of the nasopharynx and can commonly become inflamed (enlarged adenoids) and block the passage of air.
35. near the auditory tube.
36. between the "pillars of fauces".
37. on the posterior surface of the tongue.
38. trigeminal: V2,V3
39. upper pharynx, auditory tube, tonsils
40. gag reflex, sore throat pain.
41. vagus
42. deep cervical lymph nodes.
Showing posts with label tonsils. Show all posts
Showing posts with label tonsils. Show all posts
Friday, March 20, 2009
Wednesday, December 3, 2008
histology: vascular system
this lecture covers the circulatory system and the lymphatic system. the main types of blood vessels are reviewed (we covered this in organ systems already in much greater detail). arteries supply oxygenated blood to tissues and have three basic layers: the innermost layer is the tunica intima and has a squamous endothelium, subendothelial CT, and internal elastic lamina. the middle layer is the tunica media and has smooth muscle and external elastic lamina. the outermost layer is the tunica adventitia which has connective tissue that blends in with surrounding CT, with a network of blood vessels (vasa vasorum) and nerves (nervi vascularis). arterioles are the next level after arteries, which have a thicker smooth muscle tunica media layer which aids in their function, which is mainly to regulate blood flow to capillary beds. there are three types of capillaries which are distinguished by size and continuity of the endothelium: type 1 continuous, which have a tight endothelium which do not allow much leakage, type 2 fenestrated, which allow for some leakage and are present in the renal glomerulus, and type 3 discontinuous, which are much larger and have huge holes that allow for entire cells to pass through- found in the bone marrow, spleen, and liver. after the capillaries come the venules and veins, which are different from arteries in that they have no internal elastic lamina, a thinner tunica media, and rely on the contraction of skeletal muscle and a series of valves for blood flow back to the heart.
the lymphatic system is a sort of complementary system to the circulatory system in that it recirculates body fluids which have been picked up from the interstitial space outside of capillaries. it also functions in red blood cell production and destruction, aids in immunodefense (in the production and circulation of lymphocytes), and aids in fat absorption in the GI tract (think of the central lacteal in the lamina propria of the small intestine). there are several orders of lymphatic organization, the first of which is diffuse lymph tissue, which is just a scattering of lymphocytes in a general area, such as right underneath the epidermis in the airways or GI tract. next is nodular lymph tissue, which are more discrete aggregations of lymphocytes which might have germinal centers in the middle for profilerating new cells- such as the Peyer's patches in the ileum. next is a lymph node, which is an encapsulated "inline filter" for lymph vessels, a small container into which lymph gets poured in through many afferent lymphatic vessels, filtered through the subcapsular and medullary sinuses, and poured back out through a larger efferent lymphatic vessel.
finally, we get to the lymph organs, which are large scale lymph and blood filtering factories. first is the spleen, the functional part of which is called the splenic pulp, which comes in two varieties- red and white. the red is the bulk of the spleen and is filled with RBC's, and white pulp are little islands of lymphocytes that are found alongside blood vessels. the tonsils are another lymph organ, consisting of a series of lymphatic tissue masses covered by a stratified squamous epithelium which is thrown into "crypts". the thymus is the third and last lymph organ, and is a bi-lobed organ beneath the sternum in which t-lymphocytes are trained to differentiate self from non-self.
questions
1. what are the three basic layers to arteries?
2. describe the tunica intima layer of arteries.
3. describe the tunica media layer of arteries.
4. describe the tunica adventitia layer of arteries.
5. what is an arteriole?
6. what are three major differences between veins and arteries?
7. what is a venule?
8. what are the three types of capillaries?
9. describe type I capillaries.
10. describe type II capillaries.
11. describe type III capillaries.
12. what are the main functions of the lymphatic system?
13. describe lymphatic vessels.
14. what are the two types of lymphoid tissue?
15. describe diffuse lymphoid tissue.
16. describe nodular lymphoid tissue.
17. what are the four examples of lymph organs?
18. describe the structure of a lymph node.
19. what is the flow through a lymph vessel?
20. describe the structure of the spleen.
21. what is the thymus?
22. describe the structure of the tonsils.
answers
1. tunica intima, tunica media, tunica adventitia.
2. tunica intima is the innermost layer of an artery and contains squamous endothelium, sub endothelial CT, and internal elastic lamina.
3. tunica media is the middle, thickest layer that contains smooth muscle with elastin.
4. tunica adventitia is the outermost layer containing CT with a network of blood vessels (vasa vasorum) and nerves (nervi vascularis)
5. an artery with a luminal diameter of less than 100um that plays a role in distributing and controlling entry of blood into capillary beds.
6. no internal elastic lamina, relatively thin tunica media, and endothelium is thrown into valves to prevent backflow.
7. a vein with a luminal diameter of less than 200um.
8. type 1 continuous, type 2 fenestrated, type 3 discontinuous.
9. the most common capillary in the body, the endothelium is held tightly together and is relatively leak proof.
10. small holes in endothelium allow some leakage, seen in glomerulus, exocrine ducts, choroid plexus.
11. larger (up to 30um) diameter with large holes in endothelium that allow entire cells to pass, seen in liver, bone marrow, spleen.
12. recirculation of body fluids, defense, hematopoeisis (adding lymphocytes), recycling RBC's (spleen), absorption of fat in GI tract. recirculate blood in defense of fat recycling.
13. vessels that gather and remove excess tissue fluid from capillaries and circulate back into venous system. rely on skeletal muscle and valve system for pumping (much like veins).
14. diffuse and nodular
15. scattering of lymphocytes; often associated with epithelial linings of GI tract and respiratory airways.
16. semi discrete (but unencapsulated) mass of lymphocytes, sometimes with a germinal center where new cells proliferating.
17. lymph nodes, spleen, tonsils, thymus.
18. encapsulated mass of lymph nodules that serves as an in line filter (for lymph) with multiple afferent "feeder" lines and one or two efferent "drainer" lines.
19. afferent lymph vessel, subcapsular sinus, medullary sinus, efferent lymphatic vessel.
20. inline filter (for blood) with two types of "pulp" in the parenchyma: red pulp is the bulk of the spleen and has masses of RBC's, white pulp is small lymphocytes islands associated with blood vessels.
21. a bilobed t-lymphocyte manufacturing center underneath the sternum
22. series of masses of lymphoid tissue with stratified squamous epithelium thrown into crypts that cover aggregations of nodules.
the lymphatic system is a sort of complementary system to the circulatory system in that it recirculates body fluids which have been picked up from the interstitial space outside of capillaries. it also functions in red blood cell production and destruction, aids in immunodefense (in the production and circulation of lymphocytes), and aids in fat absorption in the GI tract (think of the central lacteal in the lamina propria of the small intestine). there are several orders of lymphatic organization, the first of which is diffuse lymph tissue, which is just a scattering of lymphocytes in a general area, such as right underneath the epidermis in the airways or GI tract. next is nodular lymph tissue, which are more discrete aggregations of lymphocytes which might have germinal centers in the middle for profilerating new cells- such as the Peyer's patches in the ileum. next is a lymph node, which is an encapsulated "inline filter" for lymph vessels, a small container into which lymph gets poured in through many afferent lymphatic vessels, filtered through the subcapsular and medullary sinuses, and poured back out through a larger efferent lymphatic vessel.
finally, we get to the lymph organs, which are large scale lymph and blood filtering factories. first is the spleen, the functional part of which is called the splenic pulp, which comes in two varieties- red and white. the red is the bulk of the spleen and is filled with RBC's, and white pulp are little islands of lymphocytes that are found alongside blood vessels. the tonsils are another lymph organ, consisting of a series of lymphatic tissue masses covered by a stratified squamous epithelium which is thrown into "crypts". the thymus is the third and last lymph organ, and is a bi-lobed organ beneath the sternum in which t-lymphocytes are trained to differentiate self from non-self.
questions
1. what are the three basic layers to arteries?
2. describe the tunica intima layer of arteries.
3. describe the tunica media layer of arteries.
4. describe the tunica adventitia layer of arteries.
5. what is an arteriole?
6. what are three major differences between veins and arteries?
7. what is a venule?
8. what are the three types of capillaries?
9. describe type I capillaries.
10. describe type II capillaries.
11. describe type III capillaries.
12. what are the main functions of the lymphatic system?
13. describe lymphatic vessels.
14. what are the two types of lymphoid tissue?
15. describe diffuse lymphoid tissue.
16. describe nodular lymphoid tissue.
17. what are the four examples of lymph organs?
18. describe the structure of a lymph node.
19. what is the flow through a lymph vessel?
20. describe the structure of the spleen.
21. what is the thymus?
22. describe the structure of the tonsils.
answers
1. tunica intima, tunica media, tunica adventitia.
2. tunica intima is the innermost layer of an artery and contains squamous endothelium, sub endothelial CT, and internal elastic lamina.
3. tunica media is the middle, thickest layer that contains smooth muscle with elastin.
4. tunica adventitia is the outermost layer containing CT with a network of blood vessels (vasa vasorum) and nerves (nervi vascularis)
5. an artery with a luminal diameter of less than 100um that plays a role in distributing and controlling entry of blood into capillary beds.
6. no internal elastic lamina, relatively thin tunica media, and endothelium is thrown into valves to prevent backflow.
7. a vein with a luminal diameter of less than 200um.
8. type 1 continuous, type 2 fenestrated, type 3 discontinuous.
9. the most common capillary in the body, the endothelium is held tightly together and is relatively leak proof.
10. small holes in endothelium allow some leakage, seen in glomerulus, exocrine ducts, choroid plexus.
11. larger (up to 30um) diameter with large holes in endothelium that allow entire cells to pass, seen in liver, bone marrow, spleen.
12. recirculation of body fluids, defense, hematopoeisis (adding lymphocytes), recycling RBC's (spleen), absorption of fat in GI tract. recirculate blood in defense of fat recycling.
13. vessels that gather and remove excess tissue fluid from capillaries and circulate back into venous system. rely on skeletal muscle and valve system for pumping (much like veins).
14. diffuse and nodular
15. scattering of lymphocytes; often associated with epithelial linings of GI tract and respiratory airways.
16. semi discrete (but unencapsulated) mass of lymphocytes, sometimes with a germinal center where new cells proliferating.
17. lymph nodes, spleen, tonsils, thymus.
18. encapsulated mass of lymph nodules that serves as an in line filter (for lymph) with multiple afferent "feeder" lines and one or two efferent "drainer" lines.
19. afferent lymph vessel, subcapsular sinus, medullary sinus, efferent lymphatic vessel.
20. inline filter (for blood) with two types of "pulp" in the parenchyma: red pulp is the bulk of the spleen and has masses of RBC's, white pulp is small lymphocytes islands associated with blood vessels.
21. a bilobed t-lymphocyte manufacturing center underneath the sternum
22. series of masses of lymphoid tissue with stratified squamous epithelium thrown into crypts that cover aggregations of nodules.
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