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Dental Second Block
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Thorax, Abdomen and Skull Dental Students
TITLE: Opening of the thoracic and abdominal walls (Groups C and D), Introduction to the superior mediastinum ,(Group B), Introduction to the pleural cavity and lungs (Group A) GENERAL OBJECTIVES:
Groups C and D: Open the thoracic and abdominal walls
INSTRUCTIONS FOR OPENING ANTERIOR THORACIC AND ABDOMINAL WALLS 1. Reflect laterally the breast, pectoralis major, pectoralis minor and serratus anterior en bloc on undissected side. Protect subclavian vein as it enters the axilla. 2. Detach sternal insertions of sternocleidomastoid muscles on both sides. Make sure that sternal attachments of pectoralis minor have been cut on both sides. 3. Open sternoclavicular joints using scalpel and chisel. Pry joint open with chisel and sever costoclavicular ligament between 1st rib and clavicle. Run scalpel blade laterally from head of clavicle to separate the clavicle from the subclavius muscle. This will allow ligaments to be severed without damage to subclavian vessels. 4. Block body up in posterior midline. This will permit the shoulders and the clavicles to retract. 5. Cut the first rib anterior to the subclavian vein. First, cut intercostal mm. in 1st interspace with a scalpel and then cut 1st rib using bone cutters. A flat saw may also be used. 6. Cut ribs 2-10 in midaxillary line using bone cutters and cut intercostal muscles with a scalpel. Protect pleura by sweeping fingers between ribs and lungs during cutting and elevation of ribs. 7. After rib 10 is cut, extend an incision from the 10th interspace to the anterior superior iliac spine and carefully reflect each layer of abdominal muscles to expose transversalis fascia, extraperitoneal fat and peritoneum. Press the peritoneum onto the viscera as widely as is possible! 8. Return to retrosternal space and cut attachments of infrahyoid muscles and internal thoracic arteries. With hand, press parietal pleura away from chest wall and onto lungs. Try to keep pleura intact! 9. Raise chest wall laterally until attachments of diaphragm to costal margins are observed. Diaphragm should be cut from its attachments in a cranio-caudal direction. Again, protect pleura and peritoneum. 10. Gently fold chest and anterior abdominal wall forward and cut any remaining attachments of the diaphragm. Sweep any remaining pleural or peritoneal attachments as the wall is lifted.
Group A: Pleural Cavity and Lungs.
It is the responsibilty of Group A to see that ALL groups examine the thoracic cavity before the lungs are removed. (1) Examine the two pleural sacs and mediastinum. Define the mediastinum (Dissector p. 23- 24). (2) Identify the visceral and parietal pleura. (3) Identify the pleural recesses. (4) What are the various parts of the parietal pleura? (5) What is the root of the lung? (6) Examine the pericardial cavity with the heart in situ. Once the structures listed above are examined, Group B should remove the lungs and begin their dissection in order to demonstrate the following: (1) Examine the root of the lung and the pulmonary ligament. (2) Be able to demonstrate where a pleural tap is performed. (3) Before removing the mediastinal pleura, what structures can be identified through this membrane? (4) Identify the sympathetic trunk and the two rami communicans. (5) Identify the greater splanchnic nerve.
Next examine both lungs and identify the following: (1) Three surfaces of the lungs. (2) The lobes of the lungs. (3) Identify as many impressions on the lungs as possible. (4) Examine the hilus of both lungs. (5) Dissect the bronchial tree from the main bronchus to the segmental bronchi. It will not be necessary to identify the segments of the lungs although you should know what defines a segment.
Group B Dissection of the superior mediastinum. (1) What are the boundaries of the superior mediastinum? (2) Identify the thymus gland or its fatty remnant. What is its function? Blood supply? (3) Identify the brachiocephalic, superior vena cava, and azygos veins. (4) Identify the arch of the aorta and its three branches. (5) Identify the phrenic, vagus, and recurrent laryngeal nerves. (6) Note the ligamentum arteriosum. It is derived from what embryological structure? (7) Identify the deep cardiac plexus and tracheobronchial lymph nodes. (8) Identify the bifurcation of the trachea (carina). DISSECTOR MODIFICATIONS: Group C and D should have removed the anterior thoracic wall and the intercostal muscles, vessels Once your table examines the general organization of the pleural and pericardial cavities as described above, begin your dissection according to the directions in the dissector (pp. 17-20). Group A may reflect the sternocleidomastoid muscle (SCM) superiorly by first making a vertical saw cut through the clavicles lateral to the clavicular attachment of the SCM. Then saw horizontally through the manubrium of the sternum. Now reflect the clavicles and manubrium with the attached SCM superiorly. LABORATORY DEMONSTRATIONS: Examine the thymus gland and ductus arterio
TITLE: Introduction to heart (Group D); Introduction to posterior mediastinum (Group C); Continue lungs (Group A); Continue superior mediastinum (Group B). PAGES: Group (C) Dissector: 32-34 Moore: 114-120 Group (A) 17-23 60-78 Group (B) 34-38 107-114 Group (D) 24-32 80-107; 120 (Case 1-1) 121 (Case 1-4)
GENERAL OBJECTIVES: (A) Group D: Receive instructions for dissecting the heart.
(C) Group A: Continue dissecting the lungs. (D) Group B: Continue dissecting the superior medastinum. SPECIFIC OBJECTIVES: Group D: Heart dissection (1) Examine the pericardium. Identify its two layers. (2) Identify the transverse and oblique pericardial sinuses. (3) Review the projection of the heart and the anterior chest wall (Dissector p 9 , Fig. 1.5). (4) After removing the heart, identify the great vessels which enter and exit the heart. (5) Identify the coronary arteries and their major branches.
DISSECTOR MODIFICATIONS: Use the containers provided at your table to soak and wash out the interior of the heart. DO NOT FLUSH THE CLOTTED BLOOD DOWN THE SINKS. You will clog the drains.
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Group C: Dissection of posterior mediastinum (l) Review the boundaries of the posterior mediastinum. (2) Identify the course of the esophagus. (3) Identify the right and left vagus nerves. (4) Examine the location of the thoracic duct within the posterior mediastinum. (5) Examine the descending aorta. (6) Identify the azygos and hemiazygos veins (Atlas Fig. 1.87). What are their tributaries? (7) Identify the splanchnic nerves. What are their functions? NOTE: Although the sympathetic chains are not located within the posterior mediastinum, review their structure.
ALL: All groups should examine the peritoneal cavity and viscera before dissection of the abdomen begins. Group A will lead this examination. Groups not receiving prosections (A and B) will lead ALL groups in examining the abdominal contents before proceeding with further dissections. Using your dissector (pp. 55-61) as a guide: (1) Understand the difference between the abdominal and peritoneal cavities. (2) What are the greater and lesser sacs? (3) Identify the ligaments, mesenteries, and omenta formed by peritoneum as listed in your dissector. (4) Note the general distribution of the abdominal organs. (5) Identify those organs categorized as associated digestive organs such as the liver, gallbladder, pancreas and spleen. (6) What are peritoneal gutters?
All groups: Parasagittal sections: Study the parasagittal sections of abdomen in the Atlas of the Visible Human Male(AVHM.) Identification of the major abdominal organs in the sections will help you to understand relationships within this crowded and vital abdominal cavity. Identify these organs (eg. stomach , spleen, liver, regions of the small intestine (duodenum, jejunum, ileum), and regions of the large intestine (ascending colon, transverse colon, descending colon, and sigmoid colon) on the transverse sections available in the laboratory.
LABORATORY DEMONSTRATIONS: In a heart with the atria removed, observe the fibrous skeleton of the heart from above. It consists of interconnecting fibrous rings surrounding the AV and semilunar orifices. It reinforces the valves; the cusps cannot be spread apart around their periphery. They also provide attachment for atrial musculature above the AV valves and ventricular musculature below the AV valves. LABORATORY DEMONSTRATIONS: A demonstration showing the course and structure of the sympathetic chain will be given.
TITLE: Continue posterior mediastinum (Group C); Complete superior mediastinum (Group B); Present lungs, Introduction to celiac axis(Group A); Continue heart (Group D); ALL: Examination of peritoneal cavity and abdominal viscera. PAGES: Group (C) Dissector: 32-34 Moore: 114-120 Group (A) 61-64,67-71 165-168;177-178;197- 199 (Case 2-1, 2-6) Group (B) 34-38 107-114 Group (D) 24-32 80-107 (Case l-l); l20 (Case l-4); 121 GENERAL OBJECTIVES: (A) Group C: Continue posterior mediastinum. (B) Group B: Complete dissecting the superior mediastinum.
(D) Group D: Continue dissecting the heart. ALL: All groups should examine the peritoneal cavity and viscera before dissection of the abdomen begins. Group C will lead this examination. SPECIFIC OBJECTIVES:
Group A : Dissection of celiac trunk (1) Identify branches of celiac trunk, namely common hepatic, splenic, and left gastric arteries. (2) Follow each artery to its termination. Identify and trace branches as described in the dissector. (3) Identify veins that contribute to the portal system. (4) Trace the course of the common bile duct and understand how the duct is formed. Open the G.I. tract from pylorus of stomach to second (descending) part of duodenum. Note: pyloric sphincter, duodenal bulb and major and minor duodenal papilla (dissector p. 71). (5) Identify main pancreatic duct, divisions of pancreas and blood supply. (6) Examine spleen and note hilus and borders.
(7) Next, examine gallbladder (dissector p.69). (8) Examine liver (dissector p. 68-70), associated ligaments lobes, and porta hepatis. (9) Cross-sectional anatomy: A. In the AVHM identify the major and minor branches of the celiac artery such as the A.) short gastric arteries (p82), B.) left gastric arteries (p84), C.) hepatic artery (p90), and D.) splenic artery (p94). Look for these and other branches of the celiac axis in the cross-sectional materials in the laboratory. B. Identify the spleen. Under which ribs does the spleen lie ? What is the position of the spleen relative to the position of the left kidney in transverse section ?(AVHM, p82-96) C. Identify the portal vein in cross-section. (AVHM, p94,96). D Identify the liver and its lobes, the pancreas, gallbladder, and comon bile duct in cross-section (AVHM, p96). E. Identify these structures in the cross-sections within the laboratory.
NOTE: To observe all four lobes as well as diaphragmatic and visceral surfaces, cut coronary and triangular ligaments thus freeing liver from its attachment to diaphragm. Next, cut inferior vena cava as it exits the liver and reflect the liver forward.
DISSECTOR MODIFICATIONS: NONE
TITLE: Continue celiac artery, portal vein, bile passages and associated organs (Group A); Present superior mediastinum, Introduction to superior and inferior mesenteric arteries. (Group B); Complete heart (Group D); Complete posterior mediastinum (Group C). PAGES: Group (A) Dissector: 61-64,67-71 Moore: 165-168;177-178;197- 199 (Case 2-1, 2-6) Group (B) 64-66 180-181;205-209 Group (D 24-32 80-107 (Case 1-1) (Case 1-4) Group (C) 32-34 114-120
GENERAL OBJECTIVES: (A) Group A:Continue celiac artery, portal vein, bile passages and associated organs. (B) Group B:Present superior mediastinum, receive instructions for dissection of superior and inferior mesenteric arteries (C) Group D: Complete heart dissection (D) Group C: Continue dissection of the posterior mediastinum. SPECIFIC OBJECTIVES: (l) Identify origins of branches and fields of supply of superior and inferior mesenteric arteries. (2) Identify marginal artery. (3) Identify superior and inferior mesenteric veins and note contribution to portal venous system. (4) Examine and compare mucosa of jejunum and ileum. (5) Identify ileocecal valve. (6) Cross-sectional anatomy: A. Identify the superior mesenteric vessels in cross-section. Which region of which organ do these vessels make direct contact with? Hint: What is the uncinate process of the pancreas? (AVHM, p98)
B. Identify the ileocecal junction in transverse section (AVHM. p 126) C. Identify the duodenum(p98-106), jeujunum (p98-116), ileum (p124-134), cecum (p126-130). ascending colon (p124), descending colon (p124), and transverse colon (p106-108 ) in cross section in in the AVHM . D. Identify the intestinal branches of the superior mesenteric artery within the mesentery (AVHM p104) in transverse section. E. Identify the above structures on the transverse sections available in the laboratory. DISSECTOR MODIFICATIONS:
Do Not remove G.I. tract (p. 66-67)
LABORATORY: #17 TITLE: Continue superior and inferior mesenteric vessels and associated structures (Group B); Present heart, prosection for posterior body wall will be in Lab 18 (Group D); Present posterior mediastinum., introduction to inguinal region. (Group C); Complete celiac artery, portal vein, bile passages and associated organs (Group A). PAGES: Group (B) Dissector: 64-66 Moore: 180-181;205-209 70-71 (Case 2-4) Group (D) 73-79 229-237; 210-224; 224-229 (Case 2-5) Group (C) 47-51(parts) 142-152(Case2-3) Group (A) 61-64,67-71 (Case 2-1, 2-6) 165-168; 177-178, 197-199 GENERAL OBJECTIVES: (A) Group B: Continue superior and inferior mesenteric vessels and associated organs.
(C) Group C: Present posterior mediastinum, receive instruction in dissection of inguinal region (D) Group A:Complete dissection of celiac artery, portal vein, bile passages and associated structures. SPECIFIC OBJECTIVES:
Group C: Inguinal region (1) Understand how membraneous layer of superficial fascia (Scarpa's):
(2) Demonstrate the following derivatives of external oblique aponeurosis:
(3) Demonstrate derivatives of inferior part of internal oblique muscle (cremaster muscle) and fascia of internal oblique muscle; at each middle inguinal ring they form cremasteric fascia, which take loops of cremaster muscle as far inferior as caudal ends of testes. (4) Demonstrate transversalis fascia, which continues out over cords as their innermost coverings, the internal spermatic fascia, at deep inguinal rings. (5) Note that superficial rings are most medial, deep rings are most lateral; inguinal canal pass obliquely through the body wall between these rings on each side. (6) On females, carry your incision superior to the superficial ring (leave ring intact) when reflecting external oblique. Identify cremaster and falx inguinalis. Split cremaster and find the deep ring lateral to inf. epigastric vessels as in males. Note that:
(7) Know that the inguinal canal contains the ilioinguinal nerve, and the spermatic cord (ductus deferens, vessels, nerves, lymphatics; male) or round ligament of uterus (female), but do not dissect these structures at this time. (8) Identify the conjoint tendon and the muscles that contribute to it. (9) Define the boundaries of the inguinal (Hesselbach's) triangle. Distinguish between a direct and indirect inguinal hernia. (10) Examine inguinal region of both sexes (arrange to switch with other tables or use prosections). DISSECTOR MODIFICATIONS: (1) Reflection of integument: continue midline incision E-C (Dissector Fig. 2.2, p44) on each side, around root of penis and scrotum, or labium majora, and down the medial side of the upper third of each thigh. Continue the incision laterally across the front of each thigh. Beginning superiorly,use blunt dissection to reflect skin and superficial fasica laterally. If at all possible, identify membranous layer of superficial fascia and free it from fatty layer of superficial fascia as you proceed. As you expose the spermatic cord, on each side, see if it is undisturbed on the right side (no surgical repair). If so, dissect its layers on the right side. If not, inform the dissectors of the abdominal wall so you can all dissect the other side. Leave the cord (and external spermatic fascia) intact on the opposite side. 2) On the dissected side, where dissectors of abdominal wall have freed external oblique from iliac crest, free it from inguinal ligament to superficial ring. Cut external spermatic fascia free from external oblique aponeurosis on the superior aspect of the superficial ring. Reflect external oblique medially to pubic tubercle. (3) If possible, trace ilionguinal nerve deep to internal oblique. This will give you the cleavage plane between internal oblique and transversus abdominis. Split cremaster muscle away from the rest of internal oblique to join the vertical incision made by the dissectors of the anterior abdominal wall. Work together with them to reflect internal oblique medially and define the conjoint tendon. (4) Reflect cremaster inferiorly and define the deep inguinal ring. If the inferior epigastric artery is visible through transversalis fascia (pull on it in the rectus sheath) leave well enough alone. Otherwise cut through transversalis fascia just enough to expose the vessel. (5) On the females (optional on males): clean the exposed portion of sartorius muscle. Define, by blunt dissection, the femoral sheath (the femoral nerve lies just lateral to it, the adductor muscles lie just medial to it). Transect the sheath and its contents about midway between inguinal ligament and sartorius. Note the cut ends of femoral artery and vein. Cut tributaries free proximally so that the sheath can be elevated to expose the pectineal ligament deep to it, on the pectineal line (Dissector 2.1). Palpate the femoral canal (empty space in the sheath between femoral vein and lacunar ligament). The blind pocket of transversalis fascia that occupies this space, and transmits lymphatics, is the femoral canal.
Cross-sectional anatomy: A. Identify the spermatic cord. as it travels through the inguinal canal in transverse section (AVHM p144-How many of its constituents can you name? Identify the ductus deferens within this cord.(p152). B. Identify the testicle, scrotum,tunica albuginea, and epididymis in transverse section and in the AVHM (p164-66) What is missing in the cadaver used for AVHM cross-sections?
TITLE: Introduction to diaphragm and posterior abdominal wall (Group D): Continue inguinal region (Group C); Present celiac artery, portal vein, bile passages and associated sructures , introduction to skull 1(Group A); Complete superior and inferior mesenteric vessels and associated organs (Group B). PAGES: Group (D) Dissector: 73-79 Moore: 229-237; 210-224; 224-229 (Case 2-5) Group (C) 46-51 142-152(Case 2-3) Group (B) 64-66 180-81, 205-209;
Group (A) GENERAL OBJECTIVES: (A) Group D: Introduction to diaphragm and posterior abdominal wall. (B) Group C: Continue dissection of the inguinal l region (C) Group A: Present celiac artery, portal vein, bile passages and associated structures, introduction to Skull I. (D) Group B: Complete dissection of superior and inferior mesenteric vessels and associated structures.
SPECIFIC OBJECTIVES:
Group D: Diaphragm and posterior body wall Identify: (1) kidneys and suprarenal glands. (2) renal vessels and ureters noting their origins and courses. (3) structures composing kidney. (4) blood vessels supplying suprarenal glands. (5) testicular or ovarian vessels noting origin and course. (6) muscles composing posterior abdominal wall. (7) nerves along posterior abdominal wall. (8) parts of diaphragm. (9) structures passing through diaphragm?
Cross-sectional anatomy: A. Identify the kidneys in transverse section. Be aware that the living kidneys have mobility which gives them some variability in postition. Viewing cross-sections of the kidney (AVHM p96-112) , however, helps you to appreciate that one kidney is slightly higher than the other. Which one is higher and which organ is responsible for this effect? Which vertebral levels do the kidneys span? B. Identify the suprarenal glands (AVHM, p98-100) , the hilus of the kidney, and the renal vessels (AVHM, p102) in transverse section C. Identify the abdominal aorta(AVHM , p96-120) and the inferior vena cava ( AVHM, p96-118) in transverse section. D. Identify the psoas major muscle (AVHM, p120), the iliacus muscle (AVHM ,p126) and the qudaratus lumborum muscle (AVHM, p120) in cross-section. Can you identify the diaphragm (AVHM p80-86) and the crura of the diaphragm (AVHM p90-98) in transverse section.? E. Identify these structures on the transverse sections available within the laboratory.
TITLE: Complete inguinal region (Group C); Present superior and inferior mesenteric arteries, introduction to skull II (Group B); Continue skull I (Group A); Continue diaphragm and posterior abdominal wall (Group D). PAGES: Group (A) Dissector: Group (B) Group (D) 73-79 (Case 2-5) 229-237 210-224; 224-229 Group (C) 46-51 142-152 (Case 2-3) GENERAL OBJECTIVES: (A) Group C: Complete inguinal region. (B) Group B: Present mesenteric arteries and receive instruction on skull II (C) Group A: Continue skull I (D) Group D: Continue dissection of the diaphragm and posterior abdominal wall.
LABORATORY: #20
TITLE: Continue skull II (Group B); Complete skull I (Group A); Complete diaphragm and posterior abdominal wall, (Group D);Present inguinal region ,introduction to radiology (Group C). PAGES: Group (A) Dissector: Group (B) Group (D) 73-79 229-237; 210-224 224-229 (Case 2-5) Group (C)
GENERAL OBJECTIVES:
(A) Group A: Complete skull I.
(D) Group C: Introduction to radiology.
LABORATORY: #21 TITLE: Present skull I (Group A); Complete skull II (Group B); Present posterior body wall(Group D); Continue radiology (Group C). PAGES: Group (A) Dissector: Moore Group (B) Group (D) Group (C)
GENERAL OBJECTIVES: (A) Group A: Present skull I. (B) Group B: Complete skull II. (C) Group D: Present diaphragm and posterior abdominal wall. (D) Group C: Continue radiology.
SPECIFIC OBJECTIVES:
LABORATORY: #22 TITLE: Present skull II (Group B); .Complete radiology (Group C) PAGES: Dissector: Moore: Group (B) Group (C) GENERAL OBJECTIVES: . (A) Group C: Complete radiology. (B) Group B: Present skull II..
SPECIFIC OBJECTIVES:
DISSECTOR MODIFICATIONS: NONE
LABORATORY: #23 TITLE: Present radiology (Group C);
PAGES: GENERAL OBJECTIVES: SPECIFIC OBJECTIVES: None
LABORATORY: #24 TITLE: All review PAGES:
SPECIFIC OBJECTIVES: ALL GROUPS: perform well on the exam.
DISSECTOR MODIFICATIONS: None. |