Ebook High-Yield gross anatomy (5th edition): Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook High-Yield gross anatomy (5th edition): Part 2
Ebook High-Yield gross anatomy (5th edition): Part 2
CHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2 which lies between the descending colon and rectum.•The sigmoid colon begins at vertebral level SI (i.e., the sacral promontory or pelvic inlet) and endsal vertebral level S3 (i.e.. the rectosigmoid junction)Rectosigmoid junctionAnorectal junction ponneal flexure (90°)Pectinate lineFigure 12-1 Sagi Ebook High-Yield gross anatomy (5th edition): Part 2ttal view of the male pelvis. The Sigmoid colon (SC) extends from vertebral level SI to S3 suspended by the sigmoid mesocolon (M) and ends at the rectEbook High-Yield gross anatomy (5th edition): Part 2
osigmoid junction (dotted line). The rectum (R) and ampulla of the rectum (AMP) are shown along with the transverse rectal folds (TF) (Houston valves)CHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 20 degrees The anal canal IS divided into the upper anal canal (U) and lower anal canal (I) by the pectinate line TC. teniae coli; RV, rectovesical pouch, B, urinary bladder, T, testes; PC, peritoneal cavity; RA. rectus abdominis muscle.129130 Chapter 12•Al the rectosigmoid junction, the teniae coli Ebook High-Yield gross anatomy (5th edition): Part 2which are longitudinal bands of smooth muscle characteristic of the large intestine spread out to form a circumferentially continuous layer of longituEbook High-Yield gross anatomy (5th edition): Part 2
dinal smooth muscle of the rectum and the appendices epiploicae arc discontinued.•The sigmoid colon is highly variable in both position and shape•SincCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2 colon is suspended by the sigmoid mesocolon (i.e.. intraperitoneal).•The left ureter and left common iliac artery lie at the apex of the sigmoid mesocolonB. Arterial Supply•The arterial supply of the sigmoid colon is from the sigmoid arteries (abdominal aorta —> inferior mesenteric artery —> sigmoi Ebook High-Yield gross anatomy (5th edition): Part 2d arteries).c. Venous Drainage• The venous drainage of the sigmoid colon is to the sigmoid veins (sigmoid veins -> inferior mesenteric vein —> portalEbook High-Yield gross anatomy (5th edition): Part 2
vein —> hepatic sinusoids —> central veins —> hepatic veins —> inferior vena cava).D. Innervation. See Chapter 11 VlllE. Clinical Considerations1ColonCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2ce of ganglionic cells in the myenteric and submucosal plexuses most commonly in the sigmoid colon and rectum resulting in a narrow segment of colon (i e., the colon fails to relax). Although the ganglionic cells arc absent, there is a proliferation of hypertrophied nene fiber bundles. The most char Ebook High-Yield gross anatomy (5th edition): Part 2acteristic functional finding is the failure of internal anal sphincter to relax following rectal distention (i.e., abnormal rcctoanal reflex). MutatiEbook High-Yield gross anatomy (5th edition): Part 2
ons of the rearranged during transfection (RET) protooncogene (chromosome lOq. 11.2) have been associated with Hirschsprung disease. Clinical findingsCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2peristalsis in the colon segment distal to the normal innervated colon The barium radiograph shows a narrowed rectum and a classic transition zone (arrows). The upper segment (*) of normal colon is distended with fecal material. The distal segment (♦•) of the colon is narrow and is the portion of co Ebook High-Yield gross anatomy (5th edition): Part 2lon where the myenteric plexus of ganglion cells IS absent.Figure 12-2 Hirschsprung disease.Sigmoid Colon, Rectum, and Anal Canal 1312Diverticulosis (Ebook High-Yield gross anatomy (5th edition): Part 2
Figure 12-3) IS the presence OÍ diverticula (abnormal pouches or sacs) most commonly found in the sigmoid colon in patients >60 years of age. Il is asCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2include [lain in left lumbar region, palpable inflammatory mass in left lumbar region, fever, leukocytosis, ileus, and peritonitis. The postevacuation barium radiograph shows numerous small outpouchings or diverticula (arrows) from the. colonic, lumen. These, diverticula are. filled with barium anil Ebook High-Yield gross anatomy (5th edition): Part 2 fecal material. Nole the hernia (I I) on the right.Figure 12-3 Diverticulosis.3Flexible sigmoidoscopy permits examination of the sigmoid colon and reEbook High-Yield gross anatomy (5th edition): Part 2
ctum. During sigmoidoscopy, the large intestine may be punctured il the angle at the rectosigmoid junction is not negotiated properly. At the rectosigCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2st be negotiated also.4Colostomy. The sigmoid colon is often used in a colostomy due to the mobility rendered by the sigmoid mesocolon (mesentery). An ostomy is an intestinal diversion that brings out a portion of the Gl trad through the rectus abdominis muscle A colostomy may ablate the pelvic nerv Ebook High-Yield gross anatomy (5th edition): Part 2e plexus which results in loss of ejaculation, loss of erection, urinary bladder retention, and decreased peristalsis in remaining colon.ii RectumA.GeEbook High-Yield gross anatomy (5th edition): Part 2
neral Features•The rectum IS a segment of the large intestine which lies between the sigmoid colon and the anal canal•The rectum begins at vertebral lCHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine Ebook High-Yield gross anatomy (5th edition): Part 2ineal flexure. The ampulla of the rectum is a dilated portion of the rectum that lies just above the pelvic diaphragm.•The rectum is normally empty or nearly so ol fecal mass. When mass movement contractions occur in the sigmoid colon, lecal mass moves into the rectum. When the local mass distends t Ebook High-Yield gross anatomy (5th edition): Part 2he rectum to >25% of its capacity, a reflexive relaxation of the internal anal sphincter and a reflexive contraction of the external anal sphincter ocEbook High-Yield gross anatomy (5th edition): Part 2
curs (called the ret rosphir icteric reflex). I his generates the urge to defecate.CHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestine CHAPTER 12Sigmoid Colon, Rectum, and Anal CanalI Sigmoid Colon (Figure 12-1)A. General Features•The sigmoid colon is a segment of the large intestineGọi ngay
Chat zalo
Facebook