Large Intestine Flashcards
Talk about large intestine
(6)
1- horse shoe shape
2- from ileicecal valve
3- ends in anus
4- 1,5 metre
5- 7,5 cm in diameter
6- function
• reabsorption of water
• absorption of vitamins
Compare between small , large intestine
Small
- longer
- thinner
- mobile except duodenum
- villi
- plicae circularis
Large
- shorter
- widder
- fixed except transverse - sigmoid and appendix
- tenia coli ( 3 , 100 cm )
- appendicies epiploica
- sacculations ( haustrations)
A-L- N of large intestine
Midgut : colic branches of sma
Hindgut : colic branches of ima
Lymphatic
Sm lymph nodes : midgut
Im lymph nodes : hindgut
Innervation
Sm plexus : syma & para from vagus
Im plexus : sympa &Para: from pelvic splenichic nerve
Caecum
- right iliac fossa above the lateral 1/2 of inguinal ligament
- 6 cm , the widest part in large intestine ( 7,5cm)
- partially or completely covered by peritoneam بمزاجها
Appendix
(6)
1- worm shaped musclar tube
2- musclar as the 3 tenia coli converges to its base forming longitudinal musclar layer on it
3- 10 cm
4- completely covered by peritoneum ( mesoappendix)
5- mcburney point :
• point of tenderness of appendicitis
• line from umblicus to ASIS
• at the junction of medial 2/3 ant lateral 1/3
6-different positions of it
• retrocecal : behind cecam , ileum (65%)
• subcecal : below cecam ( 3%)
• preileul : infront of ileum (1%)
• postileul : behind ileum (1%)
• pelvic : hangs over brim of lesser pelvis(30%)
• retrohepatic : very rare
Ascending colon
(3)
1- lumbar region till the under surface of rt lobe so iturns to left forming right flexure at the rt hypochodriam
2- 15 cm
3- covered infront , sides ( fixed )
Transverse colon
(3)
• rt hypochondriam - epigastric - lt hypochondriam forming lt flexure
• 50 cm
• the most mobile part of large intestine covered completely by peritoneam except the right end is not completely covered
Descending colon
(3)
• inthe left hypochondriam at the lt flexure taking lumbar region till the left sude if brim of lesser pelvis
• 25 cm
• covered infront , sides by peritoneum ( fixed )
Sigmoid colon
(4)
1- left side of brim of lesser pelvis forming S shape till S3
2- consists of 3 parts
3- 40 cm
4- completely covered by peritoneum ( mobile )
Compare between rt , colic flexure
Rt ( hepatic)
- in the rt hypochondriam at junction if ascending , transverse colon
- covered by peritoneum except posterior
- related anteriorly to rt lobe of liver
Posterior to rt kidney , diaphram
Lt ( splenic )
- in the hypochondriam at junction between transverse , descending,
- attached to diaphragm through phrenicocolic ligament
- anteriorly : spleen
Posterior : lt kidney , diaphram
Rectum
(10)
1- continution of sigmoid
2- at the level of s3
3- ends giving anus
4- 15 cm
5- follow sacrococcgeal curve ( concave infront - convex back )
6- 3 lateral curvature ( upper , lower in same side while middle in opposite )
7- 3 characteristics in large intestine does not exist
8- covered by complete longitudinal musclar coat rather than tenia coli
9•upper third covered by peritoneum ( fronts , sides)
• middle third ( front )
• lower third is devoid of peritoneam
10- relations
•Anterior
Male : coils of small intestine in recto vesical pouch above and back of bladder , prostate , seminal vesichles and vas deferns below
Female : coils of small intestine in recto uterine pouch ( dogglas ) above and back of vagina below
•Posterior : saccram
•Lateral : ileum , sigmoid colon
Anal canal
(8)
1- continution of rectum
2- one finger below tip of coccyx
3- 4 cm
4- relation
• on passing the pelvic diaphragm, anteriorly there is vagina , urethra and it is held forward by puporectalis sling
• after passage , it is surrounded by sphincter ani externus, while ishciorectal fossa laterally
5- sphincters
• internal : the thick lower part of inner circular layer of gut
• there is white line separating between external , internal sphinctors
• external : 3 parts
* sub cutaneous: surrounds the lowermost portion of canal
* superficial: attached to perineal body , coccyx posteriorly
* deep (3): • surrounds the uppermost portion
• continous with superficial part
• attached to puporectalis posteriorly
6- internal structure
Upper half :
- vertical mucosal folds ( rectal columns )
- end in anal valves
- which bound to anal sinuses
The enlargement of their venous plexus ( portal hypertension) causes internal piles ( hemorrhoids )
Lower half : lower limit of anal valve there is a line ( pectinate ) ( dentate ) line , the area below it is pectin
7- blood supply
Superior rectal : continuation of ima
Inferior rectal : anterior trunk of iia
Middle rectal : anterior trunk of iia
Median sacral : aorta
8- innervation
•Sympathetic: vasomotor
•Parasympathetic: supplies internal anal sphincter
•Somatic motor : supplies external anal sphinctor ( inferior rectal , perineal branch of 4 th sacral nerve ( SN4) )
• somatic sensory : concerned with reflex control of sphincter and pain , so the anal canal is very senitive , external piles is very painful
