1. Abdomen

2. Abdomen
Abdomen is the part of the trunk between the thorax and pelvis.
It is covered by the musculoaponeurotic walls anterolaterally, the diaphragm superioly, and muscles of the pelvis inferiorly, which are suspended between and supported by the inferior thoracic skeleton, pelvic girdle and semirigid lumbar vertebrae posteriorly.

3. Abdomial Regions Two vertical lines midclavicular lines
Two horizontal lines subcostal plane and trans tubercular plane
R. & L. Hypochondriac
Epigastric
R. & L. Lumbar
Umbilical
R. & L. Iliac
Hypogastric or pubic

4. Abdominal wall
The wall consists of skin and subcutaneous tissue(superficial fascia) composed of fat,muscles and their aponeuroses and deep fascia, and parietal peritoneum
Inferior to umblicus, the subcutaneous tissue has two layers
Superficial fatty layer(camper fascia)
Deep membranous layer(scarpa fascia)
The membranous layer continues inferiorly to perineal region as superficial perineal fascia(colles fascia)

5. Muscles of the abdominal wall
3 flat muslces(external oblique,internal oblique and transverse abdominal) and 2 vertical muscles(rectus abdominus and pyramidalis)

6. Esophagus
Esophagus, a muscular tube is continuous with laryngopharynx.
The pharyngoesophageal junction has the superior esophageal sphinchter, a constriction producted by the cricopharyngeal part of the inferior constrictor muscle, is the narrowest part of esophagus
When the esophagus is empty it has a slit like lumen which expands when the food bolus descends.

7. The cervical esophagus lies between trachea and cervical vertebral column.
The esophagus remains posterior to the arch of aorta, left main bronchus and left atrium and then it passes through the esophageal hiatus in the diaphragm at the level of T10 vertebrae.

8. thoracic esophagus
The thoracic esophagus has 3 constrictions because of the compression of
Cervical constriction: at the beginning of phryngo-esophageal junction
Thoracic constriction: compound constriction caused by the compression of arch of aorta and left main bronchus
Diaphragmatic constriction: when it passes thru the diaphragm

10. Abdominal esophagus
Abdominal esophagus after passing through the esophagus is only 1.25cm long and it ends in the cardiac orifice of the stomach.
Gastro esophageal junction lies at the levl of t11 at the tip of xiphoid process.
Immediately superior to this junction, the diaphragmatic musculature forms the physiologic eesophageal sphincter

11. stomach
The stomach is the expanded part of the alimentary tract between the esophagus and the small intestine.
Its functions are
Acts as a resorvoir of food
Enzymatic and mechanical digestion
An empty stomach is only slightly larger than large intestine which it is capable of considerable expansion that it can hold 2-3 L of food.

12. Stomach The stomach has 4 parts
Cardia: the part sorrounding the cardiac orifice
Fundus: the dilated superior part
Body: the major part of stomach between the fundus and the pyloric antrum.
Pyloric part: funnel shaped outflow region of stomach

13. Small intestine Primary site for absorption of nutrients. Has 3 parts:
Duodenum
Jejunum
ileum

14. Duodenum Shortest,widest and more fixed part of small intestine
Bile and main pancreatic ducts enter through Hepatopancreatic ampulla
Celiac trunk and superior mesentric artery supplies the blood.

15. Jejunum and ileum together is 6-7 m long.
Superior mesentric artery(direct branch of aorta) supplies the jejunum and ileum

16. Large intestine
Water is absorbed from indigestible residues of liquid chyme, converting it into feces.
It consists of
Cecum
Appendix
Ascending colon
Transverse
Descending
Sigmoid
Rectum
Anal canal

17. Cecum and appendix
Cecum is blind intestinal pouch approximately 7.5cm in both length and breadth, located in the right lower quadrant.
Appendix is a blind intestinal diverticulum containing masses of lymphoid tissue

18. Appendix arises from the postero medial aspect of the ceum inferior to the ileocecal junction.
The cecum is supplied by the ileocolic artery, the terminal branch of SMA.
The appendicular artery, the branch of ileocolic artery supplies the appendix

19. colon The ascending colon is narrower than cecum.
Ileocolic and right colic arteries, the branches of SMA supplies the ascending colon.
The transverse colon is 45 cm long and is most mobile part of large intestine, extending from right to left colic flexure
Middle colic artery,branch of SMA supplies the transverse colon.

20. Descending colon passes anterior to the lateral border of left kidney
Sigmoid colon is characterized by the S-shaped loop of variable length
The arterial supply is thru left colic and sigmoid arteries, branches of inferior mesentric artery.

21. Rectum is the fixed terminal part of large intestine,has 3 sharp lateral flexures
Superior,intermediate and inferior.