Lecture 42 - Gastrointestinal Tract 1 Flashcards
What are the compartments in the bulk of the body?
Thorax
Abdomen
Pelvis
Perineum
What separates the thorax from the abdomen?
Diaphragm
What separates the abdomen from the pelvis?
No obvious structural demarcation
Indicate the transumbilical plane
along belly button
Indicate the quadrants of the stomach area
Right upper
Left upper
Right lower
Left lower
List some tubular viscera
Eosophagus
Stomach
Intestines
Gall badder
List some solid viscera
Liver Pancreas Spleen Kidneys Adrenal
When learning about viscera, what four things do we need to know?
- Location: quadrant
- relationship to peritoneum
- blood supply
- identifying features
What are the two abdominal walls?
Posterior
Anterior
Describe the structure of the anterior abdominal wall
Three flat layers of muscle:
- external oblique
- internal oblique
- transverse abdominus
Describe the structure of the posterior abdominal wall
Three muscles:
- Quatratous lumborum
- psoas major
- iliacus
What is the function of a mesentery?
1/ Mobility
2/ pathway for nerves and vessels
What lines the abdominal cavity?
Peritoneum
What are the two terms to describe an organs relation to the peritoneum?
Intraperitoneal: suspended in cavity
Retroperitoneal: outside the peritoneal cavity
What are the features of intraperitoneal viscera?
Suspended in the cavity
Mobile
Have a mesentery
Surrounded by visceral peritoneum
What are the features of retroperitoneal viscera?
Outside the peritoneal cavity
Stable
No mesentery
Partially covered by the parietal peritoneum
Where does the oesophagus run?
From pharynx
Behind trachea
Through diaphragm
To right side of stomach
What are the constrictions of the oesophagus?
Cervical
Thoracic
Diaphragmatic
Describe the tissue structure of the oesophagus
Two complete layers of muscle:
inner circular
outer longitudinal
What is the name of the region where the oesophagus becomes the stomach?
Z line
Oesophagogastric junction
Describe the shape of the stomach and important features of the shape
J shaped
Greater curvature
Lesser curvature
Which quadrant is the stomach in?
What is its relationship to the peritoneum?
Upper left quadrant
Intarperitoneal
What are the features of the stomach?
Two orifaces
Two curvatures
Two surfaces
Four regions
What are the four regions of the stomach?
Fundus (air filled)
Body
Pyloric antrum
Pyloric canal
Where is the cardia of the stomach?
Just below the oesophagus; the opening
What stops food flowing from the stomach straight into the duodenum?
The pyloric sphincter
Describe the inner surface of the stomach
Rugae: gastric folds
More pronounced rugae towards the distal end of the stomach
What is the function of the rugae?
To allow the organ to expand when required
What are the names of the two orifaces of the stomach?
Cardiac oriface
Pyloric oriface
What are the four regions of the duodenum?
- Superior
- Descending
- Inferior / horizontal
- Ascending
Which organ does the duodenum durround?
The pancreas
What is the general shape of the duodenum?
C shaped
What is the relationship of the duodenum to the peritoneum?
Retroperitoneal
In which section of the intestine are the duodenal papillae?
In the 2nd / descending part of the duodenum
How do bile and enzymes enter the duodenum?
From gall bladder:
- bile comes down common bile duct
From pancreas:
- enzymes come down main pancreatic duct
Into duodenum via the major duodenal papilla
What is the function of the minor duodenal papilla?
Some pancreatic enzymes come through here
What are the parts of the small intestine
Jejunum: 40%
Ileum: 60%
How are the jejunum and the duodenum distinguished?
Jejunum:
- greater calibre, thicker wall
- larger circular folds
- better vascular supply
- less fat in the mesentery
What is the thickness of the wall also called?
Calibre
What is the difference between the vasculature of the jejunum and the ileum?
Ileum: much more branched and disorganised
Describe the structure of the muscularis in the intestine
Two layers:
inner circular
outer longitudinal
Describe the different regions of the large intestine
Caecum Ascending colon Transverse colon Descending colon Sigmoid colon Rectum Anal canal
What are the names of the corners of the large intestine?
Hepatic flexure
Splenic flexure
Where is the large intestine in relation to the small intestine
It is like a frame around the small intestine
List the important features of the large intestine
- wide diameter
- Tenia coli
- Haustra
- omental appendices
Describe the structure of the muscularis of the lagre intestine
Inner circular
Tenia coli: three disparate bands of longitudinal muscle
What are Haustra?
This is the baggy external appearance of the large intestine
Where is the caecum located?
What is its relationship to the large intestine?
Right lower quadrant,
Inferior to the ileocaecum junction
Intraperitoneal
Where is the appendix located?
What is its relationship to the large intestine?
Lower right quadrant
Intraperitoneal
- base attached to the caecum
Is the appendix mobile?
Yes, it can be have many different positions:
- pre-ileal
- postileal
- pelvic
- subcaecal
- retrocaecal
What is the relationship of the large intestine to the peritoneum?
Ascending: retro
Transverse: intra
Descending: retro
Sigmoid: intra
Describe the muscle in the rectum
No tenia coli
How does the rectum differ from the large intestine?
No tenia coli
No omental appendices
No haustra
What makes up the pyloric region of the stomach?
Pyloric antrum
Pyloric canal
