Contents of the Abdomen

Question 1

anatomical regions of the abdomen

Answer 1

Question 2

quadrants of the abdomen

Answer 2

Question 3

Origins of Viscera:

Answer 3

• foregut
• midgut
• hindgut

Question 4

Foregut & its Derivatives:

Answer 4

• all structures proximal to the major papilla
• stomach
• duodenum
• liver and billiary tract
• spleen
• pancreas

Question 5

Midgut & its Derivatives:

Answer 5

• all structures distal to the major papilla to
  2/3rd along transverse colon
• duodenum small intestine
• ascending colon
• caecum
• appendix
• transverse colon

Question 6

Hindgut & its Derivatives:

Answer 6

• all structures beyond distal 1/3rd transverse
  colon
• sigmoid colon
• rectum
• anal canal

Question 7

Functions of the GI Tract:

Answer 7

• Ingestion
• Secretion (digestive fluids)
• Mixing and Propulsion
• Digestion (breaking down)
• Absorption
• Defecation

Question 8

Key Histological Layers:

Answer 8

• Serosa
• Muscularis propria/externa
• Submucosa
• Mucosa

Question 9

Serosa/Adventitia

Answer 9

an outer covering (peritoneum)

Question 10

Muscularis Propria/Externa

Answer 10

• longitudinal (outer) and circular (inner)
• responsible for peristalsis (forward
  movements) of contents

Question 11

Submucosa

Answer 11

• loose connective tissue
• blood vessels, nerves, lymphatics

Question 12

Mucosa:

Answer 12

• 3 subdivisions: epithelium (glandular), lamina
  propria (loos connective tissue), muscularis
  mucosa (smooth muscle)
• inner layer
• secretory to aid peristalsis

Question 13

Key Histological Layers

Answer 13

Question 14

What is the most dilated part of the GI Tract?

Answer 14

Stomach

Question 15

Stomach:
- where is it situated
- shape
- muscle layers

Answer 15

• between the oesophagus and small intestine
• J-shaped
• three layers of muscle: longitudinal, circular,
  oblique

Question 16

Functions of the Stomach:

Answer 16

• mechanical (muscle)
• chemical (gastric juices) initial phase of
  digestion

Question 17

Anatomy of Stomach (5):

Answer 17

• Cardia: Cardiac Sphincter
• Pylorus: Pyloric Sphincter
• Lesser Curvature: superior right border
• Greater Curvature: inferior left border
• Antrum

Question 18

Small Intestine:
- is
- from where
- how long

Answer 18

• convoluted tube
• pylorus of stomach to ileocaecal junction
• 5/6 meters in length

Question 19

Small Intestine is subdivided into:

Answer 19

• duodenum
• jejunum
• ileum

Question 20

Functions of the Small Intestine:

Answer 20

• digestion
• absorption

Question 21

Duodenum:
- how long
- location
- Shape and divisions
- joining of
- ends

Answer 21

• 20-25 cm
• retroperitoneal locations (except first 2 cm)
• C shaped: 4 parts: superior, descending,
  horizontal, ascending
• Medial border 2nd part:
  - pancreatic duct + common bile duct join to
  form hepatopancreatic ampulla (ampulla of
  vater) to drain at the major duodenal
  papilla
• ends at the duodenojujenal junction (flexure)

Question 22

Jejunum and Ileum:
- how long
- situated
- anchored to posterior abdominal wall by

Answer 22

• approx 3m
• from duodenojujenal junction to ileocaecal
  junction
• anchored to posterior abdominal wall by
  peritoneal mesentery

Question 23

Jejunum and Ileum Function:

Answer 23

• site of absorption:
  
  • large surface area
  • increased by circular folds + villi + microvilli
  • motility

Question 24

Duodenum

Answer 24

Question 25

Jejunum: - what % of small intestine - characterised by - arcades

Answer 25

- 40% of small intestine - multiple folds with pronounced villi - Arcades: fewer vessels, long vasa recta

Question 26

Ileum: - what % of small intestine - characterised by - arcades:

Answer 26

- 60% of small intestine - thin walls and less fat in mesentery - arcades: many but short vasa recta

Question 27

Large Intestine: - location - comprises of - length

Answer 27

- ilocaecal junction to anal canal - comprises of colon, rectum and anus - 1.5m in length: large surface area

Question 28

Large Intestine: - subdivisions

Answer 28

- ascending, transverse, descending, sigmoid and caecaum - hepatic flexure consists of ascending and transverse - splenic flexure consists of transverse and descending

Question 29

Anatomy of Large Intestine

Answer 29

Question 30

Large Intestine: Rectum:

Answer 30

- 15cm long - Rectosigmoid junction

Question 31

Large Intestine: Anal Canal:

Answer 31

anal sphincters

Question 32

Function of Large Intestine:

Answer 32

- absorption of water, forms and expels faeces (defecation)

Question 33

Three main branches of the abdominal aorta to the three sections of GI Tract:

Answer 33

- coeliac trunk/artery - superior mesenteric artery - inferior mesenteric artery

Question 34

Blood Supply to GI Tract:

Answer 34

Question 35

Coeliac Trunk: - arises from - 3 main branches for foregut and what each supplies

Answer 35

- arises from the aorta at T12 - Branches: - left gastric artery (supplies stomach) - splenic artery (supplies spleen) - common hepatic artery (supplies liver, gallbladder, stomach, duodenum and pancreas)

Question 36

Venous drainage of GI Tract structures that are supplied by the coeliac trunk:

Answer 36

- stomach: local branches drain into the Portal Vein - spleen: splenic vein: joins superior mesenteric vein to form the portal vein - liver: hepatic veins: drain into the IVC

Question 37

Label the branches of the coeliac trunk

Answer 37

Question 38

Superior Mesenteric Artery: - arises from - supplies - branches (4)

Answer 38

- arises from the abdominal aorta at L1 - supplies distal part of duodenum to proximal 2/3 transverse colon - Branches: - Jejunal and Ileal branches - Middle Colic - Right Colic - Ileocolic

Question 39

Branches of the Superior Mesenteric Artery

Answer 39

Question 40

Venous Drainage of the Small Intestine:

Answer 40

All branches of the superior mesenteric artery drain into the Superior Mesenteric Vein

Question 41

Inferior Mesenteric Artery: - arises from - supplies - branches (3)

Answer 41

- arises from the abdominal aorta at L3 - supplies distal 1/3 transverse colon to upper half of anal canal - Branches: - left colic - sigmoid - superior rectal

Question 42

Branches of the Inferior Mesenteric Artery:

Answer 42

Question 43

Venous Drainage of the Colon and Rectum:

Answer 43

All branches of the inferior Mesenteric Artery drain into the Inferior Mesenteric Vein, which drains into the Splenic Vein

Question 44

Lymph nodes of the GI Tract:

Answer 44

Question 45

Sympathetic Innervation of foregut, midgut and hindgut:

Answer 45

- Thoracoabdominal splanchnic nerves: - Greater Splanchnic Nerve (T5-T9): Foregut - Lesser Splanchnic Nerve (T10/11): Midgut - Least Splanchnic Nerve (T12): Hindgut - Lumbar Splanchnic Nerve (L1-2): Hindgut: Pelvis - Sacral Splanchnic Nerve (S2-S4): Hindgut: Pelvis

Question 46

Innervation of the foregut, midgut and hindgut: Label and mark which nerves are sympathetic and parasympathetic.

Answer 46

Question 47

Parasympathetic innervation of the foregut, midgut and hindgut:

Answer 47

- Vagus (CNX): Foregut and Midgut - Pelvic Splanchnic Nerves (S2-S4): Hindgut

Question 48

Blood/Nerves/Lymphs of the Gut

Answer 48

Question 49

Answer 49