Anatomical Organisation Of Digestive System

Question 1

What are the general components of the digestive system?

Answer 1

Oral cavity containing salivary glands
Oesophagus
Stomach
Liver
Pancreas
SI: duodenum, jejunum and ileum
LI: ascending/descending colon
Rectum and anus

Question 2

The structure of the oesophagus?

Answer 2

23-30 cm in length, and extends forwards from the pharynx immediately behind the trachea
Outer longitudinal skeletal muscle layer
And the inner circular skeletal muscle layer

Question 3

The structure of the stomach?

Answer 3

• longitudinal muscle layer
• circular muscle layer
• oblique muscle layer
  Attached to the oesophagus and duodenum
• cardiac sphincter at top and pyloric sphincter at bottom
  Fundus top, body (corpus) mid and antrum (bottom)

Question 4

What is the structure of the intestinal walls of the SI?

Answer 4

Intestinal villi: (finger like extensions of the mucosa)
- thin projections of the mem of each villi is called microvilli
Plicae: permanent folds of the mucosa and submucosa in the intestinal lining to increase SA and slow the movement of chyme

Question 5

What is the structure of a villi?

Answer 5

Villi:

• enterocytes line the top
• have a capillary network, lamina propria, lacteal, goblets cells
• submucosa
• crypts if lieberkukn (open intest gland)

Question 6

What is the structure of the large intestine?

Answer 6

Ileum feeds into the cecum

• appendix
• cecum
• ascending colon
• transverse colon
• descending colon
• rectum to anus

Question 7

What is the structure of the liver?

Answer 7

Right and left lobes

• hepatic portal vein and artery proper
• gallbladder
• left hepatic vein and interior vena cava
• common bile duct

Question 8

What is the structure of the gallbladder?

Answer 8

Gallbladder

• cystic duct
• common bile duct
• common hepatic duct
• bile canaliculi

Question 9

Name some examples of blood supply to the intestines?

Answer 9

Arterial:
- left inferior phrenic artery
- celiac trunk (foregut)
- left gastric artery
- right inferior phrenic artery
- superior mesenteric artery (to midgut)
- inferior mesenteric artery (to hindgut)
Venous:
- splenic vein
- portal vein
- right gastric vein
- pancreaticoduodenal vein
- inferior/superior mesenteric veins 
- superior rectal veins

Question 10

Describe the cross sectional slice through the GI tract?

Answer 10

SI: longitudinal muscle, circular muscle, submucosa, muscualris mucosa and mucosa (longer villi)
LI: same bit with shorter villi

Question 11

What are the anatomical features of the pancreas?

Answer 11

• tail, body, and head
• pancreatic duct (duct of Wirsung)
• accessory duct (duct of santorini)
• hepatipancreatic ampulla (ampulla of Vater)