Physiology Of The Pancreas Flashcards
How long is the pancreas?
18cm
Describe the location of the pancreas
Found behind posterior peritoneum.
Lies in the curve of the duodenum.
The rest of the gland lies horizontal in the posterior abdominal wall
The pancreas has both an endocrine and exocrine function:
Explain and differentiate between the two:
Endocrine: Islets of Langerhans found dispersed in exocrine portion.
- A cells: Glucagon
- B cells: Insulin
Exocrine: Cells arranged in acini
- Secretion of pancreatic juice by hormone control
- Discharge of products via exocytosis into lumen of panc. ducts.
- Juice contains water, Na+, bicarbonate, K+, digestive enzyme amylase.
- This is an alkaline juice neutralizing stomach acid
Describe the connection between small pancreatic ducts, bile ducts and
Small ducts coalesce into single duct, duct of Wirsung.
• Duct of Wirsung joins common bile duct to form ampulla of Vater
- Opening into duodenum.
•Orifice of duodenum is encircled by sphincter of Oddi.
What is an accessory duct duct of Santorini?
Opens independently and more proximally in the duodenum.
Which enzyme digests starch?
Amylase
Name 3 enzymes that digest proteins:
Trypsin.
Chymotrypsin.
Carboxypeptidase
What kind of enzymes break down nuclei acid into nucleotides?
Nucleases.
What is the inactive form of trypsin that is released?
Trypsinogen.
What enzyme activates trypsin?
Enterokinase
Trypsin proceeds to activate 2 specific enzymes, name them:
Chymotrysinogen.
Carbxypeptidase.
Pancreatic secretions are under hormonal control.
Gastric secretions are classified into 3 phases, name them:
Cephalic
Gastric
Intestinal
Explain the cephalic phase of gastric secretions:
Cephalic phase: Conditioned and unconditioned reflexes
- Sight, smell and taste of food excites efferent Vargas fibers
- The juice secreted is viscid and has a high enzyme quality
- Small in volume though
Explain the Gastric phase of gastric secretions:
- Make mention of the 2 mechanisms involved:
Gastric phase: Triggered when food enters the stomach.
- Reflex response due to distention involving afferent and efferent Vargas fibers
- Gastrin is released from the Antral mucosa of the stomach
How is gastrin released?
Gastrin is released from the astral mucosa of the stomach.