Page 206 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)

5- Small intestine

Layers:

a. Mucosa contain many microvilli (folds)  help in absorption.
b. Submucosa contains lymph vessels & capillaries.

Absorption:

Absorption requires both pancreatic enzymes & brush border enzymes.

Most pancreatic enzymes are produced as zymogens (inactive)  must be

activated in intestine:
pancreatic

enzymes  E.g., Trypsinogen is activated into Trypsin by Enterokinase
 Then trypsin activates more trypsinogen by autoactivation &

activates the other zymogens

• Microvilli contain brush border enzymes (intestinal enzyme)  not
Brush
border secreted into the lumen  remain attached to cell membrane with their
enzymes active sites exposed to the chyme.
• e.g. Carboxy peptidase, aminopeptidase, sucrose & lactase, etc..

1- Large intestine

 Absorbs H2O, electrolytes, vitamin B12, vitamin K and folic acid from the food before

going to rectum.
 Produce significant amounts of folic acid and vitamin K by normal flora.
2- accessory digestive organs

1- Liver:

 Largest & most important metabolic organ in the body
 Body’s major biochemical factory

 Importance to digestive system  synthesis of bile salts
 Functions not related to digestion.
b. Metabolic processing of the major categories of nutrients

c. Detoxifying body wastes, hormones, drugs & other foreign compounds
d. Synthesizes plasma proteins.

e. Stores glycogen, fats, iron, copper, and many vitamins
f. Participates in activation of vitamin D.
g. Removes bacteria & worn-out red blood cells.

h. Excretes cholesterol & bilirubin.

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