INTESTINAL GLAND :
- Present in Duodenum and Jejunum part of small intestine.
They are of two types :
(a) Brunner's gland / submucosal gland :
- Present in submucosa of Duodenum.
- Secret mucoid secretion.
- Help to neutralize acidic chyme.
- Secretion is stimulated by duocrinin(a local hormone).
(b) Crypts of Lieberkuhn :
- Present in mucosal layer of Duodenum and Jejunum.
- Type of simple tubular glands.
- Secretion in stimulated by enterocrinin (local hormone).
- They have four types of cells :
(i) Surface cells = release enzymes
(ii) Paneth cells = release lysozyme and zinc
(iii) Goblet cells = release mucus
(iv) Argentaffin cells = secrete serotonin(vasoconstrictor)
INTESTINAL JUICE / SUCCUS ENTERICUS :
- Normal volume = 1-2 litre per day
- pH of intestinal juice = 4.6-4.8
- Enzymes :
(i) Dextrinase (carbohydrate digesting)
(ii) Maltase (carbohydrate digesting)
(iii) Isomaltase (carbohydrate digesting)
(iv)Lactase / beta-glactosidase (carbohydrate digesting)
(v) Sucrase / Invertase (carbohydrate digesting)
(vi) Nucleotidase (nucleic acid digesting)
(vii) Nucleosidase (nucleic acid digesting)
(viii) Phosphatase(nucleic acid digesting)
(ix) Aminopeptidase (protein digesting)
(x) Dipeptidase (protein digesting)
(xi) Intestinal lipase
(xii)Enterokinase (activate trypsinogen)