Digestive system - Entrance preparation bscag, CEE

Digestive system under human system comprises of mouth, alimentary canal, assessory organs including liver and pancreas in human body. It is an important system for entrance applicants of Medical, para-medical and applied science students.


Video Notes:

DIGESTIVE SYSTEM 

 

Mouth

 

Vibrissae/whiskers------------->upper lip of rabbit

 

philtrum-------------> upper lip of man

 

Vestibule-------------> space between lip and gum   / cheek and gum

 

Buccal cavity and pharynx separated by isthmus.

 

Jacobson organ------------->Present on upper jaw of rabbit (take smell)

 

Palate

 

  • Soft palate------------->Have uvula(Uvula or venum)

  • Hard palate------------->Have rugae

 

Teeth of mammal------------->thecodont, diphyodont, heterodont

 

Teeth of frog------------->acrodont, polyphyodont, homodont

 

Tusk of elephant is modified upper incisor and tusk of walrus is modified canine.

 

Enamel is hardest substance in body.

 

Ectodermal origin and secreted by amyloblast cell.

 

Dentine is mesodermal in origin and secreted by odontoblast cell.

 

 

  • Man------------->2 1 2 3/ 2 1 2 3 (adult 20+)

  • Man-------------> 2 1 0 2/ 2 1 0 2 (Child)

  • Rabbit------------->2 0 3 3 / 1 0 2 3

  

Tongue

 

 endodermal origin

 

Divided into oral(2/3) and pharyngeal (1/3) by sulcus terminalis.

 

Nuhn’s gland/ Ebner’s gland / Weber glans or mucus secreting gland on upper surface of tongue.

 

  • Filliform------------->small and many (No taste buds)

  • Fungiform------------->Mushroom shaped, medium, less

  • Foliate-------------> in rabbit (man absent)

  • Circumvallate------------->largest, least, posterior

 

Sweet------------->tip

 

Salt------------->middle

 

Sour------------->side

 

Bitter------------->posterior

 

3 pairs of salivary gland in man, 4 pairs in rabbit.

 

Parotid------------->stenson’s duct(Largest in size)

 

Sub-maxillary/sub-mandibular------------->wharton’s duct(maximum secretion)

 

Sub-lingual------------->duct of ruvinus

 

Infra orbital salivary gland

 

Epiglottis absent in frog.

 

Oesophagus

 

Peristalsis, only mucous gland, voluntary and involuntary also mixed

 

Stomach

 

Peritoneal covering is ometum. Folds are rugae.

 

Fundus absent in frog.

 

  • Oxyntic/parietal cell------------->HCl

  • Zymogen/peptic/chief cell------------->pepsinogen, pro-renin, lipase

  • Mucous/goblet cell------------->Mucus

  • Argentaffin cell------------->Somatostatin(deactivate gastric gland)

  • G-cell------------->Gastrin(activate gastric gland)

 

Intestine

 

Duodenum------------->Brunner’s gland(only in duodenum)

 

Common bile duct open anteriorly and pancreatic duct in distal part.

 

In human hepato-pancreatic duct open in middle of duodenum.

 

Peyer’s patches------------->phagocytic cell of intestine

 

Crypts of Liberkuhn has parieth cell secreting lysozyme which kill germ/bacteria.

 

Succus entericus------------->Secretion of Crypts of Lieberkuhn

 

Sacculus rotundus is terminal bulb like part of ileum in rat and rabbit(not in man).

 

Colon

 

Pouch haustra

 

E. coli present I colon (vit B2, B12, K2 synthesis)

 

Rectum is retroperitoneal (like oesophagus tunica adventia is outermost layer.)

 

Muscularis layer consists of inner circular and outer longitudinal layer except in stomach.

 

Liver lobes

 

  • 3 frog @(4 letters -1)

  • 4 human @(5 letter -1)

  • 5 rabbit @(6 letter -1)

 

Glisson’s capsule -------------> characteristic feature of mammal

 

Billirubin------------->yellow

 

Billiverdin------------->green

 

Pancreas

 

Wirssung’s duct is main and sentorni is accessory pancreatic duct.

 

Hepatopancreatic duct has spincter of oddi and ampulla of vater.

 

α-cell------------->glucagon (increase sugar level)

 

β-cell------------->insulin

 

δ -cell------------->somatostatin(inhibit gastrin and secretin)

 

pp-cell------------->polypeptide(inhibit pancreatic juice)

 

 




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