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A Handbook of Biology

BÜÇÇÅL ÇÅVÏTÝ (ØRÅL ØR MØÜTH ÇÅVÏTÝ):



Consists of palate (roof), teeth & muscular tongue.

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Palate has anterior hard palate and posterior soft palate.

Tongue is a muscular organ attached to the floor of oral cavity by

the frenulum. Tongue has small projections called papillae. Some

papillae bear taste buds.

Type of papillae are: filiform, fungiform, circumvallate

At the back, on either side of tongue tonsils are present.

PHÅRÝÑX:

Common passage for digestive and respiratory systems.

When food materials pass through the pharynx, the cartilaginous

epiglottis closes the glottis (opening of larynx) and prevents the entry

of food into trachea.

An eustachian tube connects the middle ear cavity with the Pharynx

ØËSØPHÅGÜS:

Muscular tube (30 cm) that conducts food into J – shaped structure

called stomach.

Posterior part of the oesophagus has gastro-oesophageal sphincter

(a circular muscle). It controls the opening of oesophagus into

stomach.

STØMÅÇH :

'J' shaped structure for storage

and digestion of food.

4 parts: upper (anterior) fundus,

cardiac,

main

body,

&

lower

(posterior) pyloric (antrum).

Pyloric stomach leads to small

intestine by an opening called

Pylorus,

guarded

by

pyloric

sphincter muscle.

Inner wall of stomach bears rugae

(longitudinal muscular folds).