Digestive System

Mechanical digestion

Breaks down food without altering chemical composition

Chemical digestion

Enzymes chemically break down food molecules into building blocks

Alimentary canal

Tubular part of the digestive tract from the mouth to anus

What are the general parts of the alimentary canal?

Mouth, pharynx, esophagus, stomach, small and large intestine, anal canal

What are the structural parts of the alimentary canal?

Mucosa, submucosa, muscularis, serosa

What is the function of the mucosa?

Increases absorptive surface area and absorbs substances from the diet

What is the function of the submucosa?

Nourishes surrounding tissues and carries away absorbed materials

What is the function of the muscularis?

Provides movement of the digestive tube and encircles it, causing it to contract and shorten

What is the function of the serosa?

It protects the underlying tissues and secretes serous fluid

What is the purpose of serous fluid?

Allows organs to in the abdominal cavity to slide freely against one another

Mastication

Chewing action

Oral cavity

Chamber between the palate and the tongue is responsible for the initial stages of digestion, including the mechanical breakdown of food and mixing it with saliva.

Oral vestibule

Area between the teeth, cheeks, and lips that aids in food manipulation and speech.

What is the root of the tongue anchored to?

Hyoid bone

What is the hyoid bone covered with?

Masses of lingual tonsils

Palate

Forms roof of the oral cavity and consists of bony and muscular tissues, separating the oral cavity from the nasal cavity

Anterior (hard) palate

The front portion of the palate that is bony and forms the hard surface of the roof of the mouth.

Labial frenulum

A narrow band of tissue that connects the inner surface of the lips to the gums. It plays a crucial role in maintaining the position of the lips by providing stability during activities such as chewing, speaking, and other oral movements.

Posterior (soft) palate

The back portion of the roof of the mouth, formed by flexible and muscular tissues

What does the posterior palate form?

Uvula

Primary teeth

Erupt through gums

How many primary teeth are there?

10

At what ages do primary teeth develop?

6 months to 2-4 years old

What is the primary teeth sequence?

Central incisor, lateral incisor, canine, first molar, second molar

Secondary teeth

Permanent

How many secondary teeth are there?

32

At what ages do secondary teeth develope?

6 to 17-25 years

What is the secondary teeth sequence?

Central incisor, lateral incisor, canine, first premolar, second premolar, 1st, 2nd, 3rd molar

What are the two main parts of a tooth?

Crown and root

What covers the crown of the tooth?

Enamel

Dentin

Found beneath the enamel, bonelike substance that forms the bulk of the tooth

What do the salivary glands consist of?

HCO3- to help buffer acid

What is a neutral PH for the salivary glands?

6.5-7.5

Parotid gland

The largest salivary gland, located near the ear, that produces serous saliva containing enzymes

What does the parotid duct secrete?

Clear, watery fluid