Digestive system

Question 1

What is the structural and chemical composition of enamel?

Answer 1

-Crystalline rods/prisms of calcium phosphate and carbonate

Question 2

Does enamel contain cells?

Answer 2

No. There is no sensation.

Question 3

What kind of cells does dentine have?

Answer 3

Odontoblasts.

Question 4

Where are the odontoblasts located?

Answer 4

They occur nearby in the pulp.

Question 5

Describe the pulp of a tooth?

Answer 5

Made out of soft tissue.

Contains blood vessels, nerves, lymphatics.

Question 6

What is the cementum?

Answer 6

Calcified connective tissue which covers the root.

Question 7

What is the periodontal ligament and what does it do?

Answer 7

Collagen fibres which link the bone of the socket (alveolar bone) to the cementum.

Question 8

What three muscles make up the tongue?

Answer 8

• Longitudinal
• Transverse
• Vertical

Question 9

What are the three forms of buds on the tongue?

Answer 9

• Filliform
• Fungiform
• Circumvallate

Question 10

What does the filliform do?

Answer 10

Moves food.

Question 11

What does the circumvallate do?

Answer 11

Samples food and produces saliva.

Question 12

Name the three salivary glands.

Answer 12

1) Parotid (by the ear)
2) Submandibular
3) Sublingual

Question 13

What aspect of the saliva does the partoid salivary gland secrete?

Answer 13

The watery stuff (serous cells)

Question 14

What aspect of the saliva does the sublingual produce?

Answer 14

The viscous, mucuous stuff (mucous cells)

Question 15

What aspect of the saliva does the submandibular produce?

Answer 15

Both serous and mucus.

Question 16

What stimulates the secretion of saliva?

Answer 16

• Seeing, smelling, tasting, thinking about food.

Question 17

What makes up saliva?

Answer 17

Water, mucus, enzy,es.

Question 18

How does the digestive system gain surface area?

Answer 18

Through

• folds
• simple tubular glands
• Finger like projections
• Convolutions

Question 19

wHAT are the 4 tunics of the gut tue

Answer 19

• mucous membrane
• submucosa
• external smooth muscle
• serosa

Question 20

What doe the mucous membrane comprise of?

Answer 20

• epithelium (protection, absorption, secretion)
• lamina propria: soft connective tissue, carries nerves, blood capillaries, w/ defensive cells.
• moscularis mucosae: 2 thin layers of smooth muscle = inner circular, outer longitudinal.
  This provides the mucosa with some movement independent of the external muscle coat.

Question 21

What does the submucosa comprise of?

Answer 21

A thick bed of loose connective tissue carrying larger blood vessels, lymphatic vessels and nerve (submucosal plexus).
- It connects the mucosa to the external muscle coat, but allows some movement between the two.

Question 22

What is the external smooth muscle all about?

Answer 22

It is in 2 layers to produce peristalsis.
Inner layer = circular
~Myentric nerve plexus layer~
Outer layer - longitudinal.

Question 23

What is the serosa all about?

Answer 23

A slipper outer covering for the gut tube (except oesophagus).
It is 2 layered, with outer mesothelium sitting on a bed of connective tissue. (Is also known as the visceral peritoneum).