Digestive system Flashcards
(23 cards)
What is the structural and chemical composition of enamel?
-Crystalline rods/prisms of calcium phosphate and carbonate
Does enamel contain cells?
No. There is no sensation.
What kind of cells does dentine have?
Odontoblasts.
Where are the odontoblasts located?
They occur nearby in the pulp.
Describe the pulp of a tooth?
Made out of soft tissue.
Contains blood vessels, nerves, lymphatics.
What is the cementum?
Calcified connective tissue which covers the root.
What is the periodontal ligament and what does it do?
Collagen fibres which link the bone of the socket (alveolar bone) to the cementum.
What three muscles make up the tongue?
- Longitudinal
- Transverse
- Vertical
What are the three forms of buds on the tongue?
- Filliform
- Fungiform
- Circumvallate
What does the filliform do?
Moves food.
What does the circumvallate do?
Samples food and produces saliva.
Name the three salivary glands.
1) Parotid (by the ear)
2) Submandibular
3) Sublingual
What aspect of the saliva does the partoid salivary gland secrete?
The watery stuff (serous cells)
What aspect of the saliva does the sublingual produce?
The viscous, mucuous stuff (mucous cells)
What aspect of the saliva does the submandibular produce?
Both serous and mucus.
What stimulates the secretion of saliva?
- Seeing, smelling, tasting, thinking about food.
What makes up saliva?
Water, mucus, enzy,es.
How does the digestive system gain surface area?
Through
- folds
- simple tubular glands
- Finger like projections
- Convolutions
wHAT are the 4 tunics of the gut tue
- mucous membrane
- submucosa
- external smooth muscle
- serosa
What doe the mucous membrane comprise of?
- 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.
What does the submucosa comprise of?
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.
What is the external smooth muscle all about?
It is in 2 layers to produce peristalsis.
Inner layer = circular
~Myentric nerve plexus layer~
Outer layer - longitudinal.
What is the serosa all about?
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).
