Digestive Flashcards
Why can enamel not regenerate?
no cells
What are the three parts of a tooth?
Crown
Neck
Root
What makes up the Crown?
Enamel
1/2 Dentin
What makes up the Root?
1/2 Dentin
Pulp
Cementum
Periodontal Ligament
What is enamel made out of?
Crystalline Rods or Prisms of Calcium Phosphate & Carbonate
What is the hardest tissue of the body?
Enamel
Also has no sensation
What can erode Enamel?
Acid + Bacteria
What is Dentin made of?
Cells (Odonoblasts)
What is Pulp made of?
soft tissue
blood vessels, nerves, lymphatics
What is Cementum made of?
calcified connective tissue covering the root
What is Cementum used for?
tooth support and anchorage
What is the Periodontal Ligament?
Collagen fibres linking the bone of the socket (alveolar bone) to the cementum
Purpose of the Periodontal Ligament
Join tooth to alveolar bone
What are the 3 types of Papillae (bumps) on the tongue?
Fungiform
Filiform
Vallate (taste buds found here)
What are the 3 major pairs of Salivary Glands in order?
Parotid (serous only)
Sublingual (serous, but mainly mucous)
Submandibular (mixed)
When is saliva secreted?
Following Parasympathetic stimulation induced by seeing, smelling, tasting or thinking about food
What is Saliva made of?
Water + Mucus + Enzymes
Lysozome
Enzyme
Antibacterial
Gross Convolutions
Tubes intertwined such as the Small Intestine
Luminal Folds
Circular Rings (SI)
- Plicase Circularis
Projections towards the lumen
Villi
Evagination (into lumen)
Projections away from lumen
Glands
Invagination (away from lumen)
Stomach + intestines
What are the four tunics of the small intestine in order?
Mucosa
Submucose
Muscularis Externa
Serosa
Mucosa (mucous membrane)
epithelium
lamina propria
muscularis mucosae
Submucosa
loose connective tissue
carries large blood vessels, lymphatic vessels and nerves
connects the mucosa to the external muscle coat
Muscularis Externa (external smooth muscle)
Two layers to produce peristalsis
Inner layer - circular
Outer layer - longitudinal
Serosa
slippery outer covering for the gut tube (except oesphagus)
Two layered (outer mesothelium on a bed of CT)
What occurs between the two layers of the Muscularis Externa?
Myenteric Nerve Plexis
Epithelium
specialised for protection or absorption or secretion
Lamina Propria
soft fibrous bed of loose CT on which the epithelium rests
carries nerves and capillaries, populated with defensive cells
muscularis mucosae
two thin layers of smooth muscle, inner circular/ outer longitudinal
Provides the mucosa with some movement independent of the external muscle coat (not peristalsis, localised movement instead)
