Week 2 - Oral Cavity Flashcards
Number of normal teeth
32
2 types of digestion in the oral cavity
Mechanical and chemical
How many large salivary glands are there in the oral cavity
3
How many litres of saliva is secreted a day
1-1.5L
Functions of saliva
Keeps oral cavity moist, suspension of food in solution that aids taste, begins digestion, protects
Two types of enzymes secreted in the oral cavity that help with digestion
Salivary amylase
Lingual lipase
Salivary amylase
Starch splitting enzyme which breaks down 3-5% of carbs
Lingual lipase
digests small amounts of lipids
An enzyme secreted to protect against bacteria
Lysozyme
Three parts of the Pharynx
Nasopharynx, oropharynx and Laryngopharynx
Which 2/3 parts of the pharynx are associated with digestion
Oropharynx and Laryngopharynx
Uvula/soft palate function
Stops food from entering nasopharynx
Epiglottis function
Prevents food from entering Larynx/wind pipe
Where is the Oesophagus located and how does it enter the diaphragm
Posterior to the trachea and enters the diaphragm through the hiatus (opening)
How is food controlled entering into the oesophagus
The upper and lower oesophageal sphincters
Phases of swallowing
- Voluntary phase
- Pharyngeal phase
- Oesophageal phase
What gives the stomach its large surface area to stretch
Submucosa and mucosa are folded (rugae), which assists with increasing its surface area and expands the stomach when it receives food
Stomach secretions
Mucous, hydrochloric acid, enzymes and hormones
Name the stomach enzymes secreted and what they do
Gastric lipase - breaks down fats/lipids
Pepsin - breaks down protein
Name the hormone secreted by the stomach and what it does
Gastrin - increases gastric secretions
How does the body regulate stomach secretions (3 phases)
Cephalic phase, Gastric phase, Intestinal phase
Cephalic phase - stimuli and PNS action potentials caused
Stimuli - smell or taste food, chewing and swallowing or even the thought of food
PNS - Secretion of stomach mucosa, Increases chief and parietal cell secretion, stimulates secretion of gastrin
Gastric phase - stimuli and PNS action potentials caused
Stimuli - Enlargement of the stomach, presence of protein
PNS - similar to cephalic phase
Intestinal phase
Chyme entering the duodenum triggers the enterogastric reflex and reduces gastric secretions
How long is the small intestine
~ 6 metres long
3 parts of the small intestine and their lengths
Duodenum (25cm)
Jejunum (2.5m)
Ileum (3.5m)
Where do most of the absorption occur in the small intestine
Jejunum
What hormones does the small intestine secrete and what do they do
Cholecystokinin and Secretin
They decrease gastric secretions and stimulate liver and pancrease secretions
What enzymes does the small intestine secrete and what do they do
Disaccharidases and peptidases
Assists the break down of food
