Overview And The Mouth Flashcards
What is the mouth the opening to?
The alimentary canal
What is the function of digestion?
To process food
What is the process of absorption?
Transfer of nutrients to circulation
What are the 2 groups of organs in the alimentary system?
- Digestive tract
2. Accessory glands e.g. salivary glands, gallbladder, liver, pancreas
What organs and structures are included within the alimentary system?
- Oral cavity
- Pharynx
- Oesophagus
- Stomach
- Small intestine (duodenum, jejunum, ileum)
- Large intestines (caecum, ascending, transverse, descending, rectum, anus)
What is the type of epithelium found in the oesophagus and why?
- Stratified squamous (many layers)
- Has a protective role
What is the structure of tissue in the GI system?
- Mucosa (epithelium, lamina propria, muscularis mucosae)
- Submucosa (contains secretory glands and connective tissue)
- Muscularis propria (Inner circular, outer longitudinal)
- Adventitia (contains major blood vessels and large nerves)
What is metaplasia?
- A change in epithelium from one that is normally found in that tissue to one which is not
What is Barrett’s oesophagus?
- A change in epithelium from stratified squamous to columnar epithelium (epithelium from the stomach starts to move upwards into the oesophagus)
What is G.O.R.D
Gastro oesophageal reflux disease
What is dysplasia?
The presence of cells of an abnormal type within a tissue which may signify a stage preceding the development of cancer
What are fundic glands?
- A gastric gland in the fundus of the stomach
What is coeliac disease?
- An absorptive abnormality
- Due to callous atrophy (death or loss)
- Hyperplastic crytps
- Increase in inflammatory cells (lymphoid cells)
What is a hyperplastic crypt?
A small tubular gland which becomes bigger or increases in number
What are 2 examples of absorptive/protective diseases of the GIT?
- Inflammatory bowel disease
- Ulcerative colitis
What are the different functions of the GIT?
- Secretion: lubrication, digestive ‘juices’
- Digestion: mechanical, chemical
- Motility: smooth muscle under involuntary control
- Absorption: Mostly in small intestines
- Excretion: faeces
How much fluid is excreted through faeces per day?
100 ml
How much fluid is absorbed from the body per day?
7500 ml
What is meant by mechanical digestion?
- Breakdown of particles
- Ease of movement, mixing
What is meant by chemical digestion?
- Complex –> simple molecules (breakdown)
- Specific enzymes facilitate process e.g. saliva, pancreas
- Secreted at different points in GIT
What are the different uses of motility in the GIT and where do these occur?
- Mouth: chewing, swallowing
- Stomach - churning
- Intestine - peristalsis
- Mass movement/defaecation
What is another name for the mouth?
The oral/buccal cavity
What is the primary sensory function of the mouth?
Senses/taste - heat/cold, spices etc
What is the primary motor function of the mouth?
Movement/mastication - chewing
What are the functions of the mouth other than the primary motor and sensory function?
- Speech
- Expression
- Breathing
What are the general sensory functions of the mouth?
- Nociception
- Mechanoreception
- Thermoreception
What is nociception?
Pain
What is mechanoreception?
Movement
What is Thermoreception?
Heat senses
What is the special sensory function of the mouth?
Gustation (taste)
What does gustation mean?
Taste
What are ‘higher’ level perceptions in the mouth?
- Do you like something/ the way you feel about things
What are the 2 motor functions of the mouth?
Feeding
- Transport e.g. deglutition (swallowing)
- Breakdown
- Swallowing
Communication
- Speak/show facial expression
What is deglutition?
Swallowing
What are the functions of salivation in the mouth?
- Protect
- Lubricate
- Digestion
What is the function of lymphoid tissue in the mouth?
- ‘tonsils’ - first line of defence
What are the functions of reflexes in the mouth?
- Swallowing
- Vomiting
- Gagging
What is the anterior boundary of the mouth?
Lips
What is the lateral boundary of the mouth?
Cheeks
What is the inferior boundary of the mouth?
Mylohyoid/tongue
What is the superior boundary of the mouth?
Palate
What is the posterior boundary of the mouth?
Fauces (pillars)
What are the muscles of mastication?
- Temporalis
- Masseter
- Medial pterygoid
- Lateral pterygoid
What is the role of the buccinator?
Push food and fluid into the centre of the oral cavity
What are the 3 major salivary glands?
- Parotid
- Submandibular
- Sublingual
What are different types of exocrine secretions?
- Salt and water
- Mucous
- Amylase
What are the different abnormalities/pathologies of salivary glands?
- Mumps: swelling - attacks the parotid gland
- Sialolithiasis- blocked duct
- Sialoadenitis - inflammation of gland/duct
- Tumours e.g. parotid
What is Sialolithiasis?
A blocked duct
What is Sialoadenitis?
Inflammation of a gland/duct
