Mucosa Flashcards
What is mucosa?
moist lining made from a layer of epithelium over a layer of connective tissue called the lamina propria
What are the functions of oral mucosa?
protection, secretion, sensation, absorption,
What kind of epithelium is found in mucosa?
stratified squamous
What are the usual layers of mucosa?
epithelium, lamina propria, submucosa, bone
What are the types of oral mucosa?
gustatory
masticatory
lining
What is masticatory?
mucosa on the hard palate
thick lamina propria (mucoperiosteum)
no or thin submucosa
subjected to friction
para keratinised
What is gustatory?
mucosa on dorsum of tongue
keratinised
similar to masticatory
characterised by papillae, some bearing taste buds
What is lining?
mobile and stretchable mucosa (cheeks, lips, floor of mouth, soft palate, ventral tongue)
non keratinised
loose lamina propria and wide submucosa
rapid turnover
What are the epithelium layers?
stratum basal
stratum spinousum
stratum granulosum
stratum corneum
What is the difference between keratinised, para-keratinised and non-keratinised?
keratinised = dead cells, better protection
non-keratinised = living cells
para-keratinised = atypical keratinisation that has some nucleai
What are rete pegs?
epithelial extensions that project into the underlying connective tissue in both skin and mucous membranes.
What are tonofilaments?
keratin intermediate filaments that combine as bundles to make tonofibrils
What is the role of keratohaylins granules?
found in the stratum granulosum
role is to cross-link tonofilaments and provide a protective barrier
What is the mucogingival junction?
junction between the soft, fleshy mucus membrane of the oral cavity and the tough, collagen rich gingiva
What % do keratinocytes make up of epithelium?
90%
What other cells are present?
Langerhans = antigen presenting cells (dendritic cells)
Merkel = sensory cells associated with mechanoreceptor neurons
Melanocytes = pigment producing
What are the keratin projections emerging from the tongue?
filiform papilla
What are the raised structures that contain tastebuds and look like mushrooms?
fungiform papilla
What are the prominences at the dorsal tongue that also provide taste?
vallate papilla
What is the red lip around the lip called?
vermillion border
What is the inner lining of the lip called?
labial mucosa
What are the two glands of the oral mucosa?
sebaceous glands
salivary glands
What occurs in geographical tongue?
no filiform papillae in irregular patches causing smoothness
What are the glands in the lamina propria of the lining epithelium?
exocrine
What is the purpose of these minor salivary glands in lining mucosa?
Lubricate the surface of the cheek with mucous saliva
Recalling the histology microscopy class on muscle tissues, what type of muscle is present deep to the glands in lining mucosa?
skeletal
What layer should mitosis occur and what is the consequence if it occurs in another layer?
basal layer
can be a sign of cancer if mitosis is occuring in the upper areas
What are the epithelium layers of lining mucosa?
stratum basale, stratum spinosum, stratum intermedium, stratum superficiale
What is the difference between parakeratinised and keratinised?
parakeratinised has some cells present, keratinised has none
What are the main histological differences between serous and mucous gland cells?
serous - stain pink, cell nuclei in the centre
mucous - foamy cytoplasm, cell nuclei at outer edge
What cranial nerves provide sensorial function to the mouth?
glossopharyngeal (IX) - provides taste sensation to posterior 1/3 of tongue
facial (VII) - provides taste sensation of anterior 2/3 of tongue
trigeminal (V) - mandibular division provides mucous membranes and floor of the oral cavity, anterior 2/3 of the tongue (only general sensation0
Lower molar, incisor and canine teeth and the associated gingiva
What cranial nerves provide motor function to the mouth?
hypoglossal (XII) - motor function to extrinsic/intrinsic tongue muscles
facial (VII) - motor function to buccinator and orbicularis iris
trigeminal (V) - motor function to muscles of mastication
What attaches the basement membrane to the stratum basale?
hemidesmosomes
What do minor glands secrete?
all mucous apart from lingual which has serous and mucous ducts
What papilla do not have taste buds?
filliform papilla
