Histology of the head and neck Flashcards
Describe the composition of protective mucosa in the oral cavity
- stratified squamous epithelium
- high wear areas are keratinized
- can have cornified ‘spikes’ (cats, herbivores)
- epithelium supported by dense collagenous tissue (lamina propria)
What structure can be found in the submucosa of the oral cavity?
small salivary glands
Describe the keratinisation of the lip
Outer part - keratinised to provide support and protection
Inner part (buccal) - also keratinised but less densely packed together
Label this diagram of a lip
What are the different types of oral papillae?
Mechanical and gustatory
Describe the function and structure of mechanical oral papillae
- physical protection, markedly keratinised
- conical
- marginal (at edge of tongue)
- filiform (small, numerous)
Describe the structure and function of gustatory papillae
- taste, contain taste buds
- fungiform (front of tongue)
- circumvalate/valate (back of tongue)
- foliate (flat, leaf shaped)
What is the function of the tongue?
Prehension
Food capture
Moves food over teeth
Prepares food bolus for swallowing
Catches ruminal bolus during cudding
Carries taste buds (gustation)
Suckling in neonatal mammals
Label this dog tongue
How is a pigs tongue shape related to function?
Flat, muscular and well-developed tip allows them to root in soil for insects as well as manipulate a diverse diet
How does a horses tongue shape relate to its function?
Muscular, smoother and cylindrical
Allows effective grasping and manipulating of long stem grass
How does an ox tongue shape relate to its function?
long, muscular, rough surface due to papillae
well adapted for grazing and pulling grass
rough surface helps strip leaves from plants and aids in grinding process
Which nerve contains the motor supply to the muscles of the tongue?
Hypoglossal
Which nerves carry the sensory fibres to the tongue?
Lingual and glossopharyngeal
Label these local muscles
What is wooden tongue?
Bovine actinobacillosis - bacterial infection -> inflammation of the tongue which becomes hard, swollen and painful
Where are taste buds found?
Within the clefts of the papillae
Where are stem cells found on the tongue?
at the base of the papillae
How are tongue muscles arranged?
They run in various directions allowing for precise movements
Label this cat tongue
Why do gustatory papillae need to be wet?
saliva plays a crucial role in taste perception and the gustatory papillae is where taste receptors are located
What type of oral papillae is this and what is it’s function?
Mechanical (cat)
For grooming and rasping soft tissues from bones
Physical protection
What type of oral papillae is this?
Gustatory
Label this salivary gland
Label the salivary glands of the dog
Orange = parotid
Light blue = mandibular
Yellow = sublingual
Pink oval = zygomatic
Pink, linear = buccal
Label the salivary glands of the pig
Orange = parotid
Light blue = mandibular
Yellow = sublingual
Pink, linear = buccal
Label the salivary glands of the cow
Orange = parotid
Light blue = mandibular
Yellow = sublingual
Pink 7 = buccal
Label the salivary glands of the horse
Orange = parotid
Light blue = mandibular
Yellow = sublingual
Pink 5 = buccal
Label this mixed salivary gland
What do myoepithelial cells do?
aid in expulsion of excretory products from glandular cells
What is the purpose of the mitochondria in salivary glands?
provide energy for cellular activities for endocrine and exocrine functions
What is the purpose of the folded basement membrane in salivary glands?
supportive and structural element
Label this diagram of the oesophagus
Label this diagram of the oesophagus
Label this diagram of the palatine tonsil
Label this diagram of lymphoid tissue
