Digestive System (Oral Cavity to Stomach) Flashcards
What is the digestive system comprised of?
Oral cavity and alimentary canal
Alimentary canal
Includes esophagus, stomach, small and large intestines and several glands
Hollow tube with 4 layers
What are the layers of the alimentary canal?
- T. mucosa
- T. submucosa
- T. muscularis
- T. Serosa (CT covered by mesothelium) / T. adventitia
What is included in the oral cavity?
Lips, palate, teeth, tongue and salivary glands
Epithelium of the lip and cheek (oral cavity)
Outer surface: Strat. squamous keratinized with hair
Inner surface: Strat. squamous non-keratinzed (dogs) and keratinized (ruminants and horses)
Hard palate
Strat. squamous keratinized (thick in ruminants and forms the dental pad rostrally)
Blended lamina propria and submucosa covering bony tissue
Soft palate
Strat. squamous on oral side
Pseudostrat. ciliated on nasal side
Blended lamina propria with lymphatic tissue
What are the functions of the tongue?
Mastication, taste, licking and suckling
Mucosa form papillae
Filiform (keratinized in horses, ruminants and cats, most numerous, no TB)
Fungiform (mushroom shape)
Foliate (RABBITS, leaf shape)
Circumvallate
Conical and lenticular (lent. only in ruminants, lentil shape)
Mechanical papillae
Filiform
Conical
Lenticular
Gustatory
Circumvallate (taste buds on lat. side)
Foliate (TB on lat. side)
Fungiform (few TB on dorsal side)
How many planes does the skeletal muscle on the tongue have?
3: longitudinal, vertical and transverse
What glands are present on the tongue?
Serous/ mucous (VonEdner associated with circumvallate papillae)
Lyssa (tongue)
Fatty tissue and muscle in CT capsule
Dog, cat and pig
Horse tongue
Dorsal lingual cartilage (hyaline) with CT
(fibroelastic CT and fat)
Ruminants tongue
Torus linguae (thickened mucosa on caudal dorsal aspect)
Lenticular papillae
Birds tongue
Lingual bone
Taste bud
Bell-shaped
Taste cells, supporting cells, and nerve fibers innervating taste cells
4 taste qualities: sweet, salt, bitter and acid
What are the salivary glands?
Parotid, mandibular, sublingual, zygomatic (canivores) and molar (cats)
Parotid
Serous
Striated ducts
Saliva
Contains amylase which starts the carbohydrate digestion in the oral cavity
What do teeth consist of?
Soft tissues (pulp cavity and periodontal ligament)
Hard tissues (enamel, dentin and cement)
Enamel
Covers the crown
Hardest substance in the body
Acellular and avascular
Have prisms synthesized by ameloblasts (non-regernative)