Foundations 2 Exam 1 Histology

Lips

Vermillion Zone: transition from keratinized stratified squamous of skin on outer lip to wet keratinized stratified squamous of the mucosa of the inner lip

Oral Cavity

keratinized/wet keratinized stratified squamous(depends on diet)

GALT

found in lamina propria. Tonsils are an example of nodules of this

Tounge

Keratinized/WK stratified squamous. Lingual papillae

Filiform Papillae

Most numerous in most species. No taste buds

Fungiform papillae

fewer in number. Thin, Keratinized/WK stratified squamous. Have taste buds

Foliate Papillae

Large animals, pigs, several taste buds

Vallate Papillae

Few in number, largest, have a crypt, taste buds on sides, salivary glands ope in crypts

Taste Buds

Made up of: taste receptor cells, supporting cells, and basal cells

Outer Enamel Epithelium

Dental Papilla

Predentin

Pink

Ameleoblasts

Pink

Odontoblasts

Orange-Produces predentin which mineralizes into dentin

Developing Brachydont tooth

Dentin

Light Blue-70% mineral

Dential Tubules

Turquoise-odontoblastic processes travel through dentin via this

Enamel

Orange-96% mineral

Alveolar Bone

Pink

Periodontal Ligament

Turquoise

Cementum

Orange

Gingiva

Light Blue- Keratinized/WK stratified squamous

Pulp Cavity

Houses blood vessels, lymphatic vessels, nerves

Mucosa

-epithelium, lamina propria, and muscularis mucosa

submucosa

fibrous CT, submucosal glands, larger blood vessels, nerves, lymphatics, submycosal ganglia

muscularis externa

smooth muscle, inner circular layer, outer longitudinal, myenteric ganglia between inner and outer layer

Serosa/Adventitia

Adventitia: CT of variable thickness. Serosa: simple squamous mesothelium

Esophagus

Myenteric Ganglia

Duct

Stratified cuboidal. Exocrine cells have these, endocrine don’t

Secretory

Simple cuboidal

Serous Glands

Nuclei near basal side-parotid gland

Mucous glands

heterochromatic nuclei-sublingual gland

separate mixed glands

mandibular gland

serous demilunes

serous cells look like they form a cap

myoepithelial cells

Striated duct

simple columnar epithelium

intercalated duct

low cuboidal, simple- green arrows

Interlobular ducts

Fundus and Body of Stomach

Contain surface mucous cells, mucous neck cells, parietal cells, chief cells, and enteroendocrine cells

Gastric Pits

Blue

Neck/Isthmus

Pink

Gastric Glands

Orange

Surface Mucous Cells

Mucous neck cells

parietal cells

eosinophilic

chief cells

basophilic

cardia and pyloric part

surface mucous cells and primarily mucous secreting cells in glands. Rare parietal cells, no chief cells

surface mucous cells

enteroendocrine cells

communicate with nervous system. Only seen with special stain

margo plicatus

separates non-glandular and glandular portions of equine stomach

Gastric Wall

gastric muscularis externa

mainly for churning and mixing

oblique smooth muscle

internal to circular and longitudinal muscle layers

circular smooth muscle

longitudinal smooth muscle

Gastric Serosa

Villi

Blue

Crypts

Orange

Enterocytes

Simple columnar epithelium with microvilli

Enteroendocrine cells

regulate pancreatic secretions, energy homeostasis, digestion, and absorption

Stem Cells

Located in crypts. continuous replacement of intestinal epithelial cells

Plicae circulares

amplified SA. Permanent folds of mucosa and submucosa in small intestines. Don’t flatten out like rugae of simple stomach

lacteals

enterocytes transport absorbed lipids into these

duodenum

has brunners glands(G) which secrete alkaline mucus to protect against acidic secretions from the stomach

Cecum/Colon

Have no villi, only crypts. epithelium is primarily goblet cells and stem cells for regeneration

Ano-Rectal Junction

Rectum mainly has goblet cells and Anus has stratified-squamous wet keratinized epithelium

Rumen

stratified-squamous wet keratinized epithelium. Papillae increase SA for absoprtion. No muscularis mucosa, submucosa is very thin

Reticulum

Smaller papillae found on floor and base of walls. stratified-squamous wet keratinized epithelium. squeezes out fluid/small particles into omasum. contracts larger particles back into rumen for further fermentation. muscularis mucosa only found in walls

Omasum

squeeze out fluid/electrolytes. May absorb residual VFAs and bicarbonate. stratified squamous epithelium(K/WK). Both muscularis mucosa and externa in core of laminae. Papillae found on laminae and floor

Abomasum

12 abomasal folds. break down microoraganisms, products of fermentation. Have surface mucus cells, mucus neck cells, parietal, chief and enteroendocrine cells

primarily mucous secreting cells in glands