Gi Histo Lab

Front 1

Lip tissue

Back 1

Black = Keratinized Stratified squamous epithelium of external lip

* Notice the Orbicularis oris MM at bottom left

Red = NON-keratinized stratified wet squamous epithelium of oral mucosa

*circle = salivary glands in submucosa

Front 2

Taken from lip

Back 2

Vermillion Zone

Transition from external keratinized epithelium of skin (red) to internal non-keratinized epithelium of oral mucosa (Black)

*Vermillion zone lacks salivary glands and thus needs to be continuously moistened

Front 3

Dorsal Tongue

Back 3

A = Filliform Papillae = Rough keratinized papillae w/ no taste buds

B = Fungiform Paillae = rounded/elevated non-keratinized papillae w/ taste buds on upper surface

Front 4

Dorsal Tongue

Back 4

Black = Fungiform Papillae with taste bud at surface (circle)

Red = Filliform Papillae (lack taste buds)

Front 5

Dorsal Tongue from papillae upper surface

Back 5

Taste bud at the upper surface of a fungiform papillae

Front 6

Dorsal Tongue

Back 6

Circumvallate Papillae - taste buds on lateral wall

*Located in a V-shaped line at posterior 1/3 of tongue

Front 7

Tongue

Back 7

Foliate Papillae

*Vertical Ridges on sides of tongue

*Taste buds on dorsal surface (circle)

*Occur in rows (vs fungiform that occur singly)

Front 8

Taken from tooth

Back 8

Peridontal Ligament

*made of Sharpey's fibers of collagen that connect alveolar bone to to cementum

*shock absorbers

Front 9

esophagus

Back 9

Mucosa Layer of Esophagus, comprised of...

1) non-keratinized stratified squamous epipthelium (arrow)

2) Lamina propria (circle) of loose CT and immune cells

3) Muscularis mucosa (box)

Front 10

Back 10

Esophagus Layers

*Black arrow = Stratified squalmous epithelium of mucosa

*Red arrow = lamina propria (indicated by lymphoid nodule)

*white X = submucosa CT

*Black X = Inner circular smooth mm of muscularis externa

*Red X = Outer longitudinal smooth mm of muscularis externa

Front 11

Back 11

Myenteric (aka Auerbach) Nerve Plexus

*located b/w inner circular and outer longitudinal layers of the muscularis externa

*regulates peristalsis

Front 12

Where are the Meissner's nerve plexi located and what are their function?

Back 12

Submucosa of Esophagus

*fxn to regulate glandular secretions

Front 13

Back 13

Esophageal-Gastric Junction

*Esophagus (red X) shows 3 layers of mucosa, submucosa, and Muscularis externa

*Cardiac Stomach (yellow x) is pale staining glandular tissue

*LES = black star

Front 14

Back 14

Stomach Fundus

A = mucous surface cells (line the most superficial part of gastric pit.

Arrow = Mucous neck cells (w/ interspersed parietal cells)

Front 15

Back 15

Parietal Cell

*Located in neck of gastric gland - spherical, often binucleate

*Secrete H+ via intracellular canalicculi as well as intrinsic factor to find cobalamin in SI

Front 16

Back 16

A = parietal cell

B = Cheif Cell - located at base of pit, basophilic cytoplasm due to large amount of RER to make pepsinogen

Front 17

Back 17

Enteric Endocrine Cell

*scattered along gastric gland to release endocrine and paracrine substances

*Can be closed or open type

Front 18

Back 18

A = pareital cell

B = cheif cell

C = Muscularis mucosa

Front 19

What stomach layer contains Lymph vessels, aa, VV?

Gastric pits and stem cells?

Back 19

1) Submucosa

2) Mucosa

Front 20

Back 20

Parotid Gland - completely serous gland

A = striated gland - process initial secretions

*serous acini to left of A

B = intercalated gland

Path of Drainage = acini -> striated -> intercalated

Front 21

Back 21

Parotid

*all serous acini

Front 22

Back 22

Submandibular Gland

Mostly Mixed Acini (mucinous w/ serous demilunes at tips)b w/ some scattered serous

Front 23

Back 23

Sublingual

*Mostly mucinous glands w/ few scattered mixed acini