Exercise 7: The Digestive System

Oral cavity:

1. Oral epithelium, The Lip – H&E

2. The Tongue – H&E

3. The Salivary Glands, Parotid Gland – H&E

Photo credit: Roch Bandala

Photo credit: Roch Bandala

Keratinized stratified squamous

Obicularis oris

fungiform papilla

Vallate papilla

Skeletal muscle

Stratified squamous epithelium

Taste bud near taste pore

Filiform papilla

Photo credits: Aki Fujikawa/Ronneil Bilbao

Intralobular ducts

Serous acinar secretory cells

striated duct

Excretory duct

Serous glands

stroma

parenchyma

4. Submandibular gland – H&E

Alimentary canal:

1. Esophagusa. Human upper third – H&E

b. Human lower third – H&E

Photo credits: Erika Agana

submucosa

Mucous type glands

Lamina propria

adventitia

Stratified squamous

mucosa

Muscularis mucosa

submucosa

Muscularis externa

2. Human stomach, fundic region - H&E

3. Intestinea. Mammal stomach-duodenum junction section – H&E

b. Large intestines – H&E

mucosa

Photo credit: Tanya Ho

Photo credit: Mairen Lacerna

Photo credit: Tanya Ho

muscularis externa

serosa

lamina propria

c. Ano-rectal junction – H&E

Photo credit: Tanya Ho

Photo credit: Tanya Ho

simple columnar

goblet cells

stratified squamous

internal anal sphincter muscle

stratified squamous epithelium

d. Appendix – H&E

Accessory glands:

1. Pancreas – H&E

Photo credit: Tracy Prado

Photo credit: Tracy Prado

connective tissue

Islands of Langerhans

secretory acini

Interlobular ducts

2. Pig Liver, cross section – H&E

3. Gall bladder – H&E

Photo credit: Francis Dale Deiparine

Photo credits: Precious Yson

Simple columnar epithelium

Mucosa

Lamina propria

Dense connective

tissue

muscularis

stratified squamous epithelium

interlobular septum

portal triad

portal vein

bile duct

hepatic artery

Answers to Questions:

What type of tissue comprises the submucosa (middle third)?

The connective tissue which composes the submucosa is mostly collagenous fibers with some elastic fibers.

What is the secretion of each of these cell types: parietal cell, surface mucous cells, and chief cells?

Parietal cells secrete hydrochloric acid into the lumen to establish an extremely acidic environment. Surface mucous cells secrete bicarbonate-rich mucus into the gastric surface for coating and lubrication. Chief cells secrete chymosin/rennin which is a protease that coagulates milk protein, found in young animals. Chief cells and mucous cells also secret pepsinogen into the gastric juice which becomes the pepsin in stomach when activated.

Which of these three muscle layers hypertrophies to form the pyloric sphincter?

The middle circular layer of the muscularis thickens to form the pyloric sphincter.

Sources:

University of Michigan Medical School. 2010. Pharynx, esophagus, stomach. <http://histology.med.umich.edu/medical/pharynx-esophagus-and-stomach/>.

Richard Bowen. 2014. Gastric secretions. Hypertexts for Biomedical Sciences. <http://biology.about.com/library/organs/bldigeststomach3.htm/>.

Maria Theresa A. Elizaga October 17, 2014ZOO115 D3-L

Exercise 8: The Respiratory System

1. Larynx, Human, H&E

2. Mammal Trachea, cross section - H&E

Photo credits: Roch Bandala

Tonsil mass

Photo credit: Franics Dale Deiparine3. Lung, Mammal

(Monkey)/Human, H&E

Photo credits: Roch Bandala

Photo credits: Iris Quero

What muscle type is the trachealis muscle made up of?

it is made up of smooth muscle.