1. 2x2 Week 2 The Digestive Tract
ROBERT FREDERICK GABRIEL ONTIVEROS JR AND LITERALLY NOBODY ELSE. ESPECIALLY NOT JACOB.

2. Stomach is important in the digestion of food.
The stomach is located between the esophagus and the duodenum of the small intestine.
Four parts of the stomach:
Cardia where the contents from the esophagus comes in.
Fundus
Body (Corpus) this is the main central region (most important part)
Pylorus after this the stomach empties into the small intestine
Pathway: mouth pharynx esophagus esophageogastric junction stomach (cardia, fundus, body, pyloris), pylorus sphincter duodenum jejunum ileum ascending colon transverse colon descending colon rectum anus

3. Ascending Colon up
Transverse Colon across
Descending Colon down
Rectum
- The folds here are gastric folds (called ruggae) which help in moving things along and are found mostly in the body part of the stomach

4. Non keratinized stratified squamous epithelium
Gastric pits
junction
ESOPHAGEAL JUNCTION (same as the esophageogastric junction)
Right part: Esophagus (non-keratinized stratified squamous epithelium)
Left part: Stomach (simple columnar epithelium)
Gastric Pits: an indentation in the stomach which denotes the entrance into the gastric glands
This junction connects the esophagus to the stomach
The space is used to increase surface area for absorption
Ratio of pits to gland: 4:1; 4 gastric pits for every 1 gland

5. Epithelium/mucosa/ submucosa glands Innermost oblique
This is a longitudinal section of the Gastric Fundus.
The Innermost Oblique turns food to help digestion
As you enter the fundus, gastric pits become shorter and shorter.
NO GOBLET CELLS IN THE STOMACH!!!
Instead, you have pepsin, which helps break down enzymes and is composed of pepsinogen and hydrochloric acid
Four types of cells here:
Parietal Cells secrete hydrochloric acid (HCL) located in the stomach
Mucous Cells secrete mucus into the gastric pits to move things into the stomach for lubrication
Enteroendrocine Cells produce hormones in response to the various peptides (hormose) and releases them into the bloodstream (1) to release them to the bloodstream, (2) diffuse them as messengers or (3) transmit them to the nervous system; most numerous endocrine cells of the body and is located in the stomach, intestines, and pancreas
Chief Cells secrete pepsinogen and rennin
Outer longitudinal
muscularis

6. submucosa villi Plica circularis Brunner’s glands microvilli
LONGITUDINAL SECTION OF THE DUODENUM
Duodenum Cells no goblet cells; entire inside is Plica circularis
Submucosa has Brunner’s Glands, which secrete bicarbonate ions to neutralize chyme, which is from gastric juices
Villi increases the surface area for absorption
microvilli

7. Fig 315 LONGITUDINAL SECTION OF THE JEJUNUM Has elongated villi
Less Plica Circularis
NO Brunner’s Glands
NO Peyers Patches
A few goblet cells, but not that many, because you are getting close to cecum
Goblet cells are only found mostly in the small intestines

8. Fig 316 Lymphoid nodules Germinal centers Peyer’s Patches
LONGITUDINAL SECTION OF THE ILEUM
NO Plica Circularis
NO Brunner’s Glands
There are Peyers Patches loaded with lymphocytes; important in immunity; located in the germinal center

9. Fig 316 Temporary folds 1 LONGITUDINAL SECTION OF LARGE INTESTINE
NO villi
NO Brunner’s glands
NO Plica circularis
Here, getting closer to cecum, so a lot of goblet cells to lubricate the feces as they move down
FUNCTION: to absorb water, minerals, and electrolytes

10. Fig 329 CROSS-SECTION OF VERMIFORM APPENDIX Attached to the cecum
CENTER OF THE SCREEN: POOP!
Triangular portion white part if the lumen; orange thing is feces
Submucosa
Lymphoid Nodule a circle of lymphocytes
Germinal center
Muscularis externa
Serosa connective tissue
PATHWAY: mucosa submucosa inner circulatory muscles outer longitudinal muscles serosa (going from in to out)