Digestive System Part II Esophagus & Stomach
|The pharynx provides what 2 functions?||Digestive & Respiratory functions|
| What is the esophageal hiatus?|
What are the two sphincters in the esophagus and their respective location?
| 1. Hole in diaphram were esophagus travels through|
2a. pharyngoesophangeal sphincter = upper
2b. gastroesophageal sphincter = lower
|What 2 main layers compose the esophagus?|| 1. Protective Epithelial layers (stratified squamous)|
2. Peristalitic muscular layers
| Deglutition is what?|
Involuntary deglutition begins where?
| 1. The process of swallowing|
|What are the 3 processes of deglutition?|| 1. soft palate pushes up against the back of the throat|
2. epiglottis drops down to cover larynx
3. larynx rises
|What is paristalsis?||synchronous muscular contraction pushing food along digestive tract|
|What is the most distendible part of the GI tract?||stomach|
|What are the 5 main functions of the stomach?|| 1. stores food|
2. churns food w/gastric juices
3. initiate chemical digestion of proteins
4. forms chyme (called this once it leaves the stomach)
5. production of intrinsic factor
| Intrinsic factor is required for what?|
As people age they make less __________ _______.
| 1. Absorption of VB12 in the ileum of the small intestine|
2. intrinsic factor
|The muscular layers of the stomach contain circular, longitudinal and ____________ .||Oblique (deeper than circular)|
|The folds that create more surface area in the stomach are called what?||Rugae|
| What are the holes on the stomach's inner mucosa called?|
The gastric pit contains _____________ _______ that secrete various gastric substances.
What are the 5 cells that produce various substances throughout the inner mucosa?
| 1. Gatric pits|
2. Gastric Glands
3a. Golblet cells
3b. Parietal cells
3c. Chief Cells
|1. What type of cells will you find at the top region of the gastric pit? What do they secrete?|
2. What cells would you expect to find in the middle portion? What do they secrete?
3.What cells would you find just below/deeper than parietal cells or lower portion of the gastric pit? What do they secrete?
4. Which 2 cells lack a specific location? What do they both secrete?
| 1. Goblet cells = Mucous cells|
2. Parietal cells = Hydrochloric acif (HCL) and Intrinsic Factor
3. Chief cells = pepsinogen
4a. G-cells = gastrin hormone
4b. D-cells = somatostatin hormone
|Pepsinogen is an ____________ substance.||1. inactive|
| What is step 1 in the chemical digestion of protein?|
What is "the chemical digestor of protein"?
| 1. HCL + Pepsinogen = Pepsin|
|What is step 2 in the chemical digestion of protein? (2)|| 1. Additinal HCL is released to lower pH <2|
2. Therefore, Increasing activity of Pepsin
|The small intestine does what to Pepsin?||Increases pH to make Pepsin inert (so it will not digest the small intestine)|
| Mucous has what 2 functions in the Stomach?|
When is it secreted?
| 1a. Provides seal to Pepsin from entering the gastric pits|
1b. prevents ulcers
2. AFTER parietal and chief cells send out their products (creating pepsin)