Flashcards in GASTROINTESTINAL SYSTEM Deck (55):
What are the two types of Digestion?
Mechanical and Chemical Digestion
Describe Mechanical Digestion.
Tongue, teeth, stomach, and sm. intestine mix/cut/churn food
Describe Chemical Digestion.
Enzymes secreted from salivary glands, tongue, stomach, pancreas, and sm. intestine breakdown nutrients
Where is the Parotid Gland located?
Inferior-anterior to ear. Between skin and masseter.
Where is the Submandibular Glands located?
Floor of mouth
Where is the Sublingual Glands located?
What is Bolus?
Soft, flexible mass (chewed food)
Describe the function of the Pharynx (Throat)?
Contractions moves bolus from mouth, to pharynx, to esophagus
Describe the structure and function of Esophagus.
Collapsible tube running from pharynx, through diaphragm, to stomach. - secrets mucous and moves bolus
What is the 'Esophageal Hiatus'?
A hole in the Diaphragm where the Esophagus runs through
Wave-like contractions moving bolus from esophagus to anus
What are the structures controlling food passage in the Upper Esophageal Sphincter?
Pharynx into Esophagus
What are the structures controlling food passage in the Lower Esophageal Sphincter?
Esophagus into Stomach
The GI Tract extend from ____________ to __________.
Lower Esophagus to Anal Canal
List the layers of the GI Tract walls. (deep to superficial)
Describe the Mucosa layer of GI Tract.
Mucous membrane consisting of:
- Epithelium (secrets)
- Lamina Propria (absorbs)
- Muscularis Musoca (contraction)
Describe the Submucosa layer of GI Tract.
- Nutrient transport with blood/lymph vessels
- GI control from Enteric N.S
Describe the Muscularis layer of GI Tract.
Contain Circular and Longitudinal Fibres causing contractions controlled by Enteric N.S
Describe the Serosa/Visceral Peritoneum layer of GI Tract.
Outermost layer of organs in abdominal cavity
Describe the Peritoneum.
Large folds that bind organs to one another and to the walls of the abdominal cavity
What are the two layers of Peritoneum?
- Visceral Peritoneum/Serosa
- Parietal Layer
What is the space in between the Peritoneum layers?
What are Retroperitoneal?
Peritoneum layer covering organs on the anterior side
Where is the Stomach located?
Below Diaphagrm - Runs from esophagus to sm.intestine
Soupy mix of food in the stomach
Where do food particles pass through once they are small enough?
Pyloric Sphincter into Sm.Intestine
What do Mucous Neck cells in the stomach secret?
What do Parietal cells in the stomach secret?
Intrinsic factor and HCI
What do Chief cells in the stomach secret?
Pepsinogen and gastric lipase
What do G Cells in the stomach secret?
What is the function of Gastrin?
- Gastrin juice production
- LES contractions
- Increase stomach peristalsis
- Relaxes pyloric sphincter
What additional layer does the stomach have to facilitate mixing?
Oblique layer of smooth muscle
List the order of the 3 regions of the Sm.Intestine.
What are the Circular Folds in the Sm.Intestine?
Ridges in Mucosa/Submucosa increasing surface area
Finger-like projection covered in epithelium, increasing surface area
What is the function of Absorptive cells?
What is the function of Goblet cells?
What is the function of Paneth cells?
What is the function of Enteroendocrine?
Brush border found in Absorptive cells
What does each Villus contain?
Arteriole / Venule / Lacteal
What is Chyme mixed with in the Sm.Intestine?
Intestinal and Pancreatic Juices
Where do absorbed nutrients in the Sm.Intestine pass into?
Blood stream to Liver
Lymphatics (lipids) via Lacteal
Ileocecal Valve/Sphincter to Lg.Intestine
What are the two functions of the Pancreas?
Endocrine and Exocrine
Define the Exocrine function.
Secretes Pancreatic Juices into Duodenal Lumen
Pancreatic Juice are secreted into the Duodenum via 2 main ducts:
- Common Duct formed by Pancreatic Duct joining Bile Duct
- Accessory Duct
What passes through the Hepatic Artery?
What passes through the Hepatic Portal Vein?
Deoxygenated blood containing nutrients, medications, microbes and toxins
What is the function of Hepatocyte (Liver Cells).
- Absorb oxygen/nutrients/toxins
- Release nutrients
- Make/secrete bile
If low blood pressure is present, hepatocytes will...
Breakdown glycogen and release into blood