Transcript Digestive System PowerPoint Part II

GI
(Gastrointestinal)
System - Part II
aka digestive system
the Stomach
The Mucosa Layer
•
Secretes mucus (check spelling!) to protect the
stomach from its own gastric juices (hydrochloric
acid - HCL)
•
HCL changes pepsinogen (there’s that “genesis”
word part again!) to pepsin.
•
Pepsin works further on the proteins and makes the
stomach even more acidic (pH scale)
•
Doesn’t absorb nutrients, only water and ?
The Liver and Portal
Circulation
Portal circulation
Portal = “doorway”
Portal
Ordinary
Systemic
organ
Systemic
organ
Portal vein
Systemic
Organ
The liver has been called the antechamber
of the heart because if collects and
processes all the gastrointestinal blood and
delivers it to the right side of the heart.
The liver is unusual in that it has a double
blood supply; the arteries coming from the
heart carry oxygenated blood to the liver,
and the portal vein carries venous blood to
the liver from the intestines
http://www.dkimages.com/discover/previews/740/76623.JPG
• The liver receives blood through two vascular
systems, the portal vein and hepatic artery.
• All blood leaving the intestine will flow into
the portal vein and then into the liver.
• The liver is a complex and unique organ
serving many functions vital to sustaining life.
From digestion to circulation, the liver is
constantly processing blood for use by the
rest of the body.
The liver is the most resilient of all of the
body's organs. It is capable of regenerating
itself. When part of the liver is removed, a
healthy organ will often grow back to its
original size.
Pop Quiz
• Why is the digestive system called the
alimentary tube or canal?
• Name the 3 types of digestion
•
What happens in the mouth with regards to
mechanical digestion?
•
What happens in the mouth with regards to
chemical digestion?
•
Why does your mouth starts watering from
smelling dinner cooking or watching a food
commercial?
• What role does the tongue play with digestion?
• What is saliva made from?
• How do you pronounce ‘pharynx’?
• What is the purpose of the lower esophageal
sphincter?
• What does the muscular layer of the stomach do?
• What does the mucosa layer of the stomach do?
• Where does HCL come from and what does it do?
• What are the three parts of the small intestine?
• What is another name for the large intestine?
• What happens in the large intestine?
• What do you know about bile?
• Briefly explain the function portal circulation
• The pancreas is called an exocrine organ and an
endocrine organ. Why?
• Where does the uptake of nutrition take place?
• What prevents the stomach from digesting itself?
• What does the stomach absorb?
• What is the name of the area where the
appendix is located?
• Which is the most complex to digest,
carbs/sugars, fats, or proteins? Why?
• Where does fat digestion start?
• Where does sugar digestion start?
• Can you label a diagram of the digestive
system?
• Can you spell and define the terms in the
chapter?