1. Pancreas, Liver, GB and Small and Large Intestine

2. Pancreas Found posterior to stomach Extends across the abdomen
Only gland to produce enzymes to digest every type of food
Amylase – carbs
Lipase – fats
Proteinase - proteins

3. Secretes enzymes into the duodenum
Enzymes are mixed with an alkaline fluid that neutralizes the acidic chyme coming from stomach
When chyme enters the duodenum the hormone cholecystokinin is released to signal the release of pancreatic juice
Hormones also produced by the pancreas
Insulin
Glucagon

5. Gallbladder Pear shaped sac found in hollow of liver
Bile made by liver is stored in gallbladder
Bile storage sac (bile produced in liver)
Bile digests fatty food - bile goes into the duodenum from the gallbladder
Cholecystokinin signals the gallbladder to release bile
Gallstones are crystallized cholesterol which can cause blockages

7. Liver Can regenerate if part of it is damaged or removed
Largest gland in the body
Located on the right side of the body under the diaphragm
Consists of four lobes suspended from the diaphragm and abdominal wall by a ligament
Connected to the gallbladder via the common hepatic duct
Can regenerate if part of it is damaged or removed

8. Metabolic Functions of the Liver
Store glycogen
Convert glycogen to glucose
Create new glucose

9. Metabolism of Carbohydrates
Hyperglycemia—excessively high levels of glucose in the blood
Excess glucose is stored in body cells as glycogen
If blood glucose levels are still too high, excesses are converted to fat
Hypoglycemia—low levels of glucose in the blood
Liver breaks down stored glycogen and releases glucose into the blood

10. Protein Metabolism
Proteins are conserved by body cells because they are used for most cellular structures
Amine groups are removed from proteins as ammonia
The rest of the protein molecule enters the Krebs cycle in mitochondria
The liver converts harmful ammonia to urea which can be eliminated in urine

11. Fat Metabolism Fats and fatty acids are picked up by the liver
Uses some fats to make ATP
The rest are broken down into simpler compounds and released into the blood
Body cells remove fat and cholesterol to build membranes and steroid hormones

12. Fat Metabolism
Most cholesterol is produced in the liver (85%) and is not from diet (15%)
Cholesterol is not used to make ATP
Functions of cholesterol
Serves as a structural basis of steroid hormones and vitamin D
Is a major building block of plasma membranes

13. Role of the Liver in Metabolism
Several roles in digestion
Manufactures bile
Plays a central role in carbohydrate, fat and protein metabolism
Stores glycogen and vitamins
Produces cholesterol, blood proteins (albumin and clotting proteins)
Detoxifies drugs and alcohol
Decomposes red blood cells
Degrades hormones

14. Bile Produced by cells in the liver Composition is
Yellow/green color – not an enzyme
Salt
Cholesterol
Electrolytes
Function—
emulsify fats by physically breaking large fat globules into smaller ones
Breakdown Red Blood cells

15. Small Intestine The body’s major digestive organ
Site of nutrient absorption into the blood
Muscular tube extending from the pyloric sphincter to the ileocecal valve
Suspended from the posterior abdominal wall by the mesentery

16. Subdivisions of the Small Intestine
Duodenum
Attached to the stomach
Curves around the head of the pancreas
Finishes digestion – pancreas and GB attached

17. Subdivisions of the Small Intestine
Jejunum
Attaches anteriorly to the duodenum
2/5ths of absorption
Ileum
Extends from jejunum to large intestine
3/5ths of absorption

19. Small Intestine Anatomy
Villi – increase surface area
Villi—fingerlike structures formed by the mucosa
Microvilli—tiny projections of the plasma membrane (create a brush border appearance)
Circular folds (plicae circulares)—deep folds of mucosa and submucosa

23. Small Intestine Physiology
All about absorption and transporting the nutrients to the blood stream
Peristalsis moves the chyme through the SI to the LI through the ileocecal sphincter

24. Small Intestine Physiology
Mucus – secreted by cells for easy passage and to help absorption
Peptidase – breaks down protein
Sucrase – breaks down sugars
Lipase – splits fats

25. Large Intestine
Larger in diameter, but shorter in length, than the small intestine
Frames the internal abdomen
Reabsorption of water and electrolytes

26. Large Intestine Anatomy
Cecum—saclike first part of the large intestine – attached to SI by ileocecal valve
Appendix
No digestive purpose
lymphatic tissue that sometimes becomes inflamed (appendicitis)
Hangs from the cecum

27. Large Intestine Anatomy
Colon
Ascending—travels up right side of abdomen
Transverse—travels across the abdominal cavity
Descending—travels down the left side
Sigmoid—enters the pelvis (S shaped)
Rectum and anal canal —also in pelvis

28. Large Intestine Anatomy
Anus—opening of the large intestine
External anal sphincter—formed by skeletal muscle and under voluntary control
Internal involuntary sphincter—formed by smooth muscle
These sphincters are normally closed except during defecation

30. Large Intestine Anatomy
No villi present
Banded muscles
Mucus – lubricate for feces passage
Haustra (pocketlike sacs) – pouches for holding fecal material

31. Large Intestine Physiology
Little to no digestive function
Vitamin B and K – bacteria living in LI produce these vitamins
Reabsorb water, vitamins and minerals

32. Large Intestine Physiology
Peristalsis and mixing occur 2-3 times a day
Mass Movement – movement of material happens in large sections that constrict at once
Defecation reflex – forces out rectum when sphincter relaxes