Test 4.4 Flashcards
What does rugae in the stomach allow for
Allow for expansion and can increase the stomach by 50x
What happens to food in the stomach
Mechanical digestion
Chemical digestion -proteins denatured by acid -plant and connective tissue acid breakdown -fats and carbs
Lingual lipase and amylase still work until stomach pH drops under?
4.5
What are gastric pits
Stomach lining
-cells last 3-7 days
Mucus cells
-protect stomach from digesting itself
What does gastric glands consists of
Makes gastric juice
What are the different cells in the Gastric glands
Parietal cells
Cheif cells
G-cells (gastrin)
What do the parietal cells do in the gastric glands
Instrinic factor (B12 absorption)
Hydrochloric acid
What is the pH for an empty stomach
2
What does the chief cells in the gastric glands consist of
Pepsinogen (proenzyme) degrades protein
Activated by acid—–> pepsin
What does the G-cells do in the gastric glands
Hormone activates gastric glands
What are the three phases of _______
Cephalic phase
Gastric phase
Intestinal phase
What does the cephalic phase consist of
Sight,smell, sound
•sight of food activates PNS
- signals via vagus nerve (ANS) - cells in gastric pit activated
What does the gastric phase consist of
Depends on stomach stimuli
- stretch of stomach
- increased pH
- proteins (empty slow)
- carbs, alcohol, coffee (empty quickly)
How long does food stay in your stomach
Up to 3-4 hrs
What does the intestinal phase consist of
-food moves on to intestine
-chyme emptying is controlled to maximize absorption
•pyloric sphincter
-enterogastric reflex activated as intestines are stretched
•gastric glands inhibited
•intestine hormone secretion activated
decreased intestinal pH
CCK
Cholecystokinin
GIP
Gastric inhibitory peptide
What happen at the small intestine
90% of absorption
It the size of a tennis court
What are the segments of the small intestine
Duodenum
Jejunum
Ileum
What does the duodenum consist of
Receives stomach chyme and pancreas secretion
What does the jejunum consists of
Chemical digestion and nutrient absorption
What does the ileum consist of
Peyers patches
Ileocecal valve
What are the internal features of the small intestine
Plica circularis: surface area ( does not expand like rugae)
Lacetal
- lymph vessel
- fat absorption
Capillary beds
-facilitate absorption
What are the external fractures of the small intestine
Mucus cells
Microvilli
If food enters the stomach what happens to pH
It increases
small proteins and carbs enter ________ for nutrient transport
Capillaries
-direct transport to liver
Larger lipids enter ______ for nutrient transport
Lacetals
- make a round trip in the lymph system
- enter CV system via large vein
- eventually circulate to liver
What are the components of the liver
Hepatocytes adjust nutrient content
Bile production (break up lipids)
Bile stored in gallbladder
Bile is recycled
What are hepatocytes
Liver cells
What are the characteristic of hepatocytes
-receives venous blood from digestive organs
-has reserve to add nutrients: carbs, lipids, proteins
•under hormonal control
•nutrients exit via leaky capillaries
What does bile production in the liver consists of
Emulsification
Salt breaks up lipids
What does bile stored in the gallbladder consists of
CCK tiggers release
- duodenum horomone
- opens hepatopancreatic sphincter
- Gall stores form from bile salt if too concentrated
Where is bile reabsorbed
Ileum
Do you need your gallbladder
No
The liver secretes roughly how much per day
1 liter
What are the characteristics of the pancreas
Shared structure
-digestive (exocrine)
•makes enzymes and buffers (pancreatic juices) in acini
•neutralizes stomach acid
What does trysinogen (proenzyme) activate
Intestine secretions
What’s the transport that occurs in the pancreas
To duodenum via pancreatic duct
How long is food in the intestine
5 he’s
Absorption in the pancreas is regulated by
Duodenum hormones
What are the duodenum hormones
GIP
CCK
VIP
What are the different parts in the large intestine
Cecum
Colon
Rectum
What does the cecum do
Ilieocecal valve
What does colon do
Stores waste
Reabsorbs water
Harbors bacteria
What does the rectum do
Anal canal
Anus
- internal sphincter is involuntary
- external sphincter is voluntary
What are the functions of the large intestine
Stores waste
Reabsorbs water
Harbor bacteria
Little absorption (
What content is contain in the large intestine when it harbor Bacteria
Obtain vitamin K, biotin, and B5
Make hydrogen sulfide gas
Eat non digestible carbs
Glands in the large intestine contain mostly
Mucus cells
Why is poop brown
Heme from RBC breaks down into bilirubin (yellow color) in liver
Bilirubin —-> urobilin and stercobilin
