Digestion and Absorption Flashcards
When chyme leaves the stomach, where does it go first?
a. The Jejunum
b. The Esophagus
c. The duodenum
d. The Ilium
c. The duodenum
Glucose is absorbed from the small intestine into the blood by:
Select one:
a. Facilitated diffusion
b. Simple diffusion
c. Secondary active transport
d. Osmosis
a. Facilitated diffusion
Polysaccharides are broken down in the Select one: a. Mouth, stomach, colon b. Stomach, duodenum, micro-villi c. Mouth, oesophagus, stomach, duodenum d. Mouth, micro-villi, duodenum
d. Mouth, micro-villi, duodenum
Monosaccarides and disaccharides are absorbed by Select one: a. Active transport only b. Facilitated transport only c. Facilitated transport and osmosis d. Active transport and osmosis e. Active transport and facilitated transport f. Only osmosis
e. Active transport and facilitated transport
Select the correct statement(s) about zymogens (select all that apply):
Select one or more:
a. Amylase, lipase, trysinogen
b. Trypsinogen, chymotrypsinogen and procarboxypeptidases
c. Pepsinogen, trypsinogen, lipsinogen
d. Converted to their active form in order to break
down food substances
c. Pepsinogen, trypsinogen, lipsinogen
d. Converted to their active form in order to break
down food substances
How does exercise intensity effect gastric emptying?
- gastric emptying is not affected up to about 80% VO2 max
- Above this a reduction in delivery of fluid and nutrients to small intestine may occur
- this may be important in intermittent type activity where there is a low average VO2 max but lots of short intermittent bouts of high intensity
Role of… Kinases
transfer phosphate group
Role of… Isomerases
rearrange molecule/change structure
Role of… Dehydrogenases
remove water
Role of… Synthetases
synthesis/makes a larger molecule
Role of… Mutases
rearrange molecule
Role of… Decarboxylases
removes carboxyl group
Role of… Phosphatase
removes phosphate group
Role of… Phosphorylase
catalyze the addition of phosphate group to an acceptor
Role of… Deaminase
removes amine group
What are the three parts of the stomach
Fundus
Corpus (body) - gastric glands that release mucus, pepsinogen and HCL
Antrum - secretes mucus, pepsinogen and gastrin
What are the 6 stages related to digestion and absorption and explain them.
Ingestion: taking food in
Secretion: of water acids buffers and enzymes
Motility: contraction and relaxation of the smooth muscle e.g. peristalsis
Digestion: Larger molecules into smaller ones through mechanical and chemical digestion
Absorption: The products of digestion enter the cells within the body, mainly from the small intestine
Defecation: Indigestible substances, cells, digested materials not absorbed leave the body as feces
The semi-liquid mass of partly digested food expelled by the stomach is called
Chyme
What is the Type of lipoprotein that transports cholesterol back to liver from peripheral cells.
HDL
What is the function of the mouth?
The mouth is the first part in the process of digestion. Salivary glands help food go down the oesophagus.
What is the function of the oesophagus?
The oesophagus is a long tube that leads from the mouth to the stomach. The epiglottis opens and closes to allow food to enter into the stomach.
What is the function of the stomach?
The stomach secretes gastric juices that are used to break down food and turn it into bolus to semiliquid mass, (chyme).
Once food is broken down it will start to move into the small intestine causing the pyloric sphincter to close the stomach from intestine.
What is the function of the small intestine?
Once food has entered the small intestine it will first pass through the duodenum by digestive juices from bile duct in pancreas & gallbladder, then pass through the jejunum, and continue until it reaches the ileum.
What is the function of the large intestine (colon)?
Once food has traveled the length of the small intestine it will enter the large intestine by Ilocecal valve that will close small intestine from large intestine. large intestine absorbs fluid and creates bile (solid) and passes it off to the rectum.
What is the function of digestion?
To render all foods into basic units of carbohydrates, fats, and protein so that the body can absorb and build tissue from them.
How are nutrients transported?
The bloodstream vascular, and the lymphatic system are used to carry nutrients to various parts of the body.
How are lipids transported in the body?
VLDL (very-low-density lipoprotein): made primarily by liver cells to transport lipids; made of triglycerides
LDL (low-density lipoproteins): carry cholesterol & triglycerides from liver; made of cholesterol
High has greater risk of heart disease.
HDL (high-density lipoproteins): transport cholesterol back to liver from peripheral cells; made of protein. High has low risk.
What is the function of the Pancreas when it comes to metabolism?
Contributes digestive juices to GI tract, Produce insulin & glucagon to regulate body’s use of glucose.
Insulin Promotes cells to take up glucose for use as fuel,
Prompts liver cells to store glucose as glycogen.
What is the function of the kidneys when it comes to metabolism?
Filter waste products from the blood for excretion in urine.
Reabsorb needed nutrients, maintaining chemical balances.
Convert a precursor compound to active vitamin D
How is iron absorbed from the gut?
Fe(III) is converted to Fe(II) by iron reductase, so that it can enter enterocytes.
Some is re-oxidised back to Fe(III) and stored in ferritin, a storage protein in enterocytes.
Then bound to transferrin which transports it in the blood.
What are the three salivary glands
- Parotid
- Submandibular
- sublingual
Which cells produce the primary salivary secretions? A) Bartoiln B) Myelin C) Kupfer D) Acinar
D) Acinar
Parietal cells in the stomach secrete -???-and HCL.
Intrinsic factor
What is pepsinogen an example of
A zymogen
Describe the cephalic phase of digestion
Prior to arrival of food in stomach, vision, smell, chewing, taste stimulate gastric secretion – Parasympathetic nervous system also stimulates release of gastrin
Describe the gastric phase of digestion
Stretch and products of protein digestion stimulate gastric secretions via local vaso-vagal reflex – Gastrin also released by same stimuli – All stimulate motility, larger meals increase rate of emptying
Describe the intestinal phase of digestion
Chyme entering duodenum decreases gastric secretion and motility,
Removal of food leads to a decrease in pH (pH<2 inhibits gastrin release).
Distension of duodenum leads to release of hormones (including cholecystokinin) which inhibits gastrin release – ]
How is the small intestine motility controlled? (3 factors)
Intrinsic, enteric NS
Hormones e.g. gastrin + CCK
Extrinsic nerves e.g. parasympathetic
How are water soluble vitamins absorbed? Select one or more: a. diffusion b. osmosis c. active transport d. bulk flow
a. diffusion
c. active transport
Where is bile stored
gall bladder
