Exam 1 digestion and absorption Flashcards
Digestion
the process by which food is broken down into components small enough to be absorbed into the body
Absorption
the process of taking substances from GI tract into the interior of the body.
Key components of digestive system
Mouth, pharynx, esophagus, stomach, SI and LI
Accessory components of digestive system
salivary glands, liver, gallbladder and pancreas
Steps of digestion for starch
Mouth: amylase Stomach: stop chemical digestion Si: pancreatic amylases convert into glucose
Steps of digestion for mono sugar
SI: taken into the blood
Steps of digestion for di sugar
SI: turned into mono and taken into the blood
Steps of digestion for fiber
LI: bacteria break it down
steps of digestion for lipids
Stomach: churned SI: bile emulsify lipids, lipase break it down into fatty acids, break apart micelle and into chylomicrons and put into the lymphatic system
steps of digestion for protein
Mouth: mechanical break down. Stomach: HCl unfold protein and break down into smaller units SI: break into amino acids and put into the blood.
What are the end products of protein?
Amino acids
What are the end products of CHO?
glucose, galactose and fructose
What are the end products of fats?
triglycerides, free fatty acids and glycerol
What are the functions of HCl in the stomach?
Kills most bacteria present in food, unfolds proteins.
What happens of HCl is too low?
You can get ulcers and lower immunity
What lines the SI?
large circular folds and villi
What is bile, where is it made and what does it do?
A digestive fluid made in the gallbladder tjat is released into the SI where it aids in fat digestion and absorption
What is the role of the pancreas in digestion?
secrets pancreatic juice and digestive enzymes
pancreatic amylase
enzyme that cont. the job of breaking down starches into sugars
Pancreatic proteases
Break protein into shorter chains of amino acids and lipases
Where are biocarbonates formed and where are they secreted into the GI tract? Function?
formed in SI and they make the environment in SI neutral or slightly basic
What is the role of gastrin and secretin?
regulates pH levels. If lower than 1.5 secretin is released.
What is the role of CCK and ghrelin
If hungry, ghrelin makes stomach growl and CCK is released when food reaches the SI
What are the functions of the LI
Most water is absorbed here. Break down of unabsorbed portions of food and synthesize nutrients that can be use by the microflora or absorbed into the body
Where does acid kill bacteria?
Stomach
Where does amylase start starch digestion?
SI
Where does bacteria chemically break down fiber?
LI
Where do biocarbonates neutralize acid?
SI
Where does bile break up fat?
SI
Where does chewing break down food?
Mouth
Where does churning cause mechanical digestion of food?
Stomach
Where are micelles formed?
SI
Where does most chemical digestion and absorption occur?
SI
Where do pancreatic enzymes chemically digest food?
SI
Where does peristalsis start?
esophagus
Where is chyme produced?
stomach
Where do proteins unfold because of acid?
stomach
Where does saliva lubricate?
mouth
Where is the site of villi and microvilli?
SI
