Accessory digestive organs Flashcards
accessory digestive organs
pancreas, gallbladder and liver
pancreas
Lies deep in the abdominal cavity, on the posterior abdominal wall; elongated and flattened
Part of both the digestive and endocrine systems
what does the pancreas secrete
Secretes hormones (insulin and glucagon) to regulate blood sugar
Produces pancreatic juice with sodium bicarbonate to neutralize chyme acidity
Releases enzymes to break down carbohydrates, proteins, and fats
what does the pancreas do to chyme
chyme leaves the stomach with a pH of 1
Pancreatic juice raises the pH to 8, protecting the small intestine
liver
largest internal organ in the body
about the size of a football
located right below the diaphragm
3 Main Structures Between the Lobules
Bile Duct → Branch of Hepatic Artery → Branch of Hepatic Vein
Bile Duct
takes bile away from the liver
Branch of Hepatic Artery
brings oxygen rich blood to the liver
Branch of Hepatic Vein
transports nutrients from intestine
what does the liver filter
filters the blood,
also makes plasma proteins from amino acids
how does the liver regulate glucose
store extra glucose as glycogen
converting glycerol from fats and amino acids into glucose
Where is bile produced and stored
produced in the liver and stored in the gallbladder
What do bile pigments and bile salts do in digestion
do not aid digestion but help eliminate waste,
bile salts emulsify fats and increase the surface area for enzyme action
What is bile made of, and what is its role
Bile is made of bile pigments and bile salts. Bile salts emulsify fats, breaking them into smaller molecules for easier digestion
7 Ways the Liver Helps to Maintain Homeostasis
- Detoxifying blood
- Storing iron
- Making plasma proteins
- Stores glucose as glycogen (also breaks down glycogen to glucose)
- Produces urea after breaking down amino acids
- Removes bilirubin from the blood and excretes it into the bile
- Helps to regulate the blood cholesterol levels
structure of the gallbladder
The gallbladder is a pear-shaped, muscular sac attached to the liver
What happens to water in the gallbladder
reabsorbs water, making bile thicker and more concentrated
What does the gallbladder store
stores bile produced by the liver between meals
Bile is released through the bile duct into the duodenum when fats are present in the small intestine
What role does bile play in fat digestion
Bile breaks down large fat droplets into smaller ones, aiding in mechanical digestion
What causes gallstones and how are they treated
high cholesterol and may block the bile duct,
sometimes requiring gallbladder removal
How do food molecules enter the bloodstream
Small food molecules are absorbed directly by the cells of the villi
Food molecules diffuse into the blood vessels of the villi, entering the bloodstream.
What does the large intestine absorb
mainly absorbs water from waste before elimination
types of enzymes
Carbohydrases digest carbohydrates.
Lipase digests fats.
Proteases digest larger polypeptides.
Nucleases digest nucleic acids
What are digestive enzymes
proteins that speed up chemical reactions, aiding in chemical digestion.
break down food into nutrient molecules, such as glucose, amino acids, fatty acids, and glycerol
what factors effect enzyme activity
Enzyme activity is affected by temperature and pH, which help maintain the enzyme’s shape and optimal function
Temperature Effect: Higher temperatures increase enzyme activity by adding more energy
Hydrolytic
they break down molecules when water is introduced
salivary amalyase
Found in saliva
Has a neutral pH.
first enzyme to act on carbohydrates (starch)
starch breakdown by salivary amalyse
Starch is digested into maltose, a sugar
Maltose cannot be directly absorbed by the intestine; additional digestive enzymes are needed
Pepsin
enzyme that is found in the stomach
creates gastric juice when it is mixed with hydrochloric acid
protein breakdown by pepsin
chemical digestion of proteins into peptides
peptides are usually too large to be absorbed by the intestines
get broken down into amino acids in the small intestine
Pancreatic Amylase
found in pancreatic juice
created in pancreas but enters the duodenum of the small intestine
digests starch
also works to help neutralize the chyme
Lipase
another pancreatic enzyme
digests fat molecules after they have been emulsified by bile salts
after the lipase digests the fat, it is in the form of glycerol and fatty
these are small enough to be absorbed in the villi
Peptidase
produced in the small intestine
completes the digestion of protein into amino acids
Maltase
Produced in the small intestine, completes starch digestion by breaking down maltose.
Absence of enzymes can cause illness, lactose intolerance (lactase deficiency) leads to trouble digesting dairy.
