DIGESTIVE SYSTEM Flashcards
breakdown of food into smaller, usable form
Digestion
Process of digestion
ingestion
🞇 peristalsis
🞇 digestion
🞇 absorption
🞇 defecation
2 types of digestion
Mechanical and chemical digestion
Ingested food is physically broken down into smaller pieces by chewing or mastication and peristalsis
Mechanical Digestion
Food is acted upon by catalytic enzymes to be broken down into its absorbable forms
Chemical Digestion
🞇mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
🞇Digestive tract
Food may not necessarily pass through them but participate or assist process of digestion.
It includes teeth, tongue, salivary glands, liver, gall bladder, pancreas
🞇Accessory organs
•Taste
🞇 Mechanical
breakdown of food
🞇 Chemical digestion of
carbohydrates
🞇 Ptyalin or
salivary amylase in saliva secreted by 3 pairs of salivary glands
Mouth/oral cavity/ buccal cavity
3 pairs of salivary glands:
Parotid, sublingual, submandibular glands.
Saliva contains how much H2O?
99.5% H2O
Lubricates food and begins digestion.
Saliva
Info
There’s no enzymes that can enzymatically acts on proteins and fats.
Savourful of flavorful
UMAMI
Begin digestion of carbohydrates while in the mouth.
Enzymes act on food while food is in the mouth.
Ptyalin and Amylase
Act on specific substrates
Enzymes
•Seals the food in the mouth while masticating or chewing.
•Prevents food from coming out.
Lips
Common passageway for food and air
🞇 Function – where swallowing begins
Pharynx ( throat)
Swallowed food
Vulus
25 cm or 10 in long.
It is made up of several layers called the secret mucus
Transport food through peristalsis.
Esophagus
smooth muscle contractions
propel food thru a
sphincter
(Upper Esophageal Sphincter & Lower Esophageal Sphincter)
Peristalsis
It is made up of pair of muscles, one of the muscles works to constrict or close and other muscle work to dilate or open.
Sphincter
🞇 Mixes & stores ingested
food with HCl into chyme
🞇 chemical and mechanical breakdown of food
🞇 Secretes hydrochloric acid & digestive juices that break down proteins and fats and may kill bacteria
🞇 Peristalsis - mechanical digestion begins.
• begin while in the (blank)- chemical
Stomach
Folds in stomach called
Rugae
Food turns semi solid consistency.
It is sour because of hydrochloric acid.
Vomitus
It is the final digestion and absorption of nutrients.
It is where most enzymatic hydrolysis or macromolecules from food occurs and absorption of digested food by its villi.
- absorption follows after digestion.
- involves chemical and mechanical
Small Intestines
Finger like projections
Villi
Info
From lumen absorb really bought by blood to capillaries.
6 meters long ( small diameter longer in length)
Small intestine
6m divided into 3 parts:
Duodenum
Jejunum
Ileum
25cm/ 10 in. (Shortest)
Complete digestion of food by enzymes.
Duodenum
8ft.
Absorb H2O and products of digestions into bloodstream.
Jejunum
12ft( longest)
Absorption of end products with villi and microvilli.
Arranged tightly in coiled manner.
Ileum
Larger diameter, shorter length(1m long).
Concentrates & stores undigested matter by absorbing Na, Vit K & water
🞇 Doesn’t have villi
nor coils
🞇 Many bacteria live, thrive & process undigested material into feces
🞇 Cecum – pouch-like
area
🞇 Colon - ascending, transverse, descending, sigmoid;
w/ haustrae = pouches
Large intestine
Pouch like area
Cecum
3 parts of colon:
It is with hustrae= pouches
Ascending
transverse
descending
sigmoid
Sequence of digestive system
Mouth
pharynx
esophagus
stomach
duodenum
jejunum
ilium
secum
ascending colon
transverse colon
descending colon
sigmoid colon
rectum
anal canal
anus
short extension of the large intestine
🞇 Final segment of
the DT
🞇 Where compacted undigested food from the colon are pushed via peristalsis
🞇 Distention triggers expulsion of feces
Rectum
terminal opening of the digestive system thru which feces are expelled
🞇 controlled by internal and external sphincters
Anus
It is below the stomach functions enzymatic function and endocrine function.
Pancreas
In pancreas we have the enzymatic function which is the (blank)
Its secrete digestive enzymes that break down all major food molecules.
ACINI
In pancreas we have what we call the endocrine process or function it is called (blank)
It secrete insulin and glucagon that control glucose metabolism.
Islets of Langerhans/ Pancreatic Islets
(blank)produces bile salts that emulsify fats and bile is stored (blank)
Liver and Gallbladder
It helps emulsify fats
Bile salts
Largest gland of the body
Liver
4 lobes of Liver:
right, left,
quadrate, caudate
– basic structural component
🞇 Hepatocyte
– for blood circulation
🞇 Hepatic vein
– carries nutrients, chemicals, drugs, etc in the blood absorbed by the intestines into the liver
🞇 Portal vein
Neutralizes & eliminates toxins in the blood
thru portal vein
🞇 Stores vitamins, iron and glucose
🞇 Synthesizes proteins like albumin & fibrinogen
🞇 Converts highly toxic ammonia (accumulates
from breakdown of proteins) into urea
🞇 Produces bile that contains cholesterol, bile acids, bilirubin which aids in lipid digestion which is stored in the gallbladder
Functions of the Liver
Neutralizes & eliminates toxins in the blood
thru
portal vein
ANATOMY OF GALLBLADDER
Hepatobiliary tree: Canaliculi from Liver form bile ducts or
intrahepatic ducts drain to R & L hepatic ducts merge to form common hepatic duct.
Gallbladder’s cystic duct & CHD form common bile duct. CBD & pancreatic duct/duct of wirsung form ampulla of vater that drains into duodenum
Endocrine; Islets of Langerhans secrete insulin & glucagon
🞇 Exocrine: acinar glands secrete digestive enzymes like trypsinogen, chymotrypsinogen, carboxypeptidase into duodenum by the pancretic duct and ampulla of vater
PANCREAS FUNCTION
acinar glands secrete digestive enzymes like trypsinogen, chymotrypsinogen, carboxypeptidase into duodenum by the pancretic duct and ampulla of vater
Exocrine:
Islets of Langerhans secrete insulin & glucagon
Endocrine;
