Anatomy: digestive system

Villi

modifications increases the surface area in the small intestine with fingerlike extensions of mucosa

Liver and pancreas

two organs release secretions into the duodenum of the small intestine

Duodenum

first, and shortest part of the small intestine. Enzymes and bile are carried by the pancreatic duct and bile duct here.

Primary function of the small intestine

Absorption of nutrients

Large intestine functions

organ responsible for drying out indigestible food residue through water absorption and elimination of feces. Also vitamin and ion absorption.

Amylase

An enzyme that digests starch

How many teeth does an adult have?

32

role of the gallbladder

store bile

role of the liver

produce bile

chemical digestion

The sequence of steps by which large food molecules are broken down into their respective building blocks by catalytic enzymes within hydrolysis reactions

persitalsis

The propulsive process that moves food from one organ to the next

segmentation

The process by which food within the small intestine is mixed with digestive juices by backward and forward movement across the internal wall of an organ

cellulose

a type of carbohydrates that the human digestive system is unable to break down to simple sugars

Amino acids

the building blocks of proteins

absorption

Transport of digested end products from the lumen of the GI tract into the bloodstream or lymphatic fluid.

Parasympathetic division of the autonomic nervous system

Primarily control digestion

Starch

the first nutrient to be digested. DIgestion begins in the mouth and finishes in the small intestine

esophagus

Primary role is to serve as a tube that connect the pharynx to the stomach. Has no digestive function

Pepsin

an enzyme found in the stomach that breaks down proteins.

Pyloric sphincter (valve)

regulates the release of food from the stomach into the small intestine

cardioesophageal sphincter

a "doorway" between the esophagus and stomach

Lingual frenulum

fold of mucous membrane that secures the tongue to the floor of the mouth and limits its posterior movements. "Tongue tied" babies often need this cut to allow proper tongue movement for feeding and later speaking.

digestion

The process of physically and chemically breaking food particles down

Hard and soft palates

Separate the oral cavity from the nasal cavity.

Fundus

The upper, expanded part of the stomach lateral to the cardiac region

Rugae

Large wrinkle-like folds in the stomach lining, present when the stomach is empty, that allow for expansion when the stomach is filling

Villi

The fingerlike projections of the small intestine increase surface area

Lacteal

The rich capillary bed and modified lymphatic capillary found within each villus

Goblet cells

Cells abundant within the large intestine that produce large amounts of lubricating mucus to aid in the passage of feces to the end of the digestive tract

Mastication

The process of chewing

Defication

The process of eliminating indigestible wastes from the GI tract

Bolus

the name for chewed food that you swallow

Chyme

The name for digested food that moves from the stomach to the small intestine

HCL

necessary in the stomach for the conversion of pepsinogen into its active protein-digesting pepsin.

Pancreatic juices

The chemical responsible for about half of the protein digestion and all of the fat digestion

jejenum

the second part of the small intestine

ileum

the third and final part of the small intestine

ileocecal valve

the valve or doorway between the small intestine and the large intestine

cecum

the first part of the large intestine

appendix

the invagination off of the cecum that can often become infected.

ascending colon

the segment of colon that moves waste superiorly.

transverse colon

the segment of colon that moves waste across the abdomen.

descending colon

the segment of colon that moves waste inferiorly

sigmoid colon

the portion of colon that is s shaped and located between the descending colon and rectum.

rectum

the last segment of the colon, where food is stored until it is eliminated.

brush border enzymes

Important enzymes located in the microvilli of the small intestine. They break double sugars into simple sugars and complete protein digestion.

pancreas

A soft pink, triangular organ that lies across the abdomen. It produces enzymes that break down all categories of digestible foods including lipase that breaks down lipids. It secretes this in an alkaline fluid that neutralizes the acidic chyme that comes out of the stomach. It also produces the hormones insulin and glucagon for the endocrine system.

bicarbonate

The alkaline substance that provides the proper environment for the activation and activity of intestinal enzymes. Secreted by the pancreas that neutralizes acidic chyme and brings the ph of the intestine to 8.

Monosaccharides

building blocks of carbohydrates

Fatty acids, glycerol, and monoglycerides

building blocks of lipids

heartburn

When the cardioesophageal sphincter fails to close tightly and the gastric juice backs into the esophagus

hiatal hernia

protrusion of a part of the stomach upward through the opening in the diaphragm, this can lead to a weak cardioesophageal sphincter.

vomiting

caused by bacterial food poisoning activating the medulla of the brain causing reverse peristalsis of the stomach coupled with contraction of the abdominal muscles and diaphragm.

Locations of chemical digestion

mouth, stomach and small intestine

locations of mechanical digestion

mouth, stomach and small intestine

locations of absorption

small intestine: nutrients, large intestine: water

Bile

A substance produced by the liver that breaks up fat particles. (Physical/ mechanical digestion)