Digestive System - PP

Notes from Digestive System PP only

Digestion

Breaking down food to small molecules

Absorption

Uptake of molecules through the intestinal walls into the blood stream

Defecation

The passing of the food and water that does not get absorbed

Enzyme

Catalysts that speed up a reaction

H20, vitamins, minerals, fiber, carbohydrates, protein, and lipids

The 7 essential nutrients are:

Carbohydrates, protein, and lipids (fats)

Calories (energy) come from the three macronutrients:

Amylase

The enzyme that breaks down complex carbohydrates/polysaccharides is called…

Monosaccharides and disaccharides

Complex carbohydrates/polysaccharides get broken down to…

Protease

The enzyme that breaks down protein is called…

Amino acids

Proteins get broken down to…

Lipase

The enzyme that breaks down lipids (fats/triglycerides) is called…

Glycerol and 3 fatty acid chains

Lipids (fats/triglycerides) get broken down into…

Glycogen

The preferred energy form in the body that we can store in the liver and skeletal muscle, its make up is a multitude of glucose stuck together

Pancreas

The organ responsible for manufacturing amylase, protease, and lipase

Liver

The organ responsible for manufacturing bile…

Gallbladder

The organ responsible for storing bile…

Bile

Necessary for the emulsification of fats, making it smaller so enzymes can easily digest it

Common bile duct

The duct in which the hepatic duct and the cystic duct meet

Liver —> Hepatic duct —> Cystic duct —> Common bile duct —> Duodenum

How bile makes its way into the digestive tract

Duodenum

First part of the small intestine; where digestion “really begins” with the presence of enzymes and bile (Note: that digestion technically begins in the mouth)

Jejunum

Second part of the small intestine where most digestion takes place and absorption begins

Ileum

Third part of the small intestine where absorption is completed

Hydrochloric acid

The substance that breaks down food in the stomach:

Fundus

The top portion of the stomach is called…

Pylorus

The bottom portion of the stomach is called…

Cardiac sphincter

The ring of muscle at the end of the esophagus leading into the top portion of the stomach

Pyloric sphincter

The ring of muscle at the bottom portion of the stomach leading into the duodenum

Amylase + H2O

Digestion technically begins in the mouth due to the chemical makeup of saliva which is…

H2O and Vitamin B12

The only substances that can be absorbed by the large intestine

Cecum

The first part of the large intestine

Ileocecal valve

The sphincter muscle at the junction of the ileum and the cecum

Parietal Peritoneum

Double sided serous membrane that lines the wall of the abdominopelvic cavity

Visceral peritoneum

Serous membrane that covers the surface of the abdominal organs

Pancreas and kidneys

These organs from the abdominal cavity are considered retroperitoneal (behind the peritoneum):

Omenta

A membrane that has fat dripping off of it and anchors the digestive system organs in the abdominopelvic cavity to each other and the walls of the cavity

Greater omentum

The omenta that extends from the greater curvature of the stomach to the small intestines/colon

Lesser omentum

The omenta that extends from the lesser curvature of the stomach to the liver

Mesenteries

A fold of the peritoneum that attaches organs to the posterior abdominal wall

Mesoduodenum

The mesentery that attaches the duodenum to the dorsal body wall

Mesentery Proper

The mesentery that attaches jejunum and ileum to the dorsal body wall

Mesocolon

The mesentery that attaches majority of the colon to the dorsal body wall

Mesorectum

The mesentery that attaches the rectum to the dorsal body wall

Falciform ligament

Ligament that attaches the diaphragm to the liver. Also divides the liver into right and left halves

Ligamentum Teres (aka round ligament)

The ligament that extends from the falciform past the liver

Gastrosplenic Ligament

The ligament from the spleen to stomach

Saturated fat

Has single bonded carbon chains that are surrounded by hydrogen atoms which allows the molecules to pack closely together thus making it a solid at room temperature

Unsaturated fat

Fewer hydrogen atoms because of multiple double bonds between carbon atoms creating a loose structure between the molecules thus making it a liquid at room temperature