Home > Uncategorized > Human Anatomy: Digestion 4

Human Anatomy: Digestion 4

Today Ratfink covers the intestines. The lecture costs about 50 minutes.

The small intestine is 20 feet long. In a dead body, the SI is 20 feet long. Physiologists study a living body and find a 12 foot long SI. From the pyloric sphinctor to the iliocecal sphinctor.

The SI has three parts: the duodnum (10 inches) where most digestion occurs. Shaped like the letter C. The jujunum is the middle and the ilium is the last part. The nutrients are absorbed in the last 2/3rds. The linings of the SI is folded into villi with simple columnar epithelium.

Histology might be the most important and referre to subspecialty. The lumen is the opening or passageway. Villi increase surface area. The brush border is the nickname for the microvilli.

The intestine has four layers. The serosa is the outside layer. Muscularis is the next layer in. Next is the submucosa. Lymph nodes in the SI can act as the tonsils of the intestine. Next is the mucosa which has fingerlike projections.

The lamina propria is the outer layer of the microvilli. Lactiles are lymphatic vessels. Fatty acids are absorbed into the lymphatic vessels. The other nutrients go into blood vessels.

The stomach is j shaped. The duodnum is c shaped. The pancreas lies underneath the stomach. The gallbladder is a green sac. The liver makes bile that goes through the common hepatic bile duct. Bile is green soap. Soap allows grease and oil to dissolve in H2O. Biliruben gives the green color.

Amylase breaks amylose into maltose. Trypsin breaks protein into peptide chains.
Pancreatic lipase breaks neutral fats into fatty acids.
Pancreatic nuclease breaks nucleic acids into nucleotides.

glucose + glucose = maltose
glucose + fructose= sucrose
glucose + galactose= lactose

Tissues: nerve, muscle, epithelial, connective
Epithelial: simple/stratified/pseudo, cuboidal/columnar/squamous/transitional
PV = nRT, point source, high temp, low pressure

Categories: Uncategorized
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