The Digestive System: Accessory Organs, Intestines, Nutrient Absorption

Flashcards for studying key vocabulary and concepts related to the digestive system.

Liver

Largest gland in the body, produces bile.

Bile

Fat emulsifier produced by the liver.

Gallbladder

Stores and concentrates bile.

Pancreas

Supplies enzymes and bicarbonate to the small intestine.

Bile ducts

Transport bile from the liver to the intestine.

Portal hepatis

Point where hepatic portal vein and hepatic artery enter the liver.

Hepatic portal vein

Carries nutrient-rich blood from the intestine to the liver.

Hepatic artery

Supplies oxygenated blood to the liver.

Hepatic lobules

Microscopic functional units of the liver.

Hepatocytes

Liver cells that process nutrients and produce bile.

Central vein

The main vein in the center of a liver lobule.

Portal triad

Contains a branch of the hepatic artery, portal vein, and bile duct.

Sinusoids

Capillary-like vessels in the liver where blood is filtered.

Bile salts

Cholesterol derivatives that aid in fat emulsification.

Bilirubin

Pigment formed from the breakdown of heme in hemoglobin.

Pancreatic juice

Alkaline solution that neutralizes stomach acid and contains enzymes.

Enteropeptidase

Enzyme that converts trypsinogen to trypsin.

Lacteals

Lymphatic capillaries in the small intestine that absorb fat.

Micelle

Aggregate of bile salts and lipid digestion products.

Teniae coli

Three bands of longitudinal smooth muscle in the large intestine.

Haustra

Pocket-like sacs of the large intestine.

Cecum

First part of the large intestine.

Appendix

Lymphoid tissue; part of immune system.

Colon

Main region of the large intestine, divided into ascending, transverse, descending, and sigmoid sections.

Rectum

Last part of the large intestine; stores feces.

Anal canal

Final segment of the large intestine with internal and external sphincters.

Gastroileal reflex

Enhances force of segmentation in the ileum.

Cholecystokinin (CCK)

Hormone that stimulates bile release and pancreatic juice.

Secretin

Hormone that stimulates bicarbonate release from pancreas.

Small intestine

Major organ for digestion and nutrient absorption.

Duodenum

First part of the small intestine; most features are found here.

Jejunum

Middle section of the small intestine, primarily responsible for absorption.

Ileum

Final section of the small intestine, joins large intestine at ileocecal valve.

Villi

Fingerlike projections that increase surface area for absorption in the small intestine.

Microvilli

Cellular extensions that create a brush border and contain enzymes.

Histology

The microscopic structure of tissues present in the gastrointestinal tract.

Enterocytes

Absorptive cells in the intestinal mucosa containing microvilli.

Goblet cells

Mucus-secreting cells found in the intestinal lining.

Pancreatic amylase

Enzyme that breaks down starch into sugars.

Pepsin

Enzyme that begins protein digestion in the stomach.

Chylomicrons

Lipoproteins that transport lipids from the intestinal cells.

Proteins

Large biomolecules that are digested into amino acids.

Lipids

Fats and oils that require emulsification for digestion.

Nucleic acids

Genetic material digested into nucleotides.

Absorption of water

Majority occurs in the small and large intestines through osmosis.

Motility in the small intestine

Segmentation and peristalsis facilitate movement and mixing.

Clinical note: Diarrhea

Result of insufficient water absorption in the large intestine.

Clinical note: Constipation

Result of excessive water absorption, leading to hard stools.

Digestion

The catabolic process of breaking down food into smaller components.

Bicarbonate

Neutralizes stomach acid in the small intestine.

Lactase

Enzyme that digests lactose; deficiency leads to lactose intolerance.

Proteases

Enzymes that break down proteins into smaller peptides.

Absorption process

Movement of nutrients from the gut into the body.