Digestive NEED TO KNOW

appendix

serves as a reservoir for beneficial gut bacteria and can repopulate the digestive microbiome if it is flushed

esophagus

aids in swallowing; transports food and lipids from the pharynx to the stomach via peristaltic movements; composed of skeletal and smooth muscle

gallbladder

stores and concentrates bile produced by the liver, releasing it into the small intestine to aid in fat digestion

large intestine

absorb water and electrolytes; transforms liquid chyme into solid feces; moves waste toward rectum for elimination

liver

produces and secretes bile; processes nutrients from food, converting them to energy; converts glucose to glycogen for storage; filters toxins from blood

mouth (oral cavity)

ingestion, mechanical digestion through mastication, chemical digestion, swallowing

pancreas

produces enzymes that are released into the duodenum and aids in digestion by breaking down carbohydrates, proteins, and fats

rectum

stores feces before it is expelled from the body through the anus. It plays a role in the elimination of waste

parotid gland

produces a watery (serous) saliva that contains the greatest percentage of salivary amylase and aids in digestion and lubrication; largest salivary gland; secreted near the second molars.

sublingual gland

produces a thick, mucous saliva that helps lubricate food and aids in digestion; secreted under the tongue.

submandibular gland

produces a mixed serous (watery) and mucus saliva that aids in digestion and lubrication; secreted under the tongue

duodenum of small intestine

receives fluid from pancreas and gallbladder for digestion and absorption

jejunum of small intestine

most nutrient absorption and digestion occurs here

ileum of small intestine

largest portion of small intestine; digestion and absorption

stomach

stores food, mechanically breaks up food, liquifies food into chyme, begins chemical digestion of proteins and fat

epiglottis

guards opening of larynx, closes airway to direct food to the esophagus behind it, made up of elastic cartilage

gastric rugae

allow for expansion of the stomach; facilitate efficient mixing and churning of food with gastric juices

absorptive cells of villus

digestion and absorption of nutrients; actively absorb nutrients and water

goblet cells

secrete mucins that are converted to mucus to lubricate and protect the intestinal lining

lacteals

transports lipids via the lymphatic vessels into the bloodstream; absorb lipids

villus (villi)

finger-like projections in the intestine that increase surface area for nutrient absorption; distinguish the small intestine from both the large intestine and stomach

iodine reagent

test for presence of starch, positive result is indicated by a blue-black color change

Benedict’s reagent

test for the presence of sugar, color change goes from blue (no sugar) to brick-red (high sugar)

Litmus reagent

uses litmus cream as a reagent to test pH level, acidic solution is pink while alkaline solution is purplish-blue