4.2 HBS

mechanical digestion

The physical breakdown of food by the teeth and muscle movements of the digestive system.

chemical digestion 

The chemical breakdown of food by digestive enzymes and acids. 

mechanical digestion

The physical breakdown of food by the teeth and muscle movements of the digestive system.

chemical digestion 

The chemical breakdown of food by digestive enzymes and acids. 

Ceceum

Where food from the small intestine empties out

Ascending Colon

Movement of food/water and electrolytes are absorbed

Descending Colon

Mucus binds waste together

Sigmoid

Holds waste until filled and leaves through anus

Duodenum

Receives enzymes that mix with food to continue the chemical digestion

Jejunum

Chemical and Mechanical digestion- muscles move food mixture more and faster

Ileum

Process slows down, nutrients and water are reabsorbed

Digestive System

Breaks down food, absorbs nutrients, and eliminates waste

What makes up the GI tract?

mouth, Pharynx, esophagus, stomach, small intestine, and large intestine

Accessory Organs

Tongue, Salivary Glands, Liver, Gallbladder, Pancreas

Mouth

Chewing, saliva starts carb digestion

Esophagus

Moves food via peristalsis

Stomach

Mixes food, protein digestion (pepsin), acid production

Small Intestine

Main site for digestion/absorption

Large intestine

Absorbs water and forms feces

Liver

Produces Bile and stores nutrients

Gallbladder

Stores/releases Bile

Pancreas

Secretes digestive enzymes, and regulates blood sugar

Sphincters

Prevents Backflow

Feeding Tubes

Provide nutrition directly onto Stomach/intestine

Colostomy/ileostomy

Creates stomach for waste after colon removal

Colon Polyps

Growths that can become cancerous

Celiac Disease

Autoimmune reaction to gluten

GERD

stomach acid refluxes into esophagus

Peptic Ulcers

Stores from acid damage in stomach lining

Crohns Disease

Inflammatory bowel disease

Whipples Disease

Rare Infection interfering with digestion

IBS

Functional disorder causing cramps, bloating, and diarrhea

Def of Dysbiosis

Microbial imbalance in gut

Causes of Dysbiosis

Antibiotics, poor diet, stress

Symptoms of Dysbiosis

Gas, Bloating, fatigue, irregular stools

Where its made, what it acts on, and what it breaks down: Salivary Amylase

Salivary Glands, Starch, Simple Sugars

Where its made, what it acts on, and what it breaks down: Pepsin

Stomach, Proteins, Peptides

Where its made, what it acts on, and what it breaks down: Pancreatic Amylase

Pancreas, Starch (small intestine), Sugars

Where its made, what it acts on, and what it breaks down: Trypsin

Pancreas, Proteins, Peptides

Where its made, what it acts on, and what it breaks down: Lipase

Pancreas, Fats, fatty acids

Where its made, what it acts on, and what it breaks down: Bile

Made in liver but stored in gallbladder, emulsifies fats, prepares fats for Lipase

• speed up chemical reactions by lowering the activation energy (energy needed to start a reaction) 

Catalysts

Bolus

Soft rounded mass of chewed food mixed with saliva

Hard Palate

Front part of the roof of the mouth

Provides hard surface for the tongue to press food against

Hard palate

Soft Palate

Back part of the roof of the mouth

Rises during swallowing to block the nasal passages and prevent food from entering nose

Front Palate

Mechanical Digestion

Chewing and Tongue to help mix food with saliva

Chemical Digestion

Amylase in saliva begins breakdown of starches into sugars

Epiglottis

A flap of tissue that closes over trachea when you swallow

Amylase

Breaks down carbohydrates into sugars

Lipase

Breaks down fats into fatty acids and glycerol

Trypsin

Breaks down proteins into smaller peptides

Enzyme

A helper protein made by body to speed up chemical reactions

Substrate

Thing enzymes work on

Active Site

Special Spot on the enzyme where substrate fits

• Propulsion

• Movement of food through the GI tract.

• Endoscopy

• Visual examination of the GI tract.

• Biopsy

• Small tissue sample collection for diagnostic purposes.

• Peristalsis

• Wave-like muscle contractions.

• Chyme

• Partially digested food in the stomach.

What are the six key processes of digestion?

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation.

What are rugae?

Folds in the stomach lining that allow expansion.

Duodenum

Receives enzymes and chemical digestion

Jejunum

fast absorption

Ileum

Slow absorption and water reabsorption

What are the four parts of the colon?

Ascending, transverse, descending, sigmoid.

Name 2 beneficial gut bacteria.

Lactobacillus, Bifidobacterium.

What is a G-tube?

A gastric tube inserted into the stomach for feeding.

What is a J-tube?

A jejunal tube inserted into the small intestine for feeding.

What structures are found in the tongue’s histology?

Taste buds, papillae.

What structures are found in the stomach’s histology?

Gastric pits, columnar epithelium, fundic glands.

How does Celiac disease affect the villi?

It flattens them, reducing absorption.

Goblet cells

secrete mucus to help with waste movement.

What cells line the colon and what do they do?

Goblet Cells

Secretes digestive enzymes into small intestine, also secretes hormones that regulate blood sugar

Pancreas

What organ has a wall that contracts rhythmically and has mucous lining membrane that has gastric glands?

Stomach

Whats the purpose of mucous coating in the stomach

protects the epithelium from acid in the stomach

where does most absorption of digestive end products into bloodstream occur?

Small Intestine

Absorptive effectiveness of small intestine is enhanced by what

Intestinal movements, pilcae, microvilli, villi

The symptoms of GERD are due to disruption of homeostasis in which organ?

Stomach

An organisms chemical reactions are called what?

Metabolism

The pancreas produces

Proteinases, amylase, lipases, and carbohydrates

Pancreatic amylase and lipase are released into the

Duodenum

What is made by small intestine to break down disaccharides?

Sucrase

What holds info which offspring receive from their parents

nucleic acids

What substances are secreted by parietal cells in gastric pits?

HCL (hydrochloric acid) and intrinsic factor (essential for B12 absorption)

What do plicae and intestinal villi do

Increase surface area of mucosa of small intestine

What is triglyceride an example of

Lipid

Macromolecules are built from monomers through what

dehydration synthesis

Fatty acids are building blocks of

Lipids

What molecule can be used to break down polymers into smaller subunits

Water

What provides energy on a long run

Lipids

Monosaccharides are building blocks for

carbohydrates

ATP is what type of macromolecule?

Nucleic Acid

Catalase enzyme is an example of a

Protein