Pancreas and Intestines

What does pancreatic alpha-amylase do?

Breaks down carbohydrates and certain starches; almost identical to salivary amylase.

What do proteases do in the pancreas?

Break down proteins into amino acids.

What does pancreatic lipase do?

Breaks down certain complex lipids and releases fatty acids.

What do pancreatic nucleases do?

Break down RNA and DNA.

What are the three parts of the small intestine?

Duodenum, jejunum, ileum.

What is the function of the duodenum?

Receives secretions and hormones that aid in further digestion of chyme.

What is the function of the jejunum?

Major site of chemical digestion and nutrient absorption.

What is the function of the ileum?

Absorbs bile acids, fluid, and vitamin B12.

What immune structures are found in the small intestine?

Peyer's patches (secondary lymphoid organs).

What increases the surface area of the small intestine?

Villi and microvilli.

Why are epithelial cells in the small intestine important?

They have high turnover and contain digestive enzymes.

What is celiac disease?

An immune reaction to gluten that causes inflammation and damages the small intestine lining.

What causes diarrhea in celiac disease?

Changes in osmotic pressure.

What causes constipation in celiac disease?

Impaired peristalsis.

Why do patients have bloating and floating stools in celiac disease?

Colonic fermentation of undigested carbohydrates.

Why does lactose intolerance occur in celiac disease?

Damage to microvilli causes reduced lactase.

Why do patients experience fatigue and short-term memory issues in celiac disease?

Nutrition deficits and SNS activation.

What is the treatment for celiac disease?

Strict gluten-free diet to manage symptoms and promote healing.

How common is lactose intolerance worldwide?

About 68% of the world's population.

What explains variation in lactose intolerance across regions?

Lactase persistence in populations with historical cattle domestication.

What are the main functions of the large intestine?

Absorption of water, vitamins, and electrolytes; forms and propels feces toward the rectum.

What is the mesentery?

A fold of membrane that attaches the intestine to the abdominal wall and holds it in place; highly vascularized and stores fat.

What is constipation?

Fewer than three bowel movements per week.

What causes constipation?

Lack of fiber, lack of exercise, medications, IBS, etc.

How is constipation treated?

Increased fiber intake, exercise, laxatives.

What is diarrhea?

Loose, watery stools.

What causes diarrhea?

Bacterial/viral infections, food intolerance, parasites, medications, intestinal diseases.

What is the treatment for diarrhea?

Replenish water and electrolytes (Na⁺ & K⁺).

What is diverticulosis?

Pockets in the colon wall caused by weak muscle layers.

What causes diverticulosis?

Aging, low fiber diet, obesity, inactivity.

How is diverticulosis treated?

High-fiber diet and physical activity.

What are hemorrhoids?

Swollen veins in the anus and lower rectum.

What causes hemorrhoids?

Pressure on veins, low fiber diet, sitting too long, obesity, pregnancy.

How are hemorrhoids treated?

High fiber diet, fluids, physical activity.

What is the order of starch breakdown?

Starch → Disaccharides → Monosaccharides.

What enzymes break down starch?

Amylases: salivary, gastric, pancreatic.

What enzymes break down disaccharides?

Sucrase, Maltase, Lactase.

What does sucrase do?

Converts sucrose → glucose + fructose.

What does maltase do?

Converts maltose → glucose + glucose.

What does lactase do?

Converts lactose → glucose + galactose.

How do monosaccharides travel to the liver?

Through the portal vein.

What are the possible fates of glucose in the liver?

Used for energy, stored as glycogen, stored as fat, used to make non-essential amino acids, or released into the blood.

Where is insulin produced?

Beta cells in the Islets of Langerhans.

What does insulin do in the liver?

Drives glucose uptake; stimulates glycogen and triglyceride synthesis; inhibits glucose production.

What does insulin do in adipose tissue?

Binds insulin receptors; receptor sensitivity depends on adipocyte size; transports glucose & fatty acids into the cell; stimulates fat synthesis from glucose.

What does insulin do in muscle tissue?

Binds insulin receptors; receptor sensitivity depends on movement; transports glucose, amino acids, and fatty acids; stimulates synthesis of glycogen, fat, and proteins.

How does exercise affect muscle glucose uptake?

Exercise promotes passive glucose uptake without insulin.