The Digestive System

What is the pancreas classified as?

An accessory organ that is both an exocrine and an endocrine gland.

What does the exocrine function of the pancreas involve?

The secretion of pancreatic juice containing digestive enzymes into ducts.

What hormones are produced by the pancreas?

Insulin and glucagon.

What is the primary role of insulin?

To lower blood sugar levels by facilitating glucose uptake into cells.

What is the primary role of glucagon?

To raise blood sugar levels by promoting the conversion of glycogen to glucose in the liver.

What is pancreatic juice?

A digestive fluid produced by the pancreas that contains enzymes and sodium bicarbonate.

What is the function of sodium bicarbonate in pancreatic juice?

To neutralize stomach acid and maintain an optimal pH for enzyme activity in the small intestine.

What is the length and width of the pancreas?

About 18 cm long and 4 cm wide.

Where is the pancreas located?

Under the stomach and connected to the small intestine.

What digestive enzyme does pancreatic amylase act on?

Starch, converting it into maltose.

What does trypsin do?

Continues the digestion of proteins into peptides.

What is the function of lipase?

To hydrolyze fats into glycerol and fatty acids.

What does nuclease act upon?

Nucleic acids (DNA and RNA), converting them into nucleotides.

What is the normal blood sugar level in mg/100ml?

Approximately 100 mg/100ml or 0.1%.

What condition results from insufficient insulin production?

Diabetes mellitus.

What is Type I diabetes?

A form of diabetes caused by a lack of insulin production, often seen in young people.

What is Type II diabetes?

A form of diabetes that is often managed with lifestyle changes and accounts for 90% of cases.

What are the symptoms of high blood sugar levels?

Increased urination, thirst, and hunger.

What is the role of the Islets of Langerhans?

To produce insulin and glucagon in the pancreas.

What happens to blood sugar levels after a meal?

Blood sugar levels increase, prompting the release of insulin.

What is gluconeogenesis?

The process of converting protein and fat into glucose, primarily occurring in the liver.

What is the significance of maintaining blood sugar levels?

To ensure proper cellular function and energy supply.

What can happen if the pancreas is injured?

It can lead to issues with the storage and release of digestive enzymes.

What is the pH range maintained in the duodenum by pancreatic juice?

7.5 to 8.5.

What is the consequence of untreated diabetes?

It can lead to serious health complications, including damage to organs and tissues.

What lifestyle changes can help prevent Type II diabetes?

Maintaining a healthy weight, regular exercise, and a balanced diet.

What is the function of pancreatic juice in digestion?

To aid in the digestion of carbohydrates, proteins, and fats in the small intestine.

What is the primary function of the digestive system?

To break down food into smaller monomers that can be absorbed into the bloodstream.

What are the main types of molecules that food provides for the body?

Carbohydrates, proteins, lipids/fats, and nucleic acids.

Why can't the body use complex molecules directly?

They are too large to pass through membranes and into the bloodstream.

What are monomers that can be absorbed by the body?

Glucose, amino acids, nucleotides, glycerol, and fatty acids.

What is the average amount of food a person eats per year?

Approximately 500 kilograms.

What role does the mouth play in digestion?

It is responsible for mechanical and chemical digestion of food.

What is the function of saliva in digestion?

It mixes with food to form a bolus and contains enzymes that begin starch hydrolysis.

What is the role of the tongue in the digestive process?

It helps in taste, moving, mixing, and positioning food for chewing and swallowing.

What is the function of the pharynx in digestion?

It serves as a passageway for food to the esophagus and air to the trachea.

What is peristalsis?

The smooth muscle contractions in the esophagus that move the food bolus to the stomach.

What does the cardiac sphincter do?

It prevents reflux of digested food (acid chyme) back into the esophagus.

What is the primary function of the stomach?

To mechanically and chemically digest food, producing hydrochloric acid and activating enzymes.

What is the role of the pyloric sphincter?

It controls the release of acid chyme into the duodenum.

What is the duodenum's significance in digestion?

It is the first section of the small intestine where digestion and absorption of nutrients occur.

What does the liver produce for digestion?

Bile, which is stored in the gall bladder and helps emulsify fats.

What is the function of the pancreas in digestion?

It produces pancreatic juice containing digestive enzymes and sodium bicarbonate.

What is the role of the small intestine?

It is essential for the chemical digestion and absorption of nutrients.

What is the function of the appendix?

It may play a role in immune function.

What does the large intestine do?

It absorbs water and produces vitamins.

What is the rectum's function?

It stores feces and is involved in defecation.

What is the anus?

A sphincter that is involved in the defecation reflex.

Why is surface area important in the digestive system?

It facilitates the absorption of nutrients.

How long is the esophagus?

Approximately 25 centimeters.

What happens to food in the stomach?

It sloshes around and can remain there for 3-4 hours.

What unique feature does the stomach have regarding mucus?

It must produce a new layer of mucus every two weeks to prevent self-digestion.

Can a person live without their stomach?

Yes, people can live without a stomach if it has been removed due to disease.

How long can food slosh in the stomach?

3-4 hours

What must the stomach produce every two weeks to prevent digesting itself?

A new layer of mucus

Can a person live without a stomach?

Yes, if it has been removed due to disease.

What causes most of the gas in the stomach and intestinal tract?

Swallowed air

What is the role of the mouth in digestion?

It performs mechanical and chemical digestion of food.

What is mechanical digestion?

The cutting and crushing of food by the teeth.

What enzyme in saliva is responsible for starch digestion?

Salivary amylase

What is a bolus?

A food ball formed in the mouth that can be swallowed.

What is the pharynx?

The throat, a passage for food to the esophagus and air to the trachea.

What action does the epiglottis perform during swallowing?

It covers the opening to the trachea.

What is the function of the cardiac sphincter?

It prevents reflux of food and acid chyme into the esophagus.

What is heartburn?

A burning sensation in the throat caused by reflux of chyme into the esophagus.

What does the stomach produce to aid digestion?

Hydrochloric acid, pepsinogen, and mucus.

What is the role of hydrochloric acid in the stomach?

It kills bacteria and activates pepsinogen into pepsin.

What is pepsin's function?

To digest proteins into peptides.

What is the pyloric sphincter?

The muscle that controls the release of acid chyme into the duodenum.

What is the duodenum's role in digestion?

It is important for digestion and absorption of nutrients.

What does the liver do?

Performs over 500 functions including detoxification and protein synthesis.

What is unique about the liver's ability?

It can regenerate itself.

Who performed the first successful human liver transplant?

Dr. Thomas E. Starzl in 1967.

What does 'hepatoscopy' refer to?

The practice of examining livers of sacrificed animals to predict outcomes.

What is the primary component of gastric juice?

Hydrochloric acid and enzymes like pepsin.

What is the function of mucus in the stomach?

To protect the stomach lining from acidic contents.

What is the average length of the esophagus?

About 25 centimeters.

What happens to the bolus during swallowing?

It is pushed into the esophagus by a reflex action.

What is the role of salivary glands?

To produce saliva that moistens food and aids in digestion.

What is the role of the soft palate during swallowing?

It pushes down to help close the trachea.

What is hepatoscopy?

A practice involving the sacrifice of oxen or goats and examination of their livers to predict military campaign success.

What organ is referred to as the largest internal organ in the human body?

The liver.

What are the main blood vessels associated with the liver?

The hepatic artery and the hepatic portal vein.

What is the primary role of the liver in detoxification?

It removes and breaks down poisonous substances from the blood.

How does the liver maintain blood glucose levels?

By storing glucose as glycogen after meals and breaking it down between meals.

What waste product does the liver produce for excretion?

Urea.

What are plasma proteins?

Proteins produced by the liver that are found in blood plasma, such as albumin and fibrinogen.

What is the function of bile?

To emulsify fats in the small intestine.

What condition can result from liver dysfunction related to bilirubin?

Jaundice.

Where is bile stored in the body?

In the gallbladder.

What happens to bile when food moves from the stomach to the small intestine?

Bile is released through the bile duct to aid in digestion.

What is the role of bile salts?

To help emulsify fats in the small intestine.

What is the Greek word for liver?

Hepar.

What are the six functions of the liver?

Detoxification, maintaining blood glucose levels, producing urea, building plasma proteins, producing bile, and storing vitamins and iron.

What is the role of the gallbladder?

To store bile produced by the liver until it is needed for digestion.

What is the duodenum?

The first 25 centimeters of the small intestine where bile and pancreatic juice enter.

What is the role of sodium bicarbonate in pancreatic juice?

To neutralize acid chyme and make the pH slightly basic.

What are microvilli?

Tiny projections on the surface of intestinal cells that increase surface area for absorption.

What are lacteals?

Lymphatic vessels in the small intestine that absorb fats.

What enzymes are produced by the small intestine?

Maltase, peptidases, and nucleosidases.