digestive system

What is ingestion in the digestive system?

Taking in food.

What is digestion?

Breaking food into nutrient molecules.

What is absorption?

Movement of nutrients into the bloodstream.

What is defecation?

Excretes to rid the body of indigestible waste.

What are the two main groups of organs in the digestive system?

Alimentary canal and accessory digestive organs.

What is the alimentary canal?

A continuous, coiled, hollow tube running from the stomach to the anus.

What are accessory digestive organs?

Teeth, tongue, and several large digestive organs that assist digestion.

Name the organs of the alimentary canal in order from mouth to anus.

Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus.

What is the function of the mouth in digestion?

Serves as the entry point for food and begins the digestion process.

What is the uvula?

A fleshy projection of the soft palate in the mouth.

What are the two areas of the mouth?

Vestibule and oral cavity proper.

What is the function of the pharynx in the digestive system?

Serves as a passageway for food and fluids.

What is peristalsis?

The alternating contractions of muscle layers that propel food.

Describe the structure of the esophagus.

A muscular tube about 10 inches long that conducts food from the pharynx to the stomach.

What are the four layers (tunics) of the digestive tract?

Mucosa, submucosa, muscularis externa, serosa.

Where does food enter the stomach from?

The esophagus through the cardioesophageal sphincter.

What is the pyloric sphincter?

Valve that controls food emptiness from the stomach to the small intestine.

What are the regions of the stomach?

Cardial, fundus, body, and pyloric region.

What are rugae?

Internal folds of the stomach mucosa present when the stomach is empty.

What is the primary function of the small intestine?

Nutrient absorption into the blood.

What are the subdivisions of the small intestine?

Duodenum, jejunum, ileum.

What substances enter the duodenum for digestion?

Pancreatic juice and bile.

What is the function of the large intestine?

To eliminate feces and absorb remaining nutrients.

What structures are included in the large intestine?

Cecum, appendix, colon, rectum, and anal canal.

What is the function of goblet cells in the large intestine?

To produce alkaline mucus that lubricates the passage of feces.

What are the four types of teeth in humans?

Incisors, canines, premolars, molars.

What is the role of salivary glands?

To produce saliva, which moisten and bind food into a bolus.

What is the function of the pancreas?

To produce pancreatic juice which aids digestion.

What is the largest gland in the body?

The liver.

What is bile?

A substance produced by the liver that aids in the digestion of fats.

What are the functions of the liver related to metabolism?

Manufactures bile, detoxifies drugs and alcohol, degrades hormones.

What are the major nutrients?

Carbohydrates, lipids, proteins, water.

What is metabolism?

All the chemical reactions necessary to maintain life.

What is catabolism?

Breaking down substances to release energy.

What is anabolism?

Building larger molecules from smaller ones.

What is glycolysis?

The first step in cellular respiration that breaks down glucose.

What does the citric acid cycle do?

Processes glucose to produce ATP.

What is metabolic rate?

The amount of energy expended during physical activity.

What is the average basic metabolic rate (BMR) for a 70 kg adult?

60 to 72 kcal/hour.

How is energy value measured in food?

In kilocalories (kcal) or Calories.

What are low-density lipoproteins (LDLs)?

Transporters of cholesterol that can lead to atherosclerosis.

What is the role of high-density lipoproteins (HDLs)?

To transport cholesterol from body cells to the liver.

What stimulates the release of pancreatic juice?

Vagus nerves and local hormones.

What occurs during the defecation reflex?

Presence of feces in the rectum triggers the urge to eliminate waste.

What is the role of microbiota in the digestive system?

Includes all bacteria, viruses, parasites, and fungi living in or on the human body.

What are vitamins primarily needed for?

As coenzymes crucial for various biochemical reactions.

What is the main role of minerals in the body?

Important for enzyme activity.

What happens to glucose during cellular respiration?

It is oxidized to produce carbon dioxide, water, and ATP.

What must occur for digestion to happen properly in the small intestine?

Alkaline content must neutralize acidic chyme to provide the right environment for enzymes.

What is reabsorption in relation to digestion?

Process by which nutrients are absorbed back into the bloodstream from the GI tract.

What happens to undigested substances in the large intestine?

They are eliminated as feces.

What is the purpose of the process of glycogenesis in the liver?

To convert glucose to glycogen for storage.

What is gluconeogenesis?

Production of glucose from fats and proteins.

What is the significant process that occurs in newborns regarding the digestive system?

Frequent feeding and immature peristalsis.

What happens during the rooting reflex in infants?

Helps infants find the nipple for feeding.

How do the macronutrients differ in energy yield?

Carbohydrates and proteins yield 4 kcal/gram, while fats yield 9 kcal/gram.

How can the liver regenerate?

It can regenerate itself if part of it is damaged.

What is the Healthy Eating Pyramid?

A visual guide issued in 1992 outlining major food groups.

What is MyPlate?

A dietary guide issued in 2011 by the USDA showing five food groups on a round plate.

What is the role of ammonia in protein metabolism?

It is detoxified by liver cells to form urea.

What do teniae coli do in the large intestine?

They cause the wall of the intestine to pucker into haustra.

What is the function of the gallbladder?

To store bile produced by the liver.

What is the effect of excessive fat breakdown on the body?

It causes the blood to become acidic (acidosis or ketoacidosis).

What is a key feature of the alimentary canal?

It is a continuous, hollow tube present from the early fetal stage.

What condition can result from a high level of LDL cholesterol?

Atherosclerosis, which leads to heart disease.

What is the main absorption function of the large intestine?

To absorb water, vitamins, and ions.

What are haustral contractions?

Movements that occur most frequently in the large intestine.

What are the main types of digestive enzymes in the stomach?

Protein-digesting enzymes, such as pepsin.

What is the importance of water in digestion?

It acts as a dissolving medium and a softening agent.

What is the bile duct's role in digestion?

It transports bile from the liver to the duodenum.

What is the role of the diaphragm in relation to the esophagus?

It is the muscle through which the esophagus passes to reach the stomach.

What does the term 'bolus' refer to?

A mass of chewed food ready to be swallowed.

What is the purpose of gastric juice in the stomach?

To aid in the digestion of food with acidic and enzymatic action.

What is the significance of the ileocecal valve?

It regulates the flow of material from the small intestine to the large intestine.

What is the primary function of the tongue in digestion?

To manipulate food and aid in tasting.

What is the function of the digestive system?

To process food for energy and nutrients.

What happens to proteins during digestion?

They are broken down into amino acids.

What is the role of bile in digestion?

To emulsify fats, aiding in their absorption.

How is water absorbed in the large intestine?

Through osmosis across the intestinal wall.

What is the importance of fiber in digestion?

It helps regulate bowel movements and prevents constipation.

What is the function of the epiglottis?

To prevent food from entering the trachea during swallowing.

What enzymes are produced by the pancreas?

Amylase, lipase, and proteases.

What is the role of gastric acid in the stomach?

To help digest food and kill harmful bacteria.

What triggers the sensation of hunger?

The hormone ghrelin, released by the stomach.

What is the impact of probiotics on gut health?

They can enhance digestion and support immune function.

What is the role of the small intestine in digestion?

It is the primary site for nutrient absorption.

Describe the function of the liver in detoxification.

The liver detoxifies harmful substances and drugs.

What enzyme is responsible for the breakdown of carbohydrates?

Amylase.

What is the main purpose of dietary fiber?

To promote digestive health and prevent constipation.

What are the effects of high sugar consumption on the body?

Can lead to obesity, diabetes, and tooth decay.

What is the significance of the sphincters in the digestive system?

They control the flow of food through the digestive tract.

What nutrients are primarily absorbed in the large intestine?

Water, vitamins, and minerals.

What is the function of the gallbladder in digestion?

Stores and concentrates bile before releasing it into the small intestine.

How does the digestive system change with age?

Digestive efficiency may decrease, leading to issues like constipation.

What role do probiotics play in digestion?

They support the balance of gut microbiota and enhance digestive health.