Chapter 19- Digestive and Urinary Systems

What is the primary function of the digestive system?

To metabolize (break down) food for energy use by the body.

What are the two means of digestion?

Mechanical digestion (physical means) and chemical digestion (chemical means).

Where does food breakdown begin?

In the mouth (oral cavity).

What role do teeth play in digestion?

they grind food into smaller pieces to increase surface area for digestive enzymes.

What is the role of salivary amylase?

It breaks down sugars and carbohydrates like starch into maltose.

What are the effects of alcohol use on the mouth and throat?

Increased incidence of oral cancers, tooth decay, gum disease, and tooth loss.

What is the function of the tongue in digestion?

It forms a bolus (ball of food) and pushes it to the back of the mouth.

What is the pharynx and its role in digestion?

It forms the back of the throat and branches into the trachea and esophagus.

What is the function of the epiglottis?

It prevents swallowed food from entering the trachea (windpipe).

What is the role of the upper esophageal sphincter?

It prevents air from entering the esophagus and reflux of contents into the pharynx.

What is peristalsis?

Rhythmic waves of involuntary muscle contractions that push food down the esophagus to the stomach.

Where does the majority of chemical digestion occur?

In the small intestine.

What is the function of the stomach in digestion?

It degrades food further using digestive enzymes and acids, and secretes hydrochloric acid to activate pepsin.

What is chyme?

A slurry mixture formed in the stomach that contains food, digestive enzymes, and acids.

What is the role of the pyloric sphincter?

It regulates the passage of chyme from the stomach to the small intestine.

What is the primary function of the small intestine?

It is the major site for chemical digestion and nutrient absorption.

What does the large intestine do?

It absorbs water and salts from undigested material and turns waste into stool.

What are the accessory organs of the digestive system?

Liver, gallbladder, and pancreas.

What is the function of the liver in digestion?

It produces bile, which aids in the absorption of fats.

What does the gallbladder do?

It stores bile and releases it into the small intestine.

What is the role of the pancreas in digestion?

It produces digestive enzymes and buffers that neutralize stomach acid.

What is the rectum's function in the digestive system?

It stores stool until a bowel movement occurs.

What is the role of the salivary glands?

They secrete saliva, which contains enzymes that begin the digestion of carbohydrates.

How long is the small intestine in adults?

Approximately 20 feet long.

What role does the stomach play in digestion?

It uses acidic gastric juices and the enzyme pepsin to break down food, while mucus protects the stomach lining.

What is the function of the pyloric sphincter?

Regulates the movement of food from the stomach to the small intestine.

What is the function of the large intestine?

Reabsorbs water from indigestible food matter and compacts it into feces for excretion.

How do teeth contribute to digestion?

Reduce the size of food, increasing the surface area for enzymes to act upon during digestion.

What is the function of villi in the small intestine?

They are finger-like projections that increase the surface area for nutrient absorption into the bloodstream.

What is the effect of alcohol on the lower esophageal sphincter?

Alcohol relaxes the lower esophageal sphincter, which can lead to acidified stomach contents moving back into the esophagus, causing heartburn.

What is the impact of alcohol on peristalsis?

Alcohol relaxes the muscles used for peristalsis, causing food to remain in the digestive tract longer.

What is the role of alcohol dehydrogenase in the stomach?

Helps metabolize alcohol, lowering blood alcohol levels and reducing intoxication.

What are the differences in alcohol metabolism between men and women?

Women produce less alcohol dehydrogenase due to smaller stomachs and metabolize alcohol more slowly, leading to higher intoxication rates.

What is ALDH1?

ALDH1 is a variant of the alcohol dehydrogenase enzyme that metabolizes acetaldehyde more slowly, causing flushing and other symptoms in some individuals.

What are gallstones?

They are crystallized bile that forms when excess water is removed from bile in the gallbladder.

What is pancreatitis?

The inflammation of the pancreas that prevents the secretion of digestive enzymes, disrupting digestion.

What is the effect of damaged intestinal villi?

Can prevent the absorption of nutrients, leading to malnutrition and digestive disorders.

What hormone stimulates the production of acidic juices in the stomach?

Gastrin stimulates the production of acidic juices by the stomach.

What is the role of microvilli?

Tiny projections on villi that transport nutrients into the blood vessels of the small intestine.

What happens to undigested materials in the rectum?

Undigested materials are excreted as feces from the rectum.

What effect does alcohol have on intestinal villi?

Alcohol use can damage intestinal villi, preventing absorption of nutrients.

Which hormone stimulates the production of acidic gastric juices?

Gastrin stimulates the production of acidic gastric juices.

What hormones are released from the small intestine after gastrin's release?

Secretin and cholecystokinin (CCK) are released from the small intestine.

What is the primary function of the urinary system?

The urinary system removes wastes while retaining materials to be reused and recycled.

What are the major organs of the urinary system?

The major organs are the kidneys, ureters, urinary bladder, and urethra.

What organ filters and cleanses blood to create urine?

The kidney filters and cleanses circulating blood to create urine.

What is the functional unit of the kidneys?

Nephrons are the functional units of the kidneys.

What are the four phases of waste processing in the kidneys?

The four phases are filtration, reabsorption, secretion, and excretion.

What occurs during the filtration phase in the kidneys?

Blood pressure forces plasma into the nephron through tiny holes in capillaries.

What substances are reabsorbed during the reabsorption phase?

Sugars, amino acids, and water are reabsorbed into the kidney tissue.

How does alcohol affect antidiuretic hormone (ADH) secretion?

Alcohol decreases ADH secretion, leading to increased urine production.

What are the diuretic effects of alcohol?

Alcohol promotes urine formation and increases urine volume released from the bladder.

What is the blood alcohol concentration (BAC) level for legal intoxication?

A BAC level of 0.08 is considered legal intoxication.

What happens at a BAC level above 0.1?

Uncontrolled emotions, impaired reflexes, and speech occur at a BAC level above 0.1.

What is a safer strategy for engaging with alcohol?

Alternating drinking water with drinking alcohol is a safer strategy.

What are the effects of moderate alcohol consumption on cardiovascular health?

Moderate consumption may lower rates of cardiovascular disease and strokes.

What are the effects of excessive alcohol consumption on the body?

Increased risk of heart disease, stroke, and elevated blood pressure can occur.