Nutrition and Digestion Practice Flashcards

Comprehensive practice questions covering the mechanics of digestion, human anatomy, and nutritional requirements as presented in Chapter 22.

What are the four stages of food processing in their proper order?

Ingestion, digestion, absorption, and elimination.

How is a gastrovascular cavity defined compared to an alimentary canal?

A gastrovascular cavity is a digestive compartment with a single opening (mouth and anus are the same), whereas an alimentary canal has two separate openings: a mouth at one end and an anus at the other.

What chemical process is responsible for the breakdown of large biological molecules during chemical digestion?

Hydrolysis, which are chemical reactions that break down molecules by the addition of water ($H_2O$) molecules and require enzymes.

Which three dietary categories describe how most animals acquire nutrients?

Herbivores (feed on plants/algae), Carnivores (eat other animals), and Omnivores (eat animals as well as plants/algae).

What are the accessory organs of the human digestive system?

Salivary glands, pancreas, liver, and gallbladder.

What is the function of the epiglottis during swallowing?

It is a door-like flap that tips to close the entrance of the trachea (windpipe) to ensure food enters the esophagus instead of the lungs.

How does the esophagus move food toward the stomach?

By peristalsis, which are alternating waves of muscular contraction and relaxation that squeeze the food ball along the tube.

What three components make up the fluid known as gastric juice?

Hydrochloric acid, digestive enzymes (including pepsin), and mucus.

The stomach walls churn food and gastric juice into a thick soup called __________.

Chyme

According to the transcript, how often does the human stomach completely replace its lining?

About once every three days.

What is the primary cause of most gastric ulcers?

An acid-tolerant bacterium called Helicobacter pylori.

What occurs during a gastric bypass surgery?

Staples reduce the stomach to the size of a chicken egg, and the first $18$ inches of the small intestine are bypassed by attaching the downstream intestine directly to the new stomach pouch.

What is the name of the first part of the small intestine where enzymes mix with chyme?

The duodenum, which consists of the first $25 \text{ cm}$ or so of the small intestine.

What is the role of bile in digestion, and where is it stored?

Bile contains salts that break up fats into small droplets; it is produced by the liver and stored in the gallbladder.

What structural adaptations of the small intestine facilitate nutrient absorption?

Villi and microvilli, which provide an expansive surface area for the absorption of small molecules into the blood and lymph.

What are the primary functions of the colon?

It absorbs water from the alimentary canal and produces feces from undigested material.

How is a kilocalorie (kcal) defined relative to a calorie?

A kilocalorie is equal to $1,000$ calories.

What is the Basal Metabolic Rate (BMR)?

The amount of energy it takes just to maintain basic body functions.

What are the specific health risks associated with a deficiency in Vitamin A and Vitamin D?

Too little Vitamin A can lead to vision loss, and too little Vitamin D causes rickets (bone deformities).

What were the results of the injection of the protein leptin into mutant obese mice?

Mutant mice that received leptin lost weight and ended the study weighing about half as much as those that received saline.