The Digestive System: CrashCourse Biology #28

What is the main purpose of the digestive system?

• To circulate blood throughout the body.

• To break down food and absorb nutrients.

• To control body temperature.

• To produce hormones for growth.

Why do dogs have a short digestive tract compared to cows?

• Dogs eat mostly plants, which are easy to digest.

• Dogs need to digest rotten meat quickly to avoid illness.

• Cows have a simpler digestive system that works faster.

• Cows eat meat, which requires a longer digestion time.

Why is chewing food thoroughly important for digestion?

• It makes the food taste better.

• It increases the food's surface area for enzymes to work on.

• It helps to cool down hot food.

• It prevents food from getting stuck in the throat.

What is the function of salivary amylase in the mouth?

• It helps to moisten the food.

• It breaks down proteins into amino acids.

• It breaks down starches into glucose.

• It kills bacteria in the food.

What is the function of the epiglottis during swallowing?

• To break down food into smaller pieces

• To push food down the esophagus

• To prevent food from entering the windpipe

• To mix food with digestive juices

Which of the following is a primary component of gastric juice in the stomach?

• Bile

• Saliva

• Hydrochloric acid

• Bicarbonate

What structures in the small intestine greatly increase its surface area for nutrient absorption?

• Rugae

• Sphincters

• Villi and microvilli

• Cecum

What is the main role of the large intestine in the digestive process?

• To break down proteins into amino acids

• To absorb most of the nutrients from food

• To reabsorb water and bile salts from undigested food

• To produce gastric juice