Fun Facts
What is the food called once it has been chewed and mixed with saliva?
Bolus
What is the function of saliva?Moistens food, contains amylase to begin carbohydrate digestion
Moistens food, contains amylase to begin carbohydrate digestion
What hormone stimulates the release of gastric juice?
Gastrin
What is an enzyme?
A biological catalyst that speeds up chemical reactions without being used up.
What are the three parts of the small intestine in order?
Duodenum, jejunum, ileum
What is the soupy mixture of food and stomach secretions called in the stomach?
Chyme
What is the purpose of the epiglottis?Prevents food from entering the trachea during swallowing
Prevents food from entering the trachea during swallowing
What hormone triggers the pancreas to release bicarbonate to neutralize stomach acid?
Secretin
Which enzyme breaks down starch into maltose?
Amylase
What is the main function of the small intestine?
Absorption of nutrients into the blood
Because it is wider in diameter, not length.Why is the large intestine called “large” even though it’s shorter than the small intestine?
Because it is wider in diameter, not length.
What is peristalsis, and where does it occur?
Wave-like muscular contractions that move food along the digestive tract (esophagus, stomach, intestines)
What is the role of CCK (cholecystokinin)?
Stimulates gallbladder to release bile and pancreas to release enzymes
What binds to the enzyme's Active site?
Substrate
How is the surface area of the small intestine increased?
By folds, villi, and microvilli
What organ produces bile, and where is it stored?
Produced in the liver, stored in the gallbladder
what is the pathway that food takes through the upper digestive tract, including the main sphincters and structures?
→ Mouth → pharynx → esophagus → lower esophageal (cardiac) sphincter → stomach
Describe how negative feedback maintains homeostasis in digestion. Give one example.
Processes stop once balance is restored; e.g., secretin stops stomach acid once pH is neutralized
Which enzymes break down proteins, and where do they act?
Pepsin in the stomach; Trypsin in the small intestine
Name two functions of the liver and two of the pancreas.
→ Liver: produces bile, detoxifies blood
→ Pancreas: secretes enzymes, releases insulin/glucagon
What is E.Coli?
A helpful bacteria in the digestive system that produces vitamins (like K) that aid in digestion.
What kind of mechanical breakdown occurs in the digestive system?
Chewing and Churning
How does positive feedback differ from negative feedback? Give an example related to digestion or the body.
Positive feedback amplifies a process; e.g., vomiting reflex or uterine contractions during birth. Negative feedback stabilizes (like insulin regulating blood sugar).
Explain how enzymes lower activation energy and why that’s important for digestion.
They reduce the energy needed for reactions, allowing digestion to occur quicker.
What is a lacteal, and why is it important in digestion?
A lymph vessel in villi that absorbs fats (lipids)