Gastro Intestinal System Flashcards
Which of the following is NOT a stage of digestion?
A) Ingestion
B) Peristalsis
C) Absorption
D) Excretion
Answer: D) Excretion
Explanation: The stages of digestion are ingestion, peristalsis, digestion, absorption, and defecation.
Where does the chemical digestion of proteins begin?
A) Mouth
B) Stomach
C) Small intestine
D) Large intestine
Answer: B) Stomach
Explanation: Chemical digestion of proteins begins in the stomach with the enzyme pepsin.
Which part of the small intestine is primarily responsible for nutrient absorption?
A) Duodenum
B) Jejunum
C) Ileum
D) Colon
Answer: B) Jejunum
Explanation: The jejunum has many folds and villi, making it the primary site for nutrient absorption.
What is the main role of the duodenum?
A) Absorb nutrients
B) Store bile
C) Complete the first phase of digestion
D) Produce bile
Answer: C) Complete the first phase of digestion
Explanation: The duodenum mixes food with digestive enzymes and bile, completing the first phase of digestion.
Which hormone is released in response to stomach distension?
A) Secretin
B) Gastrin
C) Cholecystokinin (CCK)
D) Insulin
Answer: B) Gastrin
Explanation: Gastrin is released in response to stomach distension and stimulates gastric acid secretion.
What is the primary function of bile?
A) Digest proteins
B) Emulsify fats
C) Neutralize stomach acid
D) Stimulate peristalsis
Answer: B) Emulsify fats
Explanation: Bile emulsifies fats, making them easier to digest by enzymes.
Which enzyme is responsible for the majority of starch digestion?
A) Salivary amylase
B) Pancreatic amylase
C) Pepsin
D) Lipase
Answer: B) Pancreatic amylase
Explanation: Pancreatic amylase is responsible for the majority of starch digestion.
What is the main function of the large intestine?
A) Absorb nutrients
B) Digest proteins
C) Absorb water and electrolytes
D) Secrete digestive enzymes
Answer: C) Absorb water and electrolytes
Explanation: The large intestine absorbs water and electrolytes, forming and storing feces.
Which cells secrete hydrochloric acid (HCl) in the stomach?
A) Chief cells
B) Parietal cells
C) Goblet cells
D) G-cells
Answer: B) Parietal cells
Explanation: Parietal cells secrete hydrochloric acid (HCl) and intrinsic factor.
What triggers the cephalic phase of gastric secretion?
A) Presence of food in the stomach
B) Sight, smell, taste, or thought of food
C) Distension of the stomach
D) Presence of chyme in the duodenum
Answer: B) Sight, smell, taste, or thought of food
Explanation: The cephalic phase is triggered by the sight, smell, taste, or thought of food and prepares the stomach for digestion.
Which substance converts pepsinogen to pepsin?
A) Bile
B) Hydrochloric acid
C) Amylase
D) Lipase
Answer: B) Hydrochloric acid
Explanation: Hydrochloric acid (HCl) in the stomach converts pepsinogen to its active form, pepsin.
What protects the stomach lining from the acidic environment?
A) Mucous gel layer
B) Bicarbonate secretion
C) Tight junctions between cells
D) All of the above
Answer: D) All of the above
Explanation: The mucous gel layer, bicarbonate secretion, and tight junctions all protect the stomach lining from the acidic environment.
What is the primary stimulus for the release of cholecystokinin (CCK)?
A) Stomach distension
B) Presence of fats and proteins in the duodenum
C) Low blood glucose levels
D) High blood glucose levels
Answer: B) Presence of fats and proteins in the duodenum
Explanation: CCK is released in response to the presence of fats and proteins in the duodenum, stimulating bile and pancreatic enzyme secretion.
Which phase of gastric secretion is controlled by the medulla oblongata?
A) Cephalic phase
B) Gastric phase
C) Intestinal phase
D) None of the above
Answer: A) Cephalic phase
Explanation: The cephalic phase is controlled by the medulla oblongata through vagal stimulation.
What is the function of intrinsic factor secreted by the stomach?
A) Digest proteins
B) Absorb vitamin B12
C) Neutralize stomach acid
D) Stimulate peristalsis
Answer: B) Absorb vitamin B12
Explanation: Intrinsic factor is essential for the absorption of vitamin B12 in the small intestine.
Which enzyme initiates the digestion of carbohydrates in the mouth?
A) Pepsin
B) Salivary amylase
C) Pancreatic lipase
D) Trypsin
Answer: B) Salivary amylase
Explanation: Salivary amylase initiates the digestion of carbohydrates in the mouth.
Which part of the stomach is responsible for mixing and grinding food?
A) Fundus
B) Body
C) Antrum
D) Cardia
Answer: C) Antrum
Explanation: The antrum of the stomach is responsible for mixing and grinding food.
Which hormone inhibits gastric secretion and motility?
A) Gastrin
B) Secretin
C) Cholecystokinin (CCK)
D) Somatostatin
Answer: D) Somatostatin
Explanation: Somatostatin inhibits gastric secretion and motility.
What is the role of goblet cells in the stomach?
A) Secrete hydrochloric acid
B) Secrete pepsinogen
C) Secrete mucous
D) Secrete gastrin
Answer: C) Secrete mucous
Explanation: Goblet cells in the stomach secrete mucous to protect the lining from acidic gastric juices.
Which phase of gastric secretion is initiated by the presence of chyme in the duodenum?
A) Cephalic phase
B) Gastric phase
C) Intestinal phase
D) None of the above
Answer: C) Intestinal phase
Explanation: The intestinal phase is initiated by the presence of chyme in the duodenum, regulating gastric secretion through hormonal and neural responses.
What is the function of Brunner’s glands in the duodenum?
A) Secrete digestive enzymes
B) Secrete alkaline mucous
C) Absorb nutrients
D) Produce bile
Answer: B) Secrete alkaline mucous
Explanation: Brunner’s glands secrete alkaline mucous to protect the intestinal wall and neutralize acidic chyme.
Which of the following increases the surface area for absorption in the small intestine?
A) Villi
B) Microvilli
C) Circular folds
D) All of the above
Answer: D) All of the above
Explanation: Villi, microvilli, and circular folds all increase the surface area for absorption in the small intestine.
Which enzyme is responsible for breaking down lactose?
A) Sucrase
B) Maltase
C) Lactase
D) Amylase
Answer: C) Lactase
Explanation: Lactase is the enzyme responsible for breaking down lactose into glucose and galactose.
Where does the absorption of vitamin B12 primarily occur?
A) Duodenum
B) Jejunum
C) Ileum
D) Colon
Answer: C) Ileum
Explanation: The absorption of vitamin B12 primarily occurs in the ileum, with the help of intrinsic factor.