where does digestion begin in the digestive system

HESI A2

Anatomy HESI A2 Practice Test

1. Where does digestion begin in the digestive system?

A. Stomach
B. Mouth
C. Small intestine
D. Esophagus

Correct answer: B

Rationale: Digestion begins in the mouth. Mechanical digestion through chewing and chemical digestion through saliva initiate the breakdown of food. Enzymes in saliva start breaking down carbohydrates, marking the beginning of the digestive process. The stomach primarily functions in further breaking down food and mixing it with gastric juices. The small intestine is where most of the digestion and absorption of nutrients occur. The esophagus is a muscular tube that helps move food from the mouth to the stomach, but digestion does not begin there.

2. Which of the heart's four chambers is the largest and the strongest?

A. Right atrium
B. Left ventricle
C. Right ventricle
D. Left atrium

Correct answer: B

Rationale: The left ventricle is the largest and strongest chamber of the heart. It pumps oxygenated blood to the body, making it vital for systemic circulation. The right atrium receives deoxygenated blood from the body, the right ventricle pumps this blood to the lungs, and the left atrium receives oxygenated blood from the lungs.

3. What is the function of the pancreas in digestion?

A. Secreting digestive enzymes
B. Producing bile
C. Storing glucose
D. Regulating blood sugar levels

Correct answer: A

Rationale: The correct answer is A: Secreting digestive enzymes. The pancreas aids in digestion by secreting digestive enzymes that are essential for breaking down carbohydrates, fats, and proteins in the small intestine. These enzymes help in the absorption of nutrients from food, facilitating the digestive process. Choices B, C, and D are incorrect. The pancreas does not produce bile (choice B), store glucose (choice C), or primarily regulate blood sugar levels (choice D) in the context of digestion.

4. The orthopedic surgeon informs you that you have broken the middle region of the humerus. What area is he describing?

A. Epiphysis
B. Articular cartilage
C. Perichondrium
D. Diaphysis

Correct answer: D

Rationale: The diaphysis is the correct answer in this scenario. It refers to the middle or shaft region of a long bone like the humerus. The epiphysis is the end of a long bone, while articular cartilage is the smooth tissue covering the ends of bones at a joint. The perichondrium is the dense irregular connective tissue that surrounds cartilage.

5. Which hormone stimulates the production of red blood cells?

A. Insulin
B. Erythropoietin
C. Glucagon
D. Thyroxine

Correct answer: B

Rationale: Erythropoietin is the correct answer. It is the hormone responsible for stimulating the production of red blood cells. Erythropoietin is produced by the kidneys in response to low oxygen levels in the blood. This hormone promotes the generation of more red blood cells to increase the blood's oxygen-carrying capacity. Insulin (Choice A), Glucagon (Choice C), and Thyroxine (Choice D) do not stimulate the production of red blood cells. Insulin regulates blood sugar levels, Glucagon increases blood sugar levels, and Thyroxine regulates metabolism.