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. When an individual is under stress, hormones are released. Which of the following is not one of the locations where hormones are released when under stress?

A. Parathyroid gland
B. Adrenal cortex
C. Posterior pituitary
D. Hypothalamus

Correct answer: A

Rationale: The parathyroid gland is not a location where hormones are typically released during stress. It primarily regulates calcium levels in the blood through the release of parathyroid hormone (PTH). On the other hand, the adrenal cortex releases hormones like cortisol in response to stress, the posterior pituitary releases oxytocin and antidiuretic hormone, and the hypothalamus plays a crucial role in coordinating stress responses through the release of corticotropin-releasing hormone (CRH). Therefore, the parathyroid gland is the correct answer as it is not directly involved in the stress response pathway.

3. Which organ is involved in the immune system?

A. Heart
B. Bronchi
C. Appendix
D. Esophagus

Correct answer: C

Rationale: The correct answer is the Appendix. The appendix is now known to play a role in the immune system by housing beneficial bacteria that aid in maintaining gut health and supporting immune responses. This organ contributes to overall immune function. Choices A, B, and D are incorrect as the heart, bronchi, and esophagus are not primarily associated with the immune system.

4. Which bone does not articulate with any other bone?

A. Femur
B. Hyoid
C. Radius
D. Tibia

Correct answer: B

Rationale: The correct answer is the Hyoid bone. The hyoid bone is distinctive as it does not directly articulate with any other bone in the body. Instead, it is held in place by muscles and ligaments, playing a crucial role in supporting the tongue and providing attachment points for various muscles involved in swallowing and speech. The other choices, Femur, Radius, and Tibia, all articulate with other bones in the body. The femur articulates with the hip bone, the radius articulates with the ulna and other bones in the wrist, and the tibia articulates with the femur and fibula.

5. What is a primary function of the skeletal system?

A. Production of red blood cells
B. Support and protection
C. Secretion of hormones
D. Regulation of body temperature

Correct answer: B

Rationale: The correct answer is B: Support and protection. The primary functions of the skeletal system include providing structural support to the body and protecting internal organs. While the skeletal system also plays a role in hematopoiesis (production of blood cells) and stores minerals, its main function is to support the body's framework and protect vital organs. Choices A, C, and D are incorrect as they do not directly relate to the primary functions of the skeletal system.