what type of joint is found at the elbow

HESI A2

Anatomy HESI A2 Practice Test

1. What type of joint is found at the elbow?

A. Ball and socket
B. Hinge
C. Pivot
D. Saddle

Correct answer: B

Rationale: The correct answer is B: Hinge. A hinge joint, such as the one found at the elbow, allows for movement primarily in one plane, enabling flexion and extension similar to the movement of a door hinge. This joint structure permits bending and straightening of the arm, controlling the range of motion in a specific direction. Choices A, C, and D are incorrect. A ball and socket joint allows for multi-axial movement like the hip joint, a pivot joint allows for rotation around an axis like the joint between the first and second cervical vertebrae, and a saddle joint allows for movement in two planes at right angles to each other like the joint at the base of the thumb.

2. What is the function of hemoglobin in red blood cells?

A. To fight infections
B. To transport oxygen
C. To carry carbon dioxide
D. To store oxygen

Correct answer: B

Rationale: The correct answer is B: 'To transport oxygen.' Hemoglobin in red blood cells plays a crucial role in transporting oxygen. It binds to oxygen in the lungs and carries it to the body's tissues and organs for cellular respiration. Choices A, C, and D are incorrect because hemoglobin's primary function is to bind and transport oxygen, not to fight infections, carry carbon dioxide, or store oxygen.

3. What is the primary function of the lymphatic system?

A. Transport oxygen to cells
B. Remove carbon dioxide from the body
C. Produce hormones
D. Transport nutrients

Correct answer: B

Rationale: The correct answer is B: Remove carbon dioxide from the body. The primary function of the lymphatic system is to return excess tissue fluid to the bloodstream and assist in the body's defense against infections by filtering out harmful pathogens and foreign particles. Choices A, C, and D are incorrect because transporting oxygen to cells is mainly done by the circulatory system, hormone production is primarily carried out by endocrine glands, and nutrient transport is also a function of the circulatory system and the digestive system, not the lymphatic system.

4. Where does primary peristalsis occur?

A. Esophagus
B. Stomach
C. Nervous system
D. Small intestine

Correct answer: A

Rationale: Primary peristalsis occurs in the esophagus. Peristalsis is the coordinated muscular contractions that propel food through the digestive tract. In the esophagus, primary peristalsis is the involuntary wave-like contractions that push food from the mouth to the stomach. It is the natural and automatic process that occurs to facilitate the movement of food during digestion. The stomach (choice B), nervous system (choice C), and small intestine (choice D) are not the primary sites where peristalsis occurs in the digestive system.

5. What is the main function of the respiratory system?

A. To transport nutrients
B. To regulate body temperature
C. To absorb oxygen and remove carbon dioxide
D. To produce energy

Correct answer: C

Rationale: The main function of the respiratory system is to absorb oxygen from the air into the bloodstream and remove carbon dioxide from the body. Oxygen is essential for cellular respiration, the process through which cells generate energy. Carbon dioxide is a waste product expelled during this process. Choice A, 'To transport nutrients,' is incorrect as the respiratory system is not primarily responsible for transporting nutrients. Choice B, 'To regulate body temperature,' is incorrect as the respiratory system's main role is not temperature regulation. Choice D, 'To produce energy,' is incorrect because while oxygen obtained through respiration is used in the energy production process, the respiratory system itself does not directly produce energy.