Science TEAS Practice Test

Correct Answer: D

Rationale: The correct answer is D: Homeostasis. The endocrine system is responsible for regulating various physiological processes to maintain internal balance, or homeostasis, within the body. Hormones released by endocrine glands help control metabolism, growth, reproduction, and other functions. Choice A (Heartbeat) is controlled by the cardiovascular system, not the endocrine system. Choice B (Respiration) is controlled by the respiratory system. Choice C (Electrolyte and water balance) is regulated by the kidneys and not directly by the endocrine system. Thus, the primary function of the endocrine system is to maintain homeostasis through hormone regulation.

Correct Answer: C

Rationale: The correct answer is C: Epidermis. The epidermis is the outermost layer of the skin and is avascular, meaning it does not contain blood vessels. This is important for maintaining its protective function and preventing blood loss in case of injury. The hypodermis (A) contains blood vessels that supply the skin with nutrients and regulate temperature. The dermis (B) is rich in blood vessels, providing nourishment to the skin and regulating temperature. Option D (Hyperdermis) is not a recognized layer of the skin, making it an incorrect choice.

Correct Answer: B

Rationale: The correct answer is B: Tendons. Tendons are fibrous connective tissues that attach muscle to bone, allowing for movement. Ligaments (A) connect bone to bone, muscles (C) are the tissues responsible for movement, and bones (D) are the rigid structures that make up the skeletal system. Tendons play a crucial role in transmitting the force generated by muscles to move bones, making them the correct choice in this scenario.

Correct Answer: A

Rationale: The correct answer is A: The sinoatrial node. The SA node is known as the heart's natural pacemaker as it initiates electrical impulses that regulate the heart rate. It is located in the right atrium and generates rhythmic electrical signals that stimulate the cardiac muscle to contract. The left ventricle (B), aorta (C), and tricuspid valve (D) do not serve as electrical stimulators of the cardiac muscle. The left ventricle is a chamber that pumps oxygenated blood, the aorta is the largest artery that carries blood away from the heart, and the tricuspid valve controls blood flow between the right atrium and right ventricle.

Correct Answer: D

Rationale: The correct answer is D because the ulna, fibula, and humerus are classified as long bones. Long bones are characterized by their elongated shape, with a shaft and two distinct ends. The ulna and humerus are long bones of the upper extremities, while the fibula is a long bone of the lower extremity. A, the sacrum, is a triangular bone at the base of the spine and is classified as a flat bone. B, the clavicle, is also a flat bone that connects the sternum to the scapula. C, the patella, is a sesamoid bone located in the knee joint and is not classified as a long bone. Therefore, the correct answer is D, as the ulna, fibula, and humerus are examples of long bones based on their structure and function.