Science TEAS Practice Test

Correct Answer: C

Rationale: The correct answer is C: Alveoli. Alveoli are tiny sacs in the lungs where gas exchange occurs. Oxygen enters the bloodstream from the alveoli, while carbon dioxide exits the bloodstream to be exhaled. Kidneys (A) filter blood and regulate fluid balance, not involved in gas exchange. Medulla oblongata (B) controls vital functions like breathing and heart rate, but not where gas exchange occurs. Bronchioles (D) are air passages in the lungs, but gas exchange specifically occurs in the alveoli.

Correct Answer: D

Rationale: The correct answer is D: Adipose. Adipose tissue is a type of connective tissue that stores fat, not a type of muscle tissue. Skeletal, smooth, and cardiac tissues are the three main types of muscle tissue. Skeletal muscles are attached to bones, smooth muscles are found in organs and blood vessels, and cardiac muscles are specific to the heart. Adipose tissue does not have the contractile properties of muscle tissue, making it the correct choice.

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.

Correct Answer: A

Rationale: The correct answer is A: Dense bone. Dense bone is not one of the major types of bones in the human body. Long bones, short bones, and irregular bones are the three major types. Long bones are characterized by being longer than they are wide, like the femur. Short bones are cube-shaped, like the carpals in the wrist. Irregular bones have complex shapes and are typically found in the spine and face. Dense bone is not a separate category but rather a classification based on the density of bone tissue. It refers to the outer layer of compact bone found in all bone types. Therefore, A is the correct answer because dense bone is not a distinct major type of bone in the human body.

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.