coronary arteries are responsible for

ATI TEAS 7

TEAS Test 7 science

1. What is the primary function of coronary arteries?

A. Delivering oxygenated blood throughout the body.
B. Supplying oxygenated blood to the heart muscle itself.
C. Carrying deoxygenated blood back to the heart.
D. Regulating blood pressure through vasoconstriction and vasodilation.

Correct answer: B

Rationale: The primary function of coronary arteries is to supply oxygenated blood to the heart muscle itself. The heart is a muscle that needs a constant supply of oxygen and nutrients to function properly. Coronary arteries branch off the aorta and specifically deliver oxygenated blood to the heart muscle, ensuring its proper function. Choice A is incorrect because coronary arteries do not deliver blood throughout the entire body but specifically to the heart. Choice C is incorrect as coronary arteries carry oxygenated blood away from the heart. Choice D is incorrect as the primary function of the coronary arteries is not to regulate blood pressure but rather to provide oxygenated blood to the heart muscle.

2. What is the primary function of the heart?

A. Filtering blood
B. Exchanging gases
C. Pumping blood throughout the body
D. Producing hormones

Correct answer: C

Rationale: The main function of the heart is to pump blood throughout the body. The heart acts as a muscular pump that circulates blood, delivering oxygen and nutrients to the body's tissues and removing waste products. Option A is incorrect because blood filtration is a function of the kidneys, not the heart. Option B is incorrect as gas exchange occurs in the lungs, not the heart. Option D is also incorrect as hormone production is mainly carried out by endocrine glands, not the heart.

3. In nuclear physics, the term 'barn' is a unit commonly used to quantify:

A. Energy
B. Radioactivity
C. Nuclear cross-section
D. Half-life

Correct answer: C

Rationale: In nuclear physics, the term 'barn' is a unit used to quantify nuclear cross-section. Nuclear cross-section is a measure of the probability of a nuclear reaction occurring when an atomic nucleus interacts with a particle or another nucleus. The barn is a unit of area equal to 10^-28 square meters; it is commonly used to describe the cross-sectional area of atomic nuclei for nuclear reactions. Choice A, 'Energy,' is incorrect because a barn is not a unit for measuring energy; it is a unit of area. Choice B, 'Radioactivity,' is incorrect as radioactivity is typically measured in units like becquerels. Choice D, 'Half-life,' is also incorrect as half-life is a measure of the time it takes for half of a substance to decay, not related to the concept of a barn as a unit of nuclear cross-section.

4. Which of the following best describes eosinophils?

A. A type of granulocyte that secretes histamine to stimulate the inflammatory response.
B. The most abundant type of white blood cell that secretes substances toxic to pathogens.
C. A type of granulocyte found under mucous membranes that defends against multicellular parasites.
D. A circulating granulocyte with high phagocytic activity and aggressiveness.

Correct answer: C

Rationale: Eosinophils are best described as a type of granulocyte found under mucous membranes that defends against multicellular parasites. They release toxic substances to combat parasitic infections and play a significant role in allergic reactions and asthma. Histamine secretion to stimulate inflammation is more characteristic of basophils, while high phagocytic activity and aggressiveness are features of neutrophils, not eosinophils. Describing eosinophils as the most abundant type of white blood cell that secretes toxic substances to pathogens is inaccurate since eosinophils specifically target multicellular parasites, not a broad range of pathogens.

5. From an anterior view, which of the following vessels carries blood away from the heart?

A. Left common carotid artery
B. Pulmonary trunk
C. Subclavian arteries
D. All of the above

Correct answer: D

Rationale: The correct answer is D, 'All of the above.' When viewed from an anterior perspective, the left common carotid artery, pulmonary trunk, and subclavian arteries all carry blood away from the heart. The left common carotid artery supplies oxygenated blood to the head and neck, the pulmonary trunk carries deoxygenated blood to the lungs for oxygenation, and the subclavian arteries transport blood to the upper extremities. Therefore, all the vessels listed in the choices are correct as they function to carry blood away from the heart when viewed anteriorly.