which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow

ATI TEAS 7

Mometrix TEAS 7 science practice test

1. Which type of muscle tissue is found in the walls of blood vessels and helps regulate blood flow?

A. Skeletal muscle
B. Smooth muscle
C. Cardiac muscle
D. Striated muscle

Correct answer: B

Rationale: Smooth muscle is the correct answer. It is found in the walls of blood vessels and helps regulate blood flow by contracting and relaxing to adjust the diameter of the vessels. Skeletal muscle, found attached to bones, is responsible for voluntary movements and is not typically found in blood vessel walls. Cardiac muscle is specific to the heart and responsible for pumping blood, not found in blood vessel walls. Striated muscle, another term for skeletal muscle, is characterized by its striped appearance under a microscope but is not present in blood vessel walls.

2. Which of the following statements is true regarding a supersaturated solution?

A. It is unstable and tends to crystallize
B. It contains more solute than it could dissolve
C. It has a higher concentration than a saturated solution
D. It is rarely encountered in everyday solutions

Correct answer: A

Rationale: A supersaturated solution is unstable and tends to crystallize because it contains more solute than it could dissolve at a given temperature. This excess solute is in a metastable state and can precipitate out if disturbed, leading to the formation of crystals. Option B is incorrect because a supersaturated solution does contain more solute than it could normally dissolve, but it becomes unstable due to this excess solute. Option C is incorrect because while a supersaturated solution does have a higher concentration than a saturated solution, the defining characteristic related to its instability is the excess solute. Option D is incorrect as supersaturated solutions can be encountered in various everyday scenarios, such as certain sugar solutions used in cooking or rock candy production.

3. When referring to blood vessel walls, the term 'atherosclerosis' describes:

A. The abnormal buildup of plaque within the arterial walls.
B. The inflammation of the inner lining of blood vessels.
C. The dilation and weakening of a blood vessel wall (aneurysm).
D. The normal process of blood vessel wall thickening with age.

Correct answer: A

Rationale: The correct answer is A: 'The abnormal buildup of plaque within the arterial walls.' Atherosclerosis is the process where plaque, consisting of fat, cholesterol, calcium, and other substances, accumulates within the arteries. This buildup can lead to the hardening and narrowing of arteries, reducing blood flow and potentially causing severe health issues like heart attacks and strokes. Choice B is incorrect because inflammation of the inner lining of blood vessels is known as vasculitis, not atherosclerosis. Choice C is incorrect as it describes an aneurysm, which is a dilation and weakening of a blood vessel wall, not atherosclerosis. Choice D is incorrect as it describes arteriosclerosis, a process of blood vessel wall thickening with age, which is different from atherosclerosis.

4. After exposure to a pathogen, the immune system develops memory. What type of immune cell is responsible for this immunological memory?

A. B cells
B. T cells (specifically memory T cells)
C. Phagocytes
D. Natural killer cells

Correct answer: A

Rationale: B cells are responsible for immunological memory. Memory B cells, a type of B cells, retain a 'memory' of specific pathogens, enabling them to rapidly produce antibodies upon re-exposure. This rapid antibody production facilitates a quicker and more effective immune response. Although memory T cells also contribute to immunological memory by mounting a swift and robust immune response upon re-exposure to the pathogen, it is primarily memory B cells that play a crucial role in producing antibodies. Phagocytes are important immune cells involved in engulfing and digesting pathogens, while natural killer cells are primarily responsible for recognizing and eliminating abnormal cells, such as virus-infected cells or tumor cells. However, when it comes to immunological memory and antibody production, B cells are key players.

5. What is the function of the immune system?

A. To transport oxygen
B. To fight infection
C. To digest food
D. To produce hormones

Correct answer: B

Rationale: The correct answer is B: 'To fight infection.' The immune system's primary function is to protect the body from infections and foreign invaders by recognizing and responding to pathogens. It plays a crucial role in maintaining overall health and preventing diseases caused by harmful microorganisms. Choices A, C, and D are incorrect because the immune system is not responsible for transporting oxygen, digesting food, or producing hormones. These functions are carried out by other systems in the body, such as the respiratory system, digestive system, and endocrine system, respectively.