which of the following describes the primary function of the pyloric sphincter

ATI TEAS 7

TEAS 7 Science Practice Test

1. What is the primary function of the pyloric sphincter?

A. to regulate the movement of food material from the stomach to the duodenum
B. to neutralize stomach acid
C. to prevent digested food materials and stomach acid from entering the esophagus
D. to begin the process of chemical digestion

Correct answer: A

Rationale: The primary function of the pyloric sphincter is to regulate the flow of partially digested food material (chyme) from the stomach into the small intestine, specifically the duodenum. This control is essential for proper digestion and absorption of nutrients in the small intestine. Choices B, C, and D are incorrect. Choice B is incorrect because neutralizing stomach acid is primarily the function of the stomach lining and antacid mechanisms. Choice C is incorrect because preventing the backflow of digested food materials and stomach acid into the esophagus is mainly the role of the lower esophageal sphincter. Choice D is incorrect because the chemical digestion process primarily starts in the stomach through the action of gastric juices, not the pyloric sphincter.

2. What is the role of platelets in the blood?

A. Transport oxygen
B. Fight infection
C. Produce antibodies
D. Clot blood

Correct answer: D

Rationale: Platelets play a crucial role in blood clotting by forming clots to help stop bleeding. While red blood cells transport oxygen, white blood cells fight infection, and immune cells produce antibodies, platelets specifically function to prevent excessive bleeding by forming clots. Therefore, the correct answer is D. Choices A, B, and C are incorrect as they describe functions of other components of the blood, not platelets.

3. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

A. To initiate nerve impulses
B. To transmit sensory information
C. To speed up the transmission of nerve impulses
D. To connect neurons at synapses

Correct answer: C

Rationale: The primary function of the myelin sheath is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer around the axon, allowing for faster conduction of electrical impulses along the nerve fiber. This insulation prevents the electrical signal from dissipating or 'leaking' out, which helps in the rapid and efficient transmission of nerve impulses along the axon. Choice A is incorrect because the myelin sheath does not initiate nerve impulses; it helps in conducting them. Choice B is incorrect as the myelin sheath's main role is not in transmitting sensory information but rather in facilitating the transmission of nerve impulses. Choice D is incorrect because the myelin sheath's function is not to connect neurons at synapses; instead, it is primarily involved in enhancing the speed of nerve impulse transmission.

4. A dietitian wants to convince a patient to lose weight. Which statement below best communicates a scientific argument that justifies the need for weight loss?

A. Losing weight can lower blood pressure, increase energy levels, and promote overall health.
B. Society tends to treat overweight people unfairly.
C. Members of the opposite sex are more interested in people who maintain a healthy weight.
D. Losing weight is easy to do.

Correct answer: A

Rationale: Choice A is the correct answer as it provides a scientific argument supported by evidence. Losing weight has been shown to lower blood pressure, increase energy levels, and promote overall health. These are concrete health benefits that can be objectively measured and monitored. Choices B and C do not offer scientific justifications for weight loss but rather focus on societal perceptions and personal relationships. Choice D is incorrect as losing weight is not always easy and may require significant effort and lifestyle changes.

5. What is the scientific name for the kneecap?

A. Patella
B. Femur
C. Tibia
D. Fibula

Correct answer: A

Rationale: The correct answer is A: Patella. The patella is the scientific term for the kneecap, a small, flat, triangular bone situated in front of the knee joint. The femur, tibia, and fibula are also bones in the leg, but they are not synonymous with the kneecap. The femur is the thigh bone, the tibia is the shin bone, and the fibula is the outer lower leg bone. Therefore, the correct term for the kneecap specifically is the patella.