What are muscle contractions that normally move food along the human digestive system known as?

Correct Answer: C

Rationale: Muscle contractions that move food along the human digestive system are known as peristalsis. Peristalsis consists of a series of coordinated muscular contractions and relaxations that help propel food through the esophagus, stomach, and intestines, facilitating efficient digestion and nutrient absorption. Defecation refers to expelling waste from the body, osmosis is the movement of water across a membrane, and circulation relates to the movement of blood in the body's circulatory system, not directly involved in food transportation along the digestive tract.

Correct Answer: B

Rationale: Schwann cells are a type of neuroglia found in the peripheral nervous system. They are responsible for producing the myelin sheath around axons of neurons, which helps with the conduction of nerve impulses. Therefore, Schwann cells are typically found in the nervous system. Choices A, C, and D are incorrect because Schwann cells are specifically associated with the nervous system and are not found in the digestive, skeletal, or muscular systems.

Correct Answer: B

Rationale: The correct answer is B because the nervous system communicates with the muscular system to control voluntary and involuntary muscle movements. The nervous system sends signals to the muscles, instructing them on how to respond to various stimuli in the environment. This communication allows for coordinated movement and responses to external and internal changes. Choice A is incorrect because muscles do not produce chemicals to feed the nerves. Choice C is incorrect because the nervous system does not release chemicals to remove waste from the muscles. Choice D is incorrect because the muscular system does not provide input for the nerves to make decisions.

Correct Answer: A

Rationale: The correct answer is A: Somatic. The femoral, radial, and ulnar nerves are all part of the somatic nervous system, responsible for controlling voluntary movements and sensory input. These nerves innervate muscles and skin throughout the body, allowing conscious control of movements and sensations. The somatic nervous system is distinct from the autonomic nervous system, which regulates involuntary bodily functions. Choices B, C, and D are incorrect because the autonomic nervous system (B) is responsible for involuntary functions, while the sympathetic (C) and parasympathetic (D) divisions are subdivisions of the autonomic nervous system, not the somatic nervous system.

Correct Answer: C

Rationale: A herniated lumbar disc is most likely to cause pain along the sciatic nerve. The sciatic nerve is a long nerve that extends from the lower back down the back of each leg. Compression of the sciatic nerve by a herniated disc can lead to symptoms such as pain, numbness, tingling, or weakness that radiates down the leg. This condition is commonly referred to as sciatica. Choices A, B, and D are incorrect because a herniated lumbar disc typically affects the sciatic nerve, not the radial nerve, spinal cord, or tibial nerve.