Which two body systems are interacting when itching from a skin irritant causes receptors in the skin to send signals to the spinal cord and brain, leading a person to scratch? A) Circulatory and Excretory B) Integumentary and Nervous C) Digestive and Muscular D) Respiratory and Lymphatic

What the question is really describing

You are given a cause-and-effect chain: an irritant touches the skin, receptors detect it, signals travel to the spinal cord and brain, then the person scratches. The task is to match those steps to the body systems involved.

Matching each step to a body system

• Contact with an irritant happens at the skin, which is part of the integumentary system.
• Receptors send signals to the spinal cord and brain using electrical impulses in neurons, which is the nervous system.
• The brain processes the information and helps produce the response (scratching), also coordinated through the nervous system.

Why option B is correct and the others are not

• B (Integumentary and Nervous) fits both the site of the stimulus (skin) and the signal pathway (nerves, spinal cord, brain).
• A (Circulatory and Excretory): blood flow and waste removal are not the main pathway for detecting an irritant and signaling itch.
• C (Digestive and Muscular): muscles can move the hand to scratch, but the scenario focuses on skin receptors and nerve signaling, not digestion.
• D (Respiratory and Lymphatic): breathing and immune fluid transport are not the direct communication route described.

Quick takeaway

Itching from a skin irritant is a sensory stimulus detected by the integumentary system and communicated and processed by the nervous system.