Which of the following is not an effector organ?

Step 1: Analyze the question We need to find the option that is NOT an effector organ.

Step 2: The concept

• Receptors (sense organs) detect stimuli, e.g. the eye (light), ear (sound), nose (smell), tongue (taste), and skin (touch, pain, temperature).
• Effectors carry out the response after the brain or spinal cord processes the information. They are muscles and glands, such as salivary glands, sweat glands, and the muscles of the limbs.

Step 3: Check each option

• A. Tongue: It is a taste receptor, but it also contains muscle that moves food and helps in speech. So it can act as an effector.
• B. Skin: It is mainly a receptor for touch, but it contains sweat glands and erector muscles, which are effectors. So it can act as an effector.
• C. Nose bridge: This is just a bony and cartilage part of the nose. It has no muscle or gland that produces a response, and it is not a sense receptor either. So it is not an effector.
• D. Ear glands: These are the wax-secreting (ceruminous) glands. Glands are effectors.

Step 4: Answer The nose bridge is a structural part only, so it is not an effector organ.

Exam tip: Remember "Effectors = Muscles + Glands." If an option has neither a muscle nor a gland, it is probably not an effector. Also, sense organs such as the skin and tongue often have both receptor and effector parts, so don't let that confuse you.