Question

Rheoreceptors are
A. Thermoreceptors
B. Chemoreceptors
C. Mechanoreceptors
D. Thigmoreceptors

Answer 1

Hint: Receptors are sensory organs. They receive external or internal stimuli and impulses are passed to the nervous system. Sensory nerve fibres connect the receptors with the central nervous system. Based on the type of stimuli receptors receive, they can be classified as mechanoreceptors (respond to mechanical changes), thermoreceptors (respond to temperature), chemoreceptors (respond to chemicals), and photoreceptors (respond to light).

Complete answer:
Rheoreceptors are present in fishes and aquatic amphibians. They are stimulated by water currents. In fish, the lateral line which is considered to be a sense organ is used to detect movement and vibration in the surrounding water. The receptors which are present in the lateral line are referred to as neuromasts. Lateral lines run lengthwise from each side starting from the gill covers to the tail base. They can be seen as faint lines. Modifying epithelial cells called hair cells have helped the lateral lines in achieving sensory ability. The hair cells respond to displacement which may be caused by motion. Then these signals are transduced into electrical impulses via excitatory synapses. Sometimes the lateral lines are modified into electroreceptors that detect electrical impulses. The lateral line thus plays an important role in defense and predatory behavior.
Thus, Rheoreceptors are Mechanoreceptors. Hence, the correct Option is C

Note: Apart from rheoreceptors, there are other types of mechanoreceptors like tangoreceptors, algesireceptors, statoreceptors, and phonoreceptors. Tangoreceptors are responsive to touch and pressure. Algesireceptors respond to pain. Statoreceptors are responsive to acceleration and gravity. Phonoreceptors respond to airborne sound waves.