CIE A Level Biology复习笔记15.1.4 Sensory Receptor Cells

Category: A-level课程, 教材笔记, 福利干货 Date: 2022年8月11日上午10:17

A cell that responds to a stimulus is called a receptor cell
Receptor cells are transducers – they convert energy in one form (such as light, heat or sound) into energy in an electrical impulse within a sensory neurone
Receptor cells are often found in sense organs (eg. light receptor cells are found in the eye)
- Some receptors, such as light receptors in the eye and chemoreceptors in the taste buds, are specialised cells that detect a specific type of stimulus and influence the electrical activity of a sensory neurone
- Other receptors, such as some kinds of touch receptors, are just the ends of the sensory neurones themselves
When receptors cells are stimulated they are depolarised
- If the stimulus is very weak, the cells are not sufficiently depolarised and the sensory neurone is not activated to send impulses
- If the stimulus is strong enough, the sensory neurone is activated and transmits impulses to the CNS