Question:hard
Peripheral chemoreceptors respond to hypoxia using which channel?
Peripheral chemoreceptors respond to hypoxia using which channel?
Show Hint
Hypoxia inhibits an O2-sensitive K+ channel in glomus cells, depolarizing them.
Updated On: Jun 23, 2026
- Calcium channel
- Sodium channel
- Potassium channel
- Chloride channel
Show Solution
The Correct Option is C
Solution and Explanation
Step 1: Locate the sensor. Oxygen levels in the blood are read by the glomus (type I) cells of the carotid body, the front-line peripheral chemoreceptor.
Step 2: These cells keep a set of potassium channels open at rest, letting K+ leak out and holding the membrane stable. A specific O2-sensitive K+ channel is thought to be the actual oxygen detector.
Step 3: When oxygen falls, this K+ channel shuts. With less K+ leaving, the cell depolarises. That voltage change pries open calcium channels, Ca2+ floods in, and the glomus cell dumps neurotransmitter onto the sensory nerve, ramping up firing to the brainstem to boost ventilation.
Step 4: Although calcium entry is the trigger for transmitter release, it is a follow-on step, not the sensor. Sodium and chloride channels play no oxygen-sensing role here. The key channel inhibited by hypoxia is the potassium channel. \[\boxed{\text{Potassium channel}}\]
Step 2: These cells keep a set of potassium channels open at rest, letting K+ leak out and holding the membrane stable. A specific O2-sensitive K+ channel is thought to be the actual oxygen detector.
Step 3: When oxygen falls, this K+ channel shuts. With less K+ leaving, the cell depolarises. That voltage change pries open calcium channels, Ca2+ floods in, and the glomus cell dumps neurotransmitter onto the sensory nerve, ramping up firing to the brainstem to boost ventilation.
Step 4: Although calcium entry is the trigger for transmitter release, it is a follow-on step, not the sensor. Sodium and chloride channels play no oxygen-sensing role here. The key channel inhibited by hypoxia is the potassium channel. \[\boxed{\text{Potassium channel}}\]
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