Reflexes Flashcards
- What is the role of a receptor?
To detect a stimulus (change in the environment)
What is the role of the sensory neurone?
Transmit electrical impulses from receptors to the CNS
What is the role of the relay neurone (intermediate neurone)?
Transmit electrical impulses between sensory neurones and motor neurones. In some reflex actions there is only 1 relay neurone
What is the role of the motor neurone?
Transmit electrical impulses from the CNS to the effector
Describe the pathway of nervous communication in a voluntary response.
Receptor detects a stimulus, sensory neurones transmit electrical impulses from receptors to the CNS. The CNS processes the information and sends impulses along motor neurones to effectors which respond
. Explain why nervous communication leads to a localised and short-lived response.
Neurotransmitters are secreted directly onto the next cell. The response is shorted lived as neurotransmitters are removed quickly.
Explain why reflexes are involuntary
The pathway of communication goes through the spinal cord, not the conscious part of the brain
What are the advantages of reflexes?
As they are very rapid, do not have to be learnt, protect against damage, enable homeostatic control
What is an effector?
Cells that bring about a response to a stimulus, such as muscle cells or gland cells
What is a response?
The muscle cells contracting causing movement, or glands secreting a hormone
What is the purpose of reflexes?
They bring about responses that maintain posture and protect against harmful stimuli.
