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11. The retina in the eye contains specialised receptor cells called rods, that can detect light - Scottish Highers Human Biology - Question 11 - 2022
Question 11
11. The retina in the eye contains specialised receptor cells called rods, that can detect light. These are connected to sensory neurons, which carry impulses out of... show full transcript
Worked Solution & Example Answer:11. The retina in the eye contains specialised receptor cells called rods, that can detect light - Scottish Highers Human Biology - Question 11 - 2022
Step 1
Describe the function of sensory neurons.
Answer
Sensory neurons are responsible for carrying impulses from sensory receptors, such as rod cells in the retina, to the central nervous system (CNS), brain, or spinal cord. They play a crucial role in translating external stimuli into signals the brain can understand.
Step 2
Use the diagram to explain why this pathway can be described as a converging neural pathway.
Answer
In the diagram, several rod cells are shown connecting to a single sensory neuron. This illustrates a converging neural pathway because multiple inputs (rod cells) are funneled into a single output (sensory neuron), allowing for the integration of signals from multiple rod cells.
Step 3
Suggest how this converging arrangement of rod cells increases sensitivity to allow vision in dim light.
Answer
The converging arrangement allows for the summation of weak stimuli. When multiple rod cells are stimulated, they collectively release a small number of neurotransmitters, which can amplify the signal. If enough neurotransmitters are released, the sensory neuron can reach the threshold to trigger an impulse, enhancing sensitivity and enabling vision under low light conditions.
Step 4