Fig. 1 shows a section of human skin from a fingertip. A researcher compared the response of the fingertip with the response of skin on the upper arm when a...
Question 1 Report
Fig. 1 shows a section of human skin from a fingertip. A researcher compared the response of the fingertip with the response of skin on the upper arm when a person was touched with two fine points.
(a) Name the type of cell labelled sensory neurone in Fig. 1. [1]
(b) Describe the route of an impulse from a touch receptor in the skin until the person becomes aware of the touch. [3]
(c) Explain why fingertips can distinguish two close points more easily than skin on the upper arm. [3]
(d) Use Fig. 1 to explain why damage to a sensory neurone may reduce a person's ability to feel touch. [3]
(e) Draw a simple arrow on Fig. 1 to show the direction an impulse travels along the sensory neurone. [3]
Answer Details
(a) A sensory neurone is a nerve cell, or neurone. [1]
(b) A touch receptor is stimulated and produces an electrical impulse. The impulse travels along a sensory neurone or nerve to the brain. The brain interprets the impulse, making the person aware of touch. [3]
(c) Fingertips have more touch receptors per unit area, so their receptors are closer together. Two close points are more likely to stimulate separate receptors. The brain receives separate impulses and can identify two points rather than one. [3]
(d) A sensory neurone carries impulses from a receptor towards the central nervous system. If it is damaged, impulse transmission may be reduced or stopped. The brain receives less information, so touch may be felt less accurately or not at all. [3]
(e) The arrow must begin at a receptor, follow the sensory neurone, and point away from the receptor towards the central nervous system. [3]
Download The App On Google Playstore
Everything you need to excel in your exams
