5.2 The human nervous system

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Question 8

Medium

Many human actions are rapid and automatic, occurring without conscious thought. These are known as reflexes.

Which two of the following actions are examples of reflex actions?

Choosing to walk towards a open door
Blinking when a speck of dust touches the cornea of the eye
Rapidly pulling a foot away after stepping on a sharp pin
Listening carefully to a quiet melody
Deciding to open an umbrella when it starts to rain

[2]

The figure below shows how the size of the pupil of the human eye can change by reflex action from State $Y\,$ to State $X$ .

Diagram showing the front view of two human eyes. In State Y, the pupil is small and constricted. An arrow points to State X, where the pupil is much larger and dilated. The colored ring surrounding the pupil is labeled Structure P.

Name one stimulus that would cause the pupil to change in size from State $Y\,$ to State $X$ .
Structure $P\,$ causes the change in pupil size. Name Structure $P$ .
Describe how Structure $P\,$ causes the change in the size of the pupil from State $Y\,$ to State $X$ .

[4]

A person accidentally touches a hot pan and immediately pulls their hand away in a reflex action.

Describe how the receptor, the three neurones (sensory, relay, and motor), the synapses, and the effector work together to coordinate this reflex response.

[5]

5.2 The human nervous system

Question 8

5.2 The human nervous system Questions

5.2 The human nervous system

Question 8

5.2 The human nervous system Questions