Flashcards on Reflexes and Human Eye Anatomy

Reflexes and Human Eye Anatomy: A Student's SEO Guide

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What is a reflex and why are reflexes useful for quick responses?

A reflex is a rapid, involuntary response to a stimulus that doesn't require conscious thought. Reflexes are useful because they provide quicker-than-

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Reflexes and Eye Physiology

9 cards

Card 1

Question: What is a reflex and why are reflexes useful for quick responses?

Answer: A reflex is a rapid, involuntary response to a stimulus that doesn't require conscious thought. Reflexes are useful because they provide quicker-than-

Card 2

Question: Through which parts of the nervous system do reflex neurones pass?

Answer: Reflex neurones go through the spinal cord or through an unconscious part of the brain.

Card 3

Question: List the sequence of neurones and structures in a typical reflex arc starting from receptor to effector.

Answer: Stimulus detected by receptors → impulse along sensory neurone to the CNS → relay neurone in the CNS → motor neurone → effector (e.g., a muscle).

Card 4

Question: What happens when you touch a hot object, according to the reflex arc steps?

Answer: Receptors detect the heat and send an impulse along a sensory neurone to the CNS; a relay neurone passes the message to a motor neurone; the motor neu

Card 5

Question: Which nerve carries impulses from the eye's receptors to the brain?

Answer: The optic nerve carries impulses from the receptors to the brain.

Card 6

Question: Why does very bright light trigger a pupil-size reflex?

Answer: Very bright light can damage the retina, so a reflex makes the pupil smaller to allow less light in and protect the retina.

Card 7

Question: Describe the neurone pathway involved in the iris reflex to bright light.

Answer: Light receptors detect bright light and send a message along a sensory neurone to the brain; the message travels via a relay neurone to a motor neuron

Card 8

Question: What happens to the iris and pupil in dim light?

Answer: In dim light the brain tells the radial muscles to contract, which makes the pupil bigger so more light can enter.

Card 9

Question: What is accommodation in the eye?

Answer: Accommodation is the reflex by which the eye focuses light on the retina by changing the shape of the lens to focus on near or distant objects.