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Reflexes and Eye Anatomy Review
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Reflexes and Eye Anatomy Review
Reflexes and Eye Anatomy Review
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1
Question
What is a reflex action?
Answer
An automatic response to a stimulus.
2
Question
What is a reflex arc?
Answer
Nervous pathway for reflex actions.
3
Question
What is a stimulus?
Answer
A change in the environment of an organism.
4
Question
Do you need to think to initiate a reflex?
Answer
No; reflexes occur without thought.
5
Question
What triggers the knee-jerk reflex?
Answer
Tapping the tendon below the kneecap.
6
Question
What happens in the knee-jerk reflex when the tendon is tapped?
Answer
Thigh muscle contracts and lower leg swings forward.
7
Question
Where does the sensory impulse travel after a receptor is stimulated in a reflex?
Answer
To the spinal cord via a sensory fibre.
8
Question
How many synapses does the simplest reflex arc have?
Answer
One synapse.
9
Question
What is the effector in a reflex arc like the knee-jerk reflex?
Answer
A muscle (thigh muscle).
10
Question
Can you consciously stop a reflex action once it starts?
Answer
No; it cannot be stopped.
11
Question
What detects stretch in a reflex arc?
Answer
A stretch receptor in the stretched muscle.
12
Question
Where does the sensory impulse cross a synapse in a simple reflex arc?
Answer
In the spinal cord.
13
Question
What is the role of motor neurons in the reflex arc?
Answer
Carry impulses to the effector muscle.
14
Question
What is the sequence of events in the simplest reflex arc?
Answer
Stimulus → receptor → sensory neuron → spinal cord → motor neuron → effector → response.
15
Question
What is the knee-jerk reflex an example of?
Answer
A spinal reflex.
16
Question
What organ is stimulated in a reflex to cause pupil constriction?
Answer
The iris muscle.
17
Question
What type of input travels to the brain during a reflex like blinking?
Answer
Sensory impulses from receptors.
18
Question
Where are light-sensitive cells located that trigger the blink reflex?
Answer
In the retina.
19
Question
What is the function of the optic nerve in reflexes involving the eye?
Answer
Transmits sensory impulses to the brain.
20
Question
What does the iris determine in the eye?
Answer
The colour of the eye.
21
Question
What is the role of the choroid layer?
Answer
Contains blood vessels; forms iris and ciliary body.
22
Question
Where is vitreous humour located and what is its state?
Answer
Behind the lens; jelly-like fluid.
23
Question
What produces the aqueous humour in front of the lens?
Answer
The ciliary body.
24
Question
What is the function of the tear fluid?
Answer
Keep surface moist and wash away dust.
25
Question
What enzyme is present in tear fluid?
Answer
Lysozyme.
26
Question
What is the sclera?
Answer
The tough, white outer coating of the eye.
27
Question
What is the cornea?
Answer
Transparent front part of the sclera that allows light in.
28
Question
What is the conjunctiva?
Answer
Thin epithelium lining eyelids and sclera.
29
Question
What part of the eye changes shape to focus light?
Answer
The lens.
30
Question
What is the suspensory ligament’s role?
Answer
Holds the lens in place.