Involuntary movements in response to stimuli which usually employ circuits local to the spinal cord or in the cranial nerves, though not exclusively.
Questions tagged [reflexes]
31 questions
27
votes
2 answers
Why does looking at bright light trigger sneezing in some people?
Why does looking at bright light trigger sneezing in some people?
Are there any recent studies that have found a cause for this Photic sneeze reflex? The Wikipedia article only references studies pertaining to the effect, stating that the cause is…
luvieere
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12
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3 answers
Do spinal cord reflexes (such as the knee-jerk reflex) continue to function under general anaesthesia?
The knee-jerk reflex (patellar reflex) is an example of a stretch reflex (myotatic reflex). Stretch reflexes are monosynaptic reflexes happening in the spinal cord without involvement of the brain.
Does it mean that this reflex will continue to…
amoeba
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11
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2 answers
Why did humans evolved the scratch reflex?
I've been wondering about this for some time, and I can't come to an answer...
Everybody keeps telling me that scratching one's own skin is bad. It damages the epidermis, creates the hazard of malicious bacteria getting past the skin barrier, and…
gaazkam
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8
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1 answer
In males, why it is difficult to control orgasm?
Why it is difficult to control orgasm in male humans? How are orgasms controlled and what is different between males and females?
We can control urine for few minutes, but we can't control orgasm for more than a few seconds, but both are discharging…
user10246
7
votes
3 answers
Why do we squint when tasting very sour things?
Sometimes while tasting a very sour thing (like tamarind, lemon etc.) our eyes squint immediately and involuntarily for a second, but a little later becomes normal again.
Why, and how, does this reflexive movement occur?
Abdullah
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7
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1 answer
How are reflexes suppressed?
What neurophysiological process keeps reflex arcs in check? For example, the withdrawal reflex causes the hand to jerk back when the fingers touch something painfully hot incidentally. However, that reflex can be voluntarily suppressed when one…
Viv
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7
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Why is the Patellar reflex not triggered when the tendon is extended slowly?
I have been previously told that the Patellar reflex (knee-jerk-reaction) exists to prevent the hyper-extension of the patellar tendon. Yet if the impact to the tendon is delivered slowly - i.e. by pressing down on it rather than striking it -…
Rory M
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6
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Are there neuron mediated reactions faster than reflexes?
I'm interested in how fast the human body can respond to a stimulus. I know the fastest reflex, the blink reflex, operates around 100ms from stimulus to reaction. I also know that the blink reflex is known as the fastest reflex in the human body. …
Cort Ammon
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6
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Can low temperatures induce a withdrawal reflex?
I read in "Essentials of Pathophysiology: Concepts of Altered Health States
By Carol Porth" that
"The thermal pain receptors are stimulated only by extremes of temperature such as "freezing cold" below 5°C and "burning hot" above 45°C."
Also in…
user2419083
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5
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2 answers
Which part of the reflex arc takes the longest time?
The reflex arc is composed of 5 parts:
sensory receptors, afferent neuron(s), synapses within the central integrating station, efferent neuron(s) and the effector (includes transmission across the neuro-muscular junction and contractile mechanism -…
Benzene
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4
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Evolution of scratching
Is scratching (aka the scratching reflex) thought to be inherited from a single vertebrate ancestor or is it something that evolved several times e.g. in birds, mammals etc., i.e. is it a case of convergent evolution?
I suppose this question may be…
Fizz
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4
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Does body mass have a bearing on reflex speed?
A reflex is an unconscious action in response to some specific stimulus, e.g., blinking an eye, or pulling the hand away from a hot pin
I know from school biology, and reading online that withdrawal reflexes are quick because
CNS is involved
Danger…
Everyone
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3
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2 answers
Why do some reflex actions involve interneurons, but some don't?
According to what I know, the reflex arc of knee jerk reflex doesn't involve interneuron, but other reflex action (e.g. removing your hand when touching hot things) do involve interneurons. Why is that the case?
Sharon
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3
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Renorenal Reflex
According to this:
The kidney contains afferent sensory nerve fibers that are located primarily in the renal pelvic wall where they sense stretch.
I think the stretch is due to urine. If I am correct then, I am unable to understand the…
JM97
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3
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Why do eyes close when we sneeze?
It is a behaviour that is very difficult to control. We can't sneeze with eyes open. Is it a reflex of brain to protect the eye from possible injury in sneezing motion or the neural pathway for sneezing is programmed to do so?
YAHB
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