Why does Doctor Uncle tap his knee with a small hammer? Let's talk about these 'reflexes'!

Have you ever seen a doctor tap your knee gently with a little rubber mallet? When you tap it like that, your leg automatically goes up, right? It's not something you think about, it just happens. That's what we call a 'reflex'. This is really an amazing thing in our body. Let's talk about this a little more in detail today, as if we were talking to a friend.

What exactly is a 'reflex'?

Simply put, a 'reflex' is a response that your body makes to a stimulus (such as an external stimulus, sound, or touch) without your control, without you even thinking about it. It's not something you do thinking, 'I need to lift my leg now.' It just happens. Strictly speaking, it's a very fast, automatic process in our nervous system.

Imagine, if you accidentally touch something hot, your hand automatically moves away before your brain even realizes, "Oh, this is hot!" That's also a reflex. Things like this are very important for our body's safety.

Do we all have these 'reflexes'?

Yes, every healthy person has these reflexes. The amazing thing is, we are born with many reflexes. If you look at a small baby, you will understand this very well.

• For example, if you gently tap a baby's cheek with your finger, the baby will turn its head in that direction and move its mouth as if to suck milk. This is called the 'rooting reflex'.
• Another thing is, if you put your finger on a baby's hand, the baby will hold it tightly. That's also something that happens automatically.

Many of these responses are ingrained in us from early on in life. Some of them disappear as we grow older, while others remain throughout our lives.

Why are these 'reflexes' so important to us? - Safety comes first!

Most of the time, these reflexes are designed to protect our bodies from danger. They are like little guards inside our bodies.

• Removing your hand from something hot: As I mentioned before, if you accidentally touch a hot ember or a hot pan, you will automatically remove your hand before you even think, "This is hot." This happens in less than a second. This saves your hand from getting burned.
• Blinking when something comes into your eye: If you suddenly feel something coming into your eye, you blink without even thinking, right? This stops things like dust and insects from entering your eye.
• Coughing and sneezing: These are also two very important protective reflexes. If something harmful gets into our respiratory tract, for example, if some food gets stuck or something like dust gets in, we cough it out. The same goes for sneezing. If something like germs or pollen gets in our nose, we sneeze to quickly expel it and clean the nose.
• Reaching out when about to fall: Sometimes when we slip and fall, we instinctively reach out and grab the ground. This also helps to protect vital parts like our head from hitting the ground.

It is because of protective reflexes like these that we are unknowingly saved from many dangers.

What does the doctor mean by tapping his knee? - That 'knee-jerk'!

Okay, now let's get back to that knee tapping thing I mentioned earlier. What the doctor is doing by tapping your knee with that little rubber mallet is what's called the 'Patellar Reflex'. This is also called the 'Knee-jerk reflex'. This is actually a type of 'Deep Tendon Reflex' (DTR) .

Now let's see how this goes.

1. The doctor gently taps a special tendon called the Patellar Tendon, located just below the kneecap. A tendon is a strong tissue that connects muscles to bones.

2. When you tap like this, that tendon and the large muscle in the thigh area (quadriceps muscle) that is connected to it suddenly stretch slightly.

3. The message that the muscle has been pulled travels very quickly along the nerves to our spinal cord. The spinal cord is the main nerve cord that runs through our spine.

4. Once the spinal cord receives this message, it sends another very fast message back to that thigh muscle, telling it to "contract."

5. When that muscle suddenly contracts, our leg automatically jumps up.

This all happens in the blink of an eye! You don't even have time to think.

Why is this 'DTR' or deep tendon reflex important to us?

You might be wondering, "Why do we have something like this that goes above the knee?" Deep tendon reflexes (DTRs) like these are very important to us.

• Maintain your balance: Imagine that when you are standing, if you lean forward a little, your knees might bend just a little. If that happens, you might fall, right? At that moment, the knee-jerk reflex kicks in, straightening your knees and helping you avoid falling. This happens unconsciously.
• Check the functioning of the nervous system: Doctors check reflexes like these to see if our nervous system – that is, the brain, spinal cord, and other nerves – is working properly. When these reflexes are working properly, it means that there are no obstructions in the nerve pathways that carry those messages and that they are healthy.

Is this the only way to check the knee?

No. Doctors test these deep tendon reflexes (DTRs) in several other places besides the knee.

• Triceps reflex
• Biceps and Brachioradialis reflexes
• The wrist is right.
• Ankle jerk reflex

A doctor can get an idea of ​​the different levels of the nervous system from the reflexes present everywhere.

What if there is any difference in these 'reflexes'?

Sometimes these reflexes can be too brisk, diminished, or absent altogether . If there are such changes, it can give a doctor a clue about a problem with the nervous system, perhaps a neurological disorder, a vitamin deficiency, or another medical condition.

For example, when certain nerves are damaged, the reflexes associated with the level of damage may be weakened or lost. Similarly, problems in the upper parts of the brain or spinal cord may cause some reflexes to be activated more strongly or rapidly than they should be.

That's why a doctor will pay attention to these reflexes when examining you. They can tell him a lot of important information about your overall health.

Let's look at some more examples of 'reflexes' in everyday life.

In addition to the ones we've talked about, our bodies have many other reflexes.

• The pupil in your eye constricts when exposed to light: When you suddenly go from a sunny place to a dark room, or when you suddenly come out of a dark room, the pupil in your eye constricts, doesn't it? When there is too much light, it constricts and controls the amount of light that enters the eye. In the dark, it enlarges and lets in more light. This is also a 'reflex' to protect the eye.
• Swallowing reflex: When we put food in our mouths, swallowing it is a largely automatic process.
• Gag reflex: When something hits the back of the throat, we feel nauseous, right? It stops harmful substances from going down the throat. Some people may feel this very well when brushing their teeth.
• Shivering: When we get cold, our bodies shiver, right? That's also a reflex to generate heat. Heat is generated when muscles contract and relax rapidly.

When you think about things like this, you realize how wonderfully designed our bodies are, don't you?