What is the knee-jerk reflex?
The knee-jerk reflex, also known as the patellar reflex, is a simple reflex that causes the contraction of the quadriceps muscle when the patellar tendon is stretched. I describe the course of the reflex arc from muscle spindles in the quadriceps muscle to motor neurons that cause movement of the leg.
What is an example of a knee-jerk?
You use the phrase ‘Knee Jerk Reaction’ to indicate that you’ve made an automatic response to something. Example of use: “I hauled off and hit him when he jumped out at me. I know he was playing a trick, but it was a knee jerk reaction!”
Why is the knee-jerk reflex important for walking?
The stimulation of the patellar tendon helps us contract and relax the quadriceps and hamstrings, making the reflex important for balance and movement, for example when you walk, accidentally trip, or rock back and forth, since the without the knee-jerk reflex the pull of gravity could make the knee bend, leading us to …
How does the knee-jerk reflex protect the body?
A stretch reflex is a type of muscle reflex, which protects muscle against increases in length that can tear and damage muscle fibers. The primary purpose of the patellar reflex – the stretch reflex of the quadriceps femoris muscle – is to prevent excessive stretching of the quadriceps.
What is a reflex example?
Reflexes protect your body from things that can harm it. For example, if you put your hand on a hot stove, a reflex causes you to immediately remove your hand before a “Hey, this is hot!” message even gets to your brain.
What are the 3 types of reflexes?
There are three common somatic reflexes discussed in most anatomy and physiology courses.
- Stretch (knee-jerk, patellar) reflex.
- Withdrawal (flexor) reflex.
- Crossed-extensor reflex.
What are the 5 reflexes?
Both babies and adults may experience the following types of reflexes:
- Blinking Reflex. This type of reflex happens when the eyes blink due to sudden intense light or when they are touched.
- Cough Reflex.
- Gag Reflex.
- Sneeze Reflex.
- Yawn Reflex.
Is knee jerk somatic or autonomic?
Some examples of reflex arcs include jerking your hand back after accidentally touching a hot pan or an involuntary knee jerk when your doctor taps on your knee. Reflex arcs that impact the organs are called autonomic reflex arcs while those that affect the muscles are referred to as somatic reflex arcs.
What are the three types of reflexes?
What is the function of the knee jerk reflex?
Nerve cells that carry information toward the brain or spinal cord (Afferent neurons)
What is the purpose of the knee jerk reflex?
IMPORTANCE OF REFLEX TESTING
What happens during a knee jerk reflex?
Knee-jerk reflex, also called patellar reflex, sudden kicking movement of the lower leg in response to a sharp tap on the patellar tendon, which lies just below the kneecap. In reaction these muscles contract, and the contraction tends to straighten the leg in a kicking motion.
What nerves is responsible for the knee jerk reflex?
The Achilles’ tendon tests the first and second sacral nerves (S1,S2).