The nerve roots that exit the spine to form the sciatic nerve are extremely sensitive. When the disc bulges that can easily irritate the nerve. Therefore if the inner portion of the disc becomes too close to the nerve, the nerve may be irritated and become inflamed causing sciatic pain, or sciatica.
Symptoms of sciatica are pain, numbness, tingling and weakness in the leg. The patient's pain and sciatica symptoms can usually be traced to an injured or irritated nerve in the lower back. When the mallet hits your knee, it stretches the tendon just below the kneecap. That causes a signal to travel along a nerve to your spinal cord. There, a waiting motor neuron sends out an automatic command to contract the muscle attached to the tendon. When the muscle contracts, your leg kicks.
Most are located in the spinal cord. But some are in the motor centers of your brain. They work to protect your body from injury. And they also form the basis for more complicated physical activities, such as standing, walking, or riding a bike.
Your brain gets involved by modifying and fine-tuning reflex actions. For example, when you trip and fall, reflexes automatically command your hands and arms to reach out and break your fall. Muscles will contract throughout your body to minimize injury.
Does your blood pressure regularly drop after eating? You may have postprandial hypotension, which can affect systolic blood pressure after meals. The vagus nerve is the longest of the 12 cranial nerves. Here, learn about its anatomy, functions, and the kinds of health problems that can occur.
Muscle twitching refers to small muscle contractions in the body. Learn more about the causes and treatment here. Parosmia is term used to describe health conditions that distort your sense of smell.
If you have parosmia, you may experience a loss of scent…. Health Conditions Discover Plan Connect. Medically reviewed by Seunggu Han, M. What are the symptoms of brisk reflexes? What causes brisk reflexes? How are brisk reflexes diagnosed? How are brisk reflexes treated? Can brisk reflexes cause complications?
David Lewin, Cowley, Oxford As a medical student I was advised to look in patients' eyes if they had absent reflexes. It is accompanied by absent or diminished knee and ankle reflexes, is more common in women than men, and is of absolutely no significance.
Paul Climie, Glasgow, Scotland The questioner must have a kneejerk reflex, to allow him to reflexively respond to events such as jumping and running. When your foot touches the ground under load and your "kneejerk" tendon begins to stretch, the thigh muscles immediately begin to tense to dampen the movement and prevent your bottom touching the floor. Whether a GP can stimulate the reflex to perform with a rubber hammer is a different question.
But this raises the question: why perform the test at all if the absence of the reflex would cause the patient to "fall", rather than walk, into the GP's office? Dr John Horsfall, Bradfield, Reading The kneejerk is one of the fastest and most primitive in the body: it uses only two nerve cells via the spinal cord, and does not use the brain. However, the brain does preset the strength of the reflex. If the questioner interlaces her fingers and strains to pull her hands apart, tapping her knee will elicit a brisk reflex because the brain thinks she is carrying a heavy load and needs extra support if she stumbles.
If the brain or its connections are damaged - for example by a stroke - the reflex will be uncontrolled and grotesquely huge in the knee opposite the damaged side. This is what doctors look for. So the questioner's brain is working fine!
0コメント