A reflex action often involves a very simple nervous pathway called a reflex arc. A reflex arc starts off with receptors being excited. They then send signals along a sensory neuron to your spinal cord, where the signals are passed on to a motor neuron. As a result, one of your muscles or glands is stimulated.
What part of the nervous system controls your reflexes?
The part of the brain that controls reflexes is the cerebellum. The cerebellum regulates motor reflexes and is also involved in the synchronization of balance and muscles. The brainstem links and transmits messages to the spinal cord from the brain, regulating functions such as respiration, heart rate, and alertness.
What is an example of a reflex in the nervous system?
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 happens in a reflex action?
A reflex action is an automatic (involuntary) and rapid response to a stimulus, which minimises any damage to the body from potentially harmful conditions, such as touching something hot. … A reflex action follows this general sequence and does not involve the conscious part of the brain.
Why are reflexes faster than reactions?
Once activated, the receptors propagate nerve impulses that travel toward the brain along sensory (afferent) nerve tracts. The speed of a reflex is greater than that of a voluntary reaction, due largely to the relative complexity of the neural pathway for a reaction (Fig.
The eye blink reflex elicited by an external stimulus such as a loud noise or flash of light or a tap on the forehead is an involuntary response. It is distinguishable in latency and amplitude from spontaneous blinks and blinks made under voluntary or conscious control.
Why do they hit your knee at the doctor?
To test your reflexes, your doctor will use a rubber hammer to tap firmly on the tendon. If certain reflexes are decreased or absent, it will show what nerve might be compressed. Not all nerve roots have a reflex associated with them.
Is sneezing a reflex action?
Sneezing is a protective reflex, and is sometimes a sign of various medical conditions. … Although sneezing is a protective reflex response, little else is known about it. A sneeze (or sternutation) is expulsion of air from the lungs through the nose and mouth, most commonly caused by the irritation of the nasal mucosa.
What is a reflex action explain with the help of an example?
(a) Reflex action is a rapid and automatic response to a stimulus. It is not under the voluntary control of the brain. For example, if we unknowingly touch a hot plate, we immediately move our hand away from it. (b) The path travelled by an impulse during a reflex action is called a reflex arc.
What happens when you have no reflex actions?
If your doctor taps on a tendon and there isn’t a reflexive movement in the muscle, it’s a sign of a health issue. Usually, absent reflexes are caused by an issue with the nerves in the tendon and muscle. You may have other muscle symptoms along with areflexia, like weakness, twitching, or atrophy.
How does the brain override a reflex?
Reflexes are automatic responses to harmful stimuli around us. These are executed by special pathways involving a sensory and a motor neuron. These reflex arcs bypass the brain and occur mostly in the spinal cord. Due to this, these actions are faster than typical movements and don’t require conscious control.
What executes the response of the reflex?
In a simple reflex, a neuron brings information about a stimulus to the brain or spinal cord and connects with a motor neuron. The motor neuron sends out a message to a muscle. The muscle responds to that message by contracting. … Reflexes allow you to react automatically to a stimulus.
Why does hitting your knee make your leg move?
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.