Which nerve is responsible for reflexes?

Which nerve is responsible for reflexes?

The somatic nervous system consists of both afferent (sensory) and efferent (motor) nerves [1]. It is also responsible for the reflex arc, which involves the use of interneurons to perform reflexive actions. Besides these, there are thousands of other association nerves in the body.

What are the reflexes controlled by?

A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons do not pass directly into the brain, but synapse in the spinal cord. This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain.

Which part of the brain controls the reflex action?

brain stem
The brain stem, which consists of the medulla (an enlarged portion of the upper spinal cord), pons and midbrain (lower animals have only a medulla). The brain stem controls the reflexes and automatic functions (heart rate, blood pressure), limb movements and visceral functions (digestion, urination).

Is sweating a reflex action?

A reflex action is an automatic (involuntary) neuromuscular action elicited by a defined stimulus. Sweating is not a reflex action.

Why do they hit your knee at the doctor?

What Is a Reflex? The most familiar reflex is the knee jerk, when a healthcare provider taps on the tendon below your knee with a reflex hammer and that leg kicks out. The stimulus (the hammer) results in a signal being sent via a sensory nerve to the spinal cord.

Why are reflexes so fast?

Most reflexes don’t have to travel up to your brain to be processed, which is why they take place so quickly. 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.

Where does reflex action occur in the nervous system?

Reflex action is the result of the coordination of the spinal cord and peripheral nervous system. This action does not involve the brain. The pathway in which impulses travel during the reflex action is called a reflex arc.

How are reflexes produced in the spinal cord?

Passive stretch of a muscle (produced by tapping its tendon) stretches the spindle (intrafusal) fibers. 2. Stretching of a spindle distorts its central (chain) region, which stimulates dendritic endings of sensory nerves. 3. Action potentials are conducted by afferent (sensory) fibers into the spinal cord on the dorsal roots of spinal nerves.

What kind of reflexes are produced in hyper-reflexia?

In marked hyper- reflexia, tension in the muscle alone may produce reflex contraction, and sustained tension can produce repeated jerking movement (clonus), as seen in patellar or ankle clonus ( figure 12a,b ). If the stimulated muscle is weak, the stimulus may produce movement in powerful antagonist muscles ( paradoxical or inverted reflexes ).

How are abdominal reflexes elicited in the body?

Abdominal reflexes are elicited by scratching diagonally across the four quadrants, each normally produces contraction of the underlying muscles ( figure 14b ). The cremasteric reflex is contraction of the cremaster muscle of one side, by scratching the adjacent thigh ( figure 14c ).