Efferent pathways carry signals away from the central nervous system. Essentially, they are signals that your brain sends to tell your body to do something, like blinking. Afferent signals come from outside stimuli and tell your brain what they are sensing, such as temperature. Afferent neurons bring stimuli to the brain, where the signal is integrated and processed. The brain then coordinates a response via efferent signals back to the rest of the body.

The ventral root of the spinal cord is located anteriorly, while the dorsal root is located posteriorly. Afferent neurons enter the spinal cord through the dorsal root, carrying signals from the body to the brain. Efferent neurons exit the spinal cord from the ventral root before interfacing with their target muscles.

The typical response pattern is that a sensory afferent neuron receives the external stimulus and communicates with an interneuron. The information is then interpreted, and a response is sent through efferent motor neurons to the appropriate portion of the body. Afferent neurons communicate information from the stimulus to the brain/spinal cord. Efferent neurons communicate information from the brain/spinal cord to the appropriate portion of the body.

Afferent neurons are sensory neurons that carry nerve impulses from sensory stimuli towards the central nervous system and brain, while efferent neurons are motor neurons that carry neural impulses away from the central nervous systme and towards muscles to cause movement.

In this case, the afferent neuron would carry sensory information from your hand to your brain, letting it know your body is touching something hot. Your brain would then process this information and use efferent neurons to tell the arm muscle to contract and move your hand away.

A good way to remember afferent vs. efferent neurons is: Afferent Arrives, Efferent Exits.

Afferent neurons are neurons whose axons travel towards (or bringing information to) a central point, while an efferent neuron is a cell that sends an axon (or carries information) away from a central point. For example, if the central point in question is the brain, sensory neurons are afferent because they send information to the brain, while motor neurons are efferent because they carry information from the brain to effector organs like muscles or glands. It is crucial to keep in mind exactly which structure is the current focus of the discussion, since the terms "afferent" and "efferent" are relative to the direction of information transmission.

Monosynaptic reflexes do not require a neuron between the pre-synaptic and post-synaptic neuron, and do not require input from the brain. These reflexes can be triggered even in brain-dead individuals. The knee-jerk reflex is an example of a monosynaptic reflex.

The accommodation reflex is used to adjust the focus of the eye. The acoustic reflex reduces sound intensity by adjusting the bones of the middle ear. The suckling reflex is the complicated reflex of an infant mammal being able to breast feed. Somatic reflexes are a broad category simply involving muscle reflexes. Some of these reflexes involve input from the brain, while others (like the knee-jerk reflex) do not.

The sympathetic nervous system is activated during times of stress, and is responsible for initiating the "fight or flight" response. Part of this response in an increase in heart rate, allowing better conduction of blood and delivery of oxygen throughout the body.

The other answer options are effects of parasympathetic stimulation, which allows for rest. During this time, the body stores energy from glucose into glycogen, and allows for digestion and reproduction.

By pumping two positively-charged potassium molecules in for every three positively-charged sodium molecules that are pumped out of the cell, the sodium-potassium pump maintains a resting potential of –70mV relative to outside of the cell. This function is important for creating an electrochemical gradient along the neuron.

Remember that sodium flows down its gradient to enter the cell during depolarization, while potassium flows down its gradient to exit a cell after an action potential, causing hyperpolarization during the refractory period.

After the sodium channel is opened, sodium rushes into the cell down its concentration gradient (as previously created by the sodium-potassium pump). This causes depolarization of the membrane as its potential reaches a value of +35mV, which is eventually lowered by the opening of the potassium channels. This leads to hyperpolarization, which prevents the signal from traveling backwards.

The refractory period, a phase in which action potentials cannot be fired, is the result of hyperpolarization, during which the membrane potential drops below –70mV. The membrane potential is at this –70mV level while the threshold, which needs to be reached to fire action potential, is slightly higher at –50mV. During the period of extreme hyperpolarization, an action potential will not form.