Nerve Impulses and reflexes

Resting Membrane Potential

Difference in charge across a neuron's membrane; inside is negative compared to outside.

Local Potential

Triggered by stimulation and results in a flow of Na+ into the cell, creating a graded, decremental signal.

Action Potential

A self-propagated signal along the axon; characterized by all-or-nothing response, non-decremental, and irreversible once the threshold is met.

Presynaptic neuron

are neurons originating in CNS to the ganglion (yellow part)

Postsynaptic neuron

from the ganglion to the target organ (heart, eyes, muscle)

Somatic reflex

a reflex induced by stimulation of somatic sensory nerve endings

Somatic reflex

a reflex that innervates skeletal muscles

Somatic reflex

a reflex that contract skeletal muscles

Somatic reflex

a reflex that protects the body from injuries

Visceral reflex

a reflex mediated by autonomic nerves and initiated in the viscera

Visceral reflex

a reflex that is produced by the autonomic nervous system

Visceral reflex

a reflex that innervates soft tissue organs

Visceral reflex

a reflex that is responsible for the contractions of the digestive system and reproductive system, dilation of pupil, defecating and vomiting

Visceral reflex

a reflex that carry out the functions of the internal organs

reflex

an involuntary, predictable motor response to a stimulus without conscious thought.

extracellular fluid

ECF stands for (outside the neuron)

intracellular fluid

ICF stands for (inside the neuron)

facilitated diffusion

a process of high concentration to low concentration

polarized

the outside is positive and the inside is negative, the membrane is polarized or depolarized

depolarized

When Na+ flows into the cell, the membrane become polarized or depolarized

sodium-potassium pump

responsible for reestablishing and maintaining the resting membrane by pumping Na+ out of the cell again through active transport.

the process begins at the dendrite of a neuron

What causes the Na+ channel to open?

Action potential

This potential is not graded, all-or-nothing effect, no decremental, not reversible.

Local potential

a potential that is graded, decremental, reversible, excitatory, inhibitory

Action potential

a potential that flows of electricity along on an axon of a neuron in one direction-from the trigger zone to the synaptic knob

70%

percentage of the energy needed of the sodium-potassium pump

receptor

this reflex detects stimulus.

Afferent Neuron

these reflex carries signal to CNS.

these reflex processes message in brain or spinal cord.

Efferent neuron

a reflex that carries signal away

effector

a reflex where muscles or glands execute the response

Reflex testing

can indicate nerve damage locations.

depolarized

When Na+ flows into the cell, the membrane become polarized or depolarized