Chapter 19 A&P 1 – Neuronal Physiology & Neurotransmitters

Vocabulary flashcards summarizing key neuronal physiology concepts and major neurotransmitters from Chapter 19 A&P 1.

Resting Membrane Potential (RMP)

The electrical charge difference across a neuron’s membrane at rest;

• the membrane is polarized.

Intracellular charge in RMP

Approximately –70 mV, making the inside of the cell negative relative to the outside.

Action potential (nerve impulse)

A rapid, self-propagating electrical signal that travels along an axon.

Nerve impulse speed in somatic division

About 280 mph (≈120 m/s) in large, myelinated somatic fibers.

Information carried by action potentials

Transmits sensory input, integration signals, and motor commands.

what element causes the release of neurotrasmitters into synapse cleft?

calcium

If we get hyperpolarization of the post synaptic neuron what happens to it?

It's inhibited and the signal will not go on (it will stop) 

What type of conduction occurs in neurons with a myelin sheath? 

Saltatory (Faster) conduction  

• Without the Myelin Sheath is Continuous and slow

Continuous conduction

Slow impulse propagation along unmyelinated axons with sequential membrane depolarization.

Type of transport for neurotransmitters to cross synaptic cleft

Occurs by passive diffusion from high to low concentration.

Relative refractory period

action potential initiated with a strong stimulus

Parts of a synapse

• synaptic cleft,

• synaptic knob of presynaptic neuron;

• plasma membrane of postsynaptic neuron 

Neurotransmitter receptors

bind to receptors on the Postsynaptic neuron. 

What makes an impulse go faster?

• Myelin sheath.

• large-diameter axon.

Serotonin

thought to be involved in sensory perception, temperature regulation, control of mood, appetite, and induction of sleep. (Amines)

Acetylcholine

Chemical structure-Small molecule neurotransmitters 

• Action is excitatory at neuromuscular junction of skeletal muscle 

• Action is inhibitory at neuromuscular junction of cardiac muscle

Substance P

Neuropeptide.

• enhances the body’s perception of pain 

Enkephalins and Endorphins

(Neuropeptides) provides for body’s supply of opiates; have pain-relieving effects  

Epinephrine and Norepinephrine

play roles in arousal (awakening from deep sleep), dreaming, and regulating mood; norepinephrine is the main neurotransmitter used in autonomic nervous system. (Amines)

Dopamine

active during emotional responses, addictive behaviors, and pleasurable experiences; also helps regulate skeletal muscle tone. (Amines)

Nitric Oxide (NO)

causes widespread vasodilation and muscle relaxation.

Synaptic bulb (knob)

Location

• bulge at end of presynaptic neuron’s axon which contains vesicles which store neurotransmitters