Study Guide for Neurulation, Action Potential, and more things

Intracellular distribution of ions

• Cations:K+, Na+

• Anions: PO^-3, Proteins and bicarbonate, they’re too big to leave the cell

The inside of the cell is 70 millivolts more negative than the outside, maintained by the cell membrane.

Extracellular distribution of ions

• Cations: Na+, K+

• Anions: Cl-, HCO₃^-

Ion channels involved in action potential

• Na+, K+ pump

• Voltage gated channels: require a certain charge to open and close

• Ligand gated channels: open and close depending on hormones or neurotransmitters.

Steps of action potential

1. Resting: cell is maintaining its voltage

2. Failed initiation: sensory receptor fails to stimulate to -55mV (all or nothing)

3. Action Potential initiated

4. Depolarization: potassium will exit when sodium reaches equilibrium 

5. Peak action potential: Sodium channel is closed, potassium open and pouring out

6. Repolarization: Potassium rushing out

7. Absolute refractory period: limit frequency of action potentials, goes in one direction

Resting millivolts

-70

Threshold millivolts

-55

Maximum action potential millivolts

40

How does myelination increase the speed of an electrical impulse down an axon?

Myelinated neurons allow action potentials to be transmitted faster

Serotonin

excitatory and inhibitory. Well being and happiness

Dopamine

Excitatory and inhibitory. Movement (Internal and external), rewarding

Norepinephrine

Excitatory.  Sympathetic nervous system. Stress hormone.

Acetylcholine

Excitatory and inhibitory. voluntary movement, autonomic nervous system, memory, cognition, attention

Glutamine

Excitatory. memory, learning planning

GABA

Inhibitory. Sedative effects

Glycine

Inhibitory. Control muscle spasms

Substance P

Excitatory. CNS, pain, mood, reaction to stress.

Histamine

Excitatory. Thinking.

What is the difference between an inhibitory or excitatory neurotransmitter?

Excitatory: Increase capacity for a neuron to fire off

Inhibitory: Decrease capacity for a neuron to fire off.

What are the symptoms of Serotonin Syndrome?

• Agitation and restlessness

• Confusion

• Fast heartbeat and high bp

• Diarrhea and vomiting

• Muscle rigidity

• Sweating and shivering

• Fever

• seizures

To which division do the autonomic systems belong?

Peripheral nervous system

Compare the functions and the general characteristics of the sympathetic nervous system

Sympathetic: Agonist- Fight or flight

Parasympathetic: Antagonist-Rest and digest

What is a dermatome and what is its function?

Sections of the skin that are innervated by the cutaneous branch of spinal nerves

Where is the sympathetic nervous system nerves

T1-L2

Where is the parasympathetic nervous System nerves

brain stem or s2-s4