Class 4 Deck 2 (New Material) Flashcards
How is a cell depolarized?
- Na enters cell through open Na channels
- Na carries a positive charge which makes the inside of cell less negative.
Nerve cells make connections with one another in circuits called what?
Neural pathways
2 nerve cells are separated by what?
-Synaptic cleft
What happens to neurotransmitters left in the synaptic cleft?
- Destroyed by MAO or COMT
- Reuptake to presynaptic cell
How many types of neurotransmitters are made by any given neuron?
-Only one
Nerve cells synapse on what type of cells? to do what?
- Effector cells (muscle, glands)
- To evoke or inhibit a response
How are presynaptic neurotransmitters discharged?
-Calcium dependent after depolarization
Acetylcholine is released by what 3 things?
- All preganlionic neurons of ANS
- Post ganglionic parasympathetic neurons
- Somatic motor neurons of skeletal muscle
NorEpi is secreted by what?
Postganlionic neurons of SNS EXCEPT for sweat glands.
Dopamine is secreted by what? and what does it effect?
-Neurons originating on the substantia nigra. (usually effect inhibition)
Glycine is secreted by what? and acts as what?
- CNS
- Acts in inhibition
What is a reflex?
-Rapid, predictable and involuntary responses to stimuli
What is a reflex arc?
-Direct route from sensory neuron to interneuron to an effector.
What can increase neuronal excitability?
-Alkalosis
What can depress neuronal excitability?
- Hypoxemia
- Acidosis
