Rated A+
Electrical Synapses ANS - Fast (cells share cytoplasm)
- Can be bidirectional
Chemical Synapses ANS - Cells are separated by the synaptic cleft
- Chemical (Neurotransmitter)
- Can be excitatiory or inhibitory
- Mostly unidirectional
How does the neurotransmitter get out of the presynaptic neuron? ANS Calcium signal
Receptor-channels ANS "ionotropic receptors"
-Mediate rapid, short lasting responses
-Alter ion flow across membranes
Metabotropic recpetors ANS - G protein-mediated receptors
- Mediate slower, longer lasting responses
- Some open or close ion channels
What are the two types of autonomic neurons? ANS -Sympathetic
-Parasympathetic
Somatic motor neurons ANS -Control skeletal or striated muscles
-Often voluntary
-Single neuron CNS-skeletal muscle cell
-Can only excite muscle cells
Autonomic neurons ANS -Control smooth and cardiac muscle
, -Mostly involuntary
-Two neuron chain CNS-effector organ
-Can be excitatory or inhibatory
-More diversity in neurotransmitter receptors
-Response is extremely diverse
Parasympathetic control ANS "Rest and digest"
-Promotes digestion (GI peristalsis)
-Slows heart rate
-Constricts pupils
-Empties bladder
-Relaxes sphincters
-mediates genital erection
Sympathetic control ANS "Fight or flight"
-Increase heart rate
-Increases sweating
-dilates pupils
-inhibits GI movement
-Closes sphincters
-Diverts blood from the skin and GI tract to skeletal muscles.
Antagonistic control ANS Opposing inputs regulate parameter (variable) in opposite directions.
(sympathetic and parasympathetic).
Which pathway has the shortest preganglionic neuron? ANS Sympathetic pathway
Which branch triggers a body-wide response (as opposed to regulation of specific organs)? ANS
Sympathetic division (parasympathetic is more specific).
Autonomic targets: ANS -Smooth and cardiac muscles