Peripheral Nervous System Flashcards
Common diseases in which drugs function by mimicking or blocking actions of the nervous system
Diseases of the eye
Cardiovascular diseases
Lung diseases
Skeletal muscle paralysis
Central nervous system
Brain and Spinal Cord
Peripheral Nervous System
Sensory pathways (Afferent)
Motor Pathways (Efferent)
Autonomic Nervous System (Sympathetic and Parasympathetic)
Somatic Nervous System
How many neurons are there between the CNS and a skeletal muscle in the Somatic Nervous System
1 (ends at neuromuscular junction)
How many neurons are there between the CNS and visceral organs in the ANS
2 (there is one autonomic ganglia)
How are autonomic nerves characterized as either sympathetic or parasympathetic
Parasympathetic nerves have cell bodies in the cranial and sacral regions while sympathetic nerves originate in the thoracic and lumbar regions
Function of Sympathetic system
Respond to stress
Function of parasympathetic system
Regulates homeostasis of internal mileu
Which system is continuously active and which is organized for discrete local discharge
Sympathetic; parasympathetic
The vagus nerve ________ the heart rate
slows
Which types of potentials use summation in their response to neurotransmitters
EPSPs and IPSPs
Somatic Motor nerves use which neurotransmitter?
Acetylcholine
Preganglionic fibers for parasympathetic and sympathetic systems use which neurotransmitter?
Acetylcholine (Also with postganglionic parasympathetic fibers)
Post ganglionic Sympathetic nerves usually use which neurotransmitters (what is the exception)?
Norepinephrine
Some sweat glands use Ach as the neurotransmitter (Sympathetic cholinergic fiber)
Stimulation of the adrenal medulla causes release of ________ and ______ into the blood stream
Epinephrine and Norepinephrine
Synthesis of Norepinephrine (What is the rate limiting step)?
Tyrosine → 3,4 dihydroxy-phenylalanine (DOPA) → Dopamine → Norepinephrine
Enzymes:
1) Tyrosine hydroxylase (RATE LIMITING STEP)
2) L-aromatic amino acid decarboxylase
3) Dopamine - β-hydroxylase
What additional step to norepinephrine synthesis can create epinephrine?
Norepinephrine → Epinephrine with phenethanolamine-N-methyltransferase
What transports Dopamine into vesicles (storage granules)
VMAT2 (Vesicular monoamine transporter 2)
Reserpine
Inhibits VMAT2
Treats patient with hypertension (Decreases sympathetic system)
How is norepinephrine taken back up into presynaptic terminal
Norepinephrine transporter (NET) Returned to storage granules
What happens to norepinpehrine in the cleft (transporters and percent transported)
90% taken back up into presynaptic terminal (NET)
8% diffuses
2% brought into postsynaptic terminal (Extraneuronal transporter)
Cocaine in NE pathway
Blocks NET and enhances norepinephrine signal
Which receptor on the presynaptic terminal works as an Gαi receptor and causes negative feedback on the NE release system?
α2-adrenoceptor
What two enzymes are involved in the metabolism of norepinephrine (and epinephrine)
Monamine oxidase (MAO-A and MAO-B) - Deamination Catechol-O-methyltransferase (COMT) - Methylation
