Lecture 3 Flashcards
The Central Nervous System is comprised of the _____ and _____.
Brain
Spinal cord
Th nervous system is broken down into _____ and ______.
Peripheral Nervous System
Central Nervous System
The ____ handles information from a variety of sources and is analogous to the CPU.
Brain
The ______ is the main branch that transmits messages to and from the brain.
Spinal cord
The _____ is comprised of all the nerves “outside” the brain and spinal cord.
Peripheral Nervous System
_____ nerves carry sensory information from parts of the body to the brain for processing.
Afferent
_____ nerves carry impulses away from the brain and spinal cord.
Efferent
Efferent nerves are also known as ____ nerves.
Motor
_____ = at nerves
Afferent
_____ = exits nerves
Efferent
The Peripheral Nervous System is divided into two main divisions:
Autonomic Nervous System
Somatic Nervous System
_____ Nervous System is the involuntary response of the PNS.
Autonomic
The Autonomic Nervous System regulates _____ and _____ systems.
Cardiopulmonary
Digestive
The ANS is further divided into 3 branches:
️Sympathetic
Parasympathetic
Enteric
_____ Nervous System is the voluntary response of the PNS and is under conscious control.
Somatic
Somatic Nervous System controls ______.
Skeletal muscles during voluntary movement
Somatic Nervous System is predominantly ______ control over skeletal muscle activity.
Conscious
_____ Nervous System has one junction where the stimulus travels via a single nerve axon and then travels to a synapse.
Somatic
Describe how nerves move via the Somatic Nervous System.
It is a one junction system that travels via a single nerve axon.
No ganglia
_____ is the neurotransmitter substance found in the somatic system.
Acetylcholine
In the Somatic Nervous System the _____ is the neuromuscular junction.
Synapse
The _____ and ______ coordinate regulation integration of bodily functions and make extensive use of feedback arcs.
ANS
Endocrine System
The ANS and Endocrine System coordinate regulation integration of bodily functions and make extensive use of _______.
Feedback arcs
______ uses electrical impulses and neurotransmitters.
ANS
______ uses hormonal signals.
Endocrine system
The efferent division carries nerve impulses which _____ the CNS.
Exit
The ______ division carries nerve impulses which exit the CNS.
Efferent
After leaving the CNS the efferent nerves proceed to the ____.
Ganglia
______ = clusters of nerve cell bodies lying outside of the CNS.
Ganglia
The first neuron is a _____ or _____ neuron.
Presynaptic
Preganglionic
A ganglion is the _____ that lies outside of the CNS.
Nerve cell
The ganglion journeys from the brain to the ______.
First junction or synapse
The second neuron is the ______ or ______.
Postsynaptic
Post ganglionic
The post-synaptic neuron travels from the ganglia to the _____.
Target site
Neurotransmitter substance at both pre-ganglionic sites is _____.
Acetylcholine
Where is ACh found?
All pre-synaptic
Post-synaptic of parasympathetic.
The neurotransmitter that carries the impulse to the voluntary muscle or gland at the post ganglionic junction of the sympathetic system is ____.
Norepi
Where is the neurotransmitter norepinephrine found?
Post-synaptic junction of sympathetic nervous system
The _____ division is important because its neurons are often involved in reflex signaling arcs.
Afferent
Example of signaling arcs
Carotid bodies
_____ is the semi-autonomous part of the ANS in the GI tract.
Enteric nervous system
Enteric Nervous System is the _____ part of the ANS in the GI tract.
Semi-autonomous
Two components of the Enteric Nervous System
Myenteric Plexus
Submucous Plexus
Neurons of the Enteric Nervous System send ____ input to the parasympathetic and sympathetic nervous systems and receives ____ output from them.
Sensory (input)
Motor (output)
Parasympathetic action on ureters and bladder
Contraction of detrusor (to pee)
Relaxation of trigone and sphincter
Sympathetic action on kidney
Secretion of renin (B1 increases, A1 decreases)
Sympathetic action on male genitalia
Stimulation of ejaculation
Sympathetic action on blood vessels in skin, mucous membranes, and splanchnic area.
Constriction
Parasympathetic action on GI system
Increased motility and tone
Sympathetic action on eye
Pupil dilates (iris radial muscle contracts).
Parasympathetic action on trachea and bronchioles
Constriction
Increased secretions
Sympathetic action on female genitalia
Relaxation of uterus
Sympathetic action on ureters and bladder
Relaxation of detrusor (to not pee)
Contraction of trigone and sphincter
Parasympathetic action on heart
Decreased rate and contractility
Parasympathetic action on eye
Pupil contracts (iris sphincter muscle contracts) Lens accommodates for near vision (ciliary muscle contracts)
Sympathetic action on salivary glands
Thick, viscous secretions
Sympathetic action of trachea and bronchioles
Dilation
Sympathetic action on heart
Increased rate and contractility
Sympathetic action on blood vessels in skeletal muscle
Dilation
Sympathetic action on GI system
Decreased muscle motility and tone
Contraction of sphincter
Parasympathetic action on male genitalia
Stimulation of erection
Sympathetic action of adrenal medulla
Secretion of epi and norepi
Parasympathetic action on salivary glands
Copious, watery secretions
Parasympathetic action on lacrimal glands
Stimulation of tears
What area is sympathetic, but uses the neurotransmitter Ach?
Sweat glands
____ output is diffuse because postganglionic neurons may innervate more than one organ.
Sympathetic
Sympathetic and parasympathetic actions often ____ each other.
Oppose
Site of origin for sympathetic innervation
Thoracic and lumbar region of the spinal cord (thoracolmbar)
Length of parasympathetic fibers
Long preganglionic
Short post postganglionic
The ____ is involved in the ANS by virtue of its position in the center of many ANS reflex arcs.
CNS
____ output is discrete because postganglionic neurons are not branched, but are directed to a specific organ.
Parasympathetic
The ANS can also be affected by the CNS as a result of ________.
Strong feelings or emotions
All ____ neurons are cholinergic, meaning they release Ach.
Preganglionic
Length of sympathetic fibers
Short preganglionic
Long postganglionic
Sites of origin for parasympathetic innervation
Brain and sacral area of spinal cord (craniosacral)
All somatic neurons are _____.
Cholinergic
What 4 places only receive sympathetic stimulation?
Sweat glands
Kidney
Adrenal medulla
Piloerector muscles
Postganglionic parasympathetic neurons are ____.
Cholinergic
Location of ganglia in sympathetic system
Close to spinal cord
Most postganglionic ____ neurons are adrenergic, meaning they release norepi.
Sympathetic
____ preganglionic neurons = cholinergic
All
Where is blood pressure almost exclusively controlled?
SNS
Location of ganglia in parasympathetic system
Within effector organ
Sympathetic preganglionic = ____ neurotransmitter
Acetylcholine
The ___ is a big sympathetic ganglion releasing epinephrine and norepinephrine.
Adrenal medulla
Parasympathetic postganglionic = ____ neurotransmitter
Acetylcholine
Cholinergic neurons can have 2 receptors:
Muscarinic
Nicotinic
Postganglionic ____ neurons are cholinergic.
Parasympathetic
At the highest CNS level, ____ exist involving the most primitive parts of the brain (medulla oblongata and midbrain).
Reflex arcs
____ neurons can have nicotinic or muscarinic receptors.
Cholinergic
Most sympathetic postganglionic = ____ neurotransmitter
Norepinephrine
What is the #1 cardiovascular variable the body seeks to auto-regulate?
MAP
Adrenergic neurons can be further divided into:
Alpha
Beta
Dopaminergic
What happens when a patient is given levophed?
Heart rate and contractile force increase, but the baroreceptors begin to fire causing decreased sympathetic tone and increased parasympathetic which is why there isn’t a sustain rise in heart rate.
Parasympathetic preganglionic = ____ neurotransmitter
Acetylcholine
Where are baroreceptors found?
Aortic arch
Carotid sinus
What is the net effect of levophed?
Increase SVR and decrease heart rate even though it has direct positive chronotropic effects.
If the presynaptic neuron is inhibited by the chemical it produces it is referred to as ______.
Autoreceptor
_____ neurons can have alpha, beta, and dopaminergic receptors.
Adrenergic
The only muscarinic receptors are located at the effector ___ cells of the PNS.
Postganglionic
Muscarinic activation is AKA _____
Parasympathomimetc
6 steps of cholinergic neurotransmission
1) Synthesis of Ach
2) Uptake into storage vesicles
3) Release of neurotransmitter
4) Binding to the receptor
5) Degradation of Ach
6) Recycling of choline
If the presynaptic neuron is inhibited by chemicals that are released by neurons with which it has a synapse (that it doesn’t produce) it is referred to as _____.
Heterotrophic
The only ____ receptors are located at the effector postganglionic cells of the PNS.
Muscarinic
____ receptors are located at the neuromuscular junctions and at the ganglia of the ANS.
Nicotinic
Ach is hydrolyzed rapidly by _____.
Acetylcholinesterase
Choline has to be ____ transported.
Actively
Choline has a strong ____ charge.
Positive
The uptake of choline is the ____ step in the synthesis of ACh.
Rate-limiting
The vesicles containing ACh look like beads on the presynaptic nerve terminal and are referred to as ____.
Varicosities
_____ rushes into the nerve ending causing the vesicle to fuse with the cell membrane which frees the ACh, ATP, and other chemicals into the synaptic cleft.
Calcium
A ____ reaction allows choline to re-penetrate the presynaptic cell membrane.
Sodium-coupled
What does Muscarinic stimulation do?
Consistent with the concept of “Feed and Breed”
____ muscarinic agonists have some nicotinic action.
Most
3 examples of direct acting nicotinic agonists:
Varencline tartrate
Nicotine
Carbachol (miostat)
Future uses of nicotinics?
Alzheimer’s
3 examples of direct acting muscarinic agonists:
Bethanechol (urecholine) [bladder emptying]
Cevimeline (Evoxac) [dry mouth]
Pilocarpine (Salagen) [glaucoma]
____ nicotinic agonists have some muscarinic action.
All
How do indirect-acting reversible cholinergic agonists work?
Reversibly bind to acetylcholinesterase
blocks acetylcholinesterase which prevents the breakdown of ACh and allows levels to build up
Example of indirect-acting reversible cholinergic agonists
Edrophonium
What is an example of Edrophonium being used?
Tensilon testing for the diagnosis of myasthenia gravis
What 3 other drugs are used for treatment of myasthenia gravis?
What type of drugs are these?
Neostigmine
Pyridostigmine
Ambnonium
indirect-acting reversible cholinergic agonists
2 indirect-acting reversible cholinergic agonists used for treatment of glaucoma.
How do they work?
Physostigmine
Demecarium
Opens the drainage angle
____ is a topical organophosphate used for the treatment of glaucoma.
What type of drug is this?
Echothiophate
indirect-acting irreversible cholinergic agonists
____ are bad, bad dudes
organophosphates
7 side effects of organophosphates
Excess salivation Lacrimation Urination Vomiting, defecation, GI cramps Unable to breath Loss of muscular control Death
What can possibly be used to reverse or decrease the effects of indirect-acting irreversible cholinergic agonists?
Pralidoxime (along with atropine)
