Chapter 2: Neurophysiology Flashcards
What three things does the ANS innervate
Smooth Muscle, Glands and Cardiac Muscle
What three things does the ANS innervate
Smooth Muscle, Glands and Cardiac Muscle
What does the somatic NS innervate ?
Skeletal muscle
What are the three division of the ANS ?
Sym., Parasympathetic and Enteric
Where are the autonomic ganglia for Parasympathetic nerves ?
Near the effector organ (very long presynaptic axons)
Where are the autonomic ganglia for sympathetic nerves ?
They are in the Paravertebral Ganglia
Where do cell bodies of sympathetic nerves originate ?
T1-L3 (thoracolumbar region)
Where do the cell bodies of the Parasympathetic Nerves come from ?
Cranial Nerves and Cell of S2-4
What cells do preganglionics synapse on in the adrenal medulla ?
Chromaffin Cells
What are the two major substances secreted by the chromaffin cells ?
Epi (80%), NE (20%)
Pheochromocytoma is a tumor of the Adrenal Medulla and can be diagnosed by increased ______ in the blood and urine.
Vanillamandelic Acid (VMA)
Adrenergic neurons release
NE
Cholinergic neurons release
ACh
Certain post-ganglionic parasympathetic neurons release Substance P, VIP and NO. Where are these neurons located ?
In the GI Tract
What NT is release by both Sympathetic and Parasymphathetic pre-synaptic neurons ?
ACh
What receptor type is present in the ganglion of both post-synaptic parasympathetic and sympathetic ganglia ?
Nicotinic
Nicotinic Receptors are : GPCR’s or Gated Ion Channels ?
Gated Ion Channels (Na+)
The NT released by Post-synaptic sympathetic neurons to their target organ is…
NE
The NT released by Post-synaptic Parasympathetic neurons to their target organ is…
ACh
What are the 4 main receptors seen on target organs associated with the Sympathetic NS ?
Alpha 1,2
Beta 1,2
What is the main kind of receptor type seen on effector cells responsive to Parasympathetic neurons ?
Muscarinic (1,2,3)
Which adrenergic receptor is associated with Gq ?
Alpha 1 ( Phospholipase C Leads to an Increase in IP3/DAG)
“Alpha Males are shown in GQ magazine”
Which adrenergic receptor is associated with Gi ?
Alpha II (Decreases cAMP)
“Second Alphas are ‘I’nferior to Alpha 1’s”
Beta 1 and 2 adrenergic receptors are associated with which GPCR ?
Gs (Increased cAMP)
Where in the body do you have a high proportion of Alpha1 receptors ?
Smooth muscle of the skin/splanchnic regions, GI and bladder sphincters and the radial muscle of the iris.
Where in the body do you have many Alpha2 receptors ?
GI tract (Note: Sympathetics typically slow down gastric motility, could be because they work through Gi associated Alpha2’s )
Autoreceptors on autoniomic post-ganglionics
Platelets.
Adrenergic receptor of the heart
Beta1 ((Sinoatrial, AV and ventricular muscle)
Adrenergic Receptor of the lungs
Beta2 (
Where will you find Nm(N1) receptors ? (Nicotinic)
Skeletal muscles
Where will you find Nn (N2) receptors ? (nicotinic)
In the Autonomic Ganglia (post synaptic cells)
What GPCR is the M1 receptor associated with ?
Gq
What GPCR is the M2 receptor associated with ?
Gi (So both the Alpha 2 and M2 are Gi)
What GPCR is M3 associated with ?
Gq
Where in the body will you find the M1 receptor ?
CNS
Where in the body do you find the M2 receptor ?
Heart (AV node)
makes sense. ACh slows the heart rate, M2 is associated with the inhibitory Gi GPCR
Where in the body will you find the M3 receptor ?
Smooth Muscle and Glands
Unlike B1 ones which are equally sensitive to Epi and NE, B2 receptors are more partial to _____.
Epinephrine
Receptor responsible for Increased HR, Contractility and AV node conduction ..
B1
Receptor responsible for Decreased HR, Contractility and AV node conduction ..
M2
Constricts Blood Vessels in skin and splanchnics
A1
Dilates blood vessels in skeletal muscle
B2
T or F: Parasympathetics have no role in vascular smooth muscle control
TRUE !! (a1 and B2)
Decrease motility in GI tract
Alpha2 and Beta2
Constricts sphincters in GI
Alpha1
What receptor constricts bronchiolar smooth muscles ?
M3
What receptor dilates bronchiolar smooth muscles ?
Beta 2
which receptor mediates erection ?
Muscarinics (M3 I’m assuming)
What receptors mediate ejaculation ?
Alpha
Relaxes Bladder wall
Beta2
Constricts Urinary Sphincters ?
Alpha1
Contracts bladder wall and relaxes sphincters
M3
What kind or receptors are associated with sweat glands
Sympathetic cholinergics (Technically they are sympathetic agonists but have Cholinergic Receptors)
Mydriasis (receptor)
Alpha1 (dilation)
Miosis
Muscarinics
Lipolysis
Beta1
Three Autonomic Centers of the Medulla
Vasomotor (regulates BP stimulated by chemoreceptors, CN IX,X. C02 levels are gauged, increased levels lead to vasoconstriction)
Respiratory (Ventral = Expiratory, Dorsal=inspiratory)
Swallowing Coughing and vomitting.
Autonomic Centre of the Pons
Pneumotaxic Center ( Regulates respiratory RATE, senses stretch in the lung and relays information to Respiratory Group in the Medulla)
Autonomic Center of the Midbrain
Micturation Center (Urination)
Autonomic Centers of the Hypothalamus
Temperature Regulation
Thirst and Food intake
Function of Pacinian Corpuscles
Sense vibration
What sensory fiber neurons are found in Muscle Spindles
1A (Large and fast back to the CNS)
1A afferents
What sensory fiber neurons are found in Golgi Tendon Organ
1B (also large and fast)
What will sensory stimuli cause in the receptors ?
Opening of ion channels
Depolarization = Excitatory (Current is usually inward) Hyperpolarization = Inhibitory (current is usually going out)
What kind of stimulus do slowly adapting (Tonic) receptors sense ?
Steady Stimulus (respond repetitively to prolonged stimulus)
Examples (muscle spindle, pressure and slow pain
What kind of stimulus do rapidly adapting (Phasic) receptors respond to ?
Detect onset and offset of stimulus
Decline in AP frequency with time in response to a constant stimulus
Ex. Pacinian, light touch)
First order afferent neurons have their cell bodies in…
Dorsal Root Ganglia (spinal cord ganglia)
Receive signal and send it to CNS
Second order neurons are located in …
Spinal Cord Or Brainstem
Receive info from primary afferents and then transmit to the thalamus
Third order afferents are located in…
The thalamus (relay nuclei)
Receive info from secondary afferents and send into to the cerebral cortex
Fourth Order afferents are located in ….
Appropriate region of sensory cortex –> conscious perception of the stimuli
What 4 sensations does the somatosensory system encode ?
Touch, Movement, Temperature and Pain
What two pathways make up the somatosensory system ?
Dorsal Column
Anterolateral
What sensation does Dorasl Column relay /
Fine touch (not light touch), pressure , Two point discrimination, vibration, proprioception
What sensations does the Anterolateral system relay ?1
Temperature, Pain, Light touch
Describe the Course of the Dorsal Column system
Ascend inpsilaterally to the Nucleus Gracillis and Cuneatus of the Medulla where they cross the midline.
From the Gracilis and Cuneatus the 2nd order neurons go to the contralateral Thalmus.
From the thalamus, 3rd oder neurons go to Cerebral Cortex where they synapse on 4th order neurons
What kind of sensory fibers make up the Dorsal Column
Group II fibers (Medium sized)
Discuss the course of the Anterolateral System
Primary fibers ascend to the spinal cord where they synapse on secondary .
Secondary neurons cross immediately and ascend to the contralateral thalamus where they synapse on 3rd order neurons.
3rd order neurons synapse on fourth order neurons in the cerebral cortex
What kind of fibers make up the anterolateral system ?
Type III and IV
Destruction of the thalamus would lead to loss of sensation on the ________ side.
Contralateral
Pacinian corpuscles encode
Vibration
Meissners corpuscles encode
velocity
Ruffinis corpuscles encode
Pressure
Merkels disks encode
Location
What is the NT for most pain receptors ?
Substance P (Pain = Anterolateral)
What kind of fibers carry Fast Pain
Group III (A-delta).. Localized pain
What kind of Fibers carry Slow Pain
C-fibers (Type IV).. Aching and throbbing that is poorly localized
Reractive power of lens is measured in …
diopters
Emmetropia
Normal
Hypertropia
Farsighted (light focuses behind the retina)
Myopia
Nearsighted (Light focuses in front of the retina)
Atigmatism
Curvature of the lens is not uniform
Presbyopia
Loss of accommodation of the lens seen in aging.
Treatement for Hyperopia
Convex lens
Treament for myopia
Biconcave lens
Treament for astigmatism
cylindric lens
Pigmented epithelial cells are found farthest from the source of light in the eye. What is their role /
absorb stray light
Convert 11-cis retinal to All-Trans Retinal
What are the receptor cells of the eye ?
Rods and Cones
Where are rods and cones not present ?
optic disk
The cells that synapse of bipolar cells that lead to high acuity but low sensitivity…
Cones (very few cones synapse on these)
Better for day vision
The cells that synapse of bipolar cells that lead to low acuity but high sensitivity
Rods (many rods synapse on one bipolar cell)
High sensitivity –> Good night blindness
What are the output cells of the retina ?
Ganglion cells (bipolar cells synapse onto ganglion cells)
Axons of ganglion cells form the Optic Nerve.
Axons from which hemiretina cross at the optic chiasm ?
The Nasal hemiretina (whereas the temporal hemiretina cells remain ipsilateral
Cells from which two hemiretinas form the right optic tract ? (not optic nerve, tract forms post chiasm)
Right Temporal hemiretina and Left Nasal hemiretina (these two see your left world)
What results from cutting of the left optic Nerve /
Blindness of ipsilateral Eye
What results from cutting of the left optic Chiasm ?
Loss of the nasal hemiretina (cannot see your temporal fields )
Heteromynous bitemporal Hemianopia
What results from cutting of the left optic tract ?
Lose left temporal hemiretina (loses left nasal field) and right nasal hemiretina (Loses right temporal field)
Homonymous Contralaterl Hemianopia
What occurs with the cutting of the left Geniculocalacrine tracts ?
Homonymous hemianopia with Macular sparing
Light converts 11-cis rhodopsin to…
All-trans rhodopsi
What mediates opening and closure of Na+ channels in receptors of the eye ?
cGMP levels (high –> open, Low –> closed0)
Phosphodiesterase degrades cGMP , leading to closure of Na+ channels
Like most cells, low Na+ influx leads to …
hyperpolarization !
sound frequency is measured in
Hertz
Sound intensity is measured in
decibells
db = 20 log (P/Po)
P= measured pressure
Po: reference pressure at the threshold frequency.
Purpose of the outer ear
direct sound in to the auditory canal
Middle ear consists of
Typmpanic membrane , ossicles (Malleus, Incus and Stapes) and oval window (stapes connects to the oval window
Perilymph
Fluid that fills the outside of the duct (Scala Vestibuli and Scala Typmani)
High Na+ concentration
Endolymph
Fluid that fills the indside of the ducts (Scala Media)
High K+ concentration
Endolymph
Fluid that fills the indside of the ducts (Scala Vestibuli and Scala Typmani)
What does the somatic NS innervate ?
Skeletal muscle
What are the three division of the ANS ?
Sym., Parasympathetic and Enteric
Where are the autonomic ganglia for Parasympathetic nerves ?
Near the effector organ (very long presynaptic axons)
Where are the autonomic ganglia for sympathetic nerves ?
They are in the Paravertebral Ganglia
Where do cell bodies of sympathetic nerves originate ?
T1-L3 (thoracolumbar region)
Where do the cell bodies of the Parasympathetic Nerves come from ?
Cranial Nerves and Cell of S2-4
What cells do preganglionics synapse on in the adrenal medulla ?
Chromaffin Cells
What are the two major substances secreted by the chromaffin cells ?
Epi (80%), NE (20%)
Pheochromocytoma is a tumor of the Adrenal Medulla and can be diagnosed by increased ______ in the blood and urine.
Vanillamandelic Acid (VMA)
What is nystagmus ?
Whene the head rotates on direction the eyes will rotate the other way to maintain fixation on the object it was looking at. when they can no longer rotate they will snap back then move again
The direction of nystagmus is the direction of rapid eye movement (the snap back phase), usually in the same direction as the head rotation.
Cholinergic neurons release
ACh
Certain post-ganglionic parasympathetic neurons release Substance P, VIP and NO. Where are these neurons located ?
In the GI Tract
What NT is release by both Sympathetic and Parasymphathetic pre-synaptic neurons ?
ACh
What receptor type is present in the ganglion of both post-synaptic parasympathetic and sympathetic ganglia ?
Nicotinic
Nicotinic Receptors are : GPCR’s or Gated Ion Channels ?
Gated Ion Channels (Na+)
The NT released by Post-synaptic sympathetic neurons to their target organ is…
NE
The NT released by Post-synaptic Parasympathetic neurons to their target organ is…
ACh
What are the 4 main receptors seen on target organs associated with the Sympathetic NS ?
Alpha 1,2
Beta 1,2
What is the main kind of receptor type seen on effector cells responsive to Parasympathetic neurons ?
Muscarinic (1,2,3)
Which adrenergic receptor is associated with Gq ?
Alpha 1 ( Phospholipase C Leads to an Increase in IP3/DAG)
“Alpha Males are shown in GQ magazine”
Which adrenergic receptor is associated with Gi ?
Alpha II (Decreases cAMP)
“Second Alphas are ‘I’nferior to Alpha 1’s”
Beta 1 and 2 adrenergic receptors are associated with which GPCR ?
Gs (Increased cAMP)
Where in the body do you have a high proportion of Alpha1 receptors ?
Smooth muscle of the skin/splanchnic regions, GI and bladder sphincters and the radial muscle of the iris.
Where in the body do you have many Alpha2 receptors ?
GI tract (Note: Sympathetics typically slow down gastric motility, could be because they work through Gi associated Alpha2’s )
Autoreceptors on autoniomic post-ganglionics
Platelets.