Chapter 2 Autonomic Nervous System Exam 2
SNS Functions
"fight or flight"/ move stored energy into movement/ i.e Smooth Muscle: gastrointestinal: directs blood flow away from intestines to skeletal muscle Cardiac Muscle: heart output of blood: heart pushes an increased amount of blood out to skeletal muscle Glands: Sweat Glands: secret sweat to cool down body so it can increase body movement
PNS Functions
"rest and digest"/ causes changes in homeostasis/ i.e. Smooth: Gastro: when activated increased blood flow to intestines Cardiac: Heart blood output: when activated blood output is decreased and activities that are low impact Glands: Salivitory: help break down food. low impact
Steps in Auditory Transduction
-Key Aspect- bending of cilia changes K+ permeability -Bending in one direction increases permeabilty but in the other direction decreases permeability -thus, direction of bending determines excitation of inhibition of a single hair cell
For the excitation of photoreceptors; there must be
-a chemical transformation by light -light isomerizes 11 cis retinal to 11 trans retinal -11 cis retinal has to be regenerated *requires vitamin A -metarhodopsin 11 activates transducin, a G- Protein -Hyperpolarization decreases releases of glutamate from the synaptic terminal of the photoreceptors -the net effect of reduced glutamate depends on the type of receptor it binds to on the post synaptic neuron
Amphetamine Action
-amphetamines are shaped like dopamine and imitate dopamine in the neuron -amphetamines bind to dopamine receptors, initiating the same response as dopamine -the compete with dopamine at cellular transporters causing dopamine to remain outside the cell longer
Opiate Action
-an opiate binds to an opiate-receptor on the presynaptic neuron -opiate binding initiates a cascade of neurochemical activity -the activity signals a massive efflux of dopamine into the synaptic cleft
Steps in Auditory introductions [in depth]
-auditory hair cells are mechanoreceptors -base sits on an elastic basilar membrane -vibration of the organ of Corti causes the base to vibrate and the cilia to bend -bending causes a change in K+permeability -bending in one direction causes depolarization and the other hyperpolarization -depolarization opens voltage gated Ca2+ channels -Ca2+ influx causes release of glutamate, which excites the afferent cochlear neuron that sends signal to the CNS
Olfaction
-chemical molecules (odarants) are vaporized in gas phase (air) -binding to specific olfactory receptors activates a G-Protein that is coupled to adenylyl cyclase, increasing cAMP -cAMP- sensitive cation channels (permeable to K+, Na+ and Cl-) open, depolarizing olfactory receptor triggerin gan AP in neurons of the olfactory nerve
Olfactory Receptors
-extremly diverse -at least 1000, each encoded by a different gene -one receptor per cell -some are more selective than others -CNS interprets combinations of stimuli to detect the resulting "smell"
In reference to the coding of intensity, give some details on how the frequency of Axon Potentials (firing rate) affects the coding
-intensity of stimulus encoded in the # of aps produced -receptor potential is a diret function of strength of stimulus -assuming the threshold potential is reached, the"stornger" the receptor potential, the more the action potentials are fired - the more frequent the APs, the more NT is released at the terminus of the nerve
Describe Mechanisms of Action
-opiod receptors are coupled with inhibitory G-proteins and their activation has a number of actions: 1) closing of voltage sensitive calcium channels 2) stimulation fo potassium efflux leading to hyperpolarization and reduced cyclic adenosine monophosphate (cAMP) production 3) OVERALL, the effect is a reduction in neural excitability reduced transmission of nociceptive impuleses
Rhodopsin Composition
-rhodopsin is a photosensitive pigment that is composed of the protein opsin and retinal - photons of light convert cis-retinal and trans-retinal -a series of conformational changes in rhodopsin activate a G-protein
Conceptual Steps in Hearing
-sound is focused by physical arrangment of the ear -sound energy is amplified within the ear through mechanical forces -individual hair cells are sensitive to sounds of a specific frequency -combinatorial effects of different hair cells determine perception of sound
Hearing
-transduces sound waves
In sympathetic NS pre-post synapses occur in one of two places:
1) sympathetic chian (paravertebral ganglia) 2) prevertebral ganglia
What is the first step that take place once a stimulus activates a sensory receptor?
1) the environmental stimulus interacts with the sensory receptor and causes a change in its properties. A mechanical stimulus causes movement of the mechanoreceptor. Photons of light are absorbed by photoreceptors causing photoisomerization of rhodopsin. chemical stimulants rxt with chemorecpetors which activates g proteins and adenylyl cyclase. a change occurs in the sensory receptor
List some qualities that are specific to the Neuroeffector Junctions
1)diffuse rather than discrete nerve-effector juncitons 2)single neurons branch to release NT across effector tissue 3)NT receptors on the effector are broadly distributed 4)no specialized region on effector, unlike at somatic motor end plate 5) effector can have both sympathetic and parasympathetic innervation
List the steps in transmitting sensory information
1)sensory receptors 2) first-order sensory afferent neurons 3)second-order sensory afferent neurons 4) third-order sensory afferent neurons 5) fourth order sensory afferent neurons
How is intensity encoded?
3 ways. 1) by the number of receptors that are activated (large # of stimuli will increase larger responses) 2) differences in firing rates of sensory neurons in pathway 3) activating different types of receptors i.e a light touch on skin may activate only mechanoreceptors whereas an intense damaging stimuli to the skin may activate mechanoreceptors and nociceptors the stimuli would be ditected as stronger but not as a different modality
How many taste buds do people have and how many cells does each taste bud consist of?
5-10 thousand taste buds made up of 50/100 cells
Adrenergic uses what type of NT? Cholinergic
A: epinephrine & norepinephrine C: ACh
In parasympathetic NS what is the main NT?
ACh is the main NT but some cases it may be something else i.e. nitric oxide
In SNS what NTs are used?
ACh is used in pre-ganglionic Norepinephrine is used at post ganglion-effector junctions
Describe how afferent and efferent nerves work
Afferent nerves bring information from the root ganglion into the spinal cord where Efferent nerves take information from the spinal cord and meets back at the root ganglion
Why is smell the strongest sense of memory?
Brain Anatomy; olfactory bulb has direct connections to limbic system, responsible for memory and emotion; no relay to the thalamus [other senses do not pass through this area of the brain]
During a sympathetic response how are your adrenal glands activated?
By a hormone to release epinephrine and norepinephrine (aka adrenalin)
Cholinergic uses what type of response? Adrenergic?
C: rest and digest A: fight or flight
What type of receptors are used in adrenergic vs cholinergic
Cholinergic uses muscaritnic and nicotinic Adrenergic uses alpha and beta receptors
What two different pathways do the Somatosensory System use?
Dorsal Column: fine touch, pressure, vibration, propriception Anterolateral System: pain, temp, light touch
What are the proteins ENaC and TRP Channels
ENaC: epithelial sodium channels TRP Channels: transient receptor potential channels
Name and describe the autonomic control centers in the brain
Hypothalamus: water balance, temp, hunger Pons: respiration Medulla: respiration, cardiac, vomiting, swallowing
human ears can detect within a range of what?
Hz-----20-20,000htz
What is being detected if a mechanoreceptor is changing rapidly vs slowly?
If moving rapidly there will be a detection of changes in velocity vs slowly will detect changes to intensity and duration of the stimuli
What is the third and final step that takes place once a stimulus activates a sensory receptor?
If the receptor potential is depolarizing it moves the membrane inward toward the threshold and increases the likelyhood that an action potential will occur. If hyperpolarization is occuring the opposite effect happens
Why are whiskers a great example of mechanoreceptors?
In each whisker follicle, mechanoreceptors respond specifically to rotation of the follicle by its muscles or to deflection of the whisker shaft by external contacts, both of which encode information about the direction, velocity and duration of displacements and torques.
In the somatic nervous system where is the cell body of the motoneuron located?
In the central nervous system (CNS), in either the brain stem or spinal cord, and its axon synapses directly on skeletal muscle, the effect organ.
When ACh is released into the synaptic cleft what happens.
It binds to the sodium channel recpetors and lets the channel know its time to open and there will be an influx of Na+ into the muscle cell. Once the membrane is depolarized enough Ca+ will enter and have voltage gated calcium release.
Name the five types of receptors
Mechanoreceptors Photoreceptors chemoreceptors thermoreceptors nociceptros
List the symptoms of Cholinergic Toxidrome (muscarinic/nicotinic)
Mus: salivation, lacrimation, urination, defecation, gi crmaping, emesis (vomitting) Nic: muscle cramps, tachycardia, weakness, twitching, fasciculations
What are the two types of ACh receptors? How do they differ?
Nicotinic: ligand-gated ion channels that mediate a fast synaptic transmission of the neurotransmitter Muscarinic: G-protein coupled receptors (GPCRs) that mediate a slow metabolic response via second messenger cascades
Give and example using bladder control pertaining to PNS and SNS
PNS: emptying requires simultaneous contraction of wall and relaxation of internal sphincter SNS: filling requires simultaneous relaxation of wall and contraction of internal sphincter (autonomic)
PNS Movement
PSN: carries information through long axons to ganglion that then rxt with short axon to target cell SNS: short axon rxts with ganglion synapsis then has a long axon directly to the target cell
List the two divisions the Visceral Motor is broken into
Parasympathtic & Sympathetic
Muscarinic ACh Receptors
Produces parasympathetic nerve effects in the heart, smooth muscle and glands G-protein couples receptors (receptors influence ion channels by mean of G-Protein)
Which specific opsins determines wavelength sensitivity
R, G or B
Damaged skin releases what and how does the body react to that symptom?
Releases a vairety of chemicals including bradykinin, prostaglandins, seratonin, substance P, K+, H+, this initiates an inflamitory response. The blood vessels become permeable and as a result there is local edema and redness of the skin. [Mast cells near the cite release histamine, which directly activates nociceptors. in addition, axons of the nociceptors to stimuli that were not previously noxious or painful]
Sensory (affarent) Division:
Somatic & Visceral Sensory
Motor (efferent) Division
Somatic Motor & Visceral Motor
Where is the Autonomic Nervous System located?
Spinal Cord: SNS(middle of spinal cord; thoracic and lumbar) PNS(top or bottom of the spinal cord; brain stem and saccral)
Dopamine
The High: morphines activation of the opiod receptor in neurons of the nucleus accumbens in the brain 1) reigns in the release of the neurotransmitter y-aminobutyric acid (GABA) 2) this drop in GABA(amino acid/ most common inhibitory) causes a neighboring cell to expel dopamine 3) in turn elicits the euphoria associated with opiods
Describe the process of the Autonomic Nervous System
The cell body of each preganglionic neurons resides in the CNS. The axons of the preganlionic neuron synapse on the cell bodies of the postganglionic neurons in one of several autonomic ganglia located outside the CNS. The axons of the posts ganlionic neurons then travel to the periphery, where the synapse on visceral effector organs such as heart, bronchioles, vascular smooth muscle, gastrointestinal tract, bladder, and genitalia.
What is the third division of the autonomic nervous system? Where is it located?
The enteric nervous system and it is located in the plexuses of the gastrointestinal tract.
Describe the process of the somatic nervous system.
The neurotransmitter acetylcholine (ACh) is released from presynaptic terminals of the motorneurons and activates nicotininc receptors located on the motor end plates of the skeletal muscle. An action potential in the motoneuron causes an action potential in the muscle fiber, which causes the muscle to contract.
How are tonic receptors illustrated? Phasic?
Tonic: mechanoreceptors Phasic: pacinian corpuscles
Brain Stem
a collaboration of the medulla, pons, and midbrain. 10 of the 12 cranial nerves arise in the brainstem (carry sensory info to the brain and motor info away from it)
What two neurons do the autonomic pathways consist of?
a preganglionic neuron: originates in the brainstem or the spinal cord a postganglionic neuron: lies outside the central nervous system in collections of nerve cells
parasympatholytic
a substance or activity that reduces the activity of the parasympathetic nervous system. (The parasympathetic nervous system is often colloquially described as the "Rest and Digest" portion of the autonomic nervous system.)
Somatic Nervous System
a voluntary motor system under conscious control. Each pathway consist of a single motoneuron and the skeletal fibers it innervates.
What is the target tissue for a1, a2, B, B2, Nicotinic, and Muscarininc receptors?
a1: vascular smooth muscle, skin, renal, and splanchnic Gastro tract, sphincters bladder, sphincter Radial muscle, iris a2: gastro tract, wall Presynaptic adrenergic neurons B1: heart, salivary glands, adipose tissue, kidney B2: vascular smooth muscle of skeletal muscle, GI tract, wall bladder, wall bronchioles Nicotinic: skeletal muscle, motor end plate (N1), postganglionic neurons, SNS&PNS, adrenal medula Muscarinic: all effector organs, PNS sweat glands, SNS
Gate Control Theory of Pain
activation felt even though non-painful fibers (Aa) sends inhibitory signals to nonciceptive afferents travelin gto the CNS
Phasic Receptors
adapt rapidly to stimuli, produce APs in response to change, intial burst of APs followed by a rapid decline, allows body to ignore constant unimportant stimuli (bad smell)
Tonic Receptors
adapt slowly to stimuli, produce a constant rate of APs as long as a stimuli is present, monitors things that are continually sensed (body position)
At what point do sensory receptors "adapt" to stimuli?
adaptation occurs in receptors when a constant stimuli is applied for a period of time. When the frequency of APs declines although the stimulus continues (smell, pressure, touch adapt quickly)
Nicotinic ACh Receptors
all autonomic ganglia all neuromuscular junctions some CNS pathways
In light how do you define amplitude and wavelength
amplitude: percieved as brightness; up and down length of wave from bottom to top wavelength: (nm) perceived as hue; length of wave from left to right
what is sensory transduction
an environmental stimulis (pressure, light, chemicals) activates a receptor and is converted into electrical energy
Autonomic Nervous System
an involuntary system that controls and modulates the functions primarily of visceral organs. (the internal organs of the body, specifically those within the chest (as the heart or lungs) or abdomen (as the liver, pancreas or intestines). In a figurative sense, something "visceral" is felt "deep down." It is a "gut feeling.")
Neuroeffector Junctions
analogous to the neuromuscular junctions of the somatic nervouse system
retina
area in the back of the eye containin gphotoreceptors
pupil
arperture of the eye
Cerebellum
attatched to brainstem, coordinate movement, planning and execution of movement, maintenance of posture and coordination of head and eye movements
Kidneys are closer to chest or back
back
Beural Anatomy; Interneurons
bipolar cells, horizontal cells, amacrine cells
How is arterial blood pressure sensed?
by baroreceptors located in the walls of the carotid sinus. The information is transmitted, via the glossophyrangeal nerve, to the vasomotor center in the medulla of the brain stem- in the medulla the sensed blood pressure is compared with a set point, and the medullary vasomotor center directs changes in sympathetic and parasympathetic outflow to the heart and blood vessels, which produce appropriate adjustments in arterial pressure.
Affarent Nerves
carry information into the central nervous system
Efferent Nerves
carry information out of the nervous system
accommodation (in reference to the eye)
changing the shape of the lense to focus images on the retina caused by contracting/relaxing ciliary muscles (lens falttens when focusing on distant objects and becomes rounder for focusing on close objects.
Neural Anatomy; Pigment Epithelium
contains melanin to absorbs excess light; stores vitamin A
List Functions of Parasympathetic NS
contracts pupil, stimulates salivation, inhibits heart, constricts bronchi, stimulates digestive activity, stilumlates gallbladder, relaxes rectum
iris
controls diameter of the pupil -contraction of sphincter muscles; miosis -contraction of radial muscles; mydriasis
Neuropathic Pain
damage to A or C fibers may increase sensitivity or cause spontaneous AP firing
Primary Hyperalgesia
damaged tissue has increases sensitivity to pain -reduced threshold to pain (increased intensity of sensatino, spontaneous pain)
intensity is a function of pressure, how is it measured?
decibels
Receptive Fields
defines an area of the body that when stimulated results in a change in firing rate of a sensory neuron
lens
dense high protein structure that adjusts optical focus, focus adjusted by process called; accommodation -at rest, zonal fibers suspend lens and keep it flat (distant) -contraction of ciliary muscles releases tension in zonal fibers; lens gets more round/near objects
List Functions of Sympathetic NS
dilates pupils, inhibits salivation, relaxes bronchi, accelerates heart, inhibits digestin, stimulates glucose release by liver, secretion of epinephrine from the kidney, relaxes bladder, contracts rectum
Concerning balancing functions what allows precise control of tone and activity i.e. heart rate
dual innervation: most organs of the body by the sympathetic (on the left) and parasympathetic (on the right) divisions of the ANS
Somatic nervous system has direct innervation from CNS to __________?
effector tissue
nociceptors
extremes of pain and temp (skin) activated by extremes of pressure, temperature, or noxious chemicals
presbyopia
farsightedness that occurs naturally with age as the lens becomes less flexible
Thermoreceptors
free ending nerves with high thermal sensitivity, temp changes activates family of ion channels on the receptor membrane= TRP (transient receptor protential) channels, each TRP channel has a unique temp threshold
vitreous humor
gel of extracellular fluid containing collagen
cones
higher threshold for light, provide higher visual acuity, responsible for color vision
receptor potential
increases or decreases the likelihood that action potentials will occur
What does cocaine to do the body?
it blocks dopamine transporters so there can be no reuptake of dopamine and the dopamine receptors can continually bind to dopamine until there is none left becuase there will be no reuptake or distirbution of those molecules
If the receptive field has a higher order of the CNS neuron, will the receptive field be more/less complex? why/why not?
it will be more complex due to more neurons converge in relay nuclei at each level. ie the first order of sensory neurons have the simplist receptive field/ the fourth order sensory neurons have the most complex receptive fields
where is the location of the primary auditory cortex
lacated bilaterally, near outersurface of brain
hypothalamus
lies ventral to the thalamus, contains center that regulates body temp, food intake, water imbalance
location of the primary visual cortex
located bilaterally at lower back of brain
How is location of the stimulus perceived and conveyed in the brain?
location is endcoded by a receptive field of sensory neurons and my be enhanced by lateral inhibition. By receptive fields
Sound
longitudinal wave, meaning that the motion of particles is along the direction of propagation
rods
low threshold of response to light, sensitive to low intensity light, don tparticipate in color vision
If a receptive field is smaller will the the sensation be more general or more defined
more defined/localized/identified
Spinal Cord
most caudal portion of the CNS extedning from the base of the skull to the first lumbar vertebra. 31 pairs of spinal nerves, sensory(afferent) and motor (efferent).
General Inclusions in Somatic Motor
motor innervation of all skeletal muscles (except pharyngeal arch muscles)
General inclusions in Visceral Motor
motor innervation of smooth muscle, cardiac muscle, and glands; equivalent to autonomic nervous system (ANS)
location of thalamus
near the center midline of the brain
myopia
nearsightedness caused by inability to flatten the lens enough to focus image on retina
retina
neural portion that transduces light into electrical signals that pass down the optic nerve optic nerve exists at optic disc. devoid photoreceptors:blind spot fovea; point on the retina that has maximal vision acuity
Nociceptors have two major classes
non adapting receptor classes are mechanical nociceptors: finely mylenated A-delta afferent nerve fibers and respond to sharp, pricking pain polymodal nociceptors: hot and cold stimuli response
chemoreceptors
olfaction (olfactory mucous) taste (tongue) Arterial Po2 (carotid/aoritc bodies) pH of CSF (ventrolateral medulla) activated by chemicals / involved in detection of oxygen and CD in the control of breathing
Where ddoes the adrenal gland sit? Why is this position interesting?
on top of the kidney, there is a synapse in the gland that can cause a body-wide release of epinephrine
How many types of sensations do nerve fibers transmit?
one
Cornea
outer covering of the eye where light is first focused
Neural Anatomy; Ganglion Cells
output cells of retina project via optic nerve
Phantom Limb Pain
pain felt even though nonciceptors no longer present in missing limb -peripheral sesitization:s an increased sensitivity to an afferent nerve stimuli. -somatosensory reorgnization: children with spastic cerebral palsy: a multimodal neuroimaging study.
rhodopsin
phototsensitive pigment (composed of opsin[protein member G-protein receptor family] and retinal [an aldehyde form of vitamin A])
Where are pre/post ganglionic neurons located>
pre (the neuron proximal to the ganglion) post( the neuron distal to the ganglion)
Thalamus
processes almost all sensory info going to the cerebral cortex and almost all motor information coming from the cerebral cortex to the brainstem and spinal cord
Somatosensory System
processes info about touch, pain and temp using mechanoreceptors, thermoreceptors and nociceptors
How does a phasic receptor respond to an onset of stimuli?
receptor returns quickly to baseline, here the receptor potential remains depolarized for a longer portion of the stimulus period, and the action potentials continue. Once receptor potential begins to repolarize, the rate of action potentials declines and there is silence
How does a tonic receptor respond to an onset of stimuli?
responds to an onset of stimuli with a depolarizing receptor potential that brings the membrane to threshold, resulting in a long series of action potentials
What do both rods and cones contain?
rhodopsin
choroid
rich in blood vessels and supports the retina
medulla
rostal extension of the spinal cord, autonomic centers regulate breathing, blood pressure, coordinate swallowing, coughing and vomiting reflexes
pons
rostral to medulla, helps with balance and maintenance of posture, regulating breathing, relays info from the cerebral hemispheres to the cerebellum
midbrain
rostral to pons, helps with eye movement, contains relay nuclei of the auditory and visual systems
What is the name of the resivore inside our muscle cells that releases calcium for our disposal?
sarcoplasmic reticulum
Visual Receptive Fields
see slide 17 of 41
What features can be encoded?
sensory modality, spatial location, frequency, intensity, threshold, and duration of stimulus
Preganglionic fibers are ....... postganglionic fibers are.......
short long
a pure tone
sinsusodial wave of a signle frequency; most sounds are a mixture of different tones
Be able to draw light conversion of retinal from a cis- to a trans-configuration
slide 21 of 41
The motor nervous system has two components:
somatic and autonomic
Thalamus Details
sorts our all sensory info, compares input and determines what info is worth sending to cortex, body ignores most sensory info, example ac uni, compares info from the right and left eyes for stereotypic vision, and left ear to determine direction of sound
General inclusions in Visceral Sensory Nerves
stretch, pain, temperature, chemical changes, and irritation in viscera, nasusea and hunger (special: taste)
thermoreceptors
temperature (skin) activated by temp or changes in temp
receptive field
the area of the body that, when stimulated, produces activity in a neuron
What system controls most moment-to-moment physiological functions?
the autonomic system
if skin temp rises to damaging levels (above 45dC) what happens to warm receptors?
the become inactive
What does the CNS include?
the brain and spinal cord
What is the second step that takes place once a stimulus activates a sensory receptor?
the changes cause ion chanels in the sensory receptor membrane to open or close, which results in a change in current flow. If ionic current flow moves inward (positive charges move in receptor cell) then depolarization occurs. If current moves outward (positive charges leave the cell) then hyperpolarization occurs. This change is called the receptor potential/generator potential
If skin is wamred above 36 degree C which receptor will become quiescent
the cold
What determines the frequency tune>?
the location of the hair cell along the length of the basilar membrane; the bsilar membrane gets thinner and more flexible toward the center of the cochlea.
Diencephalon
the place between the brain made up of the thalamus and hypothalamus
The Brain-Body Connection
the portion of the nervous system that controls the visceral functions of the body and continually adapts the function of the internal organs, skin and viscera to internal and external stimuli
Encoding
the relative elasticity of the basilar membrane alon gits length determines the frequency required to
Neurotransmitters
the relay of information between neurons and their target cells at chemical synapses. Catagorized by amino acids, peptides, monoamins
The autonomic nervous system has two major divisions:
the sympathetic: the parasympathetic:
How is the stypes of sensation (sound, smell, etc) perceived?
the type of sensation percieved is determined by where the fiber synapses in the CNS
If the skin is cooled below 36 degree C what receptors will become quiescent
the warm
Nociceptors
thermal, chemical, and mechanical receptors that respond to noxious stimuli that can produce tissue damage, respond to a diverse group of stimuli, wide varitey of ion channels enables this diversity in response
cones are more location specific because
they are derived from mulitple ganglion and bipolar cells
Rods are less accurate because
they are derived from one ganlion cell
How do the somatic and autonomic nervous systems distinguished?
they are distinguished by the types of effector organs they innervate and the types of functions they control
Stimulus modality is often encoded by labeled lines, what are they?
they are pathways of sensory neurons dedicated to that modality. i.e the pathway of neurons dedicated to vision begin with photoreceptors in the retina
What do all preganglionic neurons of the autonomic nervous system release?
they release ACh
What do all postganglionic neurons of the autonomic nervous system release?
they release either ACh or norepinephrine (hormone that is released by the adrenal medulla and by the sympathetic nerves and functions as a neurotransmitter. It is also used as a drug to raise blood pressure.), or in some cases, neuropeptides (any of a group of compounds that act as neurotransmitters and are short-chain polypeptides.)
Mechanorecpetors
touch(skin) audition(organ of Corti) vestibular (macula) activated by pressure or changes in pressure
General inclusions in Somatic Sensory Nerves
touch, pain, pressure vibratio, temp, and propioception in skin, body wall and limbs (special: hearing, vision, smell)
Neural Anatomy; Photoreceptors
transduce light energy into electrical energy (rods and cones)
Mechanoreceptors
transform mechanical stimuli into electrical signals, all organsisms and most cells sense and respond to mechanical stimuli, two main types of proteins ENaC&TRP channels, channels are linked to extracellular matrix, mechanical stimuli alter channel permeability
Light
transverse waves, moving perpendicular to the direction of propagation; an electromagnetic wave
What is the difference in have two cones and three cones?
two cones can not see the color red
Photoreceptors
two types: rods and cones * both transduce light energy into electrical energy
In sensory transduction what does the conversion typically involve?
typically it will involve the opening or closing of ion channels in the receptor membrane, which leads to the flow of ions (current flow) across the membrane; leads to change in membrane potential i.e receptor potential
Five types of taste receptors
umami, fat, salty, sweet, sour, bitter
photoreceptors
vision (retina) activated by light
sound frequency
wave cycles per second, mearsured in hertz
sound waves
waves of compression and decompression
When does sensory coding beign?
when the stimulus is tranduced by senseory receptors and continues as the information is transmitted to progressively higher levels of the CNS
When your sympatheitc nervous system is activated what happens?
your pupils dilate, your salivary gland decreases in secretion, your respiratory rate will increase, your heart rate increase (i.e better oxygenation), the liver secrets sugar, the adrenal glands are activated
