Define afferent, efferent pathways, and reflex pathways
Afferent: sensory neurons carry information from the PNS to CNS
Efferent: neurons relay information from CNS to effector organ
Reflex: controls action reflex, most sensory information do not pass directly into the brain, but synapse in the spinal cord
List the function of the individual cranial nerves and state whether they are sensory, motor or mixed.
(Oh Oh Oh to touch and feel girls vaginas gives victor a hardon) (Some say marry money but my brother say big boobs matters more)
Olfactory, Sensory, Smell
Optic, Sensory, Vision
Oculomotor, Motor, Eye movement
Trochclear, Motor, Eye movement
Trigeminal, Both, Masticatory movements, sensitivity of face
Abducens, Motor, Eye movement
Facial, Both, Muscle in facial expression, taste from 2/3 of tongue
Vestibulocochlear, Sensory, hearing, balance
Glossopharyngeal, Both, Movement of pharynx and salivary secretion, taste from posterior 1/3 of tongue
Vagus, Both, Sensitivity and movement of heart lungs, gastrointestinal tract, larynx
Accessory, Motor, Movement of neck muscles, viscera, and swallowing
Hypoglossal, Motor, Tongue movement
List the 4 main regions of the spinal cord.
Explain the functional significance of the dorsal and ventral parts of the spinal cord (ie. which part is for sensory/efferent information)
Dorsal Root; carries sensory afferent information to CNS
Ventral Root: carries efferent motor information to muscle and glands
Define ascending and descending tracts.
: Sensory information from spinal cord to brain
Descending tract: Information from brain to spinal cord
List and describe (hard, soft, etc) the 3 layers of meninges.
Dura Mater, outside layer, hard
Arachnoid matter middle layer, spidery
Pia matter, soft, adherent
Describe the components and function of the Ventricular System.
Hollow spaces in brain filled with a circulating fluid
4 Ventricle, Lateral ventricles, third ventricle, fourth ventricleContains cerebrospinal fluid (proteins and glucose)Choroid Plexus modified ependymal cells, pia matter and capillaries
Purpose: provide nourishment and protection
Describe the blood-brain barrier.
Prevents toxic substances from entering brain because of tight junctions in the capillary cellsLipid soluble substances can diffuse in
List the 6 major divisions of the brain.
these two make up the forebrain
these three make up the brain stem
List the components of the midbrain and state their functions.
Conduction pathway between higher and lower brain centerTectum, inferior colliculi; are part of the auditory pathway and superior collculi, coordinates visual somatic and auditory information, adujusting movements of the head and eyes towards the stimulusTenmentum
: controls motor function regulate awareness and attention and regulates some autonomic function
List the functions of the pons
Relays information from the cerebrum to the cerebellemCo-operates with the medulla oblongata to control respiratory rate and depth
List the components and the functions of the medulla oblongata.
: contains ascednding somatosensory tracts and descending corticospinal tracts
State the function of the cerebellum.
Processes information from cerebral motor cortex, proprioceptors, visual and equilibrium
List the components of the diencephalon and describe the major functions of each.
Thalmus, relay station and memory processingHypothalmus, center of homeostasisLimbic system functional grouping involving cerebral and diencephalic structures, mediates emotional response
List the components of the limbic system and describe the function of each.
Hippocampus, learning and memoryAmygdala, fear and aggressionCingulate gyrus, involved in positive and negative emotional responsesInsular Cortex, relates visceral/autonomic sensation of emotion to the rest of the brain
Name the function of the corpus collosum.
Connects the right and the left hemispheres
Describe the layers of grey matter comprising the cerebral cortex.
Layer 1, almost has no cell bodiesLayer 2, Inhibitory internueronsLayer 3, Excitatory internueronsLayer 4 Most sensory signalsLayer 5 and 6, are the major output cells of the cortexLayers 123 connect adjacent cortical region and integrate cortical function
List the 4 cerebral cortices and identify the major functions of each.
: primary motor cortex, motor association area, skeletal muscle movementParietal Lobe: Primary somatic sensory cortex, sensory information from,skin, musculoskeletal system viscera and taste budsOccipital lobe; primary visual cortex, visual association area, vision
Temporal LObe; Primary Auditory cortex, auditory association area, hearin
Gustatory cortex, tasteOlfactory cortex, smell
Define sensory homunculus.
Map showing which areas of the somatosensory cortex are devoted to particular regions of the body
Describe the Geschwind Model of Language
The left hemisphere is where speech is processed in brain. There are primary visual cortex, to see words, the angular gyrus, the recognition of a written word, Arcuate Fasciculus, connects wernickes area to Brocas area. Primary motor cortex, primary auditory cortex and wernicke’s area. Are all areas of the brain used in language
List the functions of Wernicke’s area, the arcuate fasiculus, the angular gyrus and Broca’s area
Arculate fasciculus, connects wenickes area to brocas areaAngular gyrus, recognition of written wordsBroca area, speech planning and sequencing, language expressionWernicke’s area, speech comprehension
Recognize examples of speech due to damage of Broca’s or Wernicke’s areas (see tutorial)
Wernickes, fluent nonsenical Jargon, possible neologism (a new invented word or phrase)Brocas, difficulty in speech production, comprehension is good
Explain how one side of the brain controls the other side of the body (contralateral control).
Contralateral control, the right side of the brain controls the left side of the body, vice versaProprioception, vibration come in the top left and left the top left, vice versaPain temperature, comes in the top left and cross down to bottom right and goes up and out the top right
List the general functions of the right and left hemisphere.
right, analysis of touch, spatial visualization and analysis
Left, Speech cneter, writing, general interpretive center (langiage and mathematical calculations)
List the language capabilities of the right hemisphere.
Comprehend vocabulary of 13 year oldComprehend sentence structure of 5 year oldGive context of languageGovern emotional expression
Important with visual spatial
Be able to explain the actions of a split-brain patient – see lecture and tutorial.
Define Sensory Receptor. Name the stimuli that are detected by visceral (interoceptor) and somatic senses.
sense organ: an organ having nerve endings (in the skin or viscera or eye or ear or nose or mouth) that respond to stimulation
Visceral; detect stimuli that arise with in the body
SOmatic; receptors that detect sensations associated with the receptors associated with skin and proprioception
Define modality, the law of specific nerve energies and adequate stimulus. Under what circumstances will a receptor respond to an “inadequate stimulus”?
Modality, the energy form of a stimulusThe law of specific nerve energies and adequate stimulus, sensory receptors are specific for a particular modality
adequate stimulus, specific modality to which the receptor is most sensitive
List the major groups of receptors and their adequate stimuli.
Mechanoreceptors, pressure stretch, baroreceptors
Chemoreceptor. taste, smell, blood concentration
Thermoreceptors,sensations of coldness and warmth
List the 3 structural types of sensory receptors.
Simple receptors, neurons with free nerve endings
Complex neural receptors, have nerve endings enclosed in connective tissue
Special senses receptors, are cells that release neurontransmitter onto sensory neurons initiating an action potential
Define neural and non-neural receptors.
Neural receptor, free nerve endings
Explain how a sensory stimulus is transduced into electrical signals.
the stimulus energy must be transduced , convert the energy stimulus into changes in membrane potential, most open/ close ions channels
results in generator potential or receptor potential
Define Adaptation, Tonic Receptors, Phasic Receptors and Labelled Lines.
Adaptation, process in which sensory receptors to response to stimulus over time
Tonic receptors, adapt slowly, transmits signal as long as the simulus last (blood pressure)
Bioogical parameter that require constant monitoring
Phasic receptors, fires when the stimulus is first received then shut off when, when the stimulus is at a constant intensity
Labelled Lines,specific neural pathways, transmitting specific modality information
Define sensory unit and receptive field.
Sensory unit , a single afferent neuron with all its receptor endings
Receptive field, the region within which a sensory neuron can detect a stimulus
Describe a generalized pathway for sensory information.
To activate sensory receptor, stimulus must fall within receptive field, afferent neuron (first order neuron), then spinal cord or brain stem, second order neuron, thalmus, third order neuron, cortex
Describe how the brain can discriminate between different stimuli, with reference to modality, intensity of signal (frequency and population coding), recruitment and inhibitory modulation.
Brain can stimulate between different stimluus it modality, its intensity, and location
Modality,which type of receptor is activated,
Intensity, the number of action potential created, and the frequency of the action potential, as the stimulus increases more receptors will respond
Location, acuity ( precision) size and number of receptive fields, overlap of receptive fields, and lateral inhibition.
Explain (using receptive field, primary, secondary and tertiary neurons, and convergence) why some areas of the body are highly sensitive to sensory stimuli and others are less sensitive.
The larger the receptive field the less sensitive the area will be ( the back) the smaller
Explain how lateral inhibition helps to isolate location
When put point of pen on tip of finger, it causes high stimulus of that specific neuron causing it to inhibit the other neurons next to it
Describe the Spinothalamic Tract and the Dorsal Column pathways.
Spinothalmic tract, pain temp, from the right side of body, comes in the top left when looking at the spinal column crosses over to bottom right and goes out the top right
Dorsal Column, touch/pressure and proproception, form the right side of body, comes in the top right and leaves the top right
Describe the various fibers types involved in the transmission of somatic sensation.
A-beta, largest fibers, meylinated, and transmit signals fastest
A-delta, fibers are thin, lightly myelinated
C-fibers, are unmyelinated
Which ones are used in mechanoreception, thermoreception and nociception
Neurofibrillary tangles found inside cells due to hyperphosphoryation of microtuble protein
Amyloid beta protein thought to cause degeneration
Degeneration of cholinegic neurons in forebrain
Know the interpretation of sound: frequency, amplitude and duration.
Sounds waves strike the tympanic membrane and cause vibration, which goes into the three bones of the middle ear, the stapes is attached to the oval window, this vibration of the oval window causes fluid waves in the cochlea. The fluid waves push on membrane of cochlear duct
energy is transmitted across the cochlear duct, into the tympanic duct and dissipates back to middle ear via round window, Hair cells in the cochlear duct create action potentials in sensory neurons of the nerve
Know the anatomy of the outer, middle and inner ear.