AP Final
What are the structures of the medulla oblongata?
- Pyramids ¨Pyramidal tracts ¨Decussation of the pyramids Crossing over point of the tracts -Olives/ olivary nuclei ¨Relay sensory information from stretch receptors in muscles/ joints -Nucleus gracilis and cuneatus ¨Relay somatosensory information from spinal cord to somatosensory cortex -Nerves ¨Hypoglossal nerves ¨Glossopharyngeal ¨Vagus
What are olfaction structure like?
- The olfactory epithelium in the roof of the nasal cavity and it contains olfactory sensory neurons, columnar cells, stem cells - Sensory neurons are bipolars
What are the pathways and ganglia for autonomic nervous system>
- Two neuron chains to reach effectors -Preganglionic neuron cell body resides in the brain or spinal cord. Preganglionic axon synapses with second motor neuronThin, lightly myelinated fivers -Postganglionic neuron cell body resides in autonomic ganglion, Outside of CNS, Extends to the effector organ Very thin, nonmyelinated fibers
What is the physiology of taste?
- activation of receptors - chemical binds to receptors - graded depolarizing potential - triggers generator potentials - Depolarization of membrane opens voltage gated calcium ion channels and calcium ions enter which causes release of neurotransmitters and produce action potential in axon of sensory neuron
What is the autonomic nervous system?
- involuntary nervous system, controls visceral motor system, can stimulate or inhibit effectors
What is consciousness and how do we measure it?
- it is undefined it involves simultaneous activity of cerebral cortex , neural activity - Alertness, drowsiness/lethargy, stupor , and coma
How does pigment synthesis, pigment bleaching, and regeneration work for rhodopsin?
- rhodopsin accumulates in the dark and vitamin A is oxidized to form cis retinal - It absorbs light and changes shape to trans-isomer. It eventually breaks down and separates into retinal and opsin - Enzyme within epithelial convert to cis
What is the function of the posterior columns fasciculus gracilis?
-Ascending Pathways - Somatosensory signals to brain: fine touch, vibration, proprioception from lower limbs
What are the following multineuron pathways? - Decussation - Relay - Somatotophy - Symmetry
1. Cross from one side to the other 2. Chain of 2-3 neurons. Relay like 1st, 2nd, 3rd order neurons 3. Spatial relationship among fiber tracts, an area of the body has an exact location in CNS 4. Paired right and left. Like spinal cord that has left and right symmetry
What are the two groups of descending pathyways? - Direct/Indirect
1. Direct - pyramidal tracts have pyramidal cells in precentral gyri that send impulses through brain stem and directly connect with the spinal cord 2. Indirect- all others brain stem pathways and all other motor pathways
What is the basal nuclei? - Location and composition - Function - Where does it receive input from
1. It is a cluster of nuclei embedded in central white matter on either side of diencephalon. Composed of caudate nucleus, putamen, globus pallidus 2. It is involved in movement and also behavior, cognition & perception. It acts a filter and limits inappropriate responses and limits unnecessary movements 3. Receives input from the entire cerebral cortex
What is lateralization for left and right hemisphere?
1. Left - language, math, logic 2. Right- visual/spatial skills, intuition, emotion, art/music - Lateralization refers to typically one hemisphere is more so dominant for these traits on this side
How does light transduction work with rhodopsin?
1. Light activates rhodopsin and activates g-protein, activates PDE 2. cGMP binds to cation channels, holding them open 3. In light PDE breaks down cGMP
What are the parts of the midbrain and their function?
- Cerebral peduncles Connect midbrain to the cerebellum - Cerebral aqueduct Connects third and fourth ventricles - Corpora quadrigemina Largest nuclei in brain - Superior colliculi Visual reflex centers, Coordinate eye and head movement - Inferior colliculi Auditory relay, Reflex response to sound - Substandia nigra High melanin content, Precursor to dopamine - Red nucleus, Causes limb flexion
What allows for lens shape to change?
- Ciliary body surrounding lens relaxes when viewing distant objects which pulls sphincter like smooth muscles away which creates tension and flattens lens - Cilliary body contracts when viewing nearby object to round up lens , Cillary body moves closer to lens and suspensory ligaments slacken
What is plantar reflex?
- Cutaneous stimuluation, flexing of the sole of foot, by toes curling down (babinski) negative and positive if dorisflexion of hallux
What is the medulla oblongata?
- Decussation (crossing over) of motor corticospinal tracts (pyramids) - Regulates breathing and heart beat, near instant death if damaged
What is the pons?
- Descending motor tracts - Function is Breathing, sleep arousal
What are wavelength, frequency, normal range frequency, amplitude, hearing loss?
- Distance between peaks the shorter the wavelength the higher the frequency. - 20-20000 wave/sec (Hz) - Height of sound wave - 90+ decibels hearing loss
What are the following diseases? Raynaud's disease Autonomic Dysreflexia
- Exaggerated vasoconstriction response, certain area does not receive proper oxygenated blood -Uncontrolled activation of autonomic neurons Typically in individuals with spinal cord injuries above T6 Blood pressure spikes Can be fatal
Phasic receptors vs tonic receptor?
- Fast adapting and report changes in the environment, impulses at the beginning or end of stimulus - Sustained response so constantly open so it does not give the ability to overly stimulated and little to no adaption
What is the midbrain? Function and composition
- Function is for movement, sensation, startle reflex -Contains the substantia nigra (works with basal body ganglia, movement)
Generator potential vs Receptor potential
- Generates action potential in a sensory neuron - Receptor is a separate cell and changes the amount of neurotransmitter releases
What is the cerebral cortex? - what happens - composed of what - structure of it
- He is where consciousness resides - Composed of gray matter so no fiber tracts and has billions of neurons - Arranged in 6 layers and is 40% of the total brain mass - Hemispheres are contralateral - Lateralization of function therefore each hemisphere is slightly specific
What can you treat pain and how does it work?
- Histamine, K+, ATP, acids, and bradykinin they act upon small diameter fiber - Endorphins and enkephalins are endogenous opioid analgesics, they are inhibitory neurotransmitters
What are CNS functions?
- Interpretation of sensory information - Planning and monitoring movement - Maintaining homeostasis - Higher mental function (language & learning)
What are the three parts of the multimodal association areas? - Anterior association area/prefrontal cortex - Posterior association area - Limbic association area
- Involved in learning and personality, contains working memory - Involved in pattern recognition - Regulates emotional magnitude includes: cingulate gyrus, parahippocampal gyrus, hippocampus
What does the white matter of the spinal cord contain?
- It contains myelinated and nonmyelinated nerve fibers - Contains axons of neurons that travel to and from the brain such as ascending (towards) , descending ( away), Transcending (perpendicular)
What mass does the brain stem compose, how is it organized, and what does it do?
- Organized similarly to spinal cord - Associated with 10 of the 12 cranial nerves - Produces "programmed" autonomic behaviors
What does the posterior and anterior horn carry what info?
- Posterior is somatic sensory/motor - Anterior is visceral sensory/autonomic
What are the first, second, third-order neurons?
1st- cell bodies reside in ganglio between receptor and spine, they conduct impulses from cutaneous receptors and proprioceptors to spinal cord, they synapse with 2nd order 2nd - Reside in the dorsal horn, transmit signals to thalamus or cerebellum, between spine and the brain 3rd- cells bodies reside in thalamus, relay impulses to the somatosensory cortex of cerebrum, receives at brain and interprets signal
How many pairs of spinal nerves and how many in each region?
8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal
What are the neurotransmitters in ANS?
ACh - acetyl choline Excitatory Parasympathetic fibers NE -- norepinephrine Inhibitory Sympathetic fibers
What are nonencapsulated nerve endings?
Abundant in epithelia and connective tissue - Non-myelinated, small diameter group c fibers - Respond to temperature and pain primarily
What is the primary somatosensory cortex? - What part does it belong in cerebral cortex
Consists of postcentral gyrus - It receives information from somatic sensory receptors in skin and proprioceptors in muscles/joints/tendons - Spatial discrimination to identify the region being stimulated -Somatosensory homunculus - part of the sensory area of the cerebral cortex
What does the cerebellum do and basic structures with grey/white matter?
Coordinates movement Works with cerebrum, basal nuclei brain stem & spinal chord 2 hemispheres Connected by Vermis Grey matter Cerebellar cortex & deep nuclei White matter Arbor vitae and cerebellar peduncles
What are the three things that protect the brain?
Cranial meninges- 3 protective membranes of dense irregular connective tissue Cerebrospinal fluid - brain buoyancy, temp, waste removal Blood brain barrier - collection of structures that seperates CSF & brain ECF from blood, acts as selective filter for glucose, electrolytes, amino
What is astigmatism?
Curvature of lens or cornea is irregular; light rays are not evenly refracted; results in blurred vision at all distanes
What is itch receptor?
Dermaly located and histamine activated - Nonencapsulated
Why is the hypothalamus the master gland?
Direct control or via relays through reticular formation Mediates reaction to fear Amygdala Periaqueductal gray matter Limbic system Emotional responses Anterior Directs parasympathetic function Posterior Directs sympathetic function
What are encapsulated nerve endings?
Enclosed in a connective tissue capsule and are mechanoreceptors
what is vestibular nystagmus?
Eye will drift toward opposite direction of movement
Where is blood brain barrier not found?
Hypothalamus and vomiting center of brain
What are tendon organs? (Proprioceptors)
In tendons Encapsulated tendon fibers Compresses nerve fibers when tendons are stretched Reflex causes muscle relaxation Can sense change in muscle tension
What is the third ventricle?
In the diencephalon and connected via interventricular foramen
What is the fourth ventricle?
In the hindbrain and dorsal to the pons - Connected via the cerebral aqueduct - Has openings
What is presbyopia?
Individual near point of accomodation is 10-20 in greater - 5th decade, difficulty ready and corrected with reading glasses/bifocals
What is Reciprocal inhibition?
Inhibit antagonistic muscles
What is the 5th lobe of the brain?
Insular and forms part o the floor. It is located deep
What is the premotor cortex? - What part does it belong in cerebral cortex
It corresponds to the motor areas of cerebral cortex - Anterior to the precentral gyrus,it sequences basic motor movements into complex tasks, it supply 15% of pyramidal tract fibers
At the circuit level how does the PNS process?
It delivers impulses to appropriate regions of the cerebral cortex via ascending sensory tracts
What is segmental level motor control?
It involves the reflex arc, it will go from receptor to spinal cord then reflex will happen then the stimulus will go back to efferent
What is the diencephalon?
It is composed of four structural units: Thalamus, Hypothalamus, Epithalamus, Subthalamus
What is the gustatory cortex? - What functional area of cerebral cortex?
It is deep in temporal lobe and we use it to perceive taste - sensory
What is gyri? - name the ones on the brain
It is elevated ridges of tissue and we have postcentral and precentral
What is the vestibular cortex? - What functional area of cerebral cortex?
It is for awareness of balance and it is adjacent to parietal cortex - sensory
What is Tactile/Merkel's discs?
It is in the epidermis and is a light touch receptor - Nonencapsulated
What is the primary auditory cortex? - What functional area of cerebral cortex does it belong to
It is located at the superior margin of the temporal lobe and it interpret auditory input such as pitchm loudness, and location
What is the olfactory cortex? - What functional area of cerebral cortex?
It is located near medial temporal love and piriform lobe - Its function is awareness of odors and it is part of rhinencephalon - sensory
What is frontal eye field? - What part does it belong in cerebral cortex
It is part of the motor area of cerebral cortex. - Anterior to premotor cortex, voluntary movement of the eyes
What is the visceral sensory area? - What functional area of cerebral cortex?
It is posterior to the gustatory cortex and it is for perception of visceral/body sensations
What is Broca area? - What part does it belong in cerebral cortex
It is present in one hemisphere only and usually left - special motor speech area that helps with speaking language - part of motor area in cerebral cortex
What is cerebral white matter responsible for and how is it arranged?
It is responsible for communication between hemispheres and it is arranged in tracts
What is auditory association area? - What functional area of cerebral cortex?
It permits perception and stores sound memory - sensory
How does visible light work?
It ranges from 400-700nm and it is different colors. It absorbs a certain wavelength and outputs a different - the light travels in photons, packets of energy, travel in wave like fashion
What is the multimodal association areas? - What functional area of cerebral cortex?
It receives input from multiple sense - it sends output to multiple areas and allows for integration and storage of previous experiences
What does the quantity of neurons reflect in the spinal cord?
It reflects the amount of skeletal muscle innervated
What is Hilton's law
Joints and muscles that move them are innervated by the same nerve
What is emmertropia?
Length of eye is ideal in anterior to posterior direction - Allows light coming through lens to focus directly on retina
What is refraction
Light bending through a material that converge at single point
How does light rays change lens when objects are close?
Light rays from objects closer to eye are more scattered an need more refraction so the lens becomes more thickened and refracts more than flattened lens so more light rays are focused on retina
What is light and dark adaptation?
Light- rod system turns off, uncoupling rhodopsin from cascade, cones rapidly adapt and desensitized to bright light Dark - cones stop functions and rods are still turned off, rhodopsin accumulates, retinal sensitivity activity and can take several hours
What are errors of refraction?
Limited accommodation due to aging lens or shape of eyeball
What are bulbous corpuscles/ruffini endings?
Located in the dermis, subcutaneous tissue, and joint capsules Respond to continuous pressure, encapsulated
What is the function of the corticospinal tract?
Motor information form motor areas of cerebral cortex - Descending
What is the function of the reticulospinal tracts?
Motor information from brain stem, maintenance of posture & limb orientation during movement - Descending
what are nictonic receptors?
Nicotinic receptors Responds to nicotine All postganlionic neurons Both sympathetic and parasympathetic Always stimulatory Opens ion channels Hormone-producing cells in the adrenal medulla Sarcolemma of neuromuscular junctions
What are the stages of sleep?
Non-rapid eye movement (NREM) Stage 1 Relaxation Alpha waves Stage 2 Arousal is more difficult Irregular EEG With sleep spindles Stage 3 Sleep deepens Theta and delta waves appear Stage 4 Arousal is difficult Dominated by delta waves Rapid eye movement (REM) Muscles inhibited (except for the eyes and diaphragm) Dreaming occurs
What is the function of the anterolateral system spinothalmic tracts?
Pain, temperature, certain types of touch to brain
What is abdominal reflexes?
Reflex contraction of abdominal muscles
What is the function of the tectospinal tracts?
Reflexive movements of head & eyes
What are proprioceptors?
Respond to internal stimuli that occur in skeletal muscles, tendons, joints, ligaments, and connective tissue - Relay information about body movement via muscle stretching
What are interoceptors?
Respond to stimuli within the body - internal viscera and blood vessels - chemical changes, tissue stretch, and temp
What are muscarinic receptors?
Responds to muscarine Mushroom poison Parasympathetic and sympathetic targets Ex. Eccrine sweat glands Effects can be stimulatory or inhibitory
What are exteroceptors?
Sensitive to stimuli arising outside the body - touch, pressure, pain, and temp receptors - found predominantly in the skin
What are PNS function?
Sensory and motor functions
What is somatosensory>
Sensory system that serves the body wall and limbs
What are tactile/meissner's corpuscles
Sensory terminals surrounded by schwann cells that sense light touch on hairless skin and are encapsulated
What are the upper motor neuropathies - Spinal Shock - Babinski
Spinal shock followed by muscle spasticity, flacid Positive Babinski sign (extension of big toe rather than normal plantar reflex)
What is hair follicle receptor?
Surround the hair follicle and respond to light touch
Adaption?
The greater the signal frequency the greater the stimuli strength
What does the brain develop from?
The notochord which was previously endoderm
What is the hypothalamus? - Function - Composition
The primary control center for the body and it regulates homeostasis - Forms the infrolateral walls of third ventricle - Composed of mammillary bodies and infundibulum
What is the thalamus? - Function - Composition
The relay station for information to the cerebral cortex: here information is relayed to appropriate area, regulates emotion, directs activity of motor cortices, projects memory/sensory inputs to association cortices - composed of bilateral nuclei that have interthalamic adhesion that connects the two nucleis it also form walls of third ventricle
What are other roles of sympathetic division
Thermoregulatory responses to heat Mediates blood vessel dilation Activates sweat glands Release of renin from kidneys Enzyme that causes formation of blood pressure-increasing hormones Metabolic effects Increases metabolic rate Raises blood glucose levels Mobilizes fat for fuel
What are fissures?
They are deeper grooves - Longitudinal fissure that seperates the cerebral hemisphere - Transverse cerebral fissure that separates the hemispheres from the cerebrum
What are lamellar/pacinian corpuscles?
They are dermaly located and respond to initial deep pressure - Encapsulated
What are ventricles?
They are filled with cerebrospinal fluid and continuous with each other. They are lined with ependymal cells and help keep the brain buoyant
What are muscle spindles? (Proprioceptors)
They are in perimysium of skeletal muscle Intrafusal fibers and enclosed in a connective tissue capsule and they detect and initiate reflex response to stretch - Encapsulated
What are photoreceptors? - Outer Segment - Inner Segment
They are modified neurons Outer Segments- They have receptive regions of the receptors, contain visual pigments, change shape as they absorb light Inner segments- join outer segment to neural layer. connects to cell body
What is sulci? - name the ones on the brain
They are shallow grooves - Central sulcus which is frontal/parietal - Parieto-occipital which is between these two - Lateral Sulcus which is between temporal/frontal/parietal
How does innervation of visceral muscle and glands work?
They area where they join is called varicosities - Acetylchone or norepinephrine are the neurotransmitters
What is projection fibers and where are they located within white matter
They connect cerebral cortex to rest of brain & spinal chord - They enter from the lower brain and tie the cerebral cortex to the nervous system and into internal capsule that has thalamus and basal nuclei - Then into the corona radiate which is a fan like arrangement of fibers throughout the cerebral cortex
What is association fibers and where are they located within white matter?
They connect grey matter of cortical gyri with one another and connect different parts of the same hemisphere
What are commissural fibers and where are the located within grey matter? - The largest commisural fiber
They connect right and left hemispheres by connecting corresponding gray areas of two hemispheres which allows for coordinated function - Corpus callosum
How does innervation of skeletal muscle work?
They place they meet is called neuromuscular junctions and they are regulated by graded potential (end plate potentials) - the neurotransmitter is acetylcholine
What are lower motor neurons?
Ventral horn of motor neurons that innervate skeletal muscles or effectors
What divides the spinal cord into right and left halves?
Ventral median fissure and Dorsal median sulcus
What are ventral vs dorsal roots?
Ventral roots contain motor fibers Dorsal Roots contain sensory fibers
What are the sensory neuropathies? Visceral Somatic Lower Motor Neuropathies
Visceral Sensory - incontinence, loss control of bladder Somatic sensory - pain, constant nerve pain, problems with nerve, but you perceive it as pain Lower motor neuropathies- paralysis
What is the retinal?
Visual pigment that absorbs light and is related to vitamin A - its isomer form bent shape, cis without light and trans when absorbs light
What is white matter vs gray matter?
White matter is mainly myelinated axons while gray matter is mostly cell bodies and nonmyelinated
What is flexor/cross extensor reflex?
Withdrawal/ flexor response to painful stimuli Activates opposite limb for balance
What is the pathway for hearing ascending? (towards brain)
cochlear impulses travel through spiral ganglion bipolar cells transmit signal from cochlear nerve to the cochlear nuclei of the medulla next to the superior olivary nucleus junction of the medulla and pons continue ascension to the lateral lemniscus and inferior colliculus finally to the medial geniculate nucleus of the thalamus and primary auditory cortex unusual pathway each cortex receives signals from both ears
What is the enteric nervous system?
the nervous system of the digestive tract and control GI tract
Cerebellum? - Mass% - Process inputs from - Structures
~ 11% of total brain mass Process inputs from cerebral motor cortex, brain stem, and sensory nuclei Provides timing and appropriate patterns for coordinated movement Structures - Bilaterally symmetrical, Divided into hemispheres, Connected by the vermis - Many small gyri called folia Fissures divide lobes Anterior Posterior Floccunlonodular Outer cortex of gray matter Internal white matter Purkinje cells/ fibers- send axons through white matter to synapse with central nuclei of cerebellum Arbor vitae
How does the hypothalamus regulate homeostasis?
¨Control center for ANS ¨Initiates emotional responses ¨Regulates body temperature ¨Regulates food intake ¨Regulates water balance ¨Regulates sleep-wake cycles ¨Controls endocrine system function
What is mamillary bodies?
¨Relay station for olfactory pathways
What type of fibers correspond to the following pain: - Sharp Pain - Burning Pain - Release glutamate and substance p as neurotransmitters
- Carried by a delta fiber - Nonmyelinated c fibers - Activate second order neurons
What is the function of posterior columns fasciculus cuneatus?
- Ascending Pathways - Somatosensory signals to brian: fine touch, vibration, proprioception from truck, neck, upper limbs
Sensation vs Perception?
- Awareness of the stimuli - Interpretation of the stimuli
What is the structure of the spinal cord? - Where does it begin and end? - What are the two enlargements? - What is the end of the chord called? - What anchors onto first cocygeal vertibrae?
- It extends from the foramen magnum to between 1st and 2nd lumbar vertebrae - Had two enlargements at cervical and lumbar because nerve roots for upper/lower limbs attach here - The end of the cord forms the conus medularis but spinal nerves that extend from conus medularis form the cauda equina - Spinal pia gathers beyond conus medularis to form filum terminale that anchors onto first coccygeal vertebra
How is the gray matter organized in the spinal cord?
- It is a butterfly like in shape and is connected in center by gray commisure - Dorsal horns that are entirely composed of interneurons - Ventral horns that are composed of cell bodies of somatic motor neurons, axons fuse to become the ventral roots -Lateral horns - appear in the thoracic/lumbar region and composed of autonomic neurons
What is the structure like of the lens? - Lens structure - Lens epithelium - Lens fibers
- It is bioconvex (), transparent, flexible, avascular, can change shape to focus light - Lens epithelium is on anterior lens surface - Lens fibers that form the bulk of the lens and they pack together to form layers and contains crystallins and continually added throughout life
What is the primary somatic motor cortex? - what part does it belong in cerebral cortex
- It is located in the precentral gyrus of frontal lobe and is consist of pyramidal cells that are used for conscious control of voluntary movements and long axons project to the spinal cord. - part of the motor area in cerebral cortex
What is the somatosensory association cortex? - what functional area of cerebral cortex does it belong?
- It is located posterior to primary somatosensory cortex and it integrates sensory inputs from primary somatosensory cortex - belongs to sensory sensory area of the cerebral cortex
What composes the epithalamus?
-Dorsal portion of the diencephalon and Roof of the third ventricle -Pineal gland that secretes melatonin
What is the medulla oblongata and functions
-Inferior part of the brain stem -Functions ¨Maintains homeostasis ¨Cardiovascular center -Adjusts force and rate of contractions ¨Respiratory center -Rate and depth of breathing ¨Other centers -Vomiting, hiccupping, swallowing, coughing, and sneezing
What is the pons and composed of?
-Located between midbrain and medulla oblongata ¨Composed primarily of conduction tracts -Cranial nerves ¨Trigeminal ¨Absucens ¨Facial nerves
What is the primary visual cortex and visual association area? - what functional area of cerebral cortex does it belong.
-Occipital lobe in the calcarine sulcus and receives information from retina -Covers most of the occipital lobe and uses past visual experience for interpretation - Sensory area
What is the pathway for smell?
1. Odorants in inhaled air are detected by olfactory neurons, chemical stimuli are transduced to electrical signals, transmitted to various regions of brain for identification 2. Activation of olfactory receptors and odorants are dissolved in mucus surrounding olfactory neuron's cilia -odorant-binding proteins transport odorants through _mucus to receptors on cilia of olfactory neuron 3. Binding of odorant to receptor activates G-protein 4. Activated G-protein triggers enzyme adenylate cyclase to convert ATP into cyclic AMP (cAMP) 5. cAMP opens ion channels; allow sodium and calcium ions to enter cell; causes depolarization and action potential generation if threshold is reached 6. Once action potential is generated, odorant has been transduced from chemical stimulus to electrical (neural) signal
What is the secondary and structure of the mature brain from the hindbrain?
1. Primary vesicle is the hindbrain turns into metancephalon and myrocephalon 2. Metancephalon- brainstem: pons and cerebellum 3. Myalencephalon- brainstem: medulla oblongota
What is the secondary and structure of the mature brain from the midbrain?
1. Primary vesicle midbrain turns into mesencephalon that then turns into brainstem which is the midbrain
What are the 5 steps of reflex activity?
1. Receptor 2. Sensory Neuron 3. Integration center 4. Motor Neuron 5. Effector
What are the subdivisions of the spinal cord in white matter? - Funiculus - Posterior funiculus - Lateral funiculus - Anterior Funiculus
1. Region of white matter 2. Sensory info 3. Sensory and Motor 4. Motor
What are the 4 types of memory? - Declarative, procedural, motor, emotional, automatic
1. Short and long term that are facts 2. skills 3. muscle memory 4. emotions 5. formed via first impression
What is projection level motor control?
1. Spinal cord acts through direct/indirect pathways 2. Upper motor neurons intiated pyramidal (direct) 3. Brain stem motor nuclei regulated indirect (indirect) - Involuntary control going to brain stem or hypothalamus through direct or indirect pathway
What is the must haves for generating a signal in somatosensory?
1. Stimulus energy must match the specificity of receptor 2. Stimulus must be applied within the receptor sensory field 3. Stimulus energy must be converted into a graded potential 4. Transduction 5. Graded potential must reach the threshold level so voltage gated sodium channels open
What is the secondary and structure of the mature brain from the forebrain?
1. The forebrain is the primary and secondary is telencephalon and dicenphalon 2. Telencephalon - cerebrum 3. Diencephalon - diencephalon
What is the precommand level in motor control?
1. Voluntary action, planned coordinated and cerebellum acts on pathway via thalamus 2. Basal nuclei receives input from all cortical areas
What is the epidural space, dural space, subdural space, and subarachnoid space?
1. Where epidural is done 2. Separation of dura layers to provide sinuses for drainage of brain 3. Houses serous fluid & some drainage veins 4. Houses major brain blood vessels and CSF (spine tape done here)
What is the infundibulum?
Connects the pituitary gland
What are the 4 types of brain waves? - Hz, type, when present
Alpha (8-13 hz) Regular, rhythmic Indicate calm wakefulness Beta (14-30 hz) Less regular Mentally alert and concentrating Theta (4-7 hz) Irregular, most common in children Appear when concentrating Delta (< 5 hz) High amplitude Observed during sleep In awake adults Indicated brain damage
What are the parts of the internal chamber and fluid? - Anterior segment - Posterior segment
Anterior segment is filled with aqueous humor similar to blood plasma and drains constantly to fill scleral venous sinus and it supplies nutrients and oxygen to lens and cornea. Anterior Chamber - between corner and iris Posterior Chamber- between iris and lens Posterior segment is filled with vitreous humor which is a clear gel, transmit light, supports lends, and hold neuronal layer, contributes to interocular pressure
What is dermatome?
Area innervated by cutaneous branches of a single spinal nerve - Areas can overlap
Where does the adrenal medulla arise from embryologically?
Arise from the same tissue as sympathetic ganglia
What are upper motor neurons?
Pyramidal cells of motor cortex and neurons of subcortical motor nuceli
What are adrenergic receptors?
Binds norepinephrine Can be either excitatory or inhibitory Sub classes Alpha Beta
What are stretch reflexes? - Characteristics - Adaptibility
Branches of afferent fibers synapse with interneurons inhibiting antagonistic muscles and exciting agonistic muscle - Monosynaptic, Ipsilateral - Adjust sensitivity- brain can adapt to increase gamma motor output when speed and difficulty of motion increase
What are the regions of the brain?
Cerebrum/cerebral hemispheres Diencephalon Brain stem Cerebellum
What regulates sleep?
Circadian rhythm and by hypothalamus it is hormonally controlled
What is near point of accomodation?
Closest point at which eye can focus on an object: increases with age as lens become less flexible
What are Joint Kinesthetic Receptors? (Proprioreceptors)
Composed of: Lamellar corpuscles Bulbous corpuscles Free nerve endings Tendon organ Provide information on movement
What is the processing that the cerebellum does?
Fine-tunes motor activities Motor areas in the cerebral cortex notify the cerebellum of voluntary muscle contraction Via relay nuclei in the brain stem Cerebellum receives information from somatic proprioceptors throughout the body and visual equilibrium pathways and Evaluates body position and momentum Cerebellar cortex coordinates muscle movement Ensures smooth muscle movement Cerebral motor cortex influences motor neurons of the spinal cord
How does the sympathetic innervates adrenal medulla?
From thoracic splanchnic nerves to celiac ganglion it terminates in hormone producing cells of adrenal gland and secrete norephineprhine and epinephrine. - AKA noradrenaline and adrenaline
What is the limbic systems function and structures? - Amygdaloid body, fornix, cingulate gyrus, hippocampus
Function is to be an Emotional center and is Relayed mostly through the hypothalamus Structures: Amygdaloid body- Nucleus that rests on the tail of caudate nucleus and Responds to perceived threats Fornix- Links the regions together Cingulate gyrus- Plays role in expressive movements Hippocampus- Plays a role in emotional memory
What is the function and structures reticular formation?
Function: ¨Maintains cerebral cortical alertness ¨Filters out repetitive stimuli ¨Regulates skeletal and visceral muscle activity ¨Inhibited by sleep centers ¨Depressed by alcohol and tranquilizers Structures: ¨Raphe nuclei ¨Medial group of nuclei ¨Lateral group of nuclei ¨Reticular activating system (ras) ¨Sends impulses to cerebral cortex }Keeps brain alert
How does special and general sense differ in action potential and similar?
General- they have specialized receptive endings to detect touch, temp, or pain. Stimuli alters resting membrane potential of sensory neurons to produce action potential that reaches CNS Special- detect light, chemical, sounds and transduce them into action potentials. Also propagated through axons of peripheral neurons to CNS They both are first processed by sensory nuclei and transmitted to thalamus and primary cortex areas for awareness and identification
What is the wernicke's area?
Helps understanding language
What determines pitch and intensity?
Higher frequency (#waves Hz) is high pitch and high amplitude (Height of wave decibels) is high intensity - Pitch is determined by which area of basilar membrane vibrates - Loudness determined by how much basilar membrane vibrates
What is the function of the cerebrum?
Higher mental functions, interpretation of sensory stimuli, planning and initiation of movement
What is the function of the brain stem?
Maintains homeostasis, controls some reflexes, monitors movements, integrates and relays information
What is the function of the cerebellum?
Monitors & coordinates movement
What are the following type of reflexes? Monosynaptic Polysnaptic Visceral Somatic
Monosynaptic reflex: Only one synapse between afferent and efferent neurons (e.g. Simple stretch reflex) Polysynaptic reflex:Multiple synapses between afferent and efferent neurons (e.g. Golgi tendon reflex) Visceral reflexes: reflex arcs connected to internal organs, largely involving Autonomic nervous system Defecating or vomiting Somatic reflexes: involve somatic sensory and somatic motor neurons
What do the following parts of cerebellar peduncles do? Paired fiber tracts Superior cerebellar peduncles Middle cerebellar peduncles Inferior cerebellar peduncles
Paired fiber tracts Connect the cerebellum to the brain stem Ipsilateral From the same side of the body Superior cerebellar peduncles Connects cerebellum and midbrain Middle cerebellar peduncles Carries information from the pons to the cerebellum Voluntary motor activities Inferior cerebellar peduncles Carry sensory information to the cerebellum from muscle proprioceptors and vestibular nuclei
Local vs diffuse effects of parasympathetic and sympathetic?
Parasympathetic Rather direct stimulation ACh quickly broken down Sympathetic Innervation can be indirect Longer lasting effects Circulating hormones stay in system much longer
What is the vanilloid receptors?
Plasma membrane receptor that has ion channel opened by heat, low pH, or chemicals like capsaicin - nonencapsulated
What is tendon reflex?
Polysynaptic Opposite of stretch reflex Muscles relax when tension is applied to tendons Reciprocal activation Basically this is the contraction part of the stretch reflex. The antagonist muscle is now activated.
What is the vestibulospinal tracts?
Posture & balance
What are the 3 neocortex areas?
Primary Motor Cortex Primary sensory cortices Receive and process sensory input associate areas
What is the function of the diencephalon?
Processes, intergrates & relays information, maintains homeostasis, regulates biological rhythms
How does perceptual detection occur in PNS?
Projection Stimulation of local sensory fibers allows for location of the stimuli Detect stimulus that has occurred Inputs from several receptors must be summed for perception to occur Magnitude estimation perceived intensity increases as stimuli intensity increases Spatial discrimination Allows for identification of pattern or site of stimulation Feature abstraction Receptors are tuned to a property or feature over others Quality discrimination Differentiate the components of a sensation Qualities/ submodalities Ex. Taste something = salty and sweet, etc.... Pattern recognition
What is the function of spinocerebellar tract?
Proprioceptive signals to cerebellum
What is opsin?
Proteins that combine with retinal and produce 4 pigments
What are the five basic tastes?
Sweet- from sugars, lead paint, and ethylene glycol, alcohols. Transduced by g-protein and leads to release Ca2+ Sour - produces by acids (hydrogen ions) Salty - produced by metal ions (sodium and potassium ions) Bitter - produced by alkaloids ( nitrogen containing compounds, rancid, poisonous) transduced by g-protein and leads to release of Ca2+ Umami - amino acids, glutamate, aspartate. Taste associated with meat or broth. Transduced by g-protein that leads to release of Ca2+
Sympathetic vs parasympathetic tone?
Sympathetic/ vasomotor tone Smooth muscle of blood vessels Innervated by sympathetic nervous system Partial constriction Stimulated by low blood pressure Vasomotor fibers Fire less when BP is high Parasympathetic tone Dominate the heart and digestive tract Can be overridden by the sympathetic division under stressful conditions Activate most glands Except adrenal and sweat glands
What are lateral ventricles?
The are paired and within the cerebral hemisphere - Seperated by the septum pellucidum
What secure the spinal cord to the dura mater?
The dura mater is not attached to the vertebral column it is attached to the spinal cord from the pia mater via denticulate ligaments
What is emmetropic state?
The eye is relaxes and focusing on distant objects. Lens is in normal flattened shaped and parallel light rays are minimally refracted by cornea and focused on retina