-
What are the general functions of the Nervous System?
- -Sensory Function: Receives incoming info (stimuli) from SENSORY RECEPTORS
- -Integrative Function: Interprets and processes info to determine approproate responses
- -Effector Function: Produces OUTGOING signals (from brain) to initiate a response in muslces or glands
-
What does the CNS contol?
-Brain and spinal cord ONLY
-
What does the PNS control?
-Neural Tissue outside the CNS
-
What kind of myellin sheeth does the CNS have?
-Oligodendrocytes
-
What kind of myellin sheeth does the PNS have?
-Schwann Cells
-
Responses travel down different _________ (from stimuli)
-axons
-
What are the brain and spinal cord protected by?
-Meninges and spinal fluid
-
Where is the CNS centralized?
-Within the skull and vertebral column
-
What functions does the CNS play a part in?
- -Simple reflexes (through spinal cord)
- -Complex reflexes
- -Higher order function: Memory, learning, intelligence (WHAT THE PNS LACKS)
-
Where is the PNS centralized?
-Mostly outside of skull and vertebral column
-
What are the Peripheral nerves?
-Cranial nerves (sensory neurons off BRAIN mostly lead to head and face ex. numbind @ dentist) and Spinal nerves (Come off spinal cord)
-
What are the two types of peripheral ganglia?
- -Sensory ganglia
- -Autonomic nervous system ganglia (controls involuntary things)
-
What are ganglia?
-Pockets/collection of cell bodies, for signals coming INTO brain
-
______________ division brings sensory info FROM receptors
-Afferent: approach (sensory) into brain
-
______________ division carries motor commands TO effectors
-Efferent: Exit
-
Neurons don't __________ they only form new _____________
-divide, connections
-
What are nerve cells (neurons)
-Electrically active cells that process and conduct information in the form of electrical signals
-
Neuroglia (glial cells) are _________ cells NOT ______
support, neurons
-
In the PNS, glial cells are:
-Satellite cells, Schwann cells
-
Schwann Cells are responsible for:
Making the myelin sheath that surrounds the axon
-
In the CNS, glial cells are:
-oligodendrocytes (myeling sheath), astrocytes, microglia, ependymal cells
-
What role do astrocytes play
-They sit between neurons and hold them together
-
For the PNS, _________ are responsible for the collection of nerve cell processes (fibers) for transmission of information.
-Nerves
-
For the CNS, _________ are responsible for the collection of nerve cell processes (fibers) for transmission of information.
-White matter, fiber tract, column
-
White matter=________
-axons
-
In the PNS, ____________ are responsible for the collection of nerve cell bodies for processing information.
-Ganglia
-
In the CNS, ____________ are responsible for the collection of nerve cell bodies for processing information
-Grey matter, nucleus, cortex
-
Grey matter is composed of a bunch of _____ ________ bundled together.
-cell bodies
-
Neuroglial cells surround and support both nerve cell ______ and _____
-bodies, processess
-
Posterior (dorsal) _______ horns contain somatic and visceral sensory nuclei of grey matter.
-gray
-
Anterior (ventral) _______ horns deal with somatic motor control.
-gray
-
_________ gray horns contain visceral (ANS) motor neurons.
-lateral
-
The size of grey matter (#of nerve cells) is related to the size of body _________.
-Innervated
-
Cervical and lumbar enlargements are due to:
-A bunch of neurons leave that area ex. arm and legs
-
White matter of the spinal cord are divided into six columns (funiculi) containing ________.
-Tracts (posterior, anterior, lateral columns)
-
__________ tracts relay info from the spinal cord to the brain
-Ascending (INTO brain)
-
__________ tracts carry info from the brain to the spinal cord.
-Descending (send from to brain to EFFECTORS)
-
Dorsal (posterior) root of spinal nerve is all __________ (afferent) info
-sensory
-
Ventral (anterior) root of spinal nerve is __________ (efferent) info
-motor
-
Spinal nerves are a mixture of sensory and _______ fibers (vertebrae have both)
-motor
-
Each spinal nerve receives sensory input from one _________---
-Dermatome
-
What's a dermatome?
-A region of the skin monitored by the sensory afferents of a single spinal segment.
-
Another term that descriobes cells that function as afferent of the CNS:
-sensory neurons
-
Diencephalon consists of:
-Thalamus and hypothalamus
-
Mesencephalon is the technical term for:
-Midbrain
-
The cortex of cerebral hemisphere (grey matter on outer surface) is the _______________ level of processing
-highest
-
Where is info stored in the brain?
-Cerebral Cortex
-
Basal nuclei of cerebral hemisphere is responsible for _______ control.
-Motor
-
Thalamus is responsible for:
_Processing central info (info travels from thalamus INTO brain)
-
Hypothalamus is responsible for:
- ANS (involuntary and hormones) and endocrine control
- --very small but does alot
-
Cortex of cerebellum (outer portion of cerebellum) is responsible for:
Motor control (coordination)
-
Fibers are:
bundle of axons in brain
-
Projection fibers:
ASCENDING and DESCENDING ttracts of the spinal cord, brain stem, and brain
-
Association fibers:
- Connect between areas on the same side of the CNS
- ---constantly making new association fibers
-
Commisural fibers:
- Connect between ateas on the opposite sides of the CNS
- ---Coordinate right and left hemisphere, can function without connection
-
Meninges:
layers of connective tissue (3 total layers protecting the brain and spinal cord)
-
What are responsible for protection and support of the CNS?
- -Skull, vertebrae, ligaments, muscles (protect brain and spinal cord)
- -Meninges
- -Cerebral spinal fluid
- -Blood-brain barrier
-
Meninges are specialized CT layers, 3 types:
- -Dura mater: hard matter, outer layer
- -Arachnoid mater: middle layer
- -Pia mater: soft, sits directly on top of the brain and spinal column
-
Meninges provide _______ stability and ________ absorption
-physical, shock
-
Meninges support _____ ________ entering and exiting the CNS tissue
blood vessels
-
Spinal Meninges anchor the _____ _______
- spinal cord
- -base: to coccyx via filum terminale and coccygeal ligament
- -top: tp periosteum of foramen magnum
- -laterally: denticualte ligaments (connects to Pia mater and lateral to spinal cord)
-
How do spinal meninges provide cushioning?
- -Epidural space with epidural fat separates dura mater from walls of vertebral column
- -Subarachnoid space is filled with CSF
-
Folds of ______ _______ help stabilize the brain
- dura mater
- -contains sinuses that serve as veins
-
Cereobrospinal fluid (CSF) is produced in:
inside ventricles from incoming blood
-
CSF diffuses out of capillaries of the ________ ________ into ventricles
Choroid plexus
-
CSF exits venricles into _________ space through apertures of the 4th ventricle
subarachnoid
-
CSF circulates through subarachnoid space of spinal and cranial meninges and exits across _________ __________ into the superior sagittal sinus (vein)
arachnoid granulations
-
CSF comes from _____ and returns to ______
blood
-
CSF transports _________, _________ _________, and _______ products
nutrients, chemical messengers, waste (circulate in spinal fluid and goes to brain)
-
CSF provides _________ and buoyancy
cushioning
-
Blockage of CSF circulation causes pressure in ____________
ventricles
-
Enlarging ventricels damage ________ tissue
neural
-
What is hydrocephalus?
- "Water on the brain"
- -body makes CSF but can't transfer from ventricels, comprresses neural tissue....would need to manually open apeture for it to drain into subarachnoid space
-
__________ allow CSF to leave subarachnoid space
Apetures
-
A fiber tract form the cerebellum to the anterior horn of the spinal cord is:
-a descending projection fiber tract carrying motor info
-
Commisural fibers go from _______ to _________
tract
-
Interneurons (association neurons):
- -Located mostly within the CNS
- -Interconnect among nerve cells
- -Function in processing info
-
Satellite cells:
- surround neuron cell bodies within ganglia (regulatory function:O, CO2)
- -make up myellin sheath
-
Schwann cells:
-Ensheath axons and dendrites in PNS
-
Unmyelinated axon:
Schwann cell ensheaths sections of many axons
-
Myelinated axon:
Schwann cell ensheaths a SECTION of a SINGLE axon
-
Nodes of Ranvier:
gaps between Schwann cells
-
Myelin causes axons to to transfer _______ _______ and info quickly
Action potentials
-
Astrocytes (supporting cells):
- -largest and most numerous of CNS
- -structural support: scar tissue formation (connect between neurons, surround capillaries)
- -regulate interstitial fluid components
- - make up blood-brain barrier (acts like border control for brain)
-
Blood Brain Barrier:
- -Restricts migration of cells and diffusion of molecules out of capillaries of the brain:Tight Junctions between endothelial cells & Astrocytes cover capillary surfaces
- -Restricts diffusion of CSF our of ventricles: Tight junctions between ependymal cells
- -Incomplete barrier in areas:Parts of the hypothalamus, pituitary gland, pineal gland (mostly where hormones are produced)
-
What are ependymal cells?
- (phagocytes) surround all chambers in the CNS and help circulate what comes in and goes out
- ---Regulates CFS
-
Microglia:
Phagocytic cells-remove debris, pathogens, etc.
-
Ependymal cells:
- -Line chambers within CNS
- -Produce CSF in choroid plexus regions
- -Circulate CSF
-
Damage to nerve cell = _______ _______
- neuron death
- -Few if any germinative cells in adult brain
- --Nervous system unable to repair itself if damaged
-
What happens when nerve cell axon in CNs is damaged?
- -Oligodendrocytes reabsorb myelin
- -Astrocytes fill in area forming scar tissue (can't conduct electrical impulses so forms scar tissue)
- -Growth inhibiting factors secreted by oligodendrocytes and astrocytes (NO new production of neural tissue)
-
What happens when the nerve cell axon in PNs is damaged?
- -Schwann cell myeling pathway can guide regenerating axons and sensory dendrites
- ---SOME regeneration, can get SOME neural function back bc of schwann cells, oligos do same
-
Herpes:
Latent infection of sensory neurons in peripheral ganglia
-
Electricity: _________ of electrons
- flow
- --Force is an electrical gradient, always negative to positive
-
Bioelectricity: flow of ______
- ions
- --force is chemical gradient and electrical gradient combined
- ---Diffusion is the driving force
-
Action Potentials must be initiated at the _______
soma (or dendrites)
-
Stimulus can change the ______ of a cell if at axon hillock and AP will go forward IF storng enough
-charge
-
Transmembrane potential (resting potential)
-Driving force for ion flow across the cell
-
Extracellular fluid:
higher concentrations of Na ions, CL ions and Ca ions
-
Intracellular fluid:
- higher concentrations of K ions and negatively charged proteins
- --want to keep negative
-
Concentration gradient's ____________ by active transport of Na ions out of cell and K ions into cell
-
Charged ions must go through ______, can't go across membrane alone
protein
-
Gated channels open in response to various stimuli/responses:
- -Ions flow across membrane by diffusion DOWN conc gradient
- -Typically only open BRIEFLY
-
Ion flow across a membrane requires:
- -Chemical and/or electrical conc gradient (driving force):Transmembrane potential
- -Pathway: Ion channel through the membrane
-
Ion flow through the cytoplasm of interstitial fluid (local current) requires:
-Chemical and/or electrical conc gradient (driving forcE)
-
Local current:
- -Driving force is the conc gradient created by ions coming across membrane through open channels
- -Ions travel a short distance through cytoplasm of interstitial fluid: Cyto and inter have high resisitance to ion flow, Depolar and Hypopolar effect DECREASES with distance form open channel
-
Local currents transmit bioelectric signals over ________ distances
- short
- --Typical of dendrites and cell bodies in NS
-
Action Potentials needed to transmit bioelectric signals over ______ distances
- long
- --Typical of axons and long dendrites of unipolar and bipolar sensory neurons
- --Unique to "excitable" cells (so they can pass changes in charge rapidly)
-
Sodium ion channel:
- -Open rapidly in response to depolarization
- -Inactivate rapidly after opening and can not reopen until return to RESTING STATE (Absolute refractory period-can not reopen)
-
Porassium ion channel
- -Open slowly in response to depolarization
- -Close slowly after repolarization
-
Steps involved in an Action Potential:
- 1. Membrane depolarization stimulus occurs (some type of stimulus to open 1 of 3 channels)
- 2. Sodium channel activates, flow into cell and depolarize it MORE
- 3. Sodium channel inactivation, ions stop flowing in
- 4. Potassium channel activates: ions flow OUT of cell, repolarizing and then HYPERPOLARIZING the membrane (ESTABLISHES REFRACTORY PERIOD)
- 5. Return to normal permeability:both sodium and potassium channels close
-
Action Potentials Ion restoration:
- -Only a small amount of sodium ions and potassium ions corss the membrane
- -Transmembrane potential (store potential E for AP's) can power MANY AP's before becoming depleted
- -Sodium potassium ATPase exchange pump maintains transmembrane potential over time but isn't needed for each AP )consistent.
-
Generation of AP follows all-or-none principle:
-Requires threshold depolarization (at hillock) to initiate AP
-
Threshold depolarization:
- Amount of depolarization needed to open enough voltage gated Na channels
- -Comes from LOCAL CURRENT spreading through cytoplasm in SOMA
-
Continuous propagation definition:
- -Propagation of AP along entire membrane in series of SMALL STEPS
- --UNMYELINATED axons
- ex: playing telephone game, it eventually reaches end
-
Saltatory propagation definition:
- -Propagation of an AP from NODE TO NODE, skipping internodal membrane
- --MYELINATED axons
- ex: playing telephone game but skipping ten people each turn, much faster
-
Steps of continuous propagation of AP:
- 1. Threshold level of local current spread to AP initiation site (change of charges reaches hillock)
- 2. AP is inititated in small segment of axon:
- -voltage gate Na channels open, Na flows in, channels inactivate (depolarize)
- -Voltage gated K channel opens, K flows out causing repolarization, which closes K channels
- 3. High conc of Na ions produces local current that spread down cytoplasm, bringing adjacent segment of axon to threshold
- 4. AP is initiated in the adjacent SMALL segment of axon (spread slowly)
- 5. Propagation
- -Cycle is repeated: local current spreading from each AP creates an AP in the next adjacent segment
-
Steps of saltatory propagation of AP:
- 1. Threshold level of local current spreads to AP initiation site (hillock)
- 2. Ap is initiated in small segment of axon
- -Voltage gated Na channels open, flows in, channel inactivates
- -Voltage gated K ion channel open, flows out causing repolar which closes channels
- 3. High conc of Na ions produces local current that spread over longer distances down CYTOPLASM, bringing adjacent nodes of axon to threshold
- -Schwann cell causes current to spread faster
- 4. AP is initiated in these adjacent nodes
- 5. Propagation:
- -Cycle is repeated: local current spreading from each AP creates an AP in adjacent nodes
-
Type A fibers:
- Fast, large fibers
- -Largest diameter, myelinated
- -Motor neurons to skeletal muscles
- -Fast sensory info (pain receptors)
-
Type B fibers:
- -Small diameter, myelinated, moderate speed
- -Slow sensory info (warm/cold senses)
-
Type C fibers:
- -small diameter, UNMYELINATED, slowest
- -Efferent neurons sending AP's to smooth and cardiac muscles, gland cells
- -Slow sensory info (warm/cold senses)
-
Synapse: cell to cell _________
- junction
- -Presynaptic cell (axon), and Postsynaptic cell (Neuron, muscle, or gland)
-
Chemical synapses have ________ filled with neurotransmitters to cros synapse
vesicles
-
Electrical Synapse:
- -Rare in NS
- -Pre- and postsynaptic cells are bound by interlocking membrane potentials (GAP JUNCTIONS)
- -Ion current flows directly from presynaptic cell to postsynaptic cell
-
Chemical synapses:
- -Neurotransmitters released from axon terminal of presynaptic neuron
- -Neuro- diffuses across synaptic gap
- -Neuro- binds to receptors of chemically gated channels in post- cell membrane
- -Neuro- is removed from gap by diffusion, re-uptake, and or degradation (Acetlycholine esterase)
-
Direct acting control of chemically gated ion channels:
- -Fastest effect
- -Neurotransmitter (like Ach) binds to receptro that is part of the gated channel (acts directly ont hat channel
-
Indirect acting control of chemically gatred ion channels:
- -Slow, takes longer to have effect
- -Neurotransmitter binds to receptor that controls gated channel though secondary messenger produced by G PROTEIN or other intracellular enzymes
- --Primary messenger: neurotransmitter
- --Secondary: (opens channel) intracellular molecule (indirect receptors), often cyclic AMP or cyclic GMP
-
The type of receptor determines the ___________
response
-
Excitatory Post-Synaptic Potential (EPSP):
- -Gated channel opens for Na ion channels
- -Depolarizing synaptic potential that promotes AP initiation by bringing axon hillock closer to threshold
- ---Need SEVERAL to bring axon hillock to threshold for AP to occur
-
Inhibitory Post-Synaptic Potential (IPSP):
- -Gated channel opens for K or Cl ion channels
- -Hyperpolarizing synaptic potantial that suppresses AP initiation
-
Simplest level of info processing occurs at ________ level
- cellular (cell body):needs to be strong to get to hillock
- -Excitatory and inhibitory potentials are integrated and determine whether or not an AP is initiated
-
EPSP and IPSP local ion currents combine through __________
Summation
-
Temporal summation:
Over time, EPSP's coming at the SAME time or continually
-
Spatial summation:
2 EPSP's coming from DIFFERENT TERMINALS
-
Synaptic potentials (that trigger AP's) can only travel for a _________ distance
short
-
PNS neurotransmitters:
- -ACh- cholinergenic synapses
- -Norepinephrine- adrenergic synapses
- ----the synapses are what happnes when released
-
Cholinergenic synapses:
- -Presynaptic cell contains vesicles of ACh
- -Postsynaptic cell has chemically gated ion channels and recepetors for ACh
- -Synaptic cleft has ACh Esterase enzyme that breaks down ACh
-
Function of cholinergenic synapses:
- -AP reaches axon hillock
- -Depolarization by AP opens Ca ion channels in axon terminal, allowing Ca to flow IN
- -Ca ions cause vesicles to undergo EXOCYTOSIS, releasing ACh into synaptic cleft
- -ACh drifts across synaptic cleft, binds to receptors, causing ion channels to open
- -Synaptic delay: time required for Ca to rush inm neurotransmitter release and diffusion, and gated channels opening (small amount of time)
- -ACh is broken down by AChE: Choline reabsorbed by presynaptice neurons and recycled
-
When does synaptic fatigue occur?
-When sotres of ACh are exhausted (neurons need a break like muscles)
-
Postsynaptic receptor properties determine effect of neurotransmitter on __________ cell (receptor type)
- postsynaptic
- -Ex: ACh produces EPSPs at some synapses and IPSPs at other synapses due to diff types of postsynaptic receptors
-
Amount of neurotransmitter released into _____ ______ and how long it remains determines amount of _____ or IPSP current in postsynaptic cell
synaptic cleft, EPSP
-
Agonists (mimetics):
- -Mimic effect of neurotransmitter (stimulate receptor)
- -Biind to post synaptic receptor
- -Affect removal of NT from synaptic cleft
-
Antagonists (blocking agents):
- -Block effect of neurotransmitter (so they're not sent)
- -Bind to post synaptic receptor
- -Affect removal of NT from synaptic cleft
-
Many neurotransmitters have more than one type or __________ ________ receptor
Post synaptic
-
Nicotinic cholinergenic receptors:
- -Automatically binds choline
- -Skeletal muscles, autonomic ganglia
- -Excitatory
-
Muscarinic choinergenic receptors:
- -Excitatory OR inhibitory (depending on location)
- -Visceral muscles, cardiac muscles, CNS
- -Atropine is inhibitory
-
Alpha adrenergic (adrenaline) receptors:
- -Excitatory effect on smooth muscles of bv's of skin and viscera, causes constriction (from rush of adrenaline, high bp)
- --Alpha blockers: reduce hypertension
-
Beta adrenergic (adrenaline) receptors:
- -Beta 1: excitatory on cardiac muscles
- --Beta 1 blockers: reduce heartrate
- -BEta 2: inhibitory on smooth muscles of respiratory tract, causes relaxation
- --Beta 2 blockers: cause respiratory constriction
-
Monoamine synapses: (norepinephrine, epinephrine, dopamine, serotonin)
- -Monoamine oxidase degradation
- ---MAO inhibitors (slow breakdown of epi and norepi)
- -Selective reuptake into presynaptic terminal (anti-depressants)
- ---SSRIs(selective serotonin reuptake inhibitors): serotonin remains in synaptic cleft
- -Ecstasy (stimulates seratonin release), like being on hardcore antidepressants
- -Cocaine (blocks reuptake of dopamine)
-
Pathways connecting _______- centers to one another and to motor neurons.
- Control
- -Cortico spinal and cortico bulbas tracts (pathways or neurons going to spinal cord)
- -MEdial pathways and lateral pathways
-
Somatic motor neurons innervate skeletal muscles of _______, _________, and _______ trunk
arms, legs, body
-
Motor neuron bodies (in brainstem):
-cranial nerve motor nuclei in medulla, pons, and midbrain
-
Reflex:
Direct sensory info to motor neurons
-
Voluntary reflex:
Cerebral cortex plans and initiates voluntary muscle movements
-
Subconcious reflex:
Various brainstem centers help control basic movements
-
Cerebellum and basal nuclei modulate ________ muscle activity via input to subconcious and voluntary centers.
- ongoing
- -make it coordinated
-
Reflexes are rapid, _______, predicatable responses to stimuli
-automatic
-
Neural reflex pathways involves sesnory input to ________ and motor neuron output to effectors.
CNS
-
Reflexes can be modified by input from _____ ______ _______
higher brain centers
-
AP in sensory neuron propagates into ______
- CNS
- --NT releases onto all neurons on which sensory neuron synapses (divergence)
-
Info processing occurs at ____ _____ of nervous system
- many levels
- -Spinal cord, brain, cerebellum, basal nuclei
-
Motor neuron recieves __________ inputs that determine AP frequency (convergence)
- -mulitple
- -Strength and duration of skeletal muscle contraction determined by motor neuron AP frequency
-
Monosynaptic reflex:
- -Sensory neuron synapses directly on a motor neuron
- -Not many but some ex. patellar reflex (reflexively adjusts skeletal muscle length and tone)
- ---part of the stretch reflex
-
Polysynaptic reflex:
- -AT LEAST one INTERNEURON between sensory afferent and motor efferent
- -Longer delay between stimulus and response (bc goes thru interneuron)
- -Multiple SC segments or BS nuclei interact to form more complex responses
-
Postural reflex:
Helps maintain upright position
-
Sensory receptors are muscle __________ stretch receptors
- spindles
- --compensating refelx
-
Sensory neuron axon has __________- synapse onto motor neuron
excitatory
-
Stretch reflex is a reflex that:
Is constantly functioning to maintain proper length of body postural muscles
-
Polysynaptic reflexes produce more ________ responses
complicated
-
Polysynaptic reflexesinvolve pools of _________-
interneurons
-
Polysynaptic reflexes are __________ in distribution
intersegmental
-
Polysynaptic reflexes involve __________ inhibition
- reciprical
- --ex, biceps, they contract when triceps extend)
-
Polysynaptic reflexes involve muscle groups ___________ and __________ to stimulus
ipsalateral, contralateral
-
-
Contralateral:
Opposite side
-
Polysynaptic reflexes may __________ to produce a coordinated response
- cooperate
- --back, gluteus, etc.
-
-
Extensors ________
exten and inhibited
-
If the left leg is contralateral:
flexors are inhibited and extensors stimulated
-
Excitatory input (contraction) to flexor motor neurons and inhibitory input to extensor motor neurons of _________ leg
ipsalateral
-
Inhibitory input to flexor motor neuron's and excitatory input to extensors motor neurons of _________ leg
contralateral
-
Reinforcement:
Facilitation that enhances spinal nerve and cranial nerve reflexes (sports)
-
Inhibition:
Suppresion that reduces spinal and cranial refelxes
-
CNS damage can result in ________ reflexes
- abnormal
- -Hyperflexia of stretch reflex (ex patellar)
- -Normal plantar relfex replaced by abnormal reflex called Babinski sign
-
Babinski Sign:
- Test used when suspected CNS damage
- --Foot should curl when tested
-
Primary motor cortex: __________ gyrus
- Precentral gyrus
- -Corresponds point nby point with specific regions of OPPOSITE sides of body
- -Proportions of cortex developed to specific region of bosy proportional to number of motor units, not to body area size
-
Everything with the brain ______ ______, because of the ____________________
crosses over (decussate), precentral gyrus
-
Premotor cortex= _________ motor association area
- somatic
- -Interpret incoming data and coordinate learned motor responses
- -Speech center
- -Eye field
-
Corticospinal and Corticobulbar pathways provides ________ skeletal muscle control via rapid direct pathway
- voluntary
- -Cell body in primary motor cortex
- -Axon decussates before synapsing onto motor neuron
-
Corticobulbar tracts (in brain/cranial nerves) synapse onto motor neurons in ____________ nerve nuclei, and doesn't leave the brain
cranial
-
Corticospinal tracts (anterior and lateral) synapse on motor neurons in the _________ gray horns of the spinal cord.
- anterior
- --Go into spinal cord, crosses over in brain stem and lower, many synapse AT anterior gray horn of exit location
-
Vestibular nuclei:
Senspry input from receptors for equilibrium, balance
-
Tectum of mesencephalon:
- -Superioir colliculi: visual input (have reflex from seeing something)
- -Inferior colliculi: Auditory input (have refelx from hearing something)
-
Reticular formation:(everything travles through)
- -Input from many sensory and motor centers
- --coordination, big for sleepong (send signals to relax)
-
Basal Nuclei:
- -Adjust motor commands issued in other processing centers
- -Provide background patterns of movement involved in voluntary motor movements
- --Background positions of the trunk or limb
- --Rythmic cycles of movement in walking or running
- *not always concious, if damaged very awkward or jerky movement
- *fluid movement
-
Cerebellum: (no direct pathways to motor neurons)
- -Monitors propioceptive (recpetors in muscles that detect stretching) info, visual info, and vestibular (controls dizziness) sensations
- --Minimizes number of motor commands used to perform a movement
- --Make movements efficient, smooth, and precisely controlled
- --Compares ongoing activity with precisely learned activity patterns (muscle memory)
- *coordination and balance
-
Primary motor cortex:
- -Pre-central gyrus: organized with control of foot muscles most medial, head muscles lateral (looking at one cerebral hemisphere)
- -Directs voluntary movements: controls contralateral muscles (coming from right hemisphere controls left hand)
-
Primary sensory cortex:
- -Post-central gyrus
- -Receives contralateral somatic sensory ino: touch, pressure, pain, etc. (Info that comes from area that controls somatic system-voluntary reactions)
-
Visceral NS:
- Involuntary
- -Controlled by ANS
- -digestion
-
Olfactory cortex:
- -sense of smell
- -Medial surface of temporal lobe
-
Gustatory cortex:
- -sense of taste
- -Insular lobe
-
Visual cortex:
- -sense of vision
- -Occipital lobe
-
Auditory cortex:
- -sense of hearing
- -Superior surface of temporal lobe
-
Store info in _________________ _____________________ area/cortex
Auditory association
-
Association areas control ability to _________ sensory info and coordinate responses
- -understand
- -Somatic motor association:Premotor cortex, frontal eye field, speech center
- -Somatatosensory association area (doesn't require first hand experience)
- -Auditory association
- -Visual association
-
General interpretive area:
- -aka Wernicke's area, gnostic area
- -Receives info from all sensory areas
- -Interprets what is seen of heard based on previous experience :personality
- -Usually in Left cerebral hemisphere
-
Who mapped the cerebral cortex
Broadman
-
The speech center:
- -Regulates patterns of breathing and vocalization needed for normal speech
- --->coordinates respiratory muscles, the muscles of larynx and pharynx, muslce sof tongue, cheeks, lips and jaw
- -Damage to speech center would result in a person being able to make noise but NOT words
-
Damage to the auditory association area could result in:
A person having difficulty speaking,e ven though they know which words to use
-
Prefontal cortex:
- -Coordinates info from all association areas
- -Performs abstract intellectual functions
- -Predicts consequences of actions (anxiety, frustration, worry)
- -Planning and prioritizing
- *-Determination of appropriateness of actions for a given situation
- -Not fully mature until early adulthood
-
Speech impediment form damaged ___________ cortex
Prefrontal
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Left hemisphere is responsible for:
- -Language based skills
- -Analytical, mathematical, logical
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Right hemisphere is responsible for:
- -Spatial relationships and 3D analysis
- -Identification of objects based on SENSORY INFO
- -Recognizing faces
- -Analyze emotional context of conversation or event
-
Electroencephalogram (EEG):
Measures brain activity (measures AP's that are sent)
-
Alpha Waves:
- Healthy resting adult
- -normal waves
-
Beta waves:
Concentrating adult
-
Theta Waves:
normal CHILDREN, adults experiencing frustration or anxiety
-
Delta waves:
Normal during SLEEP
-
Brain waves are related to activity of ____________ _______________ ___________
Reticular Activating System
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Reticular Formation:
- -Extends from medulla oblongata through mesencephalon of the brainstem
- -Receives input from all parts of brain
- -Contains many functional areas: ANS regualtory centers, Somatic motor control center of medial pathway, Reticualr Activiating System
- ---Big role in sleep cycles
-
If something travels up and down what must it trave through?
Reticular formation
-
Reticular Activating System (RAS):
- -Important to arousal and maintenance of conciousness (keeps you alert and awake)
- -RAS headquarters located in mesencephalon (mid brain along reticular formation)
- -Receives input from multiple sources that act as a positive feedback loop to maintain consciousness: cerebral cortex, basal nuclei, sensory and motor pathways (all wake you up and keep you awake)
- -Becomes LESS responsive to input and fatigues after many hours of activity
-
The more input, the more _______- you are
awake
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Conscious:
- -Alertness
- -Awareness of and attention to external events and stimuli
-
Subconscious:
- 1. Sleep: can be awoken by external stimuli
- 2. Coma: can't be woken by external stimuli
-
States of Sleep:
- 1. Deep sleep (slow wave sleeo, NREM):
- -Body is in relaxed state
- -Cerebral cortex activity is LOW
- -DELTA wavs
- 2. Rapid Eye Movement (REM) sleep:
- -Active dreaming occurs (association neurons influence dreams)
- -Muscle activity inhibited
- -ALPHA waves
-
Motivational System:
- Sensory cortex, motor cortex, and associationa areas of the cortex enable you to perform complex tasks
- --The LIMBIC system makes you want to do them
-
Limbic system functions:
- -Motivational system
- -Behavioral drives
- -Extablishing emotional states
- -Facilitating mempry storage and retrieval
- ---Pleasant memory/association makes you WANT to do something more
-
Limbic system Components:
- -Cortex of cingulate gyrus, dentate gyrus, and parahippocampal gyrus
- -Hypothalamus
- -Hippocampus and fornix
- -Amygdaloid
-
Cortex of cingulate gyrus, dentate gyrus, and parahippocampal gyrus:
- link conscious intellectual function of cortex with autonomic and behavior
- --conscious decision based on emoition
-
Hypothalamus:
Center responsible for rage, fear, pain, pleasure, sexual arousal
-
Hippocampus and Fornix:
Storage and retrieval of mempory
-
Amygdaloid body:
Links emotions to memories
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