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195 Cards in this Set

  • Front
  • Back
How Information is recievied

Analog vs. Digital
Analog - is how everything comes in from the world around
Digital - how we process the world around us. It is All or None - On or Off (Action Potential)
Three overlapping functions of nervous system
Sensory Input - Gathered information
Integration - Process and interprets sensory input, the decides what should be done with it
Motor Output - the actual respones required after integration
(3) parts to a typical nerve
Cell body - inside CNS its a cell body, outside its a ganglion
dendrites -
Axons - tracts for information
Definition of ganglion

Definition of Nuclei
ganglion - cell body in CNS

Nuclei - cell body outside CNS
Description of a Neuron
High longevity - lasts a longtime
Amitotic - has no mitosis, so when it is damaged, it wont grow back
High metabolism - uses lots of ATP
Needs support cells - called neuroglia, w/o it will die
Types of Neuroglia (support cells) in CNS
Astrocyte
microglia
ependymal
oligodendrocyte
Neuroglia - Astrocyte
-helps transport nutrients in and out of neuron
-absorbs extra neurotransmitters and K+ ions
may play a role in nerve transmission
Neuroglia - Microglia
-macrophage like languherhans cell
-acts like immune
-cells of immune system are denied access to CNS
Neuroglia - Ependymal
-mostly columnar and ciliated
-circulate spinal fluid
-line inner portion of surrounding spinal cord
Neuroglia - Oligodendrocyte
-Same as Schwann cell, but in CNS
-Produces myelin sheath in white matter
Support cells in Parasympathetic system
-Satellite cells
-Schwann cell
Neuroglia (PNS)- Satellite Cells
-wrap around cell body
-help maintain cell body
Neuroglia (PNS)- Schwann Cell
-produce Schwann sheath (myelin sheath)
-produces myelin (membrane)
- wraps neuron in myelin for insulation
- speeds up process
- has outer most layer called neurolemma
Characteristics of Myelin
- myelin is made of fat
- myelin is non polar
- myelin is used for insulation
- outermost layer called neurolemma
Neurolemma
-outermost layer of myelin (Schwann) sheath
-it is nucleated and cytoplasmic
-encloses myelin sheath
Structure of Neuron
- Dendrite
- carry impulse to body
- has branching extensions of membranes containing cytoplasm
- same organelles as body
- graded potential
- lots of Rough Endoplasmic reticulum (nissel bodies)
-produces protiens
-tansports w/ cytoskeleton
- final destination is synaptic end bulbs
- usually not mylennated
Structure of Neuron
- Body
- Nucleus
- Mitochondria, Golgi, Lysosomes
- Lack centrioles
- RER (Nissl bodies)
-chromatophilic b/c they stain dark
Structure of Neuron
- axon hillock
- Highly excitable
- AP originates here
- transition from Graded Potential to Action Potentional
- Neural integrators count excitatory and inhibitory impulses
Structure of Neuron
- axon
- lead away from cell body
- collaterals
- telodendria
- synaptic knobs
- classified via structure or function
Stucture of neuron
- axon
- collaterals
- collaterals - side branches
Structure of Neuron
- Axon
- Telodendria
Axon terminal branches divided into hundrends and thousands
Stucture of Neuron
- Axon
- Synaptic Knobs
contains neurotransmitters which are protiens and peptides
Stucture of neuron
- Axon
- Classification via structure
- Multipolar - 3 or more processes (axons/dendrites)
- most common in CNS
- Bipolar - 2 processes
- dendrites converge into one before getting to axon
- found in CNS (Retina)
- unipolar - one axon opening to cell body
- w/ ganglia in periphreal nervous system
- outside CNS
Structure of Neuron
- Axon
- classification via function
- sensory - afferent
- all are unipolar
- w/ cellbodies outside CNS
- motor - efferent (effect)
- multipolar
- inside CNS
- Interneurons - association
- lie between sensory and motor neurons
- make up 99% of neurons in body
- most in CNS
- multipolar
Transmission
- voltage
Potential Energy between 2 points that have different charges
Transmission
- potential
- Difference between 2 charges at give voltage/electrical voltage difference across membrane
- separated charges of oppostie sign
Transmission
- at rest
- Resting potential = -70 mV
- -70 mV created by Disequilibrium
- Disequilibrium is created by Na+ K+ pump
Transmission
- channels
- voltage gated - opens w/ voltage
- only in axons
- ligand - opens in response to chemical stimulus
- only in dendrites
- Mechanical - opens in response to mechanical stimulus
- only in dendrites
Transmission
- Graded Potental
- Analog information
- Originates from cell body or dendrites
- different names depending on stimulus (EPSP or IPSP or others)
- is ligand or mechancial gated
- Varies in amplitude depending on strength of stimulus
- Localized - short lived, doesn't go far
Transmission
- Action Potential
- Voltage gated
- originates in Axon
- it is all or none - On or Off
- long lived, can travel long way
-
Interpretation of Action potential
* Na+ gates open
- -55 mV threshold is broken
- quick depolarization occurs
- voltage drops to 0
- at +30 mV
- Na+ gates close, K+ gates open
- called repolarization
- at -74 mV
- Hyperpolarization occurs
- Na+ K+ pump operates to restore -70 mV resting
Interpretation travels in a ...
Wave!!!

- travels down the axon
- known as prpagation
- carried via microtubules
- only in one direction (towards telodendria)
Schwann cells
- other characteristics
- have no gates
- located at Node of Ranvier
- Saltatation - wave skips from node to node
- depolarization in this way saves energy
Node of Ranvier
- Patches of exposed neuron
- gaps in the myelin (schwann)sheath
- information exchange takes place in these gaps
Graded Potential
- further information
- different names depending on location/orgin
- does not propagate itself
- very isolated signal
- IPSP - Inhibitory Post Synaptic Potential
- hyperpolarized, causes the membrane potential to be more (-)
- nerve impulse must go further to break -55 mV threshhold

- EPSP - excitatiory post synaptic potential
- depoarliezed, causing membrane potential to be less (-)
- nerve impulse has less difficulty breaking -55 mV threshold
*** view graphs***
Synapapse-Neurotransmitter
- Presynaptic
- Ca2+ voltage gates open
- breaks actin
- Synaptic vesicle drops - releasing neurotransmitter
Synapapse-Neurotransmitter
- Post synaptic
- Differing types of Graded Potential
- temporal summation
- spatial summation
Synapapse-Neurotransmitter
- Post synaptic
- Summation
- summation means that the greater the EPSP, the more likely the chance of breaking the -55 mV threshold
Synapapse-Neurotransmitter
- Post synaptic
- Temporal Summation
when summation results from the build up of neurotransmitter released by a sungle bulb 2 or 3 times in rapid succession

bang-bang-bang-bang-bang
Synapapse-Neurotransmitter
- Post synaptic
- Spatial Summation
When summation results from the build up of neurotransmitters released simultaneously by several presynaptic end bulbs

BOOM!!!!!!
Neurotransmitters
- criteria to be called one...
- must be stored and released from presynaptic end bubls
- must cause either an EPSP or IPSP
- must be naturally removed from synaptic cleft by enzyme/diffusion/uptake (ACh-ase)
Neurotransmitters
- (5) groups
1 - Acetylcholine (ACh)
2 - Amino Acids
3 - Peptides
4 - Novel
5 - Biogenic Amines
Neurotransmitters
- Acetylcholine (ACh)
- Neuromuscular
- can be either EPSP or IPSP depending on receptors
- Cardiac IPSP
- Skeletal EPSP
Neurotransmitters
- Amino Acids
- Only found in CNS
- (3)specific examples
- Glycine
- Glutamate
- GABA
Neurotransmitters
- Amino Acids
- Glycine
- IPSP
- makes up half of the neurotransmitters in the spinal cord (other half is GABA)
- Strychnine blocks its receptors
Neurotransmitters
- Amino Acids
- Glutamate
- EPSP
- Important for learning and memory
- during stroke, excessive release causes neurons to be stimulated to death
Neurotransmitters
- Amino Acids
- GABA
- Gamma Amino Btyric Acid
- IPSP
- Common in the brain
- Valium and alcohol enhance action of GABA
Neurotransmitters
- Peptides
- small chains of 30 to 40 amino acids
- (3) specific examples
- Endorphins
- Substance P
- Somatostatin & Cholecystokinin
Neurotransmitters
- Peptides
- Endorphins
- Opiates
- pleasure
- natural pain killer
Neurotransmitters
- Peptides
- Substance P
- Found where there is pain
- lets body know it is experiencing pain
Neurotransmitters
- Peptides
- Somatostatin & Cholecystokinin
- produced by tissues in the GI tract
Neurotransmitters
- Novel
(3) specific examples
- ATP
- Nitric Oxide
- Carbon Monoxide
Neurotransmitters
- Novel
- ATP
- Adenosine tri-phosphate
- can be either EPSP or IPSP
- can be found in both CNS and PNS
- Provokes pain sensation
Neurotransmitters
- Novel
- Carbon monoxide
- EPSP
- Causes pain, sensitivity to pain
Neurotransmitters
- Novel
-Nitic Oxide
- EPSP
- causes smooth muscle to relax
- release increases stroke damage
- used to treat male impotence
Neurotransmitters
- Biogenic Amines
- can be EPSP Or IPSP depending on receptors
- Variations on Amino Acids
- 3 generators and their neurotransmitters
- Tryptophan ...serotonin
- Histamine ... histamine
- Tyrosine ... dopamine, epinephrine, norepinephrine
Neurotransmitters
- Biogenic Amines
- Tryptophan
- found in turkey
- makes serotonin
- plays a role in sleep, appetite, migraines,
- LSD blocks serotonin receptors
- too little serotonin causes depression
- prozac affects uptake, leaving serotonin in synapse longer
Neurotransmitters
- Biogenic Amines
- Histamine
- Cause inflamation
- helps blood to reach areas that need to heal
Neurotransmitters
- Biogenic Amines
- Tyrosine
- depending on enzyme, synthesizes:
- Dopamine
- Epinephrine
- Norepinephrine
Neurotransmitters
- Biogenic Amines
- Tyrosine - Dopamine
- makes you feel good
- Parkinson's disease has TOO LITTLE DOPAMINE
- Schizophrenic has TOO MUCH DOPAMINE
- Chlorozine and heldal bind dopamine, stopping it from working
- Amphetamines increase dopamione release
- cocaine blocks dopamine receptors
Neurotransmitters
- Biogenic Amines
- Tyrosine - Epinephrine and Norepinephrine
- essentially adrenaline
- made by the adrenal gland
- make you feel good
- amphetamines increase production
- antidepressants and cocaine block removal from synapse
Receptors in Autonomic Nervous System
- (3) Types
- Nicotinic (cholinergic receptor)
- Muscarinic (cholinergic receptor)
- Adrenergic (sensative to NE and epinephrine)
Receptors in Autonomic Nervous System
- Nicotinic
- ACh receptor
- stimulate EPSP
- located in plasma membrane of dendrites and cell bodies of both Sympathetic and Parasympathetic postganglion neurons
- also found in neuromuscular junction
Receptors in Autonomic Nervous System
- Muscarinic
- ACh receptor
- IPSP for Cardiac
- EPSP for GI tract(intestines)
- receptors located in plasma membrane of effectors of Parasympathetic postganglions
- used in cardiac, smooth, and glands
Receptors in Autonomic Nervous System
- Adrenergic
- with (2) types
- receptor for Norepinephrine and epinephrine
- located at most sympathetic postganglion neuorns
- alpha usually stimulates
- beta usually inhibits
- for cardiac it is an IPSP
- beta blockers block receptors for beta
Embryonic Development
- 1st system to develop...
Nervous System
Neural Plate
- Embryonic origin of all neural tissue
- site where ectoderm thickens
Neural groove
Neural plate folds inward to form neural groove
Neural tube
Neural groove forms into the neural tube
Ventricles
- Hollow spaces in the spinal cord and brain
- Brain has (4)
- 1st & 2nd are lateral
- 3rd & 4th are not
4 areas of the brain that develop from the Neural tube
1 - Prosencephalon (forebrain)
2 - Mesencephalon (midbrain)
3 - Rhombencephalon (hindbrain)
4 - 4th ventricle
Develop from Neural Tube
- Prosencephalon
- forebraine
- Dicencephalon
- thalamus
- hypothalamus
- epithalamus
- 3rd ventricle
Develop from Neural Tube
- Mesencephalon
- Midbrain w/ tracts and nuclei
- corpora quadrigemina
- visual reflex center (superior)
- auditory reflex center (inferior)
- nuclei that produce dopamine
- called E. substantia nigra
- cerebral perduncles
Develops from the Neural Tube
- Rhombencephalon
- hindbrain
- 2 specfic areas
- Pons
- Medulla oblongata
- Cerebellum
Develops from the Neural Tube
- Rhombencephalon
- Pons
- Tracts
-Conduction tracts between higher brain & spinal cord and between Cerebellum & motor cortex
- Nuclei
- apneustic area, inhaltion, and pneumatoxic, (inhibits inhalation)
Develops from the Neural Tube
- Rhombencephalon
- Medulla Oblongata
- Tracts
- Decussation of pyramids
- which is the crossover for signals from left and right brain
- Nuclei
- controls heart rate, respiration, blood pressure, touch, and muscle positions
Develops from the Neural Tube
- Rhombencephalon
- Cerebellum
- has both white and grey matter
- 1/10th the brain mass, but 1/2 the total # of neurons
- Tracts
- arbor vitae tracks
- Nuclei
- give rise to axons to spinal cord and other brain centers
- controls balance, coordination, posture, skilled movements
- evaluates how well movements initiated by motor areas in the cerebrum are being carried out
Areas that develop from Neural Tube
- 4th ventricle
Yup - it does
Principle parts that develop from Neural tube
Cerebrum - Know tracts and Nuclei
Dicephalon (and its parts)
Cerebellum (and its parts)
Brain Stem (and its parts)
Areas that are continous with spinal cord...
- pons, midbrian, medulla oblongata
Fissure
Deep valley in brain
Sulcus
Shallow valley in brain
Parts of Cerebrum
- Central Sulcus
- Seperates frontal and parietal lobes
Parts of Cerebrum
- Precentral gyrus
- Before central sulcus (towards front of brain
- motor cortex
Parts of Cerebrum
- Postcentral gyrus
- after central sulcus
- sensory cortex
Parts of Cerebrum
- Longitudinal Fissure
- cuts brain into left and right cerebral hemispheres
Parts of Cerebrum
- Parieto Occipto Sulcus
- separetes the parietal lobes from the occipital lobes
Parts of Cerebrum
- Lateral Sulcus
- above temporal
- separates each temporal lobe from the lower portion of frontal and parietal lobes
Parts of Cerebrum
- Transverse fissure
Separates cerebellum from cerebrum
Parts of Cerebrum
- Cerebral Cortex
- outer layer of grey matter in brain
- conscious behavior,
- excutive control over nervous system
- it is highly convuluted with dendrites, cell bodies, unmylennated axons
- mostly designated for facial sensory and hand control
Parts of Cerebral Cortex
- (5) Hemispheres
- Frontal (1)
- Parietal (1)
- Temporal (2)
- Occipital (1)
- Insula (2 - hidden inside)
Parts of Cerebral Cortex
- Regions
- Motory
- Sensory
- Association
Parts of Cerebral Cortex
- Contralateral
- means that info on the right goes to left brain, and info on left goes to right brain
- takes place at...
- Dessucation of Pyramids in Medulla Oblongata
Parts of Cerebral Cortex
- Motor Region (4 areas)
- Primary motor
- before central sulcus
- called precentral gyrus
- Premotor cortex
- memory of how to do a motor skill (association)
- Frontal eyefiled
- muscle control of eye
- cranial nerves III, IV, and VI
- association
- Broca's area
- motor speech area
- leftside of frontal lobe
Parts of Cerebral Cortex
- Sensory region (8 areas)
- primary sensory
- Somatosensory Association Area
- Primary Auditory Cortex
- Auditory Association Area
- Primary Visual Cortex
- Visual Association Area
- Gustatory Area
- Olfactory Bulbs and Cortex
Parts of Cerebral Cortex
- Sensory region
- Primary Sensory
- Located in postcentral gyrus
- recieves info from receptors in skin/skeletal muscles
- identifies body region being stimulated
Parts of Cerebral Cortex
- Sensory region
- Somatosensory Assocation Area
- Integrates and analyzes different sensory inputs
Parts of Cerebral Cortex
- Sensory region
- Primary Auditory Cortex
- Located in Temporal lobe
Parts of Cerebral Cortex
- Sensory region
- Auditory Association Area
- Perception
- due to memories, the information actually assocaited here is different for everyone
Parts of Cerebral Cortex
- Sensory region
- Primary Visual Cortex
- for reception
- located in the Occipital Lobe
Parts of Cerebral Cortex
- Sensory region
- Visual Association Area
Again - perception
Parts of Cerebral Cortex
- Sensory region
- Olfactory bulbs and Cortex
- sense of smell - what more do ya need
Parts of Cerebral Cortex
- Sensory region
- Gustatory Area
- Taste at the tip of tongue
- located at the bottom of central sulcus
Association
Memory - the brains ability to associate information with other areas of the brain
Association
- Personality
Its your mood, how you act and what you do
Association
- Prefrontal Cortex
- MAIN AREA FOR ASSOCIATION
- most complicated region
- processing to form personality
- closely linked to limbic (emotions)
- Intellect
- Complex learning abilities
Association
- Left Brain
- concrete information
- mathematical, logic, rational tasks, performing sequential processes
Association
- Right Brain
- Abstract information
- Musical and artistic awareness
Association
- Language
- Wernicke's area
- Located in left Brain
- sounding out unfamiliar words
- translates words into thoughts
- areas on right brain add tonal inflection and emotional content
Association
- Visceral
Interpretaion from viscera
White Matter
- Characteristics (3)
- Lines of communication for brain
- take things from one area of grey matter to another
- Axons are mylennated
- (4) types of tracts
- Commissures
- Association fibers
- Projection fibers
- Fornix
White Matter
- Types of tracts
- Commissures
- tracts run between the (2) cerebral hemispheres (left and right)
- Corpus Callosum - largest
- it runs from Right to left and Left to Right between 2 ventricles
White Matter
- Types of tracts
- Association Fibers
- From one area of a hemisphere to another in the same hemisphere
White Matter
- Types of tracts
- Projection Fibers
- at spinal cord, they fan out
- Shape is circle
- Corona Radiata
- looks like fiber optic flashlight
White Matter
- Types of tracts
- Fornix
- bandlike fiber tracts concerned with olfaction as well as limbic system functions
Basal Nuclei
- Cluster of cell bodies in Central Nervous System
- it is the inside area of grey matter
Basal Nuclei
- Characteristics
- Regulates motor control
- cell bodies are packged together
Basal Nuclei
- Anterior
- Lentiform and Caudate
- Corpus Striatum
Basal Nuclei
- posterior
- Amygdaloid - functionality belongs to Limbic system (emotions)
Basal Nuclei
- middle of brain
Located here (no shit)
Cortex means area is located in...
Outer Grey matter
Diencephalon
- develops behind Basal Nuclei
- (3) Regions = Thalamus, Hypothalamus, Epithalamus
Diencephalon
- Thalamus
- GATEWAY TO CORTEX
- acts as a major sensory relay and integration center of brain
Diencephalon
- Epithalamus
- forms roof of 3rd Ventricle
- Pineal gland = Secretes malatonin involved with sleep-wake cycles and moods
- Choroid plexus = produces cerebral spinal fluid
Diencephalon
- Hypothalamus
- Neural clearing house for autonomic and emotional response
- Visceral control
- Autonomic control = respiration rate, emotions, sleep, hunger, thirst, temperature reg, sex drive, sleep/wake cycle
- ends in Infundibulum = connects to pituitary gland = releases hormones
Limbic System
The Emotional Brain
- its where emotions live
Limbic System
- Fornix
- Links limbic system regions together
- White matter
Limbic System
- 2 important parts to emotions
Amygdala = recognizes fearful/angry faces, assesses danger, and creates fear response
Cingulate Gyrus = helps w/ conflict resolution, expressing emotions through gestures
Limbic System
- Amygdala and Hippocampus
- together equal LONGTERM MEMORY
- changes new info into longterm memories
Limbic System
- special interaction with prefrontal cortex
there is a special relationship between feelings and thoughts
Reticular Activating System
Activates Cerebrum to wake up brain (and person)
Meninges
covering of the brain & Spinal cord
Meninges order
from outside in...

Skull
Duramater periosteal (not in Spinal cord)
Duramater meningeal
Arachnoid mater
Subarachoid space
Pia mater
Meninges
- Skull
The outermost covering of the brain, it is wrapped in Periosteum
Meninges
- Dura Mater
It is rough and leathery w/ 2 layers
- Periosteal =(not in spinal cord
- Meningeal = true external covering of brain
- Meningeal AKA dural sheath of spinal cord
Meninges
- Arachoid Mater
Located as the middle Mater
- loose covering not dipping into sulci
- it is made of fine fibers and is elastic
Meninges
- Subarachoid Space
- Weblike extensions attach Arachoid Mater to Pia Mater
- Contains Cerebral Spinal Fluid and the largest blood vessels serving the brain
- Arachoid Villi = Absorbs Cerebral spinal fluid into blood stream
Meninges
- Pia Mater
- Delicate, very sticky connective tissue
- many tiny blood vessels
- only layer to cling tightly to brain
Blood Barrier
-use and exceptions
- capillary endothelial cells joined by tight junctions, which is the least permeable in the body
- exceptions are the avomiting center of brain stem and hypothalamus
- not yet developed in new borns - so be careful...
Type of Stimulus
- Mechanoreceptors
- mechanical force such as touch, pressure, vibration, stretch, itch
Type of Stimulus
- Thermoreceptors
- temperature changes
Type of Stimulus
- Photoreceptors
- light energy
Type of Stimulus
- Chemoreceptors
- chemicals in solution/taste, smell
Type of Stimulus
- nociceptors
- stimuli that results in pain
Type of Stimulus
- proprioceptors
- location of stimulus
- advises brain of body movements by monitoring how much organ is stretched
Stucture of Nerve
Nerve is a bundle of neuron fibers
- Neuron is a nerve cell
- most nerves are mixed (both sensory and motor
- special coverings of neurons
Structure of Neuron
- coverings
Myelin - covers Axon
Endoneuron - surrounds myelin
perineuron- surrounds fascicle (group of axons)
Epineuron - surrounds group of fascicles and blood vessels
Cranial Nerves
- I
Olfactory
- purely sensory
- smell
Cranial Nerves
- II
Optic
- purely sensory
- vision
Cranial Nerves
- III
Oculomotor
- purely motor
- "eye mover" 4/6 extrinsic eye muscles
- Parasympathetic
Cranial Nerves
- IV
Trochlear
- purely motor
- moves one muscle of eye
Cranial Nerves
- V
Trigeminal
- Mixed (both sensory and motor)
- has 3 divisions = Opthalmic, maxillary, and Mandibular
- dentist numbs maxillary and mandibular
- lets you feel teeth
Cranial Nerves
- VI
Abducens
- Purely Motor
- moves one extrinsic muscle of eye
Cranial Nerves
- VII
Facial
- largest Cranial nerve
- Major Cranial nerve for face
- laughing, smiling, and anterior 2/3 of tongue (sweet & salty)
- Parasympathetic
Cranial Nerves
- VIII
Vestibular Cochlear
- Purely sensory
- hearing
Cranial Nerves
- IX
Glossopharyngeal
- Mixed (both sensory & motor)
- swallowing & latter 1/3 of tongue (bitter & sour)
- Parasympathetic
Cranial Nerves
- X
Vagus
- Mixed (both sensory & motor)
- only cranial nerve to extend beyond head and neck
- Parasympathetic
Cranial Nerves
- XI
Accessory
- Mixed (both sensory & motor)
- has 2 roots = cranial root from medulla oblongata, spinal root from c1-c5
Cranial Nerves
- XII
Hypoglossal
- Mixed (both sensory and motor)
- swallowing and speech
Levels of Motor Control
- (list them)
From lowest to high
- segmental
- projection
- precommand
Levels of Motor Control
- Segmental
- lowest level
- Spinal cord circuits
Levels of Motor Control
- Projection
- middle level
- upper motor neurons of motor cortex and brain stem
Levels of Motor Control
- Precommand
- highest level
- cerebellum and nuclei
Somatic Nerves
Motor neuron cell bodies in CNS and axons extend in spinal nerves to skeletal muscles
- thick and heavily myelinated
- lack ganglia
Spinal Cord
- beginning and ending
- Continous from 4th ventricle
- has a central canal
- oval shaped
- goes through Magnum foramen
- ends at L1 or L2 vertebrae
Spinal Cord
- Butterfly shape (meaning)
- Horns
- White matter outside
- grey matter inside
- Posterior Horns = dorsal = sensory
- Anterior Horns = ventral = motor
Spinal Cord
- sensory tracts
- 1st 2nd 3rd order
- Sensory tracts ascend
- 1st order = dorsal root ganglion
- 2nd order = dorsal horn
- 3rd order = thalamus
Spinal Cord
- motor tracts
- upper motor neurons
- lower motor neurons
- motor tracts descend
- upper motor neurons = go from motor cortex to motor nuclei
- lower motor neurons go from anterior horns to skeletal muscles
Spinal Cord
- Reflex centers
Interneurons are the reflex centers
- involuntary and rapid
Spinal Cord
- Reflex centers order of operations
Receptor - Sensory Neuron - Integration Center - Motor Neuron - Effector

*** just like that***
Spinal Cord
- other names for Integration center
Integration center - AKA - Interneuron - AKA - Association Center
Spinal Cord
- Cauda Equina
"Horse's tail"
- collection of nerve roots at inferior end that fan out
Spinal Cord
- Conus Medullaris
- end of cord in tapering cone shaped struture.
Spinal Cord
- Spinal Tap location
Below spinal cord, below L3 vertebrae
- b/c spinal cord ends at L1 or L2
Spinal Cord
- Filum terminale
Pia mater fastens cord in place
Spinal Nerves
- Total breakdown
31 total spinal nerves
- 8 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 1 coccygeal
Spinal Nerves
- length
They be short
Spinal Nerves
- ganglia
Group of cell bodies outside CNS
Spinal Nerves
- Dorsal root
SENSORY - AFFERENT
- cell bodies lie outside spinal cord in dorsal root ganglion
Spinal Nerves
- Ventral root
MOTOR - EFFERENT
- cell bodies lie in anterior horn
Spinal Nerves
- Rami
Spinal nerve branches into dorsal and ventral Rami
- Mixed (both Sensory & motor)
Spinal Nerves
- Plexus
Formed from ventral Rami
Spinal Nerves
- Plexus = Cervical
- C1-C4
- Phrenic nerve is most important = sensory and motor nerves for diaphram
Spinal Nerves
- Plexus = Brachial
- C5-C8 + T1
- it is entire nerve supply to upper extremities, neck and shoulder muscles
- Ulna = funny bone = nerve rests against medial epicondoyle
- Radial = largest branch
Spinal Nerves
- Plexus = Lumbar
- L1-L4
- abdominal wall, external genitals, part of lower extremities
- Femoral = Largest nerve in body = goes through thigh, buttocks,perneum, and lower extremities
Spinal Nerves
- Plexus = Sacral
- L4-L5 + S1-S4
- Sciatic nerve = thickest and longest in body
- Pudendal nerve = causes erection, involuntary urination
Spinal Nerves
- Dermatones + one exception
area of skin innervated by the cutaneous branches of a single spinal nerve
- C1 is the only spinal nerve that does not innervate a dermatone
Spinal Nerves
- Hilton's law
Same nerve will effect skin, muscle and joint in the same localized area
Spinal Nerves
- Intercostal Nerves
come from thoracic vertebrae
Autonomic Nervous System
- Traits
- Mixed (both sensory and motor)
- Part of the periphreal nervous system
- Effectors are smooth muscle, cardia, and glands
- normally involuntary
- has 2 neuron chain consisting of cell body of preganglionic neuron in brain or spinal cord preganglionic axon and cell body of ganglionc neuron outside CNS postganglionic axon
(2) divisions of ANS
Sympathetic system
Parasympathetic system
Sympathetic system
- diff from Para
- accelerates body
- arises from T1-T2
- preganglionic fibers are short
- postganglionic fibers are long
- Uses ACh for preganglion, Norepinephrine for Postganglion
-Ganglion are far away from organ, but close to CNS
- FIGHT OR FLIGHT
Parasympathetic System
- diff from Sympathetic
- Brakes
- arises from III, VII, IX, X, S2-S4
- preganglionic fibers are long
- postganglionic fibers are short
- Ganglion are near organs, away from CNS
- used for resting and digesting
Sympathetic system
- characteristics
- Rage, Terror, fear
- Dilates pupil by contracting radial muscle to open eye
- relaxes bladder muscle, contracts anal sphincter
- increases heart rate
- decreases digestion rate
- increases blood pressure, affects kidneys with renin
- relaxes bonchiole to breath more
- liver changes glycogen to glucose for energy
Parasympathetic system
- characteristics
- slows you down
- maintains homeostasis
- contracts pupil by contracting circular muscle
- contracts bladder muscle and relaxes anal sphincter
- decreases heart rate
- increases digestion rate
- constricts bonchioles
Similarities
- Sympathetic and parasympathetic systems
- serve most of the same organs
- generally cause opposing effects
- all preganlions release ACh