Neuro Exam 1 Review Flashcards
Hippocrates
Father of western medicine
Believed brain involved in sensation and seat to intelligence
Galen
showed cerebrum receives sensation and cerebellum commands muscle
discovered ventricles
Descartes
brain vs mind argument
Galvani and Bois-Reymond
electrically stimulated the brain
showed brain generates electricity
no more fluid theory
Bell and Magendie
proposed origin of motor fibers is cerebellum and destination of sensory fibers is cerebrum
Flourens
used ablations to show cerebellum plays role in coordination
localization theory
Gall
phrenology
Broca
showed phrenology was wrong
Schwann
cell theory
cell theory
all tissues are composed of unites called cells
Nissl
shows grey matter
stains nuclei of cells
distinguishes between neurons and glia
Golgi
small percent of neurons become dark in entirety
shows grey and white matter
Ramon y Cajal
used golgi stain to draw
neurons are not continuous and communicate by contact
Grey mater
unmeylinated neurons on outside of cerebrum
White matter
myelinated axons on inside of cerebrum
Neuron
functional unit of the nervous system
Cytosol
watery potassium rich fluid inside the cell
Cytoplasm
everything inside membrane except nucleus
Signal Recognition Protein
recognizes particles being made on free ribosome and can send it to Rough ER
Free Ribosome protein synthesis fate
internal structures
Rough ER protein synthesis fate
inserted into plasma membrane OR enclosed in vesicles
Golgi Apparatus
site of post translational and chemical processing of proteins
Directs trans-membrane and secretory proteins to their destination
DNA microarrays
shows which genes expressed uniquely in neurons
editing genes
delete (knockout), insert (knock in), mutate
Dendrites
shorter and branched profusely
not myelinated
Axons
maintain constant radius long branching at 90 degrees no ribosomes mitochondria present the thicker the axon the faster transfer of info
Cytoskeleton
gives neurons its shape
dynamically regulated
provides mechanical support
allows cells to migrate (tau)
Bones= Microtubules, Microfilaments, Neurofilaments
Microtubules
longest, run longitudinally down neurites
Microfilaments and Neurofilaments
give microtubules support
Axon Terminal
Microtubules dont extend into terminal
Contains synaptic vesicles
Many mitochondria
Axoplasmic Transport
Material enclosed in vesicles and walked along microtubules
Anterograde
Retrograde
Anterograde
Kinesin (to terminal)
Retrograde
Dynein (to soma)
Tract Tracing
trace path of axons to show circuits
Classification of Neurons
- Number of Neurons (unipolar, bipolar, multipolar)
- Dendritic tree shape (parametal or stellate) and presence of spines
- Connections (sensory, motor, interneurons)
- Axon Length
Golgi Type 1
projection neurons
parametal
Golgi Type 2
local circuit
stellate
Glia Cells
5:1 glia to neurons
provide structural and metabolic support to neurons
Oligodendrocytes
create myelin sheaths around axons in CNS
stop growth of neurons
Schwann Cells
create sheaths in PNS
guide axonal regeneration
Microglia
inolved in response to injury/disease in CNS
Astrocytes
Largest glia, star shaped
Control and communicate with many neurons
Form barrier to unwanted substances entering the brain
Control blood flow to neurons
Remove waste
Send nutrients to neurons
Central Nervous System
Inside of bone, brain and spinal cord
Interprets sensory input, initiates movement, mediates complex cognitive processes
Afferent Nerves
bring sensory info to CNS
Efferent Nerves
carry motor signals out of CNS
ipsilateral
structures on same side
Contralateral
structures on different sides
Cerebrum
Fissures = large grooves (longitudinal, central, lateral) divide brain into four lobes
Sulci = small grooves
Gyri = bumps (precentral, postcentral, superior temporal)
Hemispheres connected by corpus callosum
Cerebellum
Primary motor control center, “do it well”
Superior Peduncle, Middle Peduncle, Inferior Peduncle
Brain Stem (4 parts)
- Diencephalon (thalamus and hypothalamus)
- Midbrain/Mesencephalon (tectum and tegmentum)
- Pons (metencephalon)
- Medulla (Myelencephalon)
Structure Scans
CT and MRI
Function Scans
PET and fMRI
Spinal Cord
4 regions: Cervical (8) Thoracic (12) Lumbar (5) Sacral (6)
Spinal cord is shorter than column so nerves exit at cauda equina
Dorsal root brings sensory info
Ventral root carrys motor info
Grey matter on inside, white matter on outside
White matter has ascending and descending tracts
Meninges
Dura mater, Arachnoid Membrane, Pia Mater
Cerebrospinal Fluid
Fills sub-arachnoid space
Produced by choroid plexus
supports CNS and provides cushioning
Brain Blood Supply
anterior, middle, and posterior cerebral arteries
Spinal Cord Blood Supply
anterior spinal artery, right and left posterior arteries
Somatic Nervous System
Part of PNS
Involved in sensations we are aware of
Autonomic Nervous System
Unconsious part of PNS
Regulates viseral (organ) functions to maintain homeostatsis
Sympathetic and Parasympathetic Nervous Systems
Sympathetic Nervous System
Fight or flight
2nd stage neurons far from target
Parasympathetic Nervous System
Rest or digest
2nd stage neurons close to target
Cranial Nerves
On Occasion Out Trusty Truck Acts Funny, Very Good Vehicle Any How
Some Say Marry Money But My Brother Says Big Brains Matter Most
Forebrain
Telencephalon and Diencephalon
Midbrain
Mesencephalon
Hindbrain
Metencephalon and Myelencephalon
Neocortex Layers
Layer 1 = synaptic integration
Layer 2 and 3 = input/ output to other cortical areas
Layer 4 = input from thalamus
Layer 5 = output brainstem and spinal cord
Layer 6 = output to thalamus
Neocortex
Layers differ in thickness, cell density, and type
Pyramidal cells are output neurons and excitatory (layers 1,5,6)
Stellate cells are local circuits and can be excitatory or inhibitory (layers 2,3 layer 4 is spiny excitatory)
Columnar organization
50 distinct regions
White Matter Fiber Tracts (3)
- Association = connects gyri in same hemisphere
- Commissural = connects corresponding gyri in opposite hemisphere
- Projection = connect cerebrum with other parts of brain and spinal cord
Subcortical Areas
Basal Forebrain
Basal Ganglia
Limbic System
Basal Forebrain
infront of and below thalamus
Nucleus Accumbens
Nucleus Basalis
Nucleus Accumbens
Part of Basal Forebrain
Role in cognitive processing of motivation and reward learning and addiction
Nucleus Basalis
Part of Basal Forebrain
Role in sleep/wake cycle and learning and memory
Basal Ganglia
Lateral to thalamus
Plays role in selection of motor actions to execute
Striatum (caudate and putamen) and Globus pallidus
Limbic System
Basic motivations, emotions, learning, memory Hippocampus Cingulate cortex Amygdala Septum Hypothalamus Mammillary Bodies Anterior nuclei of thalamus
Diencephalon
Thalamus and Hypothalamus
Thalamus
Process/relay somatic nervous system info to cerebral cortex
Sleep/wake states
Consciousness
Ascending Nuclei and Motor Help Nuclei
Ascending Nuclei in Thalamus (3)
Medial = auditory Lateral = vision VPN = touch
Motor Help Nuclei in Thalamus (2)
VLN = cerebellum VAN = basal ganglia
Hypothalamus
Motivates search for food/drink/sleep/temp/mates
Controls activities of autonomic N.S.
Mesencephalon
Tectum (roof) and Tegmentum (floor)
Tectum
Superior Colliculi = visual motor function to direct bodys orientation towards or away from stimulus
Interior Colliculi = part of auditory system
Tementum (Major parts and tracts)
Penaqueductal Grey = pain modulation, defensive behaviors, fight or flight
Red Nucleus = motor coordination, gets input from cerebeullum
Substantia Nigra = movement selection
Medial Lemniscus = somatosensory fibers ascending to VPN of thalamus
Pyramidal Tract = motor axons from primary motor cortex descending toward spinal cord
Metencephalon
Pons and Cerebellum
Pons
Ventral pons contain pontine nuclei and receives input from descending fibers of pyramidal tract
Pontine nuclei project axons into cerebellum via cerebellar peduncle
Superior Peduncle
primary output, send to red nucleus and VLN
Middle Peduncle
input from contalateral motor cortex via pontine nuclei
Inferior Peduncle
input from ipsilateral inferior olive
Myelencephalon
Medulla Responsible for basic functions of autonomic N.S. Contains superior (hearing) and inferior (motor) olives
Medulla Major Fiber Tracts
Medial Lemniscus = ascending sensory fibers in dorsal collumn nuclei, axons cross brain stem here
Medullary Pyramids = descending motor axons from primary motor cortex
Reticular Formation
Involved in sleep/wake cycle, arousal/attention, voluntary motor control, reward and addiction, and mood
Raphe nuclei and locus coerulleus involved in mood and RAS
Ventral tegmental area = reward area
Germinal Stage
time from fertilization to implantation in uterus
Potency and types of potency
Ability to develop into different cell types Totipotent Pluripotent Multipotent Unipotent
Totipotent
fertilized egg to morula
Pluripotent
blastocyst
Gastrulation
Formation of Ectoderm, Endoderm, Mesoderm
Ectoderm
Becomes skin and nervous system
Endoderm
Internal stuff
Mesoderm
Muscle and skeleton
Neurulation
Nervous system emerges, derived from ectoderm
Neural plate edges elevate and meet at midline forming neural tube
Neural Tube
CNS
Inside Neural Tube
Ventricles and spinal canal
Neural Crest
PNS
Somite
Skull and vertebrae, also mesoderm
Differentiation
Process by which structures become specialized
First Differentiation = three swellings called the primary vesicles (proencephalon, mesencephalon, rhombencephalon)
Differentiation of Forebrain
Give rise to olfactory bulbs
Telecephalon fuses with diencephalon