unit 1-6

functions of the nervous system (6)

perception

1. special senses (5 modalities), somtosensory (5 submodalities), visceral)

movement

life-sustaining

cognition

emotion

arousal

LAMPCE

3 neuroanatomical planes

horizontal plane

coronal plane

sagittal/midsagittal plane

4 components of central nervous system with subcomponents if applicable

forebrain - cerebrum/cerebral hemisphere, diencephalon

brainstem - midbrain, pons, medulla

cerebellum

spinal cord

peripheral nervous system: somatic vs autonomic components (2 each)

somatic = sensory nerves/ganglia, motor nerves

1. sensory nerves = afferent fibers

2. motor nerves = efferent fibers

autonomic = sympathetic nerves/ganglia, parasympathetic nerves/ganglia

number of cranial nerves vs spinal nerves

cranial = 12

spinal = 31

developmental origins of neuroanatomy

3 vesicle stage (3 wks post-fertilization, cephalic/cervical flexure)

1. prosencephalon (forebrain)

2. mesencephalon (midbrain)

3. rhombencephalon (hindbrain)

5 vesicle stage (5-6 wks post-fertilization)

1. telencephalon (cerebral hemisphere), diencephalon (thalamus and hypothalamus)

2. mesencephalon (midbrain)

3. metencephalon (pons), myelencephalon (medulla)

Number corresponds to each other

4 classifications of neurons by function

sensory

motor

autonomic

interneuron

4 classifications of neurons by morphology (# extensions from cell body) + 2 classifications by shape of cell body

unipolar = 1 extension from cell body

bipolar = 2 extensions from cell body

multipolar = 3 dendrites + 1 axon from cell body

pseudo-unipolar = cell body and extensions merge (dorsal root ganglion and spinal cord)

shape of cell body

pyramidal cell and star-like cell

8 classifications by neurons and synapses by pharmacology: glutamate, gaba, acetylcholine, dopamine, glycine, serotonin, norepinephrine, histamine

glutamate - glutamatergic (most common NT)

gaba - gabaergic

acetylcholine - cholinergic

dopamine - dopaminergic

glycine - glycinergic

serotonin - serotonergic

norepinephrine - noradrenergic

histamine - histaminergic

(also pharmacologic classification of synapses)

3 qualifications to be a NT?

1. manufactured by presynaptic neuron

2. requires Ca to release into synapse

3. receptor in postsynaptic membrane

Match the neuronal structures and functional zones:

Terms: input zone, integrative zone, conducting zone, transmitting zone, insulation, action potential regeneration, transmitter release, transmitter uptake

Functional zones: axon, axon terminal, myelin, postsynaptic membrane, nodes of ranvier, initial segment axon hillock, presynaptic membrane, dendrites/sensory endings,

input zone = dendrites, sensory endings

integrative zone = initial segment axon hillock

conducting zone = axon

transmitting zone = axon terminal

insulation = myelin

action potential regeneration = nodes of ranvier

transmitter release = presynaptic membrane

transmitter uptake = postsynaptic membrane

synapse morphology and functional classifications (2)

chemical synapse = presynaptic and postsynaptic neuron separated by synaptic space

electrical synapse = cytoplasmic continuity between presynaptic and postsynaptic neuron

types of macroglia vs microglia cells

macroglia: astrocytes, ependymal cells, oligodendrocytes, schwann cells

microglia: from yoke sacs of embryo, macrophages, bone marrow, hematopoetic

how many glial cells are in the human CNS? different function of glial cells in PNS vs CNS?

~1 trillion

PNS glial cells = support, insulate

CNS glial cells = support, insulate, filtrate, communicate

smooth brain → addition of cerebral cortex, sulci and gyri fancy names

lissencephalic → gyrencephalic

how many lobes of the cerebral cortex? structure and function?

5 lobes of the brain (frontal, parietal, temporal, occipital, *insula)

structure: surface has sulci, beneath is nuclei

function: perception and movement they drive (learning their names ain’t no jive)

what is the 5th lobe and what is it covered by?

insula hidden by opeculum (frontal, parietal, temporal) aka “lips”

functional areas of cerebral cortex: primary cortex, secondary cortex, association cortex, homunculus

primary cortex = sensorimotor, M1, S1, A1, V1

secondary cortex = S1 → S2, A1 → A2, V1 → V2

association cortex = complex integrative analysis (i.e executive functions via insights, planning)

homunculus = body map (somatosensory and motor homunculus)

brodmann areas

BA 1-3, 5, 7 ~ somatosensory cortex

BA 4, 6, 8 ~ motor, premotor cortex

BA 39-40 ~ receptive language (reading, speech)

BA 44-45 ~ speech generation (grammar, planning)

gray and white matter: cerebral hemisphere (4), diencephalon (2), brainstem/cerebellum (3), spinal cord (2)

cerebral hemisphere: cortical mantel, basal ganglia, hippocampus, amygdala

diencephalon: thalamus, hypothalamus

brainstem/cerebellum: motor nuclei, relay nuclei, modulatory nuclei

spinal cord: motor nuclei, interneurosn

gray matter vs white matter

gray matter = clustered cell bodies form nuclei (nuclear groups)

white matter = myelin enveloping axons

white matter fibers form (7)

tract

pathway

funiculus

faciculus

leminiscus

penduncle

stria

cerebral cortex + neocortex, paleocortex, archicortex

cerebral cortex = a laminated mantel of gray matter

lamina history varies across cortical regions

neocortex = 6 layers

plaeocortex = <6 layers

archicortex = 3 layers

subcortical white matter: association fibers, commissural fibers, projection fibers

association fibers = anterior → posterior, posterior → anterior

commissural fibers = left → right, right → left

projection fibers = vertically oriented cortex → subcortical or thalamus to cortex

naming conventions for fiber tracts: cell body location to synapse location → name

definitions: corona radiata, internal capsule

corona radiata = regions of axons to/from cortex fanned out

internal capsule = region same axons are compressed

choroid plexus

filtration → CSF

CSF (ventricles)

lateral and medial apparatus → subarachnoid space → CSF pools in cisterns = expanded regions within subarachnoid space, CSF in perivascular space

Diecephalon and brainstem ventral surface structures

diencephalon (ventral/inferior)

CN II, optic chiasm, optic tract, infundibulum, mammilary bodies

brainstem (ventral/anterior)

midbrain: cerebral peduncle, interpendicular fossa, CN III

pons: CN V-VIII

medulla: CN IX-XII, pyramids, pyramidial decussation, olives

length of spinal cord

~17-18”

spinal cord regions: cervical, thoracic, lumbar, sacral distinguishing features

cervical (n=8): axons from UE/trunk/LE, greatest total white matter, large ventral horns (LMNs for UE muscles)

thoracic (n=12): all axons from trunk/LE, very small ventral horns (LMN for trunk muscles)

lumbar (n=5): all axons for LEs, large ventral horns (LMNs for LE muscles)

sacral: few axons for LEs, ventral horns appear prominent but cord very small in diameter, more gray than white matter

how many fasciculi does the cervical cord vs thoracic-lumbar-sacral have?

cervical = 2

t-l-s = 1

intermediolateral nucleus

clark’s nucleus T1-L2/3 and lateral horn

lateral horn vs sympathetic chain (each side of SC)

lateral horn = cell bodies for sympathetic preganglionic neurons

sympathetic chain = cell bodies for sympathetic postganglionic neurons

meninges 3 layers, 3 spaces, 2 vascular supplies

meninges: dura (makes up cerebral falx and cerebellar tentorium), arachnoid, pia

spaces: epidural, subdural (common site in bleeding), subarachnoid (normal space contains CSF)

vasculature: blood vessels, dural sinuses

tumor + herniations within dura

tumor location: hemotoma of cingulate gyrus, medial temporal lobe, cerebellar tonsil

herniations: herniates under cerebral falx, under cerebellar tentorium → compress brainstem, into foramen magnum

perosteal dura ends at ____ ____

meningeal dura envelopes _____ ___ and ____

periosteal dura ends at foramen magnum

meningeal dura envelopes spinal cord and nerves

name of anterior artery: ____ % of blood supply to brain

name of posterior artery: ____ % of blood supply to brain

internal carotid; 80%

vertebral; 20%

anterior communicating artery vs posterior communicating artery

anterior = joins left and right circulation

posterior = joins anterior and posterior circulation

motor homunculus (order)

hand, face, jaw, tongue, throat

what two arteries overlap with middle cerebral artery (MCA)?

ACA, anterior chordial artery

somatosensory fibers: dorsal….

as

all LMN functions and some somatosensory: lateral, intermediate, ventral…

somatosensory fibers: dorsal columns, roots, horns

all LMN functions and some somatosensory: lateral column, intermediate column, ventral column, roots, horns

circumventricular organs (3), lipid soluble molecules (3), active transport (3)

circumventricular organs: ion [ ], hormones, signalling molecules

soluble: alcohol, caffiene, nicotine

active transport: glucose, enzymes, essential proteins and amino acids

choroid plexus 3 layers, key components for CSF production (3)

choroid plexus: capillary, endothelial wall, fragmented pia and collagen (for filtration of blood plasma), ependymal choroid epithelium

key for CSF production: vascular fenestrations, tight junctions, choroid fronds/villi

plexus produces ____ ml CSF/day

500

note: total CSF volume = 150 ml (ventricles/subarachnoid space)

CSF circulation

lateral ventricles → 3rd ventricle → 4th ventricle → subarachnoid space -(arachnoid granulations) → superior sagittal sinus (mixes with venous blood)

somatosensory functions (5)

motor control = posture, coordination of movement, object manipulation

objetive identification

avoidance of itssue damage

formation of body schema

psychosocial = emotional wellness, communication

conscious sensory perception

first order neurons: sensory neurons, pseudounipolar/unipolar neurons, cell bodies form ganglion (DRG/PNS), peripheral region of axon forms peripheral nerve, central region of axon forms tract

second order neurons: interneurons, multipolar neurons, cell bodies forms CNS nucleus, axons may/may not decussate, axons form (fiber) tract

third order neurons: interneurons, cell bodies form thalamic nucleus, axons form tracts and cortical radiation, axons synapse in primary sensory cortex

skin mechanoreceptors vs muscle mechanoreceptors

skin:

alpha-beta: merkel cells, meissner’s corpuscle, ruffini corpuscle, pacinian corpuscle, hair receptor

muscle:

1a, II: muscle spindle

1b: golgi tendon

contraction for muscle proprioceptors

contraction shortens muscle fiber length → gamma motor shortens intrafused fibers to maintain spindle sensitivity

__ fiber senses changes in tendon tension ~ muscle contractile force

afferent fiber

sensory endings of first order neurons have mechanoreceptors embedded in _____ ____

afferent endings

receptive fields are maps of individual sensory neurons. they vary ini

location, density, spatial area size, neuron responses

dermatomes are composed of multiple RF, modalities, submodalities.

1 dermatome =

2 dermatomes =

1 dermatome = 2 receptive fields, 2 submodalities

2 dermatomes = 2 receptive fields, same modality

proprioception vs touch: receptor type, afferent axon type

proprioception:

1. muscle spindle/golgi tendon organs

2. Ia, II, Ib

touch:

1. merkel, meissner, pacinian, ruffini

2. AB

caudal receptive fields:

as

rostral receptive fields:

caudal receptive fields: medial gracilus fasiciculus (LE, trunk)

rostral receptive fields: lateral cuneate fasiciculus (UE)

DCML pathway

cortex (BA)

subcortical: corona radiata, internal capsule - posterior limb

thalamus: VPL thalamus

midbrain

pons: medial leminiscus

rostral medulla

caudal medulla: arcuate fibers, gracilis nucleus

cervical

thoracic

lumbar: dorsal column, gracilis fasciculus, DRG, AB fiber, peripheral nerve

sacral