Nervous System Flashcards

1
Q

myelinating glia in the CNS are called ______ while in the PNS they are _____

A

CNS : Oligodendroglia

PNS : Schwann cells

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2
Q

Describe the structural components of the peripheral nervous system

A

cranial and spinal nerves (all other NS structures that connect CNS to body)
-develop from neural crest cells

spinal nerve = mixed nerve (mixed with different neuronal axons) that carry motor, sensory and autonomic signals between the spinal cord and the rest of the body.
-pattern: dermatomes

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4
Q

Describe the meninges (CT) covering the CNS from external to internal layers

A

Dura (thick, overlying, most external dense connective tissue under skull - continuous with periosteum in bone)

Arachnoid (delicate sheet of connective tissue; subarachnoid: blood vessel supply, CSF fluid circulates to protect brain; arachnoid trabeculae-loose connective tissue)

Pia (innermost layer, directly adherent to the brain and spinal cord which is continuous with the perivascular connective tissue sheath of blood vessels of the brain and spinal cord.)

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5
Q

Somatic NS provides sensory and motor innervation to all parts of the body except?

A

viscera
smooth and cardiac muscle
glands

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6
Q

Sympathetic nervous system vs. Parasympathetic nervous system

A

S (fight or flight)

P (rest and digest)

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7
Q

Describe the functional components of the peripheral nervous system

A

Autonomic (visceral) NS (excitatory and inhibitory) communicates with INTERNAL organs and glands (autonomic = visceral = organs = internal)

Somatic (body) NS (excitatory) communicates with sense organs and voluntary muscles -receives info from and responds to EXTERNAL world (somatic = parietal = body = external)

  • Sensory Afferents (INPUT)
  • mostly along dorsal spine
  • Motor Efferents (OUTPOUT)
  • mostly along ventral body

(SAME DAVE!)
Sensory Afferent Motor Efferent
Dorsal Afferent Ventral Efferent

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8
Q

Describe the functional components of the peripheral nervous system

A

Autonomic (visceral) NS (excitatory and inhibitory) communicates with INTERNAL organs and glands (autonomic = visceral = organs = internal)

Somatic (body) NS (excitatory) communicates with sense organs and voluntary muscles -receives info from and responds to EXTERNAL world (somatic = parietal = body = external)

  • Sensory Afferents (INPUT)
  • mostly along dorsal spine
  • Motor Efferents (OUTPOUT)
  • mostly along ventral body

(SAME DAVE!)
Sensory Afferent Motor Efferent
Dorsal Afferent Ventral Efferent

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9
Q

How do the somatic and visceral nervous systems differ, both structurally and functionally?

A
The visceral (autonomic/organs) NS communicates with internal organs and glands after detecting information within the body in order to respond, and is broken down into:
-Sympathetic (fight or flight) and -Parasympathetic (rest and digest) divisions 
The Somatic (body) nervous system communicates with voluntary muscles and sense organs, and contains sensory afferents for input (receives info from external world) and motor efferents (responses to sensory info from external world) for motor output. 
-Innervates structures that develop from somites. 

Sensory input is along the dorsal spine/coming up your back, while motor output is primarily ventral

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9
Q

Which cells are found in the CNS? the PNS?

A

CNS

  • Neuron (functional cells)
  • group of neuronal cell bodies = nucleus
  • Glia (supporting cells): Astrocyte, Oligodendroglia (myelinating axons), Microglia

PNS

  • Neuron
  • group of neuronal cell bodies = ganglion (DRG)
  • Glia (Schwann cells)
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10
Q

Describe the PNS connective tissue layers

A

3! epi! peri! endo!

Epineurium: vascularized, dense irregular connective tissue surrounding nerve fascicles into common bundle of nerve fibers (adipose is associated with epineurium in large nerves)

Perineurium: Vascularized, specialized connective tissue surrounding a nerve fascicle that contributes to the formation of the blood-nerve barrier by serving as a metabolically active diffusion barrier

Endoneurium (around each axon and its schwann cell, nerve fiber): loose connective tissue surrounding each individual nerve fiber, visible at EM (collagen fibrils)

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11
Q

Epineurium

A

PNS
densest layer*- what we see as the nerve in lab
vascularized, dense irregular connective tissue surrounding nerve fascicles into common bundle of nerve fibers (adipose is associated with epineurium in large nerves)

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12
Q

Perineurium

A

PNS
Vascularized, specialized connective tissue surrounding a nerve fascicle that contributes to the formation of the blood-nerve barrier by serving as a metabolically active diffusion barrier
-surrounds functional group of axons

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13
Q

Endoneurium

A

PNS
around each axon AND its associated schwann cell, nerve fiber): loose connective tissue surrounding each individual nerve fiber, visible at EM (collagen fibrils)

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14
Q

Autonomic system is primarily “input”, true or false?

A

FALSE
-the bigger part of autonomic is OUTPUT to communicate with internal organs and glands

major divisions of output are sympathetic and parasympathetic nervous systems

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15
Q

Neural crest cells give rise to PNS, true or false?

A

TRUE

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16
Q

Which functional part of the nervous system drives and balances homeostasis?

A

VISCERAL (organs)
-bc it innervates both the organ systems AND their corresponding elements to respond to information it has detected within the body

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17
Q

True or False, the somatic nervous system innervates structures that develop from somites, which originate from paraxial mesoderm in embryonic development.

A

TRUE

paraxial mesoderm > somites > somatic (body)

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18
Q

Glia are the functioning cells and neurons are the supporting cells in the NS, True or False?

A

FALSE

neurons are the functioning cells, glia support

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19
Q

What are the different names for a group of neuronal cell bodies in the CNS vs PNS?

A

CNS: Nucleus

PNS: ganglion (think DRG=dorsal root ganglia)

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20
Q

True or False, the Schwann cell is doing pretty much everything to support the PNS neurons, but in the CNS this support is divided between several different cells.

A

TRUE

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21
Q

Dura mater

A

from the mesenchyme cells surrounding neural tube

thick, overlying, most external
-dense connective tissue of the 3 meninges in the CNS
-has component very closely associated with inner lining of the bone (skull, vertebrae) called the periosteum
under skull - continuous with periosteum in bone

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22
Q

Arachnoid

A

from neural crest cells

delicate sheet of connective tissue; subarachnoid: blood vessel supply, CSF fluid circulates to protect brain; arachnoid trabeculae-loose connective tissue

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23
Q

Pia

A

from neural crest cells

Innermost layer, directly adherent to the brain and spinal cord which is continuous with the perivascular connective tissue sheath of blood vessels of the brain and spinal cord

Pia-think pea (smallest/thinnest meningeal layer, it’s usually ONE CELL thin)

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24
Q

The outer lining of the dura mater is usually in close association with or adherent to the periosteum of the skull but not the vertebrae, True or False?

A

FALSE, adherent or close proximity to both the skull and the vertebrae periosteum

-specifically the VERTEBRAL CANAL (cause that’s where we find the cord, dura is covering cord)

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25
Q

True or False, There is a significant space between the dura mater layer and the arachnoid layer with a weblike network

A

FALSE

weblike network extends between arachnoid and pia layers, filled with CSF

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26
Q

An axon has to be myelinated to have an endoneurium associated with it, True or False?

A

FALSE

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27
Q
The endoneurium is around: 
A. each axon 
B. each axon and its associated Schwann cell
C. only myelinated axons
D. myelinated or unmyelinated axons
E. Both B and D
F. Both A and C
A

E. Both B and D

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28
Q

In both the PNS and CNS, there are 3 layers of connective tissue, and vasculature can be found between the 2nd and 3rd layer in both cases. True or False?

A

TRUE

PNS: vessels between epineurium and perineurium (1 and 2) AND endoneurium and perineurium (2 and 3)

CNS: vessels between arachnoid and pia layers (in subarachnoid space)

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29
Q

Vessels in the PNS are more discretely defined than in the CNS, True or False?

A

FALSE

Vessels are going everywhere in the PNS (between both epi and perineurium, as well as endo and perineurium), however in the CNS they are more restricted (think higher and more complex organization in brain, causes further compartmentalization- needs to be more restricted) and are only between pia and arachnoid layers

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30
Q

Name the general structure of a neuron

A
  1. Dendrites (sensing, stimulated by environment or activities of other cells)
  2. Cell body (contains all the stuffz: nucleus, mitochondria, ribosomes, other organelles and inclusions)
  3. Axon (conducts the nerve impulse -action potential- toward the synaptic terminals/terminal boutons)
  4. Terminal boutons (look like buttons, affect another neuron OR effector organ, ie muscle or gland)
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31
Q

Dendrites

A

INPUT END

sensing end of a neuron that is stimulated by the environment or the activities of other cells

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32
Q

Cell body of neuron

A

contains all the structures like nucleus, mitochondria, ribosomes, other organelles and inclusions, want them all concentrated in one area and then thinner extended processes (like axon) can conduct APs (nerve impulses) toward the synaptic terminal faster

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33
Q

Axon

A

conducts the nerve impulse -action potential- toward the synaptic terminals/terminal boutons

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34
Q

Terminal boutons

A

OUTPUT END

SYNAPTIC boutons/SYNAPTIC ends/Terminal ends

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35
Q

A neuron functions via signal transduction, True or False?

A

TRUE

signaling is how neurons talk and sensory info is passed from dendritic sensory input to terminal bouton output

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36
Q

Neurons talk to other neurons both chemically and electrically, true or false?

A

TRUE

electrically: propagation of polarity continued
chemically: NTs like acetylcholine (ACh)

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37
Q

What are the three types of neurons we discussed?

A

Multipolar- multiple dendritic inputs and multiple terminal outputs

Bipolar- one long process coming in as input, one long process coming out, cell body usually in center

Pseudounipolar neurons- cell body in center with one long process that quickly bifurcates (branches) with one input branch and one output branch

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38
Q

Multipolar neuron

A

multiple dendritic inputs and multiple terminal outputs (multipolar = motor efferents in somatic- spinal cord)

-in somatic NS
EFFERENT/MOTOR: multipolar
AFFERENT:pseudounipolar

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39
Q

Dorsal Root Ganglion (DRG)

A

PNS (Outside CNS) = ganglion

-clusters with somatic and visceral (autonomic) sensory (AFFERENT) cell bodies (presynaptic sensory/afferents)

shape: PSEUDOUNIPOLAR cell
dorsal = back = primary afferent neuron

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40
Q

Ventral (Anterior) Horn

A

contain Somatic MOTOR nuclei (CNS) (IN COLUMN up and down spinal cord), axons come out and coalesce with ventral root

SAME DAVE (VE = ventral EFFERENT (Motor efferent))

-going to a MUSCLE

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41
Q

Somatic sensory and visceral sensory fibers start in the ___ and synapse in the _____

A
DRG (ganglion = PNS) 
Dorsal horn (of spinal cord = CNS)
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42
Q

Lateral Horn

A
  • with ventral horn = ventral = efferent
  • contain nuclei of VISCERAL (AUTONOMIC) SYMPATHETIC PRESYNAPTIC/PREGANGLIONICs (aligned in cell columns up and down spinal cord/connected)

OUTPUT for visceral/autonomics efferents (in cord)

right above ventral horns, VE = ventral efferent= LEAVING CNS to go to PNS

contains visceral MOTOR efferents
-going to an ORGAN or gland

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43
Q

Somatic efferents and visceral efferents both exit through the ventral root, true or false?

A

TRUE

SAME DAVE

efferent, motor, going away from CNS to body/PNS, VENTRAL

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44
Q

True or False, the lateral horn is the output for all of the visceral or autonomic efferents in the CNS?

A

FALSE

its the output center for the autonomic efferents in the CORD (only part of CNS)

-the brain also contains autonomic or visceral efferent outputs

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45
Q

The gray matter in the spinal cord is located in the _____layer while the white matter is located in the ____ layer

A

Gray matter: inner layer/INSIDE: cell bodies (nuclei)

White matter: outer layer/outside: tracts and pathways running up and down spinal cord located here

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46
Q

Ventral root

A

Anterior root = ventral = front = motor efferents, contains MOTOR fibers (OUTPUT) leaving spinal cord

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47
Q

Dorsal root

A

Posterior root = back = SENSORY afferents (DAVE, DA = dorsal afferent “you get stabbed in the back, you feel it = sensory”)

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48
Q

The spinal nerve is formed when the dorsal root and ventral root come together, and exit the vertebral canal via intervertebral foramen, true or false

A

True

Remember: spinal nerves are MIXED, sensory and motor components together

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49
Q

Once a spinal nerve exits the intervertebral foramen, it no longer remains functionally and structurally mixed (with both sensory and motor), and instead you see a bifurcation that gives rise to the posterior and anterior ____

A

Rami (posterior ramus, anterior ramus)

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50
Q

The dorsal ramus is a much larger component than the ventral ramus, true or false?

A

FALSE - the ramus is where the exiting spinal nerve (which was mixed with sensory and motor as it exited through the intervertebral canal) is now divided again anteriorly and posteriorly. Since the nerve is EXITING (OUTPUT) the VENTRAL or ANTERIOR ramus will be much larger, as output (EFFERENTS) are predominantly along the ventral surface

ventral ramus also has

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51
Q

Anterior rami connect to the _____

A

sympathetic ganglia (outside cord, body = ganglia = PNS) of the sympathetic trunk

-AUTONOMIC/VISCERAL NS

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52
Q

There are ___ pairs of spinal nerves

A

31 (Think vertebrae here- there are 7C + 12T + 5L + 5S + ~2C = 31, as the vertebrae develop, the spinal nerves follow in development)

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53
Q

There are ___ cranial nerves

A

12

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54
Q

How do NS projections/tracts/pathways cross the midline?

A
  • decussation

- commissure

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55
Q

Ipsilateral

A

cell body and axon terminal on same side

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56
Q

Bilateral

A

cell body someplace, with axon terminals going to BOTH sides

57
Q

Contralateral

A

cell body on opposite side of axon terminal

58
Q

contralateral or bilateral indicates that what is happening?

A

some sort of crossing of the midline is occurring (so think decussation or commissure [=communication] is happening)

59
Q

What are the functions of general afferent (sensory) neurons?

A

touch, vibration, pain, temperature, proprioception (spatial awareness)

-segmented innervation, follows DERMATOMES

60
Q

Vision, olfaction, audition, taste, balance and equilibrium are examples of:

A. Special sensory efferent neuron functions
B. General motor efferent neuron functions
C. Special sensory afferent neuron functions
D. Special motor efferent neuron functions
E. General sensory afferent neuron functions

A

C. Special sensory afferent neuron functions

senses/INPUTS/AFFERENTS

61
Q

Motor (efferent) neuron functions

A

General (somatic)
-segmented, follows myotomes

Visceral (AUTONOMIC NS)

  • sympathetic
  • parasympathetic
  • enteric (GI)
62
Q

Sympathetic chain ganglion

A

PREganglionic sympathetic cell bodies and fibers from lateral horn will go through white ramus communicans (myelinated) and enter the sympathetic chain ganglion. These axons then will either:

a) synapse at the sympathetic chain ganglion and exit through the gray ramus communicans
b) go up OR down the sympathetic trunk to synapse somewhere else
c) exit sympathetic chain ganglia as SPLANCHNIC NERVE (go affect an organ, but has NOT synapsed yet)

63
Q

Axons that enter and then exit the sympathetic chain ganglia as splanchnic nerves have to reach a _____ to synapse.

A

collateral sympathetic ganglion

like in aorta

64
Q

True or false, the collateral sympathetic ganglia are much closer to the target organ than the sympathetic chain ganglia?

A

True

65
Q

Both the parasympathetic and sympathetic nervous systems of the autonomic NS have a two neuron chain, true or false?

A

TRUE

Autonomic NS has 2 neuron chain no matter what

66
Q

What is the location of the sympathetic preganglionic cell body?

A

SYMPATHETIC: SPINAL CORD (lateral horn)

T1 to L2 (thoracolumbar)

67
Q

What is the location of the parasympathetic preganglionic cell body?

A

Spinal cord OR brainstem (craniosacral)

-CNs (Cranial nerves) (brainstem)
AND S2-S4 (spinal cord)

68
Q

Postganglionic cell body location is where the preganglionic cell and postganglionic cell body synapses, true or false?

A

TRUE

69
Q

What is the location of the sympathetic postganglionic cell body?

A

sympathetic chain ganglia
OR collateral (prevertebral ganglia)
-via splanchic nn.

70
Q

What is the location of the parasympathetic postganglionic cell body?

A
  • 4 different cranial ganglia (head)

- all the rest reside in ganglia with organs (IN THE WALLS OF THE ORGANS THEY INNERVATE)

71
Q

Preganglionic sympathetic cell bodies are located in the thoracolumbar region, while preganglionic parasympathetic cell bodies originate in the craniosacral region, true or false?

A

TRUE

72
Q

Postganglionic parasympathetic reside in the head and the walls of the organs they innervate, true or false?

A

TRUE

73
Q

Somatic nerve plexuses

A
Cervical plexus (C1 to C4) 
Brachioplexus (C5 to T1)
Lumbar plexus (anterior rami L1 to L4) 
Sacral plexus (anterior rami L4 to S4)

NO THORACIC (some to brachioplexus but thats it)

74
Q

Visceral nerve plexuses

A

going to all organs and cavities, from sympathetic chain

Vagal trunk (vagus-innervate the internal organs)

Prevertebral plexus:

a) splanchnic nn. to Greater, b) Lesser, and Least
c) Lumbar Splanchnics (shorter, smaller)
d) Sacral Splanchnics

75
Q

What is the difference between myelinated and unmyelinated axons in the PNS?

A

BOTH have Schwann cells, but in the…

myelinated: the Schwann cell is wrapping around one axonal node each, enwrapping ONE axon via a series of Schwann cells; creating insulated thick layer of myelin and cell membranes for transduction down the axon
unmyelinated: non myelinating Schwann cell CYTOPLASM associates with MULTIPLE axons, but only engulfing it (not wrapping it); simply protects and supports axon

76
Q

What is the difference between myelinated and unmyelinated axons in the CNS?

A

BOTH have oligodendrocytes

myelinated: series of oligodendrocytes line up along ONE axon, then each dendrite creates a wrapped coating of myelin insulating the axon nodes

unmyelinated: nonmyelinating oligodendrocyte CYTOPLASM encases/associates with/engulfs MULTIPLE axons
(no wrapped coating of myelin surrounding axon)

77
Q

What gives rise to Schwann cells?

A

NEURAL CREST CELLS

PNS

78
Q

True or false, one schwann cell can myelinate one axon?

A

FALSE

one Schwann cell per one INTERNODAL SEGMENT of one axon (takes multiple Schwann cells to myelinate one axon; vs. takes one nonmyelinating Schwann cell to associate with/engulf/encase multiple axons)

79
Q

Oligodendrocytes are derived from which cells?

A

Neuroepithelial cells of the spinal cord (CNS)

80
Q

True or false, one oligodendrocyte can myelinate only one axon?

A

FALSE, one oligodendrocyte can myelinate up to 50 axons!

*Oligodendroctyte = like an *Octopus - can go grab multiple axons to myelinate them

81
Q

Neural groove (embryonic)

A

formed from the embryonic ectoderm, laterally we have neural folds that move medially until tops of folds join together and pinch off to form neural crest cels

82
Q

Neural crest cells

A

neuroectoderm (most lateral portion of that embryonic ectoderm that thickened up to become neural plate)
at the top of the neural folds, pinch off when neural folds join together in the form of a tube

Form most of PNS:

  • DRG/autonomic/CN ganglia
  • bones of face (viscerocranium)
  • melanocytes
  • Schwann cells
  • Leptomeninges (pia and arachnoid mater)
  • Adrenal medulla cells
83
Q

neural tube

A

neuroectoderm with inner neural canal

form brain and spinal cord

84
Q

Embryonic ectoderm

A

forms the epidermis

85
Q

epidermis and dermis come from embryonic ectoderm, true or false?

A

FALSE

epidermis: embryonic ectoderm
dermis: dermatomes, from paraxial MESODERM

86
Q

Where is the neural canal and what does it give rise to?

A

inside neural tube, inner fluid filled region

-goes on to form central canal of spinal cord and VENTRICLES of the brain

87
Q

When does the spinal cord develop? When does the brain develop?

A

spinal cord: Weeks 3-5

brain: almost entire span of pregnancy, up through your 20s

88
Q

Spinal cord/neural tube is made up of what cells?

A

PSEUDOstratified columnar NEUROepithelium

89
Q

Neuroepithelial cells

A

make up the neural tube and spinal cord

  • act as stem cells (divide and give rise to cells that make up our CNS)
  • first proliferate and give rise to Neuroblasts
90
Q

Neuroblasts

A

will become neurons

come from neuroepithelial cells in spinal cord dividing (shows stages of mitosis in histo slide, closest to the lumen)
-will first migrate to mantle layer of spinal cord

91
Q

Cell bodies of neuroblasts reside in the mantle layer of the spinal cord while their axons extend out into the marginal layer, true or false?

A

True

92
Q

After neuroblast cell formation has seized, neuroepithelial cells continue to divide and derive _____, which migrate and develop into _____ in the mantle layer and _____ in the marginal layer of the spinal cord.

A

gliablasts:

ASTROCYTES in mantle

OLIGODENDROCYTES in marginal layer (myelinate axons of neurons)

93
Q

After neuroblast formation stopped, neuroepithelial cells will become what and reside where?

A

Ependymal cells, residing closest to the lumen (centrally located)

94
Q

Ependymal cells

A

from neuroepithelial cells

-reside closest to lumen (centrally located), produce and move CSF (central canal of spinal cord provide nutrients)

95
Q

mesenchymal cells surrounding the neural tube give rise to what meningeal covering?

A

Dura mater

96
Q

Describe development of spinal cord

A

Neurulation > Neural tube (neuroepithelial layer, mantle layer, marginal layer) > neuroblast formation and migration > swellings of alar and basal plates > gliablast formation and migration > gliablast developing into astrocytes and oligodendrocytes (contribute to growing/larger marginal layer aka white matter) > swellings become ventral, dorsal, and lateral horns aka gray matter > neuroepithelial cells become ependymal cells and line central canal (CSF fluid production/movement)

Neural Tube:

  • neuroepithelial cells proliferate > give rise to neuroblasts > neuroblasts (become neurons)
  • neuroblasts migrate to mantle layer, make up majority of mantle layer (axons in marginal layer)
  • after neuroblast cell production is over, neuroepithelial cells (closest to lumen) continue growing and migrate to mantle (become astrocytes) and marginal layer (becoming oligodendrocytes)
As neuroblasts proliferate, we get dorsal and ventral swellings in mantle layer (MIDDLE layer almost ALWAYS functional):
Alar plates (2): Afferent (sensory/dorsal swellings/posterior) functions 

Basal plates (2) Efferent (motor/ventral/anterior) functions

97
Q

As neuroblasts proliferate, we get dorsal and ventral swellings in mantle layer. Describe the difference between these two swellings

A

(remember: mantle = middle, MIDDLE layer almost ALWAYS functional in 3 layer structures)

Alar plates (2): Afferent (sensory/dorsal swellings/posterior) functions

Basal plates (2) Efferent (motor/ventral/anterior) functions

98
Q

Alar plates

A

spinal cord development

dorsal swellings, afferent sensory functions
-smaller in spinal cord development (before butterfly shape) than basal plates

will become dorsal horns

99
Q

Basal plates

A

spinal cord development

ventral swellings, (2) Efferent (motor/ventral/anterior) functions

will become ventral and lateral horns

100
Q

sulcus limitans

A

spinal cord development

between alar and basal plates

101
Q

How do spinal nerves develop?

A

Motor neurons:

  • basal plate start with motor neuron cell bodies, send axons out of anterior region to collect and form ventral nerve root
  • motor nerve fibers collect into ventral nerve roots

sensory neurons:

  • a little more complicated
  • dorsal nerve roots = primary sensory cell bodies = pseudounipolar (from neuroblasts from neural crest cells) are in DRG (in PNS outside spinal cord), with peripheral processes coming from receptors located in skin and joints and muscles and central processes going into the spinal cord at the dorsal horns, into alar plate where they’ll synapse into alar plate neuron

-distal processes of dorsal root fibers (sensory) join ventral root fibers (motor) to form a spinal nerve (remember: MIXED)

102
Q

Where would you perform an epidural? Why?

A

L4-L5

L1-L2 is where spinal cord ends, but some peoples’ ends at L3

originally, embryonic spinal cord = length of vertebral canal allowing spinal nn to exit correct origin level in the vertebral column

as we age, vertebral column lengthens more rapidly than spinal cord, pulling roots down with it as it lengthens so they continue to exit their intervertebral foramen (pull dura down with it)

-cauda equina at L5

103
Q

conus medullaris

A

spinal cord ends around L1-L2 in adults

104
Q

spina bifada

A

“split spine” neural tube defect
vertebral arch doesnt form correctly, never fuses

  • Spina Bifida Occulata
  • Meningocele
  • Myelomeningiocele
105
Q

Spina Bifida Occulata

A

vertebral arch doesnt form but meninges and neural tube remain within vertebral canal

goes unnoticed until back xray (need radiography)

usually S2-S4, identified by patch of hair overlying that region

106
Q

Meningocele

A

meninges protrude out of where vertebral arch should’ve kept them in, creating sac

107
Q

Myelomeningiocele

A

meninges and the neural tube protrude out of where vertebral arch should’ve kept them in, creating sac

108
Q

Parts of the brain

A

cerebrum
cerebellum
brainstem (midbrain, pons, medulla oblongata)

109
Q

Brain development follows the same basic organization as the spinal cord, true or false?

A

TRUE

-distinct alar and basal plates
BUT: higher centers, accentuation of alar plates and regression of basal plates

110
Q

Are alar or basal plates more prominent in the development of the brain?

A

ALAR =afferent, SENSORY

you’re in the fucking brain, of course the sensory part is bigger

111
Q

What 3 swellings form in the neural tube during the 4th week of development in regards to the brain developing? Which brain vesicles are these called?

A

Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)

primary brain vesicles

112
Q

Prosencephalon

A

=forebrain

becomes 2 secondary brain vesicles:

1) Telencephalon
- cerebrum: cerebral hemispheres (cortex, white matter, basal nuclei)
- contains lateral ventricles

2) Diencephalon
- Diencephalon (thalamus, hypothalamus, and epithalamus)
- contains third ventricle

113
Q

Mesencephalon

A

=midbrain

becomes secondary brain vesicle Mesencephalon

  • brain stem: midbrain
  • contains cerebral aqueduct
114
Q

Rhombencephalon

A

=hindbrain

becomes 2 secondary brain vesicles:

1) Metencephalon
- brain stem: pons
- cerebellum
2) Myelencephalon
- brain stem: medulla oblongata

both Met and Myelencephalon contain the fourth ventricle

115
Q

Which adult neural canal is within the spinal cord?

A

central canal

116
Q

In what primary AND secondary brain vesicles does the brain stem reside?

A

primary: mesencephalon (midbrain) and rhombencephalon (hindbrain)
secondary: Mesencephalon, Metencephalon, Myelencephalon

117
Q

What are the parts of the brain stem?

A

midbrain, pons, medulla oblongata

-through 3 different secondary vesicles (mes-, met-, and myel- encephalons)

118
Q

The cerebellum is part of the myelencephalon, true or false?

A

FALSE

METencephalon

119
Q

Around which week do the primary brain vesicles derive the secondary brain vesicles?

A

WEEK 5

pro > tel and dien
mes > mes and met
rhomb > met and myel

(-encephalon after each)

120
Q

The fourth ventricle connects to the third ventricle via tiny narrowing called _____

A

the aqueduct of the midbrain

121
Q

Name the ventricles of the brain

A
Lateral ventricles ("1 and 2")
Interventricular foramen
Third ventricle
Aqueduct of midbrain
Fourth ventricle

contain CSF

122
Q

Lateral ventricles

A

two largest cavities of ventricular system of brain in each cerebral hemisphere (inside cerebrum)

contain CSF

123
Q

What connects the lateral and third ventricles?

A

interventricular foramen

124
Q

Myelencephalon formation

A

MEDULLA OBLONGATA (brain stem)

  • shift of medulla walls changes position of plates so basal plates (motor) become medial to alar plates (sensory)
  • roof plate moves laterally to make room for 4th ventricle
  • cells in alar plate cluster to form 3 bilateral cell columns = afferent (sensory) nuclei
  • cell bodies in basal plate also cluster to form 3 bilateral cell columns = efferent (motor) nuclei
125
Q

Metencephalon development

A

PONS (brain stem)

-cell bodies in basal plate cluster to form 3 bilateral cell columns = efferent (motor) nuclei

-cell bodies in alar plate cluster to form 3 bilateral cell columns =
afferent (sensory) nuclei

MARGINAL LAYER BIGGER (increases/grows)

126
Q

Why is the marginal layer bigger going from the myelencephalon (medulla) to the metencephalon (pons)?

A

Cerebellum develops posterior to the pons (sits directly behind the pons)

marginal layer filled with oligodendrocytes surrounding axons that communicate from cerebellum into cerebrum and spinal cord (exiting in pons = BRIDGE)

127
Q

Mesencephalon development

A

Basal plate contains two groups of motor nuclei
-Marginal layer of basal plate enlarges to form crus cerebri

Alar plate (sensory) initially two longitudinal elevations
-Eventually divides into superior & inferior colliculi
128
Q

crus cerebri

A

marginal layer of basal plates enlarged, efferent neurons travel down them

MESENCEPHALON midbrain

129
Q

superior & inferior colliculi

A

relay centers in mesencephalon

130
Q

Diencephalon

A

Contains Thalamus, Hypothalamus, and Epithalamus

-three pairs of swellings in lateral wall of 3rd ventricle

131
Q

epithalamus is formed in diencephalon from ______

A

caudal part of roof plate

132
Q

Alar plates in diencephalon form which structures

A

Thalamus and hypothalamus

133
Q

Telencephalon/Cerebrum

A

forms two cerebral hemispheres, contains 2 lateral ventricles

-surface grows rapidly to form lobes as well as gyri (elevations) separated by fissures (deep grooves) and sulci (shallow grooves)

134
Q

Visceral or autonomic NS still has visceral afferents, true or false?

A

true, just smaller portion

sympathetic and parasympathetic branches of autonomic/visceral NS are OUTPUT

135
Q

sympathetic chain is in the ____ NS, and has two connections from the ____ that connect to the sympathetic trunk at the ____

A
PNS 
anterior rami (VENTRAL-motor efferent) 

sympathetic chain ganglia
-part of autonomic or visceral NS

136
Q

preganglionic parasympathetic cell bodies are located in

A

brainstem or spinal cord

  • CNs cranial nerves (CNS nuclei)
  • S2-S4 (craniosacral)
137
Q

sympathetic preganglionic cell bodies are located in

A

spinal cord
Thoracolumbar
T1-L2

138
Q

postganglionic sympathetic cell bodies are located in

A

sympathetic chain ganglia
or
collateral (prevertebral) ganglia (via splanchnic nerves)

139
Q

postganglionic parasympathetic

A
  • think parasympathetic: craniosacral
  • 4 cranial ganglia
  • AND in the walls of the organs they innervate (ganglia with organs)