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Flashcards in Test 1 Deck (61):
1

6 Functions of the Nervous System

1. Perception
-Special senses: taste, balance, hear, vision, smell
-Somatosensory: group of modalitiles of body state; PainTouchProprioceptionTemperature
-Visceral: modulate, monitor, motivate

2. Movement
-plan, initiate, coordinate

3. Life sustaining
-seek, homeostais

4. Cognition
-memory, learning

5. Emotinon
-fear, pleasure, attatchment, desire

6. Arousal
-biological rythms; sleep, conciousness

2

4 Components of CNS

1. forebrain (cerebral hemispheres and diencephalon)

2. brainstem (midbrain, pons, medulla)

3. cerebellum

4. spinal cord

3

Components of PNS

1. Sensory nerves: from periphery/viscera to CNS

2. Motor nerves: commands from CNS to muscles/viscera

Subdivisons:
-Somatic Motor system: sensory nerve/motor nerves to skeletal muscles
-Autonomic Motor System: motor commands to viscera and smooth muscle via sympathetic, parasymphathetic, and enteric system

4

3 Primordial tissues

1. Endoderm: epithelial of GI, respiratory, and urinary
2. Mesoderm: muscle, skeletal, CT, and cardiovascular tissue, urogenital/hematopoietic systems, some microglia
3. Ectoderm: skin, neurons, macroglia, ependymal cells (line ventricles), and some microglia

-Ectoterm transforms into neuroectoderm-> tubes to become chambers

5

Development of Chambers from 3-> mature

Prosencephalon->
-telencephalon-> cerebral hemispheres
-diecnephalon-> thalamus/hypothalamus

Mesencephalon->
-mesencephalon -> midbrain

Rhombencephalon->
-metencephalon-> pons/cerebellym
-myencephalon-> medulla

6

Flexures of Development

Cephalic flexure: during 3 vent stage, remains as secondary primary axis-> cererum/brainstem different axis

Cervical flexure: 3 vent stage; straightens out

Pontine flexure: marks beginning of cerebellar differentiation in 5 vent stage

7

Neuron anatomy:
INPUT zone

Soma and Dendrites
-dendrites increase surface area for synapse

8

Neuron anatomy:
INTEGRATION (trigger) zone

Axon Hillock
-"initial segment"

9

Neuron anatomy:
CONDUCTING zone

Axon
-neurofillaments skeleton of axons
-mircotubules allow protein transport to dendrites and terminal endings

10

Neuron anatomy:
TRANSMITTING zone

Presynaptic Terminal
"axon terminal"

11

Neuron anatomy:
INSULATOR

Myelin
-in schwann cells, oligodendrytes

12

Neuron anatomy:
AP Renewal/REGENERATOR

Nodes of Ranvier

13

Neuron anatomy:
TRANSMITTER RELEASE

Presynaptic membrane
-in axon terminal
-NT made here

14

Neuron anatomy:
TRANSMITTER UPTAKE

Postsynaptic membrane
-NT uptook here

15

3 Neuron Classification classes

1. Morphology: multip, bi, uni, pseudounipolar
2. Function: sensory, motor, autonomic, interneuron
3. Neurotransmitter: chemicals they produce/release

16

4 Morphologic Classification of Neurons

1. Psuedounipolar: DRG, somatosensation
2. Unipolar: rare
3. Bipolar: special senses
4. Multipolar: almost all neurons

17

3 Glial Cell Functions

1. Neuron growth: Support neuron growth/repair after damage

2. Neuronal activity: Insulate axons/stabalize extracell activity

3. Form glial systems: Chemical signaling in CNS

18

2 Classes of Glial Cells

1. Macroglia: (astrocytes, oligodendrocytes, Scwann cells, ependymal cells)
-Astro/Oligo: CNS to many cells
-Schwann: PNS, myelinate ONE neuron at ONE location
-Emepndymal: line ventricles

2. Microglia: (few in number)
-increase when infections invade NS

19

3 Qualifications of NeuroTransmitters

1. Pres-synaptic manufactored
2. Calciam mediated release
3. Receptors on post-synaptic bind to it

20

Functions of 5 Cerbral Lobe

Frontal: cognition, voluntary motor (speech)

Parietal: somatosensation, taste, intermodal (multisens) integration

Occipatl: vision

Temporal: hearing, speech recognitino, smell, memory formation

Insula: taste, emotive pain (2 long gyri 3 short gyri)

--Limbic (not lobe): homesotasis, olfaction, memory, emotion

21

Cranial Nerve Locations in Brainstem

2: rostral to midbrain- in diencephalon
3-4: midrain
5: pons
6-8: pondumedular junction
9-12: rostral medulla

22

Divisons of Spinal Cord Termination

Cauda equina: L1-L2 when spinal cord ends; roots

Conus Medullaris: T12-L1; tapering of SC

Filum Terminale: fibrous cord of pia mater anchoring to coccyx

Additional Set nerves T1-L3: forming pregranglionic nerves for sympathetic NS

23

Gray vs. White Matter

Gray:
cell bodies forming nuclei/ganglia
light in stains
mantel of the cortex
basal ganglia, hippocampal formation, amygdala

White:
axons forming pathways
dark in stains
subcortical axon pathways to cortex
pathways in/out of cortex

24

Diencephalon Composition
(white vs. grey)

-Nuclei with small pathways in/out of gray clusters
-Bound by large white matter traveling in/out cerebral hemispheres

25

Brainstem Composition
(white vs. grey)

-Gray matter in small, lose clusters of nuclei-> sesnory/motor nuclei and centers for integrative functions
-White matter travels between nuclei along outer portions brainstem

26

Spinal Cord Composition
(white vs. grey)

-gray central location; motor and interneurons for reflexes, autonomi symp neurons, and sensorimotor functions
-White matter around spinal gray; sensory/motor pathways for trunk/limb control; autonomic control of viceral function

27

3 Types of Axons
(compose white matter pathways)

1. Projection fibers: long distances to different neural centers

2. Commisural: cross midline and synpase contralaterally
(decussate)

3. Association fibers: project ipsilaterally to cortical areas

28

Cerebral Cortex Names
(regarding number of layers)

Neocortex: 6 layers (most)
Paleocortex: less than 6
Archicortex: 3 layers

29

Functions of 6 Neocortex Layers

I/II: axons and synapses; integrate activity within column
III: cell bodies of neurons projecting to other cortex areas (association)
IV: input zone into cortex; synapse on cell bodies in IV
V: cortical neurons projecting to nuclei of brainstem/SC
VI: axons projecting to thalamus

30

Brodman Areas Function

BA 1-3: postcentral gyrus
BA 4: Primary motor cortex; discrete selective motor control
BA 5,7: somatosensory association
BA 4,6,8: motor
BA 39-40: receptive language; inferior parietal lobule
BA 44, 45: speech

31

BA 3a

Muscle spindle and GTO input determine length and force generated

32

BA 3b

Merkel and Ruffini processed in slow adapting columns
Meissner and Pacinian processed in rapid adapting columns

Pain

33

BA 1

Combine sensory info from BA 3b and 3rd VPL neurons
Texture analysis

34

BA 2

Combine infor from BA 3a, BA 3b, and 3rd VPL neurons
Integrate hand proprioception with touch modalities; analyze shape, orientation, slip

35

BA 5

Somatosens Association Cortex
Combine BA 3, BA 1, BA 2
Sense activity on both sides of bofy via commissural fibers
Projects to motor cortex; helps form body schemas to coordinate body regions with itself

36

BA 7

Somatosens Association cortex
Info from all BA 5 areas and Vision!
Contributes to body schema in space

37

4 Primary groups of Commisural Fibers

Coordinate activities between L and R hemispheres; share info, modulate, integrate

1. Corpus callosum
2. anterior commissure
3. Posterior commisure
4. Hippocampal commissure

38

Structures on Midbrain

Ventral: cerebral peduncles, intrapenduncular fossa, CN III
Dorsal: superior/inferior colliculi, CN4

39

Structures on Pons

Ventral: CN V, basis pons, cerebellar peduncles
Dorsal: floor of 4th ventricle
Pontomed junction: CN VI, VII, VIII

40

Structures on Medulla

Ventral: pyramids, olives, anterior medial fissure, CN 9-12
Dorsal: obex, 4th ventrical (rostral), gracilis/cuneate tubercles and fissures, posterior septum, intermediate septum

41

Location of ventricles

Lateral: corpus/hemispheres
Interventricular foramen: dienceph/corpus callosu
3rd vent: dienceph
Cerebral aqueduct: midbrain
4th ventricle: pons/rostral medulla

42

Tectum vs. Tegmentum

Tectum: roof of midbrain/ventricular system

Tegmentum: anterior to ventricular structures in cross section(floor)

43

Cervical SC Characteristics

Dorsal Column: gracilis and cuneate w/ intermediate dorsal septum
Lateral Column: thick
Ventral Horn: extend laterally (for hands)

44

Thoracic SC Characteristics

Dorsal Column: only one
Lateral Horn: small in intermediate gray
Ventral Horns: small and narrow

45

Lumbar SC Characteristics

Dorsal Column: only one
No Lateral horn
Central Horns: large and extend more ventral

46

Sacral SC Characteristics

Dorsal Column: only one
Round Cross section
Columns: small (minimal white)
V/DH: relatively large compared to white

47

3 Menninge Layers

1. Dura: tough outer layer
-lines skull
-2 layers: periosteal/meningeal together except at fissures-> venous sinuses
-creates: cerebral falx (central), cerebellar tentorium (transverse fissure), cerebellar flax, and diaphragma sllae
-has own blood supply

2. Arachnoid: loose thin middle layer

3. Pia: adheres to brain surface

48

3 Potential Spaces from menninge layers

1. Epidural space: meningeal artery; bleed between skull and dura

2. Subdural space: between dura and arachnoid

3. Subarachnoid space: vessels enter/exit brain-> natural space
Primary CSF holder; trabechula stabalize each position

49

Anterior Cerebral Artery Supply

Supplies:
-anteromedial surface (frontal to parietal)
-superior medial structures along longitudinal fissure
-anterior caudate nucleus/fornix

Loss Causes:
-contralat limb weak/sensory loss
-frontal lobe behavior abnormalities

50

Anterior Choroidal Artery Supply

Off Internal Carotid
-posterior internal capsule
-globulus pallidus
-putamen

51

Posterior Cerebral Artery Supply

Supplies:
-medial temporal and occipital
-medial inferior/posterior cortical regions
-midbrain
-thalamus

Loss Causes:
contralateral hemianopsia
-sensory loss
-hemiparesis
-reading probs
-aphasia

52

Middle Cerebral Artery Supply

Supplies:
-lateral surfaces of frontal/parietal
-temporal superior gyrus
-branches supplie basal ganglia, internal capsule (lenticulostriate arteries)
-lateral expanse cortex (corona radiata), internal capsule, putamen, gloubulus pallidus

Loss Causes:
-contralateral facial/arm weakness and sensory loss
-aphasia
-visual deficit

53

Vertebral Artery Supply

-medulla
-give post/ant spinal which supply caudal medulla and spinal cord

54

Basilar Artery Supply

-pons
-short circumfrential- ventral pons
-long circumfrential-dorsal/lateral pons

55

Cerebellar Artery Supplies

Superior: midbrain, superior cerebellum, rostral lateral pons, superior cerebellar peduncles

Posterior Inferior: lateral medulla, inferior cerebellum

Anterior Inferior: caudal lateral pons, cerebellum

56

Veinous Sinus System

Superior saggital: longitudinal fissure -> confluence of sinus
Inferior Saggital: above corpus collosum-> jugular vein
Transverse sinus: in transverse fissure-> confluence-

Confluence of sinus: superior, straight, and occipital sinuses join-> left/right transverse sinus-> sigmoid-> internal jugular-> heart

57

Why is somatosensation important?

-tissue protection/correct errors
-touch of objects
-interacting with environment
-coordination of fine motor movements

58

Muscle Spindles

In parallel with muscle fiber
-senses stretch and codes for amount
-fast receptors Ia, slow II fibers

59

Golgi Tendon Organs

free nerve endings interwoven within collagen of the tendon
-1b fibers
-crimp by tendon collagen to code muscle contraction force

60

PNS meninge layers

Epineurium=dura; around spinal nerve
Perineurium=arachnoid; around nerve fascicle
Endoneurium= pia; around nerve fiber

61

3 Anteriorlateral Tracts

1. Spinothalamic: pain/temp localization
VMp-insula (affective), VPL-SI (sens), MD-cingulate (emotive)

2. Spinomesencephalic: pain modulation
PAG-raphe nuclei-RexedII (seratonin modulates)

3. Spinoreticular: emotive aspects of pain/ANS modulation
Reticular formation in pons/medulla to cortex
Parabrachial nucleus to amygdala (fear and emotion)