Lecture 2

Question 1

3 types of neural systems

Answer 1

• Sensory (INPUT)
• Motor (OUTPUT)
• Association (In-Between)

Question 2

What are neural system characterized by?

Answer 2

• Components: neurons and connections dedicated to a function
  -Orderly representation
  -Division into subsystems (processed in parallel)

Question 3

Neuronal systems: basic principles

Answer 3

• Systems for point distinguishing (eg. touch)
  > TOPOGRAPHIC maps
• Other system (eg. taste)
  > COMPUTATIONAL maps
• Higher order systems (eg. language)
  > not as well understood

Question 4

Collections of neurons (6)

Answer 4

• Grey matter: cell bodies in the brain
• Cortex: thin sheet of neurons (usually surface)
• Nucleus: distinguished mass of neurons (usually deep)
• Sustantia: less distinguished, related neurons
• Locus: small well defined group of cells
• Ganglion: collection of neurons in PNS
  > in CNS, ONLY Basal Ganglia

Question 5

Collections of axons (6)

Answer 5

• Nerve: collection of axons in PNS > only optic never in CNS
• Tract: axon collection in CNS, common origin & destination
• Bundle: axon collection, no need for common origin/destination
• Capsule: connects cerebrum with brain stem
• Commisure: connects hemispheres
• Lemniscus: tract that like a ribbon

Question 6

Methods to study neural systems

Answer 6

Genetic analysis: GWAS, can do in vivo
Structural analysis:
> lesion studies for functional location
> tract tracing
> EEG, MEG, fMRI, CT, TMS

Question 7

Orientation axes

Answer 7

ALLOCENTRIC X-Y axis:
superior↑
inferior↓
posterior→
anterior ←

EGOCENTRIC at an angle
(see 2.7)
D
Rostral<———————->Caudal
V |
V | D
↓

Question 8

CNS Subdivisions (7)

Answer 8

• Spinal cord
• Cerebellum
• Brainstem
  > medulla, pons, midbrain
• Forebrain
  > diencephalon, cerebrum

Question 9

Spinal cord: internal anatomy
(4pts, 3 columns, horns)

Answer 9

4 parts (see 2.10):
-central
-thoracic
-lumbar
-sacral

Columns:
dorsal - sensory info
ventral - pain & temp ASC
> brain stem & motor cortex DSC
lateral - cerebral cortex > interneurons > MNs in the ventral horns

Horns: dorsal - sensory info
ventral - motor

Question 10

Spinal cord: external anatomy

Answer 10

Dorsal roots have afferent axons
> sensory info
Ventral roots have efferent axons
> motor commands

Question 11

Where are the brainstem & cranial nerves?

Answer 11

Between diencephalon & spinal cord

Question 12

Brainstem & cranial nerves; structure & function

Answer 12

Structure: CN nuclei; target for sensory (natural) source for motor (medial)

Functions:
1) Regulate conciousness through forebrain projection
2) Target & source of CN (Head & neck motor)
3) Throughway

Question 13

Lateral surface

Answer 13

precentral gyrus: motor cortex
postcentral gyrus: semantic sensory cortex

Question 14

Dorsal & ventral surfaces

Answer 14

see PSYC 311 notes: know basic lobes, symmetry, corpus callosum

Question 15

Midsagittal surface

Answer 15

(see 2.15 for diagram)
Calcarine Sulcus marks OL
Cingulate gyrus in limbic sys.
CC connects hemispheres
Diencenphalon has:
- Hypothalamus - homeostatic & reproductive functions
- Thalamus - relay for sensory & motor info
- INPUT from brain & spinal cord, OUTPUT to cortical areas (to brainstem via internal capsule > BG)

Question 16

Blood brain barrier & ischemia

Answer 16

BBB protects brain from toxins & ionic millieu fluctuations, between capillary walls & sounding tissue - thru endothelial membrane to brain

Ischemia: loss of blood supply causes cell death & degeneration

Question 17

Meninges (covering) 3 layers

Answer 17

Skull
↓
1) DURA MATER: outermost, hard
↓ 1.5 blood vessels
2) ARACHNOID MEM: middle, web-like
↓ 2.5 CSF
3) PIA MATER: innermost. adheres to the brain
↓
Brain Tissue

Question 18

Glymphatic system

Answer 18

• Waste clearance system
• Increased flow during sleep
  -CSF rinses metabolic & protein waste