Chapter 49

Glia

Ependymal cells line ventricles and circulate CSFMicroglia protect against microorganismsOligodendrocytes myelinate CNSAstrocytes provide support, regulate [NT], increase

blood flow, support BBBRadial glia direct embryonic neuron migration

Comparative NeuroanatomyMultiple

nerve cells = nervesElaborate

movementsBilateral

shows cephalization

Correlates with lifestyleSessile vs

active

Nervous System

Central Nervous System (CNS)

Peripheral Nervous System (PNS)

Brain Spinal CordAutonomic

(involuntary)Somatic

(voluntary)

Sympathetic(Fight or flight)-

adrenergic

Parasympathetic(Rest and digest)-

cholinergic

Vertebrate Nervous System

Integration Info in & out

ANSAfferents &

efferentsCranial &

spinal nervesParasympatheti

c & sympatheticAntagonistic,

but coordinate for homeostasis

Embryonic Brain Development

HindbrainMedulla oblongata

Heart and lungsEmesis center

PonsCommunication between cerebellum and

cortexCerebellum

Coordination and balance Learning tasks/motor skills, i.e driving, riding a

bike, piano, etc Body position awareness (proprioception)

Input from senses & muscles

Axons cross = opposite control

MidbrainAggressionAlertness and

concentration (reticular formation)

Most primitive (reptile brain)With hindbrain form

brainstemOptic lobes

Visual and peripheral vision reflexes

ForebrainDiencephalon

Thalamus Relay sensory info to cortex Sense sub-regions (gustation, tactile, olfaction, auditory,

& sight)Hypothalamus

ANS & regulates brain stem Body temp, immune system, & pituitary Sub-regions (full, hungry, & circadian rhythm)

CerebrumMost advanced (thinking, talking, & understanding)Distinct hemispheres and lobes

Cerebral CortexConvolutions increase area2 hemispheres show

lateralizationLeft: math, speech, concrete

processing, logicRight: creativity, facial and

pattern recognitionCorpus callosum

Coordinate movement & integrating info

Limbic systemHippocampus for learning &

memoryAmygdala processes

emotional input Olfactory connection to

emotions, fear, & aggression

4 Lobes

Cerebral LobesFrontal

Primary motor region & emotion/pain processing

Reasoning, planning, speech, and problem solving

Parietal (2)Primary sensory region &

integrates motor and sensory info

Temporal (2)Auditory senses & memoryBroca’s area (production) and

Wernicke’s area (comprehension)

OccipitalVisual information

Comparative Brain AnatomyBrain size (male/female)

Larger brains = larger animals, but body weight relative

Cortex (dog/cat)Convolutions increased =

more intelligenceMammals increased

association areas Complex behavior and learning

Cerebellum (dog/cat)Size and regional

developmentOlfactory bulb

(mouse/human)Size and location

Limbic systemLearning avoidance

Reticular FormationArousal

Acts as a sensory filter More info in = more alert

and aware Selective attention

SleepPons and medulla input

too = sleepFunction unknown, but

necessary for survivalActive state, varies with

stages Dolphin’s pattern

Circadian RhythmsDaily biological

rhythmsSleep, body

temps, hunger, & hormone release

Biological clock regulates gene expressionAround 24 hours,

environment resets (unnecessary)

SCN Syncs cells with day

length from eye clues

Homunculus

Nervous System DisordersSchizophrenia

Genetic connection being investigated

Medicines focus on blocking DA

DepressionGenetic and environmental

componentsBiogenic amines treatments,

SSRI’sDrug Addiction

Increases brain’s reward system & DA

Crave pleasure associated with not the drug

Neurodegenerative diseases