Biopsychology 4

Central Nervous System (CNS)

Brain and spinal cord

Peripheral Nervous System (PNS)

All nerves outside the CNS

Somatic Nervous System

Controls voluntary skeletal muscle movement

Autonomic Nervous System (ANS)

Controls involuntary bodily functions

Sympathetic Nervous System

Fight or flight; increases heart rate, dilates pupils, inhibits digestion

Parasympathetic Nervous System

Rest and digest; decreases heart rate, constricts pupils, stimulates digestion

Preganglionic neurotransmitter (ANS)

Acetylcholine (ACh)

Postganglionic Sympathetic neurotransmitter

Norepinephrine (NE)

Postganglionic Parasympathetic neurotransmitter

Acetylcholine (ACh)

Dorsal Root Ganglion

Contains sensory neuron cell bodies; damage causes loss of sensation

Law of Bell and Magendie

Dorsal = sensory input, Ventral = motor output

Hindbrain

Includes medulla, pons, cerebellum

Medulla

Controls breathing and heart rate

Pons

Sleep and relay functions

Cerebellum

Coordination and balance; damage causes uncoordinated movement

Midbrain

Contains superior and inferior colliculi

Superior Colliculus

Visual reflexes

Inferior Colliculus

Auditory reflexes

Forebrain

Largest brain region; includes cortex, thalamus, hypothalamus

Thalamus

Sensory relay station (except smell)

Hypothalamus

Hunger, thirst, temperature, hormones; controls pituitary gland

Meninges

Protective layers around CNS

Dura Mater

Outer tough layer of meninges

Arachnoid Mater

Middle web-like layer

Pia Mater

Inner delicate layer attached to brain

Ventricles

Four fluid-filled brain cavities

Lateral Ventricles

First pair of ventricles

Third Ventricle

Middle ventricle

Fourth Ventricle

Connects to spinal cord

Cerebrospinal Fluid (CSF)

Cushions brain, removes waste, provides buoyancy, maintains chemical stability

Choroid Plexus

Produces CSF

CSF Flow

Lateral → Third → Fourth → Subarachnoid space → blood

Basal Ganglia

Group of structures controlling movement

Direct Pathway

Increases movement (GO signal)

Indirect Pathway

Decreases movement (STOP signal)

Dopamine effect on Direct Pathway

Stimulates it (more movement)

Dopamine effect on Indirect Pathway

Inhibits it (less stopping)

Overall effect of dopamine

Increases voluntary movement

Parkinson’s Disease

Caused by low dopamine; tremor, rigidity, slow movement

Huntington’s Disease

Genetic disorder; uncontrolled movements, cognitive decline

Hypokinetic Disorder

Too little movement (e.g., Parkinson’s)

Hyperkinetic Disorder

Too much movement (e.g., Huntington’s)

Procedural Memory Deficit

Difficulty learning skills; linked to basal ganglia damage

Hippocampus

Forms new memories; damage causes inability to form new memories

H.M.

Famous patient with hippocampal damage and anterograde amnesia

Amygdala

Emotion processing (fear, aggression)

Klüver-Bucy Syndrome

Amygdala damage; hypersexuality, no fear, overeating

Prefrontal Cortex

Decision-making, planning, personality

Prefrontal Damage

Poor judgment, personality change, impulsivity

Frontal Lobe

Movement, decision-making

Parietal Lobe

Touch and spatial awareness

Temporal Lobe

Hearing and memory

Occipital Lobe

Vision

Precentral Gyrus

Primary motor cortex

Postcentral Gyrus

Primary somatosensory cortex

Hemineglect

Ignore one side of space; usually right parietal damage

Prosopagnosia

Face blindness; temporal lobe damage

Cortical Blindness

Damage to occipital lobe

Cortical Deafness

Damage to temporal lobe

Language Lateralization

Left hemisphere dominant for language

Music/Emotion Lateralization

Right hemisphere dominant