Brain & Behavior - Sensation & Perception Ch 5-7 Flashcards
Exam 2
What are the building blocks of the brain?
Neurons
What are neurons made of?
Cell body, nucleus, dendrites, axons and axon terminals.
How do neurons work?
Electrical impulses travel down the axon to axon terminals bringing information.
Synapse is…
presynaptic to a gap to postsynaptic which activates receptors to open sodium channels resulting in new neural impulses and so on…This is also chemical communciation.
Psychoactive Drugs….
Facilitate or inhibit the production of release of neurotransmitter into a synapse, facilitate or inhibit the removal of the neurotransmitter from the synapse, facilitate or inhibit the sensitivity of the postsynaptic receptors.
Long Term Potentiation (LTP)
Repeated activation of synapses results in strengthened synapses. This is the neural basis for learning and memory.
Subcortical Areas of Brain (Evolutionary) - Brain Stem Level
Medula, Pons, Midbrain, Thalamus
Medula does…
Vital reflexes; breathing, heart rate, posture
Pons does…
Primitive movement patterns; eating, drinking, sex, sleep and arousal
Midbrain does…
Important for reflexes (primitive); superior colliculus - visual regarding reflexes (ex when something comes at your face quickly)
Thalamus does…
Sensory relay station; sight, sound, touch, taste (but NOT smell)
Motor or Movement Areas of Brain
Basal Ganglia and Cerebellum. These parts have mirror images within the brain.
Basal Ganglia does…
Initiation of goal-directed movements. With an end state in mind (i.e. move arm to get glass). Dopamine found here (neurotransmitter). This is the area effected that causes Parkinsons Disorder.
Parkinsons Disorder - Symptoms
resting tremor, slowed movement, shuffling walk, stooped posture, ridgidity & freezing, blank face but normal cognition.
Parkinsons Disorder - Prevalence
1% of perople over 60
Parkinsons Disorder - Etiology
Death in Substantia Nigra (midbrain)=loss of dopamine projections to basal ganglia=loss of automatic motor control and motor initiation
Parkinsons Disorder - Risk Factors
Small genetic influence. Toxic exposures (pesticides)
Parkinsons Disorder - Treatment
Replace dopamine or dopamine neurons; electrical stim of basal ganglia (not cures)
Cerebellum does…
Coordination of skilled (learned) movements. ex playing of violin. this area is effected by alcohol.
Limbic System parts…
Hypothalamus
Limbic System does…
influences emotion, motivation & memory
Hypothalamus parts…
Lateral Hypothalamus, Ventro Medial Area, Medial Preoptic Area
Hypothalamus means…
below thalamus
Lateral Hypothalamus…
Initiation of eating, drinking and sex (gas pedal). If you lession this area the animal will be unable to eat, drink or have sex (no motivation)
Ventro Medial Area…
Termination of eating, drinking, and sex (brake pedal). If you lession this area the animal is unable to stop eating, drinking or having sex
Medial Preoptic Area…
Sexually Dismorphic Nucleus (SDN). Male SDN tends to be larger than females. Relates to reproduction. Prenatal androgens (testosterone) masculinizes the SDN. Influences sexual orientation.
Different ways to identify sex…
Genotype Sex - chromosomes (xx or xy), Phenotypic Sex - Internal/external genitals, Gender Identification - subjective perception, Brain Sex - structural difference in brain organization male v. female
What reduces androgens (testosterone)?
Stress does. Could effect brain sex.
Testosterone influences on brain sexual behavior…
Organizational (prenatal) - sexual orientation and Activatitonal (postnatal) - sexual desire
Pituitary Gland…
Master endocrine gland - receives input via hypothalamus.
Pleasure Centers in Brain
Nucleus Acumbens (basal ganglia), Medial Forebrain Bundle (MFB - midbrain-lateral hypothalamus-nucleus acumbens), dopamine neurotransmission, endorphins & oxytocin, pleasure drugs, incentive-motivation-reward system, deactivated in clinical depression.
Activating dopamine activates pleasure
blocks re-uptake of dopamine, crash after big high on cocaine - less sensitivity, loss of normal pleasures, losing interest in normal activities
Cerebral Cortex is what level of functioning?
Higher mental functioning (awareness, planning, etc)
Cerebral Cortex is…
made up of a right and left hemisphere (mirror images). it is a layer of cells (neurons) on the surface of the hemispheres.
Cerebral Cortex parts…
Corpus Collosum, Primary Motor Cortex, Primary Somatosensory Area, Primary Visual Cortex, Primary Auditory Cortex, Frontal Lobe, Premortor Area
Corpus Collosum….
connects similar areas of left & right cortex
Lateral Fissures….
deep indentation between temporal & frontal lobes
Central Fissure..
dividing point between frontal lobe and parietal lobe