MCAT Brain

Thalamus

Relays sensory and motor signals, regulates sleep

Hypothalamus

Mediates homeostasis and links nervous and endocrine systems

Pineal gland

produces melatonin for sleep regulation

Posterior Pituitary

produces and secretes hormones

Cerebral cortex

outer layer, involved in higher order functions

Frontal lobe

Cognition, executive functions, memory processing, planning, attention

Parietal Lobe

sensory processing

Temporal Lobe

Sound, language processing, memory consolidation

Occipital Lobe

primary visual cortex

Subcortical structures

Olfactory bulb, hippocampus, basal ganglia

Hippocampus

Memory consolidation

Basal Ganglia

motor control

Limbic system

emotion, motivation, memory (includes subcortical structures and amygdala)

Inferior Colliculus

processes auditory signals, sends to thalamus

Superior Colliculus

Processes visual signals, controls eye movements

Substantia Nigra

Coordinates voluntary motor control

Brainstem

Midbrain, medulla oblongata, pons

Midbrain

Inferior colliculus, superior colliculus, substantia nigra

Hindbrain

Cerebellum, Medulla oblongata, pons

Cerebellum

coordination of voluntary motor movements

Medulla Oblongata

Controls autonomic functions

Pons

Relay station between different parts of the brain

Acetylcholine

Primary neurotransmitter for parasympathetic responses and preganglionic sympathetic responses

Norepinephrine

Primary neurotransmitter for postganglionic sympathetic responses

Preganglionic Neurons

From CNS to a ganglion

Postganglionic Neurons

From ganglion to target organ

Somatosensation

Processed in parietal lobe at primary somatosensory cortex, postcentral gyrus

Vision

Initial processing in lateral geniculate nucleus of thalamus and superior colliculus, final processing in occipital lobe at primary visual cortex

Hearing

Thalamus, medial geniculate nucleus, to inferior colliculus, and primary auditory cortex in temporal lobe

Taste

Thalamus, then cortex

Smell

Direct path to olfactory cortex, bypasses thalamus

Premotor cortex

initiates planning of motor control

Primary motor cortex

executes movement, located in frontal lobe on precentral gyrus

Precentral gyrus

separates frontal and parietal lobes

Cerebellum and basal ganglia

coordinate muscle groups for unified movment

Glutamate

Primary excitatory neurotransmitter, induces depolarization and action potentials

GABA

primary inhibitory neurotransmitter, reduces likelihood of neuron firing

Acetylcholine

Released at neuromuscular junction, initiates muscle contraction