Neurobiology

Cranial nerve I

Olfactory (smell)

Cranial nerve II

Optic (vision)

Cranial nerve III

Oculomotor (eye muscle)

Cranial nerve IV

Trochlear (eye muscle)

Cranial nerve V

Trigeminal (facial sensation, chewing)

Cranial nerve VI

Abducens (eye muscle)

Cranial nerve VII

Facial (facial muscle)

Cranial nerve VIII

Vestibulocochlear (hearing, balance)

Cranial nerve IX

Glossopharyngeal (swallowing, gag reflex)

Cranial nerve X

Vagus (heart rate, digestion)

Cranial nerve XI

Accessory (head, neck, shoulder muscle)

Cranial nerve XII

Hypoglossal (tongue muscle)

Gyri

Brain bulges

Sulci

Brain grooves

Fissure

A large sulcus

Longitudinal fissure (aka medial fissure)

Separates the left and right hemispheres

Superior

Higher on the body; nearer to the top of the head

Inferior

Lower on the body; farther from the top of the head

Anterior

Towards the front

Posterior

Towards the back

Rostral

Anterior to the longitudinal axis

Caudal

Posterior to the longitudinal axis

Dorsal

Superior to the longitudinal axis

Ventral

Inferior to the longitudinal axis

Medial

Towards the midline

Lateral

Away from the midline

Ipsilateral

On the same side of the body

Contralateral

On the opposite side of the body

Hypothalamus

Sexual response, endocrine function, autonomic control (breathing, heart rate, blood pressure)

Brain stem

Balance, breathing, heart rate, reflexes; contains the cranial nerves

Cerebellum

Balance, coordination, proprioception, assists in other cranial functions

Frontal lobe/limbic cortex

Inhibition, storage and processing of emotional events, social skills

Occipital lobe

Visual processing

Parietal lobe

Touch, location, movement, pressure, pain

Temporal lobe

Auditory processing, language

Amygdala

Fear response, emotion

Hippocampus

Memory formation and storage

Central nervous system

Brain, brain stem, spinal cord

Peripheral nervous system

All nerves and neurons not located in the brain, brain stem, or spinal cord

Precentral gyrus

Motor strip

Motor strip chain

Precentral gyrus → upper motor neuron → brain stem → spinal cord → lower motor neuron → move muscle

Postcentral gyrus

Sensory strip (homonculus); stimulations along this area correspond to sensations all over the body

Sensation chain

Pinprick on finger → peripheral sensory nerve on finger → spinal cord → brain stem → thalamus → postcentral gyrus (“sensory strip”)

Thalamus

Processes all sensory inputs, relays to the cortex; the “switchboard operator”

Cerebellum neural density

Takes up 10% of the brain’s volume, but has over 50% of the neurons

Broca’s area

Part of speech center, left frontal lobe on left inferior frontal gyrus (usually); location can be affected by hand dominance

Wernicke’s area

Part of speech center, posterior third of upper temporal convolution

Arcuate fasciculus

Fibers that connect Broca’s area to Wernicke’s area

Aphasia

Disruption of speech

Broca’s aphasia

Disruption of speech production

Wernicke’s aphasia

Disruption of speech comprehension

Limbic system components

Amygdala, frontal lobe, hippocampus, hypothalamus, olfactory bulb, thalamus

Limbic system function

Controls functions necessary for survival; arousal, motivation, reactions

Vision chain

Image presents to eye → rods/cones in retina → optic nerve, passes through optic chiasm → thalamus → primary visual cortex (VI), occipital lobe

Auditory chain

Sound → amplification through tympanic membrane and ear bones → signal through VIII → thalamus → primary auditory cortex on superior temporal gyrus (in temporal lobe)