426 Midterm Week 1-6 GPT generated

What is the difference between anatomical and functional neuroanatomy?

Anatomical = structure-based (location, form); Functional = interaction- and circuit-based (how regions work together).

Why study functional neuroanatomy?

It connects anatomy to physiological and behavioural functions, helping explain clinical symptoms.

What are the major divisions of the nervous system?

Central (CNS = brain + spinal cord) and Peripheral (PNS = somatic + autonomic).

Define ipsilateral and contralateral.

Ipsilateral = same side; Contralateral = opposite side.

What are the major neuroanatomical planes?

Coronal, sagittal, and axial (horizontal).

What is a commissure versus a decussation?

Commissure = crosses at same level; Decussation = crosses at different levels.

What do structural imaging methods measure?

Anatomy — volume, thickness, and white-matter integrity (e.g., MRI, CT, DWI).

What do functional imaging methods measure?

Neurophysiological processes like neuronal signaling or blood flow (e.g., fMRI, EEG, MEG, PET).

What do chemical imaging methods measure?

Tissue composition (e.g., neurotransmitters via PET or MRS).

What does fMRI’s BOLD signal reflect?

The ratio of oxygenated to de-oxygenated hemoglobin as a proxy for neural activity.

What are T1- vs T2-weighted MRI scans?

T1 = CSF dark, white matter bright; T2 = CSF bright, good for pathology.

What does FLAIR MRI do?

Suppresses free water signal to highlight lesions.

Major pros and cons of MRI?

✅ High spatial resolution ❌ Expensive, slow, magnetic contraindications.

What’s the main advantage of CT?

Fast, cheap, great for bone imaging — but low soft-tissue contrast and uses radiation.

What does PET measure?

Metabolic activity or protein binding using radiotracers (e.g., FDG, flortaucipir).

Which modalities have the best temporal resolution?

EEG and MEG (≈ 1 ms).

Why does MEG have better spatial resolution than EEG?

Magnetic fields aren’t distorted by skull or tissue conductivity.

Typical trade-offs in imaging?

High spatial res (MRI, PET) vs high temporal res (EEG, MEG).

What is the gyrification index (GI)?

Ratio of total cortical surface area to outer surface area; decreases with age.

Main lobes of the cortex?

Frontal, Parietal, Temporal, Occipital (+ Insula and Limbic).

What is association cortex?

Regions integrating information beyond primary sensory or motor areas.

Unimodal vs Heteromodal association cortex?

Unimodal = one modality; Heteromodal = multi-sensory integration.

Brodmann’s areas are based on what?

Cytoarchitectonic (neuronal cell layer structure) differences.

Define localizationism vs connectionism.

Localizationism = specific region → function; Connectionism = network interaction → function.

What is topographical organization?

Adjacent body regions map to adjacent brain areas (e.g., homunculus).

Two major arterial sources to brain?

Internal carotid (anterior circulation) and vertebral arteries (posterior circulation).

What forms the Circle of Willis?

ACA, ACoA, ICA, PCA, PCoA — connects anterior and posterior systems.

ACA territory?

Medial frontal and parietal lobes → contralateral leg motor/sensory.

MCA territory?

Lateral cortex → face & arm motor/sensory, language areas.

PCA territory?

Occipital lobe and inferior temporal lobe → visual processing.

Most common artery affected in stroke?

MCA (~60%).

Define ischemic vs hemorrhagic stroke.

Ischemic = blocked blood flow; Hemorrhagic = vessel rupture and bleeding.

What is a lacunar stroke?

Small-vessel infarct in deep structures (e.g., internal capsule).

Treatment window for ischemic stroke?

~4.5 hours from onset; “time is brain.”

Name the four ventricles.

Two lateral, third, and fourth ventricles.

Where is CSF produced?

Choroid plexus lining the ventricles.

Main functions of CSF?

Cushion brain, circulate nutrients, remove waste.

Where is most CSF found?

Subarachnoid space (between pia and arachnoid).

CSF flow increases during which sleep phase?

Non-REM sleep — enhances waste clearance (β-amyloid, tau).

Three meningeal layers (from outer to inner)?

Dura mater, Arachnoid mater, Pia mater.

What creates the falx cerebri and tentorium cerebelli?

Folds of the meningeal layer of dura mater.

What is the epidural space?

Potential space between skull and dura; site of epidural hematoma.

Cause of epidural hematoma (EDH)?

Rupture of middle meningeal artery after temporal trauma → biconvex CT lesion.

Cause of subdural hematoma (SDH)?

Tearing of bridging veins → crescent-shaped CT lesion.

Cause of subarachnoid hemorrhage (SAH)?

Ruptured saccular (berry) aneurysm → blood in sulci and CSF.

Clinical triad of uncal herniation?

Blown pupil (CN III compression), hemiplegia, coma.

What is a tonsillar herniation?

Cerebellar tonsils herniate through foramen magnum → medulla compression → death.

Outline the visual pathway.

Retina → optic nerve → optic chiasm → optic tract → LGN → optic radiations → V1 (cuneus & lingual gyri).

Which retinal fibers cross at the chiasm?

Nasal fibers → contralateral hemisphere (represents opposite visual field).

Function of Meyer’s loop?

Carries superior visual field information (temporal lobe → contralateral “pie in the sky”).

Dorsal vs Ventral streams?

Dorsal = “where” (spatial parietal); Ventral = “what” (object temporal).

LGN layers and their functions?

1–2 magnocellular (motion); 3–6 parvocellular (detail & colour).

Outline the auditory pathway.

Cochlea → cochlear nuclei → superior olivary complex → lateral lemniscus → inferior colliculus → MGN → A1.

What does “tonotopic organization” mean?

Neurons arranged by frequency from low to high tones.

Vestibular organs and functions?

Semicircular canals (angular rotation) and otoliths (linear acceleration).

Vestibular outputs project to which regions?

Cerebellum, ocular motor nuclei (VOR), spinal cord, thalamus, and insular cortex.

What does the DCML pathway carry?

Fine touch, vibration, and proprioception.

What does the Anterolateral (System/Spinothalamic) pathway carry?

Pain, temperature, crude touch.

Where does the corticospinal tract decussate?

In the medullary pyramids (~90%) → lateral CST.

Corticobulbar tract controls which functions?

Voluntary movement of cranial muscle groups (face, jaw, tongue); mostly bilateral input except lower face.