Chapter 2.1 · Neuroanatomy
Brain Regions & Functions: INBDE Review
Cortical lobes, basal ganglia, limbic system, brainstem, cerebellum, and vascular territories, with the lesion patterns that show up most often on the INBDE. 11 board-style MCQs.
11 practice MCQsQuick-reference tableMnemonics + clinical pearlsFull distractor explanations
High-yield review
Concept summary & clinical relevance.
Quick-reference structure first, then nerve-by-nerve detail. Mnemonics in amber, clinical pearls in blue.
Brain regions are best learned by what they do, and what shows up clinically when they're damaged. Lesion-based reasoning is what the INBDE tests: aphasia patterns, hemineglect, hemianopia, Parkinson's, and the vascular territories of MCA/ACA/PCA strokes.
Cortical lobes: function & classic lesions
| Lobe | Key functions | Classic lesion |
|---|---|---|
| Frontal | Voluntary movement (precentral gyrus); executive (prefrontal); motor speech (Broca's, dominant) | Broca's aphasia: effortful, “broken” speech with intact comprehension |
| Parietal | Somatosensation (postcentral gyrus); calculation/praxis (dominant); spatial attention (non-dominant) | Hemineglect (non-dominant lesion); 2-point discrimination loss |
| Temporal | Auditory cortex; language comprehension (Wernicke's, dominant); memory (hippocampus); emotion (amygdala) | Wernicke's aphasia: fluent nonsense, poor comprehension; hippocampal lesion → no new memories |
| Occipital | Primary visual cortex | Contralateral homonymous hemianopia (often with macular sparing) |
Brainstem cranial nerve nuclei
| Brainstem level | CN nuclei | Clinical correlation |
|---|---|---|
| Midbrain | CN III, IV | Pupillary reflexes; eye movements |
| Pons | CN V (motor for mastication), VI, VII, VIII | Trigeminal motor + facial expression + balance |
| Medulla | CN IX, X, XI, XII; respiratory & cardiac centers | Loss of respiratory drive = medullary lesion |
Vascular territories: strokes you must recognize
| Artery | Territory | Classic deficit |
|---|---|---|
| MCA (dominant) | Lateral cortex: face & arm motor/sensory + language | Aphasia + face/arm hemiparesis |
| MCA (non-dominant) | Same region, opposite hemisphere | Hemineglect + face/arm hemiparesis |
| ACA | Medial cortex (leg motor/sensory area) | Contralateral leg weakness; abulia |
| PCA | Occipital lobe; thalamus | Contralateral homonymous hemianopia |
Clinical pearl, Aphasia in 30 seconds
If speech is fluent but the words don't make sense → Wernicke's (temporal). If speech is halting and effortful but the patient understands you → Broca's (frontal). If repetition specifically is impaired → conduction aphasia (arcuate fasciculus). “Wernicke's wonders, Broca's broken.”
Clinical pearl, Why dental students need neuroanatomy
Patients with prior strokes, Parkinson's, or dementia are common in the dental chair. Recognizing facial droop, dysarthria, or hemineglect during a routine visit can flag a new event. And drug interactions (e.g., levodopa with epinephrine, anticonvulsants) directly affect anesthetic choices.
Mnemonic, Brainstem CN nuclei
“3–4 mid, 5–8 pons, 9–12 medulla.” Cranial nerves III & IV in midbrain; V, VI, VII, VIII in pons; IX, X, XI, XII in medulla.
Mnemonic, Hypothalamus
“THE PASt”: Temperature, Hormones, Eating, Parasympathetic/Sympathetic, Arousal, Sleep. The hypothalamus regulates all of these.
Cerebral lobes
- Frontal: precentral gyrus = primary motor cortex (voluntary movement, contralateral). Prefrontal cortex = executive function (planning, judgment, impulse control). Broca's area (dominant) = motor speech.
- Parietal: postcentral gyrus = primary somatosensory cortex (touch, pain, temperature, proprioception). Non-dominant parietal = spatial attention; lesion → hemineglect.
- Temporal: primary auditory cortex; Wernicke's area (dominant) = language comprehension; hippocampus = memory consolidation; amygdala = fear/emotion.
- Occipital: primary visual cortex; lesion → contralateral homonymous hemianopia.
Deep gray systems
- Basal ganglia (caudate, putamen, globus pallidus, subthalamic nucleus, substantia nigra): smooth voluntary movement.
- Parkinson's = substantia nigra dopaminergic loss → bradykinesia, rigidity, resting tremor.
- Huntington's = caudate atrophy → chorea.
- Hemiballismus = subthalamic nucleus lesion → flinging movements.
Diencephalon
- Thalamus: relay station for all sensory information except smell.
- Hypothalamus: homeostasis (temperature, hunger, thirst, sleep, autonomics) and endocrine control via the pituitary.
Cerebellum
- Compares motor plan to actual movement → coordination and balance.
- Vermis lesion: wide-based, “drunk” gait.
- Hemisphere lesion: ipsilateral intention tremor and dysmetria.
- Flocculonodular lobe: balance and eye movements.
CSF & ventricles
- Produced by the choroid plexus in the ventricles.
- Flow: lateral ventricles → foramen of Monro → 3rd → aqueduct of Sylvius → 4th → foramina of Luschka/Magendie → subarachnoid space → arachnoid granulations → venous sinuses.
- Obstructive hydrocephalus: blocked flow (e.g., aqueduct stenosis).
- Communicating hydrocephalus: impaired absorption at arachnoid villi.
KYT INBDE
KYT INBDE: Anatomy & Physiology for Dentistry
900 MCQs · Volume 1 · Available on Amazon
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Self-assessment · Core Recall
11 board-style MCQs.
Active recall is the highest-yield study method for the INBDE. Pick an answer, check it, and read why every distractor is wrong, that's where the learning compounds.
In the book, different question type
The MCQs above are Core Recall, testing what you've memorized. The book adds a full Clinical Integration set: board-style patient scenarios where you apply this anatomy to real clinical reasoning. That's the section the INBDE actually weights heaviest.
- Question 1EasyThe precentral gyrus corresponds to which functional area of the brain?
- Question 2EasyLesion to Broca's area produces which deficit?
- Question 3EasyWhich lesion causes fluent but meaningless speech with poor comprehension?
- Question 4EasyWhich structure consolidates short-term memory into long-term memory?
- Question 5ModerateParkinson's disease results from degeneration of which basal ganglia component?
- Question 6EasyWhich sensory modality bypasses the thalamus?
- Question 7ModerateWhich brainstem structure contains nuclei for cranial nerves III and IV?
- Question 8EasyFailure of respiratory drive localizes to which structure?
- Question 9EasyWhich structure produces cerebrospinal fluid?
- Question 10ModerateA stroke in the left middle cerebral artery (MCA) of a right-handed patient is most likely to cause:
- Question 11ModerateWhich artery supplies most of the motor and sensory cortex for the legs?
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Anatomy & Physiology
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900 INBDE-style MCQs with full explanations across 18 chapters — Core Recall plus board-style Clinical Integration scenarios — alongside Learning Summaries, Integration Bridges, and Review Boxes. Built by Dr. Isaac Sun for dental students who want to think like a clinician, not just memorize.
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Founder, KYT Dental Services · Author, KYT INBDE series. These MCQs and Learning Summaries are part of a structural-thinking framework Dr. Sun uses with patients in the chair.