1. “I am a brain, Watson. The rest of me is a mere appendix
“I am a brain, Watson. The rest of me is a mere appendix.” ― Arthur Conan Doyle, The Adventure of the Mazarin Stone

2. Neuroanatomy
The Form of the Brain

3. Directional terms superior lateral medial posterior anterior inferior
Thee are 3 common ways to slice the brain: coronal also called facial that slices in the plane of the eyes, sagittal along the midline, and horizontal which is parallel to the ground
Anterior towards the front, posterior towards the back, inferior towards the ground, superior towards the top of the head, lateral towards the outside and medial towards the middle
Figure from Purves, Neuroscience, 5th Ed.
medial
posterior
anterior
inferior

4. Protecting The Brain Skin
Periosteum = leathery covering of cranial bones
Cranium = bone w/fixed joints
Meninges

5. Meninges Dura mater = tough fibrous tissue covering the brain.
Contains blood vessels that nourish the brain.
Holds in the cerebral-spinal fluid (CSF)
Arachnoid Space
Pia mater

6. Sub- v. Epidural Hematomas
Epidural = Inflammation between dura and skull
Subdural = between arachnoid space and dura

7. Cerebro-Spinal Fluid (CSF)
CSF = plasma ultrafiltrate that bathes and protects the CNS.
Produced by the choroid plexus (tissue in the lateral ventricles & 4th ventricle)
Hydrocephalus = Inflammation resulting from obstruction of the aqueduct connecting the third & fourth ventricles

8. Major Regions of the Brain
Cerebrum
Cerebellum
Spinal cord

9. Cerebral Cortex The outer layer of grey matter of the cerebrum
Grey matter consists of soma (cell bodies)and unmyelinated axons
White matter consists of myelinated axons
Cerebral Cortex

10. Soma
Axons
We've looked at isolated single neurons so far. But this is a picture showing all the neurons in a single location in the brain. As I said before, there are 100 billion neurons throughout the brain. The scale of 100 billion is tough to imagine
Let’s look inside to get a sense of how so many can be in such a small space

11. Cerebral Topography Gyri – Elevated ridges “winding” around the brain
Cingulate Gyrus – Just above the corpus callossum
Sulci – Small grooves dividing the gyri
Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe
Fissures – Deep grooves, generally dividing large regions/lobes of the brain
Longitudinal Fissure – Divides the two Cerebral Hemispheres
Transverse Fissure – Separates the Cerebrum from the Cerebellum
Sylvian/Lateral Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes

12. Specific Sulci/Fissures:
Central Sulcus
Longitudinal Fissure
Sylvian/Lateral Fissure
Transverse Fissure

13. Cerebral Lobes
Frontal
Parietal
Temporal
Occipital

14. Frontal Lobe The frontal lobe is located deep to the frontal bone.
Functions/actions:
Memory formation
Emotions
Decision Making/Reasoning
Personality
Generally, the left side of the brain controls the right side of the body

15. Frontal Lobe – Cortical Regions Broca’s Area Orbitofrontal Cortex
Primary Motor Cortex/ Precentral Gyrus
Broca’s Area
Orbitofrontal Cortex
Olfactory Bulb
Modified from:

16. Primary Motor Cortex Controls movements of the body
Betz cells  alpha motor neurons (spinal cord)  muscle fibers
The motor cortex contains a rough “map” of the body, with controls for the toes (top) to the mouth (bottom) in overlapping regions

17. Motor Homunculus
Proportional model of organs to density of neural tissue devoted to said muscle/structure

18. Broca’s v. Wernicke’s Area
BROCA =Located on the right frontal lobe
Controls facial neurons, speech, and language comprehension
WERNICKE = located on left temporal lobe
Controls content of speech and language development

19. Orbitofrontal Cortex
One of the least explored and understood regions of the cerebral cortex
Located just above the orbits (eye sockets), in the frontal lobe
Involved in adaptive learning and “personality” of an individual

20. Phineas Gage

21. Olfactory Bulb
The most rostral (forward) part of the brain in most vertebrates, but is on the inferior side of the brain in humans
Olfactory receptor neurons in the nasal cavity receive the smells, and transmit them to the brain

22. Parietal Lobe
Where? The parietal lobe of the brain is located deep to the parietal bone of the skull
What Functions?
Sensory Integration
Proprioception: aware ness of body/body parts in space and in relation to each other)

23. Parietal Lobe – Cortical Regions
Primary Somatosensory Cortex/ Postcentral Gyrus
Somatosensory Association
Cortex
Primary Gustatory Cortex
Modified from:

24. Somatosensory Cortex
Processing of tactile, temperature, nociceptive (pain), and proprioceptive (spatial) information
Neurons are also organized according to the type of sensation to which they respond (i.e. pressure, temperature, pain)

25. Somatosensory Homunculus
This model shows what a man's body would look like if each part grew in proportion to the area of the cortex of the brain concerned with its sensory perception

26. Parietal Lobe – Other Cortical Regions
Somatosensory Association Cortex
Assists with integration/interpretation of sensations relative to body position and orientation in space (kinesthetic awareness) and hand-eye coordination
Primary Gustatory Cortex
Primary site of interpretation of gustation/taste

27. Occipital Lobe
The occipital lobe is located deep to the occipital bone of the skull
Functions:
Processing, integration, interpretation of vision and visual stimuli

28. Occipital Lobe – Cortical Regions
Primary Visual Cortex
Visual Association Area
Modified from:

29. Occipital Lobe – Cortical Regions
Primary Visual Cortex
Primary area of brain responsible for sight.
Receives information via the optic nerve
Visual Association Area
Interprets information acquired through the primary visual cortex

30. Temporal Lobe
The temporal lobes are located on the sides of the brain, deep to the temporal bones of the skull
Functions:
Hearing
Organization/ comprehension of language
Information retrieval (memory and memory retrieval)

31. Temporal Lobe- Cortical Regions Primary Auditory Cortex Wernike’s Area
Primary Olfactory Cortex (Deep)
Conducted from Olfactory Bulb
Temporal Lobe-
Cortical Regions
Modified from:

32. Temporal Lobe – Cortical Regions
Primary Auditory Cortex
Responsible for hearing
Primary Olfactory Cortex
Interprets the sense of smell once it reaches the cortex via the olfactory bulbs
Wernicke’s Area
Located on the left temporal lobe
Language comprehension

33. Cerebellum “Little brain”, located inferior to the cerebrum Functions:
Motor control – doesn’t originate movement (i.e. primary motor cortex) but contributes to motor programs
Attention & language (?)
Regulating fear and pleasure responses (?)
Composed of highly regularly arranged Purkinje cells (large neurons with many dendritic spines) and Granule cells (small neurons)

34. Brainstem The posterior region of the brain
Continuous tissue with the spinal column
All information relayed between the body and brain must pass through the brainstem

35. Segments of Brainstem The brainstem is composed of three segments:
Medulla oblongata
Pons
Midbrain

36. Medulla Oblongata Lower half of the brainstem
Contains autonomic centers re:
Cardiac function
Respiratory function
Vomiting
Vasomotor

37. Pons Relay action potentials from the forebrain to the cerebellum
Deals primarily with:
Sleep
Respiration
Swallowing
Bladder control
Hearing
Posture
Equilibrium
Taste
Eye movement
Facial expressions
Facial sensation

38. Midbrain Located superior to the pons Associated with: Vision Hearing
Motor Control
Sleep/awake
Arousal (alertness)
Temperature regulation

39. Limbic System Associated with higher order behaviors
Hippocampus: corticosteroid production, spatial relations; long term memory
Amygdala: reward, fear, mating, response to stress
Limbic cortex: judgment, insight, motivation, mood,
Fornix: relay signals from hippocampus to hypothalamus