1 Basic Anatomy Chris Rorden –Coordinates –Cortex Brodmann Areas Common Names Talairach Coordinates –Best web site:

2 Relative Coordinates On the globe we talk about North, South, East and West. Lets explore the coordinates for the brain.

3 Multiple Choice Which arrow points dorsally? A.Red B.Green C.Blue D.Red and Green E.None of above

4 Multiple Choice Which arrow points dorsally? A.Red B.Green C.Blue D.Red and Green E.None of above

5 Orientation Human anatomy described as if person is standing If person is lying down, we would still say the head is superior to feet.

6 Orientation - animals Cranial head Rostral beak Caudal tail Dorsal back Ventral belly

7 Coordinates – Human Human dorsal/ventral and rostral/caudal differ for brain and spine. –Head/Foot, Superior/Inferior, Anterior/Posterior not ambiguous. Dorsal Ventral Dorsal Ventral

8 Anatomy – Relative Directions Posterior <> Anterior Ventral <> Dorsal lateral Anterior/Posterior aka Rostral/Caudal Ventral/Dorsal aka Inferior/Superior aka Foot/Head

9 Coordinates - Anatomy 3 Common Views of Brain: –Coronal (head on) –Sagittal (profile) –Axial (bird’s eye), aka Transverse. The book calls this ‘Horizontal’ but it is not horizontal when we are lying in a scanner. sagittalcoronal axial

10 Coronal Corona: ‘crown’ a coronal plane is parallel to crown that passes from ear to ear –Coronal cut creates anterior, posterior portions

11 Sagittal Sagittal – ‘arrow like’ –Sagittal cut divides object into left and right –sagittal suture looks like an arrow. top view

12 Transverse Transverse: perpendicular to the long axis –These cuts are also referred to as Axial. Example: cucumber slices are transverse to long axis.

13 Oblique Slices Slices that are not cut parallel to an orthogonal plane are called ‘oblique’. The oblique blue slice is neither Coronal nor Axial. Ax Cor Oblique

14 Anatomy Brain Planes Axis of left/right plane easy to define What is the axis for axial plane? ? ? ?

15 Bicommissural plane Axis for axial plane is defined by anterior commissure (AC) and posterior commissure (PC). Both are small regions that are clear to see on most scans. AC PC

16 Distance from midline –Medial – near sagittal midline Optic chiasm C medial of eyes –Lateral – far from sag. Midline Eyes are lateral of optic chiasm –Ipsilateral – same side Damage to A will cause blindness in ipsilateral eye –Contralateral –different side Damage to D will lead to a contralateral field cut. –Note: after brain injury (lesions) we talk about contralesional and ipsilesional Damage to visual cortex G leads to problems with contralesional vision.

17 Relative positions Distance From Body –Proximal, Central: near center of body Think ‘proximity’ Shoulders are proximal parts of arms –Distal,peripheral: away from body Think distant Fingers are distal parts of the arms Distance from Surface –Superficial, external: near surface The bump bruised superficial tissue. –Profound, deep: far from surface The car crash injured deep organs.

18 Neuron: Cell which is responsible for receiving, transmitting and synthesizing information –cell body: contains organelles for metabolism and a nucleus Glial Cells: Support cells for Neurons

19 The cortex Cortex – ‘Bark’ shell of brain ~80% of human brain ~20% of squirrel brain

20 The big folds The folds of your brain are like a fingerprint – there are a few general patterns, with individual variability. Two main folds –Central Sulcus Fissure of Rolando Rolandic sulcus –Lateral sulcus Sylvian fissure

21 Describing cortex location Brodmann Areas (BAs, 1909) Appearance of cortex under microscope Not necessarily function Arbitrary numbers are hard to remember

22 Brodmann Areas Function does not necessarily follow appearance. Some key areas: 44: Broca’s Area 22: Wernicke’s Area 17: V1 Primary Visual

23 Brodmann Areas (medial slice) Note that gray matter is located in the longitudinal fissure (between the two hemispheres)

24 Squirrels vs humans squirrel brain –Surface of human brain is grooved. –Surface of brain from many animals is flat. –If we completely flattened a squirrel brain, it would be the size of a stamp.

25 Cortical folding Cortical folding increases surface area. Ridges are called Gyri (singular = Gyrus) –Greek gyros = circle, hence a coil of brain cortex Valleys are called Sulci (singular = Sulcus). –Latin = a groove. Gyri Sulci

26 Anatomy Surface of human cortex and cerebellum is very folded –Flattened, each hemisphere 1100cm 2 –Cerebellum is also 1100cm 2 Crumpled shape hides size of cortex –Compare Folded/Unfolded (from Marty Sereno) Human Chimpanzee Monkey

27 Cortical Names Much of cortex referred to by combination of coordinate+lobe+gyrus E.G. Superior Temporal Gyrus (STG) Middle Temporal Gyrus(MTG) Lateral Occipital Gyrus (LOG)

28 Cortical names Tip of an object called a ‘pole’ Frontal Pole Temporal Pole

29 Sulci names Many of sulci referred to by combination of coordinate+lobe+sulcus –Superior temporal sulcus (STS) –Inferior frontal sulcus (IFS) –Precentral and postcentral sulci are just anterior and posterior to the central sulcus.

30 Brain function Anatomy is interested with the structure of an organism. Physiology is interested in the function of the structure. We are still learning about brain function Modern maps of brain function are primitive…

31 Brain function Much of the primate cortex devoted to vision. In some monkeys, up to 50% of neocortex is devoted to vision.

32 Brain function Two striking features of human brain 1.Lots of cortex ‘left over’ (yellow) not devoted to specific task – we are flexible 2.Not much of the cortex is solely devoted to language.

A B C D