The human brain. (Diogo Almeida 2012 version of older Pylkkänen slides)

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1 The human brain (Diogo Almeida 2012 version of older Pylkkänen slides)

2 The human brain

3 The human brain how do you make sense of something like this?

4 The human brain We can look for major anatomical features

5 The human brain We can look for major anatomical features

6 The human brain Conclusion #1: Folded surface, series of sulci and gyri

7 The human brain Conclusion #2: Two hemispheres

8 The human brain and now what?

9 The human brain We can define broad brain areas using these anatomical features: LOBES

10 And we can refine this view a little more

11 And we can also investigate how the two hemispheres are connected

12 So now we know that brains can be characterized in terms of their major visible anatomical features: a) Sulci (or fissures) and gyri can be used as boundaries for areas b) The brain has two hemispheres, connected by a massive bundle of neural tissue

13 cerebrum (latin for brain) (latin for little brain ) So now we know that brains can be characterized in terms of their major visible anatomical features: a) Sulci (or fissures) and gyri can be used as boundaries for areas b) The brain has two hemispheres, connected by a massive bundle of neural tissue c) There are some other anatomically distinct areas, like the cerebellum and the brain stem

14 cerebrum (latin for brain) (latin for little brain ) In order to learn more, we should look at two things: - What is the brain and its areas made of? - What function do these areas have?

15 What are the brain areas made of? Neurons Central nervous system is made up of about 100 billion neurons. Unlike other cells in that they can both receive and send out signals to neighboring neurons in the form of electrical pulses.

16 Neurons Typically a given neuron is connected to about ten thousand other neurons. The specific point of contact between the axon of one cell and a dendrite of another is called a synapse.

17 Neurons We are born with a complete set of neurons. What changes in maturation is the connections between the neurons. On average, we lose about 20% of our neurons by the time we die.

18 Neurons

19 Cortex - about two millimeters thick and has a total surface area of about 1.5 square-meters

20 Grey and white matter Grey matter cortex unmyelinated nerve cells White matter myelinated nerve cells the tissue through which messages pass between different area of grey matter

21 How fast is the brain? After a neuron has fired, it takes it about one millisecond to return to its normal state. Much slower than your computer! The secret of the brain lies in the vast number of neurons (tens of billions) and the complicated way they are connected.

22 Blown-up cortex video at:

23 Blown-up cortex

24 Blown-up cortex

25 Blown-up cortex to see animated:

26 Cortical layers Cytoarchitectonics: the arrangement of nerve cells in the cerebral cortex

27 Korbinian Brodmann, ( ) Defined the cerebral cortex into 52 distinct regions on the basis of their cytoarchitectonic characteristics.

28 Brodmann s areas

29 What are the functions of these brain areas? Brodmann s areas

30 Cerebral hemispheres

31 Cerebral hemispheres What happens when the two hemispheres are physically separated? Brain lesion (tumor, etc) Epilepsy treatment

32 Cerebral hemispheres What happens when the two hemispheres are physically separated? Brain lesion (tumor, etc) Epilepsy treatment short video: longer video:

33 Homunculus

34 The mind/brain view of the body How did we find this out? see 1:46 and 3:20 on this video

35 Cerebellum (Latin: "little brain"): Coordination and control of voluntary movement Brain stem: breathing, heartbeat, and blood pressure

36 Gross generalizations about function Frontal lobe: decisions, judgments, problem solving, emotions. Temporal lobe: perception, recognition, many aspects of language Parietal lobe: movement, orientation, recognition, perception of stimuli Occipital lobe: vision at large

37 Subcortical structures: basal ganglia, the limbic system and the thalamus Thalamus: Receives and organizes sensory information from the sensory organs Regulates sleep and wakefulness (during sleep the thalamus is closed. i.e., does not take input from sensory organs).

38 Basal ganglia: Caudate nucleus Putamen Globus pallidus Subcortical structures: basal ganglia, the limbic system and the thalamus E.g., voluntary movement Q: what do you think damage to these structure cause?

39 Basal ganglia: Caudate nucleus Putamen Globus pallidus Subcortical structures: basal ganglia, the limbic system and the thalamus E.g., voluntary movement movement diseases like: Parkinson s, Huntington s some neuropsychiatric disorders, like: Tourette s, OCD, etc.

40 Subcortical structures: basal ganglia, the limbic system and the thalamus Limbic System Hippocampus Amygdala emotion, memory 40

41 Subcortical structures: basal ganglia, the limbic system and the thalamus Limbic System Hippocampus Amygdala emotion, memory see also:

42 Brain lingua

43 Brain lingua

44 Brain lingua Bilateral - On both sides Ipsilateral - On the same side Contralateral - On the opposite side

Sheep Brain Dissection Picture Guide

Sheep Brain Dissection Picture Guide Figure 1: Right Hemisphere of Sheep s Brain Figure 2: Underside of Sheep s Brain Figure 3: Saggital cut of Sheep s Brain to reveal subcortical structures Figure 4: