The Brain Part Announcements read pgs end Lecture note

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					The Brain (Part 1)
~read CH3 pgs 79-end
~Lecture note volunteers: sign up
~ First set of lecture notes are due today. Will be posted shortly
~Giving directions inside your brain
~meninges and blood vessels
~The cerebrospinal fluid and the ventricles
A Developmental view
~The Forebrain = Telecephalon + Diencephalon
                    Telencephalon = 2 Hemispheres
                    Hemisphere →Cerebral Cortex
                                    Basal Ganglia
                                    Limbic system
Brain Diversity
~Not everybody has same brain
~All brains are different
(example cat vs mouse vs chimpanzee vs human brain)
~all have same shape
Brain/ Body weight
~bigger you are the bigger your brain
~for our body size our brain is much bigger than other animals
Giving Directions (look at figure 3.1 in text)
~symmetrical (2 sides that are the same)
Brain Planes of Section (see figure 3.2 in text)
Gray matter: cell bodies
White matter: axons

Nervous system : 2 parts
1) Central nervous system = brain (skull) and spinal cord (vertebral column/spine)
2) Peripheral nervous system= nerves and peripheral ganglia
~Dura mater: thick, unstretchable
~Arachnoid membrane: soft, spongy
~sub-arachnoid space: cerebro spinal fluid
~pia mater: follows brain surface, contains blood vessels
Brain vasculature
~brain (2% of the body) uses about 20% of oxygen absorbed by the lungs
~migraine, stroke
Cerebral Ventricles = cerebral spinal fluid
Lateral ventricle →third ventricle →cerebral aqueduct →fourth ventricle (subarachnoid space, central
Cerebral ventricles (look at figure 3.4 in text)
C.S.F Absorption in the sinuses
~occurs in 2/1000 children. Mostly congenital, also as a result of meningitis
Notes on clip of case study (Hydrocephalus 2)
~Nicole developed normal language skills
~had a lot of dysfunction
~had a lot of brain damage
C.S.F summary
~produced by the choroid pleni (all ventricles)
~full replacement every 6 hours
~Flows all around the brain and spinal cord
~reabsorbed into the blood
~ventricles also have a role in development
Neural Migration (see figure 3.6 in text)
~on the 18th day… we start as a tube… development of the cortext
~By 20 weeks, the brain looks ‘superficially’ like an adult
Neural development
~symmetrical cell division

Founder cell= splits up into two founder cells →increase ventricle size
~Asymmetrical cell division
Founder cell= splits up into another founder cell and a neuron →create brain tissue
~After 5 months: Apoptosis: ‘suicide’ signal for founder cells
~ventricles produce 2 times more neurons than necessary; unused neurons progressively die by
Neural development: New cells in the adult (see figure 3.7 in text)
~There is neurogenesis in the adult brain.
In rats: Hippocampus (learning and memory) and olfactory bulb (sense of smell)
Developmental Stages (see figure 3.5 in text)
4 →6 Brain developmental subdivisions
The 6 Divisions of the Adult Human Brain
1) Forebrain
2) Telencephalon
3) Diencephalon
4) Midbrain
5) Mesencephalon
6) Hindbrain
Brofmann’s Areas
Cortex: many morphologically distinct areas
The 3 Major Fissures (see figure 3.8 in text)
Sulcus- sulci
Gyrus – gyri (3 times surface area)
Notes from corpus callosum clip
~Gazzaniga- split brain
~man had “two” brains
~had to have surgery to stop epilepsy
~everything in brain is crossed (right controls left and left control right)
~speaking ability is due to left hemisphere
~left hemisphere explains thing, where action is

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