Transcript Broca`s Area

The Central Nervous System (CNS)
As you view the rest of the
lecture, label your brains
workbook AND write the MAIN
function(s) of that part of the
brain next to the name
A: Spinal cord, brainstem, and thalamus
B: Brain
1. Cerebellum
2. Lobes and cortices (Funky Moms Smoke Pot On Tuesdays)
a) frontal Funky
b) motor Moms and somatosensory Smoke cortices
c)
parietal Pot
d) occipital On
e) temporal Tuesdays
3. Corpus callosum
Video snip: The brain’s regions
C: Limbic system
1. hypothalamus
2. pituitary gland
full brain story
3. amygdala
4.
hippocampus
Female vs. Male Brain:
the differences finally revealed
WARNING: These images will reveal stereotypes, some of which
you may find offensive!!
Human brain—interior view of left
hemisphere
The Brain
For purposes of studying form and function, scientists
break the brain down in many ways: hemispheres,
regions, lobes, areas...
1. 2 hemispheres (left and right)
The brain’s 2 hemispheres are
symmetrical in form but not in function
Brain’s symmetry:
•Anatomically, the 2 hemispheres are
almost symmetrical (left hemisphere
tends to be slightly larger than right)
•All lobes and glands in brain have a
left and right version
Lateralization: The brain’s 2 hemispheres
have regions that serve different, yet
complementary functions
•e.g. Language is usually associated
with left hemisphere BUT grasping
sarcasm, metaphors, subtleties of
language occurs in right hemisphere.
Video snippet: brain hemispherectomy
2. Regions: Hindbrain, midbrain & forebrain
Exterior view of left brain (person looking to left of screen)
angular gyrus
Broca’s area
Wernicke’s area
auditory cortex
angular gyrus: connects Wernicke’s to other sensory areas
Damage results in inability to read, write, comprehend written word, read music....
Parts of the Central Nervous System (CNS)
A. Spinal cord & brainstem
Spinal cord transmits messages (motor & sensory)
between brain and rest of body and reflex messages
between nerves and spine
Q. What kind of neurons are found in the spinal cord?
A: interneurons!
Brainstem—part of spinal cord that enters brain
– Midbrain: involved in muscle movement and integration of sensory input
– Reticular formation (AKA RAS) (found throughout midbrain, pons, and medulla):
function is arousal, attention
– cut=coma
– electric stimulation=awake
– (mnemonic: tickle arouses you!! give that baby raspberries!)
– Pons: coordinates movement and facial expression; integral to REM stage of sleep (time
when dreaming occurs)
– mnemonic: pom pon girls are coordinated in movements and facial expressions
and people dream about them! the Fonz makes good facial expressions and was a
“dream boat”
– Medulla: controls heart rate, breathing
– mnemonic: (sung to tune of akuna mattata from Lion King) "medulla oblangata,
what a wonderful thing! keeps me breathing and my heart beating!” OR
Medusa: if you look at her, you turn to stone and stop breathing!
Damage to the spinal cord or
brainstem can lead to:
• DEATH (if medulla is severed, heart and breathing stop)
• CNS information highway is cut in ½ (brain and rest of body
cannot communicate)
• Paralysis and lack of feeling below area injured—YET not all
messages must go to brain!! Reflex response can remain after
spinal injury, including bladder control, sexual function, knee
jerk
The thalamus
•Location: Center of brain, above midbrain
•Function: The main processing station for all
incoming sensory information EXCEPT for
smell (that goes directly to olfactory lobe from
nose!)
•Thalamus directs traffic of incoming stimuli to
appropriate areas in cerebral cortex for further
processing
Mnemonic: Is that a mouse? It looks like one, feels like one, sounds like
one, tastes like one, but I can’t SMELL it!!
Cerebellum—the most primitive part of the brain
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LOCATION: Base of brainstem in rear of head
SIZE: Baseball (1 in each hemisphere)
FUNCTIONS:
– Coordinates voluntary movement, balance
– Stores implicit memories!
If damaged:
– loss of coordination of motor
movement/inability to reach out and grab things
– loss of ability to make motor skill memory
– seems like you are drunk
Video clip: Medical mystery boy without cerebellum
and pons
Cerebrum (80% of brain) is divided up into lobes and cortices
Mnemonic: Funky Moms Smoke Pot On Tuesdays
Cerebral cortex is layer of tissue approx. .5 cm thick that is folded onto itself
creating the folds (gyrus) and fissures (sulcus) visible on the surface
Frontal Lobes
• LOCATION: Top front of head, above
temporal lobes
• SIZE: Grapefruit (1 in each hemisphere)
• FUNCTION?
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Emotional control center
“Home” of personality
problem solving; “central executive”
long-term memories stored here
language home to Broca’s Area (speech
production)
– impulse control
– social and sexual behavior
– LAST PART OF BRAIN TO DEVELOP IN
ADOLESCENCE!!!
Phineas Gage video clip 7:40 min.
Damage to the frontal lobes can lead to:
Do we even want to go there?
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Loss of spontaneity in interacting with others
Loss of flexibility in thinking
Persistence of a single thought (Perseveration)
Inability to focus on task
Mood changes
Broca’s aphasia –inability to speak fluently
(clip)
In sum: personality and attention changes!
Somatosensory and Motorsensory Cortexes
• Somatosensory cortex and motorsensory
cortex lie on either side of fissure of
Rolando (division between parietal and
frontal lobes)
• Somatosensory cortex (on parietal lobe):
neurons receive TOUCH sensory
information
• phantom limb video clip (start at 1.5)
• Motorsensory cortex (on frontal lobe):
neurons send messages to control body
movement/muscles
Parietal Lobes
• LOCATION: Top rear of head, above
occipital and temporal lobes
• SIZE: Grapefruit (1 in each
hemisphere)
• FUNCTION? Home of the
somatosensory cortex!
– Sensory perception (integrating all
sensory information into 1
cognition/thought)
– perception of stimuli related to touch,
pressure, temperature and pain.
– Spatial relations
Mnemonic: P for perception and parietal
Damage to the parietal lobes can lead to:
Any predictions before I show you?
Damage to the left parietal lobe can result in
• inability to perceive objects normally
(agnosia) (clip)
Damage to the right parietal lobe can result in:
• neglecting part of the body or space
(contralateral neglect), which can impair
many self-care skills such as dressing and
washing visual neglect video clip (3 min)
• difficulty in making things and drawing
Occipital Lobes
• LOCATION: Rear of head, above
cerebellum
• SIZE: Baseball (1 in each
hemisphere)
• FUNCTION?
– Visual perception—all information
taken in from eyes is processed in this
lobe
Mnemonic: optometrist, o c c (see see?), optic all about eyes
Damage to the occipital lobe can lead to:
Any predictions before I show you?
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Defects in vision
Difficulty with locating objects in environment.
Difficulty with identifying colors (Color Agnosia).
Production of hallucinations
Word blindness - inability to recognize words.
Difficulty in recognizing drawn objects.
Inability to recognize the movement of an object (Movement
Agnosia).
• Difficulties with reading and writing.
Temporal Lobes
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LOCATION: Right and left side of head above ears
SIZE: Grapefruit (1 in each hemisphere)
FUNCTION?
– Hearing
– olfactory lobe –sniffing scents
– speech processing
• Home to Wernicke’s Area
Damage to Temporal Lobes can lead
to…
• disturbance of language comprehension
• altered sexual behavior (increase or decrease sex drive)
• Difficulty in recognizing faces (Prosopagnosia video clip)
(Clip 2)
• Difficulty in understanding spoken words (Wernicke's Aphasia
clip)
• Short-term memory loss
• Interference with long-term memory
• Right lobe damage can cause persistent talking
• Increased aggressive behavior
Corpus callosum
axonal fibers that connect the 2 hemispheres
to allow neurons to share information
Video snippet severed corpus callosum (5 min)
Video snippet #2: Scientific American (11 min)