Download brain

brain
From the brain and from
the brain only, arise our
pleasures, joys, laughter
and jests, as well as our
sorrows, pains, grief's and
tears. ~Hippocrates
Marilyn Rose
meninges

3 membranes

Outer- Dura mater- folds house the following:
 flax cerebri- cerebral hemisphere
 tentorium cerebelli – cerebrum/ cerebellum
 falx cerebelli- cerebellar hemispheres


Middle- arachnoid- separate from dura by subdural
space.
Inner- Pia mater- vascular, adhering to the brainseparated from arachnoid by subarachnoid spacewhich is where CSF circulates
Brain Bleeds- Hematoma



Subarachnoid Rupture AVM/ aneurysm
 Worst headache of life
 Between arachnoid and pia
Epidural
 Traumatic (artery)
 Blood between dura and skull
Subdural
 Traumatic (vein)
 Shearing/ shaken baby
 Blood between arachnoid and dura
Subarachnoid
Epidural
Subdural
tent, falx and cerebellum
Falx cerebelli
Tentorium
cerebelli
Tent
http://anatpat.unicamp.br/minDsc78051a+.jpg
Cerebellum= Posterior Fossa
ventricular system

Circulation of CSF though CNS

4 cavities:

RT/LT lateral vents- one in each cerebral hemisphere
separated by cavum septum pellucidum (frontal, (atria)
occipital, temporal horns)



Choroid plexus- blood vessel network (bright) within lateral
ventricles - producing CSF- BEGINS POSTERIOR TO 3rd vent
3rd opens downward-foramen of Monro- lateral= thalamus
4th opens from cerebral aqueduct- anterior to cerebellum and
posterior to the pons- CSF goes though Magendie (Cisterna
magna-spinal cord) and Luschka (subarachnoid space)
Head Ultrasound…
3rd vent- blood anterior
Level of 3rd with blood
Normal Choroid posterior to 3rd vent
http://www.i-am-pregnant.com/images/ventriculomegaly2.jpg
http://bstr431.biostr.washington.edu/syl/lab2/fig204.gif
http://en.academic.ru/pictures/enwiki/71/Gray735.png
Coronal
Pre and post birth imaging of the brain
http://www.childrenshospital.org/clinical
services/Site1867/Images/brain1b.jpg
Sagittal
http://www.justthefactsbaby.com/images/n
ews/2nd-tri-25wkBrainweb.jpg
axial
http://www.health.com/health/static/hw/media/medical/hw/h9991198.jpg
Choroid Plexus
Normal or abnormal???
http://www.i-am-pregnant.com/images/Choroid-Plexus-Cysts-(CPC).jpg
Level of the 3rd ventricle
cerebrum
cortex- gray/white matter

Rt/Lt hemispheres


Gyri- folds
Sulci- groove- central sulcus


Fissures- deeper grooves


frontal (motor) / parietal lobe (sensory)
longitudnal- superior sagittal sinus/ flax (Rt/Lt)
lateral- Sylvian- frontal/ parietal from temporal lobe.
Corpus callosum- largest bundle of white matter w/ in
cerebrum forms roof of the lateral vents


connects Rt/ Lt cerebral hemispheres
4 parts= rostrum, genu, body, splenium
Corpus Callosum
http://psycnet.apa.org/journals/neu/17/3/images/neu_17_3_496_fig1a.gif
http://img.medscape.com/pi/emed/ckb/radiology/336139-407730-7910.jpg
Locate the corpus callosum…
www.come-over.to/FAS/corpuscallosum3.jpg
What is wrong?
http://neurosurgerydallas.com/images/2_1_3_5b.jpg
Label the arrows- 1,4, 6, 7…
http://www.info-radiologie.ch/brain_mri_coronal_t2.php
http://upload.wikimedia.org/wikipedia/commons/1/15/26638.medium-emphasizing-corpuscallosum.png
Cisterns

Subarachnoid space- areas at brain base
that are widened where CSF pools.

Supracellar cistern- superior to sella- C of W

Quadrigeminal cistern- posterior to
quadrigeminal plate of midbrain

Cisterna magna- lower posterior fossa (largest)
Cisterns
http://pilgrimagetozion.files.wordpress.com/2009/07/cistern.jpg
http://www.aans.org/bulletin/images/Vol17_2_08/Nonenhanced-axial-CT_large.jpg
http://icanhascadherin.files.wordpress.com/2008/09/happy-face.jpg
What is wrong?
http://www.scielo.br/img/revistas/anp/v66n3b/a32fig01.gif
http://img.medscape.com/pi/emed/ckb/radiology/336139-336489-4514.jpg
Cerebral Lobes

Cortex divided into 4 lobes:

Frontal- anterior- reason, judgment, vol muscle
 Broca’s area for speech- LT frontal gyrus



Parietal- middle of each hemisphere- post to
central sulcus- temperature, touch, pain, taste
Occipital- posterior- visual stimuli from thalamus
Temporal- anterior to occipital-auditory/olfactory


Primary auditory= Heschl’s- auditory info
Secondary= Wernicke’s – comprehension/ speech
Cerebral lobes
http://space.newscientist.com/data/images/archive/2222/22224201.jpg
http://www.ispub.com/ispub/ijra/volume_4_number_1_46/neurological_damage_in_heat_stroke_i
n_a_child_ct_mri_and_spect_appearances/heat-fig2b.jpg
temporal
cerebellum
http://www.imaios.com/var/ezwebin_site/storage/images/media/images/eanatomy/brain-mri/en/brain-anatomy-axial-atlas/4651-1-eng-GB/brain-anatomy-axialatlas_imagelarge.jpg
http://www.nature.com/bmt/journal/v39/n4/images/1705571f1.jpg
Case study= Heat Stroke
The described imaging findings in heat stroke include early cerebral edema ,
loss of gray-white matter differentiation, patchy high signal intensity of the
white matter of cerebral hemispheres and vascular boundary zone infarcts
and in later stages, diffuse cerebellar atrophy -severe brain ischemia was the
underlying cause for the neurological involvement in heat stroke in our patient.
http://images.google.com/imgres?imgurl=http://www.ispub.com/ispub/ijra/volume_4_number_1_46/neurological_damage_in_heat_stroke_in_a_child_ct_mri_and_spect_appearances/heatfig2b.jpg&imgrefurl=http://www.ispub.com/journal/the_internet_journal_of_radiology/volume_4_number_1_46/article_printable/neurological_damage_in_heat_stroke_in_a_child_ct_mri_and_spect_appearances.html&usg=__MOWFvBWDRgjIN
v-DxcrF_mmMfwM=&h=575&w=477&sz=41&hl=en&start=3&itbs=1&tbnid=EXEYVfzs4fUVPM:&tbnh=134&tbnw=111&prev=/images%3Fq%3Dcerebral%2Bcortex%2Bon%2BMRI%2Bor%2BCT%26gbv%3D2%26hl%3Den%26sa%3DG
Basal Ganglia

Subcortical gray
matter



Caudate nucleus- lat to
each lat ventricle
Lentiform nucleus
Claustrum

Together they plan
and program muscle
action.
http://www.brainexplorer.org/brain-images/brain_slice_small.jpg
http://www.biomedcentral.com/content/figures/1471-2377-6-33-3-l.jpg
Diencephalon

Thalamus


Hypothalamus


Lg oval grey masses, walls of lat vents, connects in
mid 3rd vent by massa intermedia
Inferior to thalamus and posterior to optic chiasm,
making floor of lat vent- Pituitary Gland (hypophysis)connected by infaundibulum.
Epithalamus

Pineal gland- melatonin= day/night cycles (can Ca++)
Limbic System





Interconnected fibers adjacent to temporal
lobes.
Emotional aspects of behavior
Includes: hippocampus (short- long term
memory converter), amygdala, olfactory
tracts, fornix, cingulate gyrus..
Brain injury to hippocampus can cause…..
Loss of memory…
Limbic system
Brainstem

Major segments are:
 Midbrain
 Above the pons, smallest portion of brainstem
 Nerve bundles called cerebral peduncles and
quadrigeminal plate.
 Surrounds the cerebral aquaduct- which connects the 3rd
and 4th vents and contains CSF
 Pons
 Oval expansion of brainstem- “Bridge”- signals to spinal
cord and cerebral cortex
 Medulla oblongata
 Extends to the spinal cord which exits the foramen
magnum- heart rate, respiratory rate and blood pressure.
Brainstem
Cerebellum




“Little brain”
Posterior to brainstem and occupies
posterior fossa
Composed of two cerebellar hemispheres
with a midline Vermis- on the inferior
surface lie the cerebellar tonsils
Occassionally they may herniate down the
foramen magnum…..called what????
Cerebellum
Cerebellum
Dandy Walker= refers to the enlargement of the posterior fossa secondary to
cystic dilatation of the fourth ventricle as well as hypoplasia of the cerebellum
and vermis.
What is wrong?
Lt cerebellar abscess
Congenital absence of one cerebellar hemisphere
Types of brain lesions…
PNET-Primitive Neuroectodermal tumors
PNET can occur anywhere in the brain of a
child, although the most common place is
in the back of the brain near the
cerebellum. When they occur here, they
are called medulloblastomas. The
symptoms depend on their location in the
brain, but typically the child experiences
increased intracranial pressure. These
tumors are fast growing and often
malignant, with occasional spreading
throughout the brain or spinal cord.
Cerebral Vasculature





Arteries in the brain are thin and weak.
high risk for aneurysms and strokes.
No valves in the veins-blood can flow in either
direction= route for blood-bourne pathogens.
Dural sinus drains down to the IJ’s- through the
superior and inferior sagittal sinus
Unique capillaries create the Blood Brain Barrier
Arterial- Blood to Brain

Paired internal carotid and vertebral arteries.
 Internal carotid becomes- Carotid Siphon
 Anterior cerebral-ACA
 Middle cerebral-MCA
 Circle of Willis= Located in Suprasellar cistern- cerebral
arterial circle- anastomosis of 4 major arteries….
 What are they?
 Two vertebral and Two carotids….
 becoming the anterior/posterior cerebral,
anterior/posterior communicating and internal carotids
Brain Blood Supply
Circle of Willis
Venous Blood
Parietal Veins
Superior Sagital
Sinus
Confluence of
Sinus
Transverse Sinus
Sigmoid Sinus
Internal Jugular
Veins
Which is it?
MCA stroke- frontal/temporal lobe with
Wedge shaped area of decreased density and
Slight midline shift/ mass effect
Aneurysm
AVM
Cranial Nerves



12 cranial
All but 1st and 2nd arise from the brainstem
Each nerve corresponds to a function in the body
 Olfactory- smell- superior nasal septum
 Optic-sight-posterior aspect of eye
 Facial-lower pons- control facial muscles
 Vagus-”wandering”- down to splenic flexure of abd
and arise from medulla oblongata- enervates many
abdominal organs
Cranial Nerves