Download Components of the CNS

Components of the CNS
Components of the PNS
• Brain
• Spinal cord
• Enclosed in meninges
• Everything except brain and spinal cord
• Axons, dendrites, ganglia
Components of the ANS
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Which lobes and their functions?
• Parasympathetic
• Sympathetic
1. Parietal lobe – motor, initiating actions
2. Frontal lobe – personality, planning, long
term processes, decisions
3. Occipital lobe – vision
4. Temporal lobe – hearing, speech, music
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Postcentral gyrus (sensory area)
Precentral gyrus (motor area)
Central sulcus
Lateral Sulcus
Frontal pole
Frontal lobe
Motor speech area
Temporal pole
Temporal lobe
Pons
Cerebellum
Occipital lobe
Occipital pole
Parietal lobe
Medulla oblongata
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3.
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Interventricular foramen
Massa intermedia
Choroid plexus
Thalamus
Parieto-occipital sulcus
Pineal body
Cerebral aqueduct
Cerebellum
4th ventricle
Median aperture
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12.
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19.
Medulla oblongata
Pons
Midbrain
Hypothalamus
Anterior commissure
Fornix
Septum pellucidum
Corpus callosum
Cerebrum
How many neurons in the somatic
PNS?
How many neurons in the visceral
PNS?
• 1
• 2
When are the parasympathetics on?
What are their functions?
Where is it found?
What kind of outflow is it?
When are the sympathetics on?
What are their functions?
Where are they found?
What kind of outflow is this?
• Always on (unless sympathetics are)
• Vegetative functions – respiration, peristalsis,
heart rate, glandular secretion
• Smooth muscles and organs only
• Cranio-sacral outflow (4 CNs, 3 sacral nn.)
• Always off unless there is a “threat”
• Fight or Flight – increase HR, RR BP; decrease
peristalsis, reproduction, digestion
• Found everywhere there is a blood supply
• Thoraco-lumbar outflow (T1-L2 
sympathetic chain)
What is a neuron?
What does somatic efferent do?
What does somatic afferent do?
• Cells that are specifically adapted to transmit
information by electrical signal or chemical
signal
• Efferent: controls striated muscles
• Afferent: Receives information from body wall
and outside world into the CNS
What does visceral efferent do?
What does visceral afferent do?
Bone layers of the skull
• Efferent: controls smooth muscle & glandular
secretion
• Afferent: Receives information from organs
and tissues into the CNS
1. Outer table – very dense, hard bone
2. Diploe – spongy bone, soft, vascular
3. Inner table – very dense, hard bone
What are the two parts of the
skull?
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• Neurocranium – bony shell surrounding the
brain and meninges
• Viscerocranium – facial skeleton; bones arise
from pharyngeal arch precursors
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2.
3.
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9.
Parietal bone
Occipital bone
Temporal bone
Mastoid process
Styloid process
Zygomatic arch
Sphenoid bone
“Pterion”
Frontal bone
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Cranial Fossa and their borders
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Frontal bone
Parietal bone
Occipital bone
Bregma
Coronal Suture
Sagittal suture
Lambdoid suture
Lambda
1. Anterior
– Posterior border of lesser wing of sphenoid bone
and sphenoid limbus
2. Middle
– Petrous ridges of temporal bones and clinoid
processes of occipital bone
3. Posterior
What cranial nerves go through
each cranial fossa?
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• Anterior:
– Cribiform plate – CN I
• Middle:
– Optic canal – CN II, opthalamic a.
– Superior Orbital fissure – CN III, IV, V1, VI, opthalamic
vv.
– Foramen rotundum – CN V2
– Foramen ovale – CN V3
– Foramen spinosum – middle meningeal a.
• Posterior:
–
–
–
–
Internal auditory meatus – CN VII, VIII, labyrinthine a.
Jugular foramen – CN IX, X, XI, superior jugular bulb
Hypoglossal canal – CN XII
Foramen magnum – spinal cord, meninges, CSF, spinal
aa. & vv., vertebral aa.
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2.
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Foramen cecum
Cribiform foramina
Anterior & Posterior ethmoidal foramina
Optic canal
Superior orbital fissure
Hypophyseal fossa
Foramen rotundum
Foramen spinosum
Foramen ovale
Foramen lacerum
Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
Groove/hiatus of greater petrosal n.
Cerebellar fossa
Brain markings
Frontal crest
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3
?
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4
1. Supraorbital foramen
2. Frontal bone
3. Superior orbital fissue
4. Zygomatic bone
5. Maxilla
6. Posterior and anterior ethmoidal foramina
7. Optic canal
8. Ethmoid bone
9. Lacrimal bone
10.Infraorbital foramen
1. Frontal bone
2. Ethmoid bone
3. Lacrimal bone
4. Maxilla
5. Nasal bone
6. Maxilla
Green ring: supraorbital foramen
Blue circles: posterior & anterior ethmoidal foramina
Red circle: lacrimal canal
Orange circle: infraorbital foramen
What are the 5 layers of the
scalp?
What two muscle bellies are found
on the skull?
What connects them?
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•
•
S – skin
C – CT (dense)
A – aponeurosis
L – loose CT
P - pericranium
• Frontal and occipital bellies of occipitofrontalis
• Epicranial aponeurosis
What innervates the anterior
muscles of the scalp?
What innervates the posterior
muscles of the scalp?
Are cranial vv. deep or superficial?
Where do they drain?
• Anterior: CN V
• Posterior: Spinal nn.
– Greater occipital
– Third occipital
– Lesser occipital
– Great auricular
– Posterior & anterior rami
• Superficial
• Jugular v.
What vv. connect the skull veins
to the dural sinuses?
Where do lymph nodes first
appear in the skull?
• Emissary vv.
• At the “collar” area
What kind of scalp cuts gape the
worst?
What do skull fractures tend to
do?
• Coronal cuts
• Coup-countrecoup fractures