Part 1: Spinal Anatomy (Brain, Tracts, CN’s & Eye) Flashcards
Endoderm Derivatives
- Organs
- Gut
- Respiratory tract
- Tubular structures
Mesoderm Derivatives (paraxial)
Muscles, tendons & ligaments
Smooth muscle of organs
Mesoderm Derivatives (intermediate)
Urogenital & Kidneys
Mesoderm derivatives (head)
Skull muscles & dentine of teeth
Mesoderm derivatives (lateral plate)
- Adrenal cortex
- connective tissue
- cardiovascular
- lymph
Surface ectoderm derivatives
- epidermis
- ant. Pituitary
- eye lens
- skin
- enamel, hair & nails
The neural tube and crest form from the
Ectoderm
Neural tube derivatives
- post. Pituitary
- eye retina
- CNS
- oligodendrocytes
The neural crest forms: (6)
1) Sympathetic chain ganglion
2) DRG
3) ANS & PNS
4) Schwann cells
5) Parafollicular cells of thyroid
6) Adrenal medulla
Embyological order:
Notochord -> Neural plate -> Neural groove -> neural tube -> neural crest cells
Vitamins that prevent Spina Bifida
- B9 / Floic acid
- methyl folate / tetrahydrofolate
Stages of spinal Bifida & what they mean:
Meningocele: meninges protrude
Myelocele: spina cord protrudes
Meningomyelocele: spinal cord & meninges protrude
Arnold Chiari syndrome Type II is…
Type 1 + meningomyelocele in lumbar spine
What bones fail to fuse in a cleft palate?
MAXILLARY & PALANTINE
The notochord persists as the
Nucleus pulposus
The scleretome of the mesoderm +
Membranous skeletal column
Splanchinic Myotome of the mesoderm +
Visceral smooth muscle
The epimere of the mesoderm +
Dorsal / posterior / extensor muscles
The hypomere of the mesoderm =
Ventral / anterior / flexor muscles
The gubernaculum in males becomes
Scrotal ligament
The gubernaculum in females becomes
- Suspensory ligament of ovary
- ovarian ligament
- round ligament
The procephalon splits into
Telencephalon & Diencephalon
The rhombencephalon splits into
Metencephalon & Myelencephalon
The Telencephalon derivatives
Cortices & basal ganglia
CN # for Telencephalon
1
Ventricle for Telencephalon
Lateral ventricle
Diencephalon derivatives
Thalamus & Pineal gland
CN # for Diencephalon
2
Ventricle for Diencephalon
3rd ventricle
Derivatives of Mesencephalon
Midbrain
CN # of Mesencephalon
3 & 4
Ventricle for Mesencephalon
Aqueduct of Sylvius
Derivative of Metencephalon
Pons & Cerebellum
CN # for Metencephalon
5-8
Ventricle for Metencephalon
4th ventricle
Derivatives of the Myelencephalon
Medulla oblongata
CN # for Myelencephalon
9-12
Ventricle for Myelencephalon
4th ventricle
________ is the only sensation that bypasses the thalamus
Smell
Muscle vs. Neuron resting membrane potential:
Muscle: -85 through -90mV
Nerve: -65 through -70mV
At resting membrane potential the cell is more ___________ inside the cell and more ________ outside the cell
Negative; positive
Pacinion corpuscles detect
Vibration
Ruffini receptors detect
Joint position sense
Meissners/Merkels receptors detect
Accurate touch
Spinothalamic tracts free naked endings detect
Pain, temperature and crude touch
When does the Absolute Refractory Period occur during an action potential?
When potassium leaks out of cell during repolarization when signal is back to resting membrane potential
When is the relative refractory period during an action potential?
During repolarization when sodium leaks out and the membrane voltage is more negative than the resting membrane potential
How many sodium flow out and how many potassium flow in?
3 Sodium out / 2 Potassium in
What part of the brain controls respiratory and cardiac centers, CN 5-12 & reticular formation?
Medulla & pons
What part of the brain controls reflexes to light and sound, proximal flexor relay & CN 3-4?
Midbrain
What part of the brain controls relay station & sensory fibers?
Thalamus
The ventral posteromedial thalamus controls sensory information from the
Face
The ventral posteromedial thalamus controls sensory information from the
Arms & legs
The lateral geniculate thalamus controls sensory information from the
Eyes
The medial geniculate thalamus controls sensory information from the
Ears
Role of the Parietal lobe:
Localization, Brodman 1,2,3 & problem solving
Role of the Occipital lobe:
Vision, Brodman area 17
Role of the superior temporal lobe:
Hearing
Role of the inferior temporal lobe:
Long term memory, smell
Damage to the hippocampus leads to
Anterograde amnesia
Memory is associated with what cells
Hippocampus cells
Smell is associated with what cells
Parahioopcampal cells in the Uncal area
Where is Wernicke’s area?
Junction of parietal, occipital & temporal lobes
Role of Wernicke’s area:
Sensory matching
Can read & see but can’t understand
Damage to Wernicke’s area is caused by
B1/Thiamine deficiency d/t alcoholism (Wernicke’s Korsakoff syndrome)
Contents & role of the frontal lobe:
Voluntary motor, precentral gyrus, Brodman 4,4S,6, corticospinal tracts
Pyramidal tracts start as
Giant cells of Betz
Where is Broca’s speech area located?
Interior frontal lobe on the left
What artery supplies Broca’s area?
Middle cerebral artery
What structure inhibits the thalamus?
Basal ganglia (stops motor response)
Dysfunction of the basal ganglia is associated with
Parkinson’s
AKA for Parkinson’s
Paralysis agitans
What cells are found in Parkinson’s disease?
Inclusion / Lewy Bodies from decreases dopamine in the substantial nigra
The Caudate Basal ganglia secretes
GABA
What is the genetic defect in the caudate basal ganglia called?
Huntingtons Chorhea
Basal ganglia Striatum consists of:
Putamen & caudate
Basal Ganglia Lentiform consists of:
Globes Pallidus & Putamen
Hypothalamus is responsible for:
- hunger & thirst
- temp regulation
- sex
- rage & fear
Role of the cerebellum:
- balance/equillibrium
- involuntary coordination
- unconscious propriception
What forms the blood brain barrier
Astrocytes & tight capillary beds
What structure stores glucose in the brain
Blood brain barrier
What are microglia?
Macrophages of CNS
What are ependymal cells
Line ventricles and CSF
CSF is made in the
Choroid plexus of the lateral ventricles
CSF is reabsorbed by
Arachnoid granulations of the superior Sagittal sinus
What are Oligodendrocytes?
Myelin of the CNS
Demyelination of the CNS is called
MS
What are Schwann cells?
Myelin of the PNS (from neural crest)
What causes demyelination of the PNS?
Guillian-Barre Syndrome (ascending paralysis)
When does Guillian Barre syndrome occur?
Post infection or post vaccination
What causes Hirschprung’s disease?
Absense of meissner’s & auerbachs plexuses
What is Hirschprung’s disease?
No peristalsis -> congenital megacolon
What cells inhibit the alpha motor neuron?
Renshaw cells (negative feedback)
Brain Waves (what they are): Alpha
Quiet, meditative
Brain Waves (what they are): Beta
Intense mental activity
Brain Waves (what they are): Delta
Deep sleep or coma
Brain Waves (what they are): Theta
Normal in children, stress/suicidal in adults
What do the association fibers of the cerebrum do:
Connect same hemisphere from frontal to temporal
What do commissural fibers of the cerebrum do?
Connect L & R brain
What do projection fibers of the cerebrum do?
Connect up & down in both directions passing through the internal capsule
Central chemo receptors are found in
Carotid and aortic bodies of the Brain stem
Central chemo receptors are most sensitive to:
Increased pCO2 THEN Decreased O2
Peripheral chemo receptors are most sensitive to
Decreased O2 THEN Increased pCO2
If increased pCO2 or decreased O2 is detected by central chemo receptors…
Cerebral blood vessels dilate
Vertebral arteries feed into
The circle of Willis
Where do vertebral arteries enter the spine?
C6 transverse foramen
Where do vertebral arteries enter the skull?
Foramen magnum
Damage to PICA =
Wallenberg Syndrome
What is Wallenberg syndrome?
Ipsilateral loss of pain and temperature to face, Contralateral to body
STUDY CIRCLE OF WILLIS DIAGRAM PAGE 4 SPINAL ANATOMY
What is the 1st branch of the internal carotid artery?
Ophthalmic artery to the eye
What is the MC artery involved in stroke?
Middle cerebral
The straight sinus is located in what structure
Tentorium Cerebelli
The great cerebral vein drains into
Straight sinus
Superior cerebral vein drains into
Superior agitate sinus
In what structure is the superior Sagittal sinus located in?
Flax cerebra
What does the superior Sagittal sinus contain?
Arachnoid granulations for reabsorbing CSF
What are the anterior and posterior attachments of the falx cerebri?
Anterior: Christ galli of ethmoid
Posterior: Tentorium cerebelli
Where is the confluence of sinuses and what is it called?
Torculus Herophilus; inner portion of occipital bone
Damage to the brain sinuses =
Subdural hematoma
Flow of CSF (6 steps)
Monroe Foramen -> 3rd Ventricle -> Aqueduct of Sylvius -> 4th Ventricle -> Magendie Foramen (midline) & Lushka Foramen (lateral), central canal & subarachnoid space -> reabsorbed in superior saggital sinus
Damage to middle meningeal artery =
Epidural hemorrhage
Damage to brain venous system =
Subdural hemorrhage
Damage to circle of Willis =
“Geri Aneurysm” AKA Subarachnoid hemorrhage
What are the motor (descending) tracts? (5)
1) Rubrospinal
2) Reticulospinal
3) Tectospinal
4) Vestibulospinal
5) corticospinal/pyramidal (lateral & ventral)
What is the role of the Rubrospinal tract?
Proximal muscle flexors or upper & lower extremity
What is the role of the reticulospinal tract?
Extensor muscles of back and arms
What is the role of the tectospinal tract?
Neck muscles
What structure controls reflex to light?
Superior colliculus
What structure controls reflex to sound?
Inferior colliculus
What is the role of the Vestibulospinal tract?
Extensor muscle of back & legs
What is the Vestibulospinal tract to the eyes called
Medial longitudinal Fasciculus
What is the role of the lateral corticospinal tract?
Flexors of distal extremities
What is the role of the ventral corticospinal tract?
Flexors of the trunk
Where does the corticospinal tract start?
Precentral gyrus of frontal lobe (Giant Cells of Betz)
Where does the lateral corticospinal tract decussate?
Medulla at medullary pyramids
Where does the ventral corticospinal tract decussate?
At the spinal level
What is the role of the Substantia Gelatinosa?
Blocks pain through tract of Lissauer & spinothalamic tract
What are the Reced Lamina of the spinal cord? (II, VII, IX, X)
II: Substantial Gelatinosa
VII: Nucleus Dorsalis of Clarke
IX: Anterior horn / alpha motor
X: Gray Commissure / Central canal
Where does the spinothalamic tract cross?
At spinal level
What is the role of the Lateral spinothalamic tract?
Pain & temperature
What is the role of the Ventral spinothalamic tract?
Crude touch & pressure
What are the receptors of the spinothalamic tract and what fiber type are they?
Free naked nerve endings; unmyelinated C fibers
Damage to the lateral spinothalamic tract =
Syringomyelia (dilation of central canal)
What is the role of the Dorsal Columns medial Lemniscus?
Conscious proprioception, vibration, position sense, 2 point discrimination
2 point discrimination come from _________ in the legs and _______ in the arms
Gracilis; Cuneatus
What is the role of the flocculonodular lobe of the cerebellum?
Balance of spine
What is the role of the anterior lobe of the cerebellum?
Balance from arms & Legs
What is the role of the posterior lobe of the cerebellum?
How the cerebellum talks to the cortex
The Fastigial cerebellar nuclei is responsible for:
Spine
The globus cerebellar nuclei is responsible for:
Proximal joints (GH & Hip)
The Emboliform cerebellar nuclei is responsible for:
Middle joint (elbow)
Globus + Emboliform cerebellar nuclei =
Interpose nuclei
The dentate cerebellar nuclei is responsible for:
Distal joints (digits)
What connects the midbrain to the cerebellum?
Superior cerebellar peduncle
What connects the pons to the cerebellum?
Middle cerebellar peduncle
What connects the medulla to the cerebellum?
Inferior cerebellar peduncle
Information traveling from the cerebellum to the cortex travels via the
Superior cerebellar peduncle
Information from the cortex to the cerebellum travels via the
Middle cerebellar peduncle
Information from the Body travels to the cerebellum via the
Inferior cerebellar peduncle
The posterior portion of the rectus contains the
Superior and inferior colliculi (corpora quadrigemina = the 4 colliculi)
The tegmentum portion of the midbrain houses:
CN 3&4 and cerebral aqueduct
The cerebral peduncle portion of the midbrain houses:
- Corticospinal tracts
- red nucleas
- substantial nigra
What CN’s originate from the frontal lobe?
I (Olfactory)
What CN’s originate from the Thalamus?
II (Optic)
What CN’s originate from the Midbrain?
III: Oculomotor
IV: Trochlear
What CN’s originate from the Pons?
5-8
What CN’s originate from the Medulla?
9-12
What structure does the Olfactory nerve travel through?
Cribiform plate
What foramen does the Optic nerve travel through?
Optic foramen of the sphenoid
What CN’s travel through the superior orbital fissure of the sphenoid bone?
IV, V(1), VI
What CN travels through the foramen rotundum of the sphenoid?
V(2)
What CN travels through the foramen ovale of the sphenoid?
V(3)
What CN’s travels through the Internal auditory meatus of the temporal bone?
VII & VIII
What CN pierces the parotid gland?
Facial
What CN’s travel through the Jugular foramen of the Temporal/occipital bones?
IX, X, XI
What CN’s travel through the Hypoglossal foramen of the occipital bone?
XII
Actions of the Optic CN
Vision & Pupillary Light reflex
Actions of the Oculomotor CN (3)
1) All eye muscles (except SO & RL)
2) Pupillary constriction
3) Efferent Pupillary Light Reflex
Actions of the Trochlear CN
Superior Oblique Muscle
What cranial nerve innervates sensory to the tongue?
Mandibular branch of Trigeminal
What CN innervates the muscles of mastication and the Tensor Tympani?
CN 5 (Trigeminal)
Actions of the Abducens CN
Lateral Rectus
What CN is called the CHordae Tympani in the middle ear?
7 (Facial)
What CN Innervates the stapedius?
7 (Facial)
What CN is responsible for Lacrimation & Salivation?
7 (Facial)
What CN innervates the palate, pharynx & larynx?
10 (Vagus)
What CN Innervates the intrinsic muscles of the tongue?
12 (Hypoglossal)
Trigeminal CN AKA:
Gasserian Ganglion
What muscles close the jaw? (3)
Temporal is, Masseter & Internal/Medial Pterygoid
Origin & Insertion of the ____________ muscle: Temporalis
O: Temporal fossa
I: Coronoid of Mandible
Origin & Insertion of the ____________ muscle: Masseter
O: Zygomatic process
I: External angle of jaw
Origin & Insertion of the ____________ muscle: Internal/Medial Pterygoid
O: Medial Pterygoid process
I: Internal angle of jaw
Origin & Insertion of the ____________ muscle: External/Lateral Pterygoid
O: Lateral Pterygoid process
I: Disc of TMJ & Condyle of mandible
What are the parasympathetic CN’s + Sacral levels?
CN 3, 7, 9, 10
S2-4
CN3 turns into the _________ nerve
Edinger-Westphal
CN7 turns into the _________ nerve
Superior Salvitory
CN9 turns into the _________
Inf. Salivatory nucleus -> otic ganglion -> parotid
CN10 turns into the _________ nerve
Vagal
Function of S2-4 parasympathetic nerves
[pelvic splanchnic]
Erection, bladder control, bowel control (distal 1/3 colon)
CN3 turns into the ____________ ganglion:
Ciliary
CN7 turns into the ____________ ganglion:
Sphenopalatine & sphenomandibular
CN9 turns into the ____________ ganglion:
Otic
Function of the ciliary ganglion
Pupillary constriction
Function of the Sphenopalatine ganglion
Crying/lacrimation
Function of the Sphenomandibular ganglion
Salivation
Function of the otic ganglion
Parotid glands
What receptors stimulate the breakdown of glycogen into glucose?
Adrenergic (Norepinephrine & Epi)
Alpha receptors are more sensitive to:
Norepinephrine
Beta receptors are more sensitive to:
Epinephrine
Function of Alpha 1 receptors: (2)
1) Vasoconstriction of central arteries
2) dilation of pupils
Function of Alpha 2 receptors:
Autoinhibitory to Alpha 1
Function of Beta 1 receptos: (2)
1) Increase heart rate
2) Increase contractibility
Function of Beta 2 receptors: (2)
1) shut down digestion
2) bronchodilation
ALL Parasympathetic receptors are
ACh receptors
What vertebral segments are included in the Superior sympathetic chain ganglion?
Above C4
What vertebral segments are included in the Middle sympathetic chain ganglion?
C4-C5
What vertebral segments are included in the Inferior sympathetic chain ganglion?
C6-C8
What vertebral segments are included in the Stellate ganglion?
C8-T1
What ganglion is the merger between the Inferior sympathetic chain ganglion and the T/S ganglion?
Stellate Ganglion
What disease results from disruption of the cervical chain ganglion?
Horner’s syndrome
3 clinical features of Horner’s syndrome:
1) Ptosis
2) Miosis
3) Anhydrosis
Steps of the Catecholamine pathway: (6)
Phenylalanine -> Tyrosine -> L-Dopa -> Dopamine -> Norepinephrine -> Epinephrine
The anterior chamber of the eye consists of the __________ to the __________
Cornea to Iris
The postrior chamber of the eye consists of the __________ to the __________
Iris to Lens
The anterior and posterior chambers of the eye are filled with
Aqueous Humor
Where is Aqueous humor of the eye made?
Made by ciliary epithelium in ciliary bodies
Excess aqueous humor in the eye =
Glaucoma
Features of Glaucoma: (2)
1) increased intraocular pressure
2) cupping of disc
The Posterior CAVITY consists of the ________ to the _________
Lens to Retina
The posterior cavity of the eye is filled with:
Vitreous Humor (jelly-like, maintains its shape)
Embryology of the Retina & Iris:
Optic Stalk gives rise to the Optic Cup
Function of the Fovea Centralis:
Most acute vision / Bright Lights & Colors d/t CONES
Function of the Rods in the eye
Peripheral vision, dim light, night vision
Function of the Rhodopsin in the eye
Purple pigment
MC cause of blindness in elderly is:
Macular degeneration
Macular degeneration means:
Can’t see in the light
Glaucoma effects the ______ first
Rods
What is the 1st signs/symptoms of Glaucoma?
Rings around lights
What is the vitamin for rods in the eye, and if it’s deficient what does it produce?
Vitamin A; Nyctalopia (night blindness)
What is Keratomalacia?
Softening of cornea
The Optic nerve decussates at the
Optic chasm
The nasal tracts decussate at the
Optic chasm
AKA for tunnel vision
Bilateral Hemianopsia
What lobe of the brain and area of the brain are responsible for vision?
Occipital and Brodman area 17
What is responsible for the reflex of eyes with neck movement?
Sup. Colliculi -> Lateral Geniculate/Thalamus
What is responsible for the reflex of ears with neck movement?
Inf. Colliculi -> Medial Geniculate/Thalamus
