Mod 1 Flashcards
Organization of the nervous system
Mechanisms underlying embryogenesis
- Induction of cell differentiation
- Neuron generation and apoptosis
- Neuronal guidance
- Synapse formation
Cell differentiation
Each layer will develop different types of cells.
The nervous system will develop from ectoderm.
Ectoderm
Nervous system
Skin
Mesoderm
Muscle
Skeleton
Kidneys
Reproductive system
Endoderm
Endocrine glands
Lungs
Digestive tract
Liver
Most common group of congenital deficits
Abnormal neural tube closure
Axonal transport
Proteins carry substances along the microtubules
Anterograde: toward axon terminal
Retrograde: toward cell body
Action potential
Na+ ion movement across into the cell causes depolarization, which triggers voltage-gated K+ ion channels to open slowly and remain open.
Voltage-gated K+ ion channels open slowly and remain open (repolarization) allowing K+ to rush out swiftly (hyperpolarization).
Overview of neurotransmitters
Acetylcholine: excitatory and inhibitory
Dopamine: excitatory and inhibitory
- norepinephrine and epinephrine
GABA: most common inhibitory
Glutamate: most common excitatory
Serotonin: excitatory and inhibitory
- modulates catecholamine levels
- common in brainstem
Gross anatomy of spinal cord
Cervical enlargement: C3-T2
Lumbar enlargement: T11-L1
Conus medullaris: L1
Cauda equina
Filum terminale
Lumbar cistern
Spinal nerves
Spinal roots joint to form spinal nerves
Spinal nerves divide into the ventral and dorsal rami
Arteries of spinal cord
Serves the length of the spinal cord
- anterior spinal artery (one)
- posterior spinal arteries (paired)
Branch off at each level
- segmental radicular arteries
Intercranial hemorrhages
Epidural: above the dura; biconvex shape
Subdural: below the dura; crescent shape
Subarachnoid: follows contour of the brain, midline shift
Spaces within the meninges
Dural veneous sinus
- separated layers of dura
- venous circulation
Ventricles of the brain
- ependymal lines cavities
- CSF filled spaces
2 main arteries of the intracranial structures
Internal carotid
Vertebral
Join together to create the Circle of Willis
Vertebral artery course
Through transverse processes of cervical spine
Gives branches to spinal arteries
Join together to form the basilar artery
Basilar artery
Primarily supplies posterior cerebral artery
Gives rise to:
- pontine arteries
- cerebellar arteries
Circle of Willis
Gives rise to:
- anterior cerebral artery
- middle cerebral artery
- posterior cerebral artery
Cerebral arterial supply
Three branches of the circle of Willis supply most of the cerebral hemisphere
Brainstem structure
The cross section of the brainstem roughly has 3 zones
Cranial nerves
CN I: olfactory
CN II: optic
CN III: oculomotor
CN IV: trochlear
CN V: trigeminal
CN VI: abducens
CN VII: facial
CN VIII: vestibulocochlear
CN IX: glossopharyngeal
CN X: vagus
CN XI: accessory
CN XII: hypoglossal
