1.3 Flashcards
How do you find the best spot for a lumbar puncture?
L4-L5 to avoid spinal cord
Follow iliac crest
Lay on side
Which spinal level correlates within inntervation of the upper extremity?
C5
Cervical enlargement level
C3-T2
Lumbar enlargement level
T11-L1
Conus medullaris level
L1
Spinal roots
Join to form spinal nerves
Spinal nerves divide into the ventral and dorsal rami.
Spinal nerves exit the vertebral column via intervertebral foramen.
Roots carry sensory OR motor.
Rami carry sensory AND motor,
Dermatomes of neck, thumb, elbow, pinky, nipple, and umbillicus
Neck: C3-C5
Thumb: C6
Elbow: C7,C8
Pinky: C8
Nipple: T4, T5
Umbilicus: T10
Note differences between nerve fibers.
Cross sectional anatomy of the spinal cord
The spinal cord in symmetrical bilaterally.
Ventral, dorsal, and lateral columns of grey matter.
White matter is peripheral.
Ventral and dorsal median sulcus or fissure.
Grey matter = cell body of neurons
White matter gets its color from myelin
Commissure = crossing
Funiculus
Area of white matter
Both motor and sensory
Funiculus - neighborhood
Fasiculus - house
Bundle of nerve fibers enclosed in a sheath of connective tissue or forming one of the main tracts of white matter in the spinal cord
Spinal tracts
Bundles of neural fibers going to the same destination.
- carry either sensory or motor fibers
- can be called fasiculi
Spinal cord vasculature
Serving the length of the spinal cord:
- anterior spinal artery (one)
- posterior spinal arteries (paired)
Branching off at each level:
- segmental radicular arteries
Right and left cerebral hemispheres
Anatomically symmetrical
Connected by corpus callosum
Significant landmarks:
- central sulcus
- lateral sulcus
- frontal, temporal, parietal, and occipital lobes
- insula
- limbic (cingulate gyrus and parahippocampal lobe)
Brodmann’s areas
Numbered areas of the brain that identify areas of the brain
Though the brain is symmetrical anatomically, there are differences in function between the right and left
Cerebrum: grey matter: horizontal organization
Cells of cerebral cortex are arranged in layers, with each layer made up of one cell type which has a unique function
Each region of the brain has 3-6 layers which work together cooperatively.
Cerebrum: grey matter: vertical organization
Each region is functionally divided into columns
Narrow columns each serve one specific area of the body
Cerebrum: white matter
3 types of fibers make up the white matter
1. Commissural - connects right and left
2. Projection - connects upper and lower on same side
3. Association - stays close, goes to gyri on same side, adjacent
Basal nuclei
Groups of cell bodies involved in modification of movement
Basal nuclei are embedded in the deep cerebral white matter and in the brainstem
Diencephalon
Develops from the prosencephalon which becomes the telencephalon and diencephalon. As the fetal brain matures, the telencephalon grows to surround the diencephalon.
The mature diencephalon surrounds the third ventricle and consists of thalamic structures.
Cerebellum
Develops from the rhombencephalon, part of which becomes metencephalon then the pons and cerebellum. The close association between pons/cerebellum persists into the mature brain.
Brain
The 3 parts of the brainstem develop from the mesencephalon and rhombencephalon.
The structures of the brainstem surround the 4th ventricle and cerebral aqueduct.
Mesencephalon/midbrain
Surrounds the cerebral aqueduct (passage which connects the 3rd and 4th ventricles)
Metencephalon: Pons and cerebellum
The pons forms part of the floor of the 4th ventricle
Myelencephalon: medulla oblongata
Contains the 4th ventricle
Continuous with the spinal cord
Imaging modalities for the CNS
X ray: plain film
CT: computed tomography
MRI: magnetic resonance imaging
CNS imaging
Xray for certain fractures
CT for time sensitive - most acute situations
CT for initial scans for stroke, tumor
- MRI for follow up scans
MRI for multiple sclerosis, seizure
Lumbar cistern
CSF chamber often used for spinal taps
Spinal nerves exit the vertebral column via the
intervertebral foramen
Grey matter is composed of
neurons, their processes, and neuroglia
Subdivided into ventral, dorsal, and lateral columns
