5. Overview of CNS/PNS and Embryo Flashcards
Major Segments of the Brain and what they include (5)
- Telencephalon-cerebral hemispheres
- Diencephalon-hypothalamus and thalamus
- Mesencephalon-midbrain
- Metencephalon-pons and cerebellum
- Rhombencephalon-medulla
Gray v White Matter
Gray=neurons, white=axons; in brain gray is outer and white is deep; in spinal cord white is outer and gray is deep
5 major subdivisions of the forebrain
frontal parietal temporal limbic occipital
Basal Ganglia (4) and general function
Basal Ganglia smooths out motor movements Caudate Nucleus Putamen Globus Pallidus Externa Globus Pallidus Interna
Numbers of Cord Segments and Vertebrae
8 Cervical Segments, 7 Cervical Vertebrae
12 Thoracic Segments and 12 Vertebrae
5 Lumbar Nerves and 5 Vertebrae
5 Sacral Nerves with fused sacral bone
Where does spinal cord end?
T12-L1
Who sits in the back of the spinal cord bus? Front?
Afferent Sensory are the cool kids
Efferent Motor are the med students
What is the only motor pathway to the periphery that we must learn?
Corticospinal (pyramidal) Tract
Describe Pyramidal Tract generally
Motor Cortex–>post internal capsule–>decussate at decussation of pyramids–>lateral corticospinal tract–>terminate on LMN in anterior horn–>ventral spinal root–>peripheral nerve–>muscle
Spinothalamic Tract senses what?
pain and temperature from periphery
Describe Spinothalamic Tract generally
pain/heat–>peripheral nerve–>thru DRG into dorsal spinal cord–>up/down 1-2 segments in Lissauer’s Tract–>Synapse in post horn–>2ndary neuron decussates and travels in anterolateral spinothalamic tract–>terminates in VPL of thalamus–>3rd neuron thru internal capsule to somatosensory cortex
Posterior (Dorsal) Column senses what?
vibration and position changes
Describe Posterior Column Tract generally
vibes/movement–>thru DRG into dorsal spinal cord –>ascends ipsilateral in posterior column–> synapse in gracile/cuneate nuclei–>decussate as internal arcuate fibers and form medial lemniscus–> synapse in VPL–>axon to sensory cortex
Sympathetic Neurons lie where? Para?
sympathetic–>thoracic and lumbar regions;
para-cranial/sacral
Brain development begins when and what is first step?
Week 3 with formation of neural fold and neural crest cells
