Exam I Flashcards
what are the steps of embryological development?
Stage 1: Neurulation Stage 2: Cell Proliferation Stage 3: Migration Stage 4: Cell Differentiation Stage 5: Synaptogenesis
what is neurulation?
formation of the neural crest
& neural tube (Stage 1 of embryological development)
what is cell proliferation?
cell growth within the neural tube (Stage 2 of embryological development)
what is migration?
an aggregation of cells within a specific location (Stage 3 of embryological development)
what is cell differentiation?
formation of axons and dendrites; development of cranial nerves (Stage 4 of embryological development)
what is synaptogenesis?
connections between
nerve cell to nerve cells or muscle cells; permanent learning / neural plasticity can now occur (Stage 5 of embryological development)
what is the Cephalic flexure?
division between the brain and brain stem
what is the Cervical flexure?
division between brain and the spinal cord
what is the pontine flexure?
division between metencephalon and myelencephalon
what does the neural crest eventually develop into?
peripheral nervous system
during development, what does the prosencephalon go on to become? (2)
telencephalon and diencephalon (the forebrain)
during development, what does the mesencephalon go on to become? (1)
mesencephalon (the midbrain)
during development, what does the rhombencephalon go on to become? (2)
metencephalon and myelencephalon (the hindbrain)
what occurs with failure of the posterior neuropore to close?
spina bifida
what occurs with failure of the anterior neuropore to close?
anencephaly
during cell proliferation, the sulcus limitans creates dorsal and ventral portions; what is the DORSAL portion called?
alar plate (site for sensory tracts)
during cell proliferation, the sulcus limitans creates dorsal and ventral portions; what is the VENTRAL portion called?
basal plate (site for motor tracts)
what is the ependymal or germinal layer?
lines the ventricles and develop cilia to move CSF
what does the intermediate or mantle layer become?
becomes gray matter of spinal cord
what does the marginal layer become?
white matter
how does radial migration occur? what does this require?
from spinal cord through telencephalon; requires radial glial cells
where does tangential migration occur?
brainstem
what is dyslexia?
difficulty reading due to problems identifying speech sounds and learning how they relate to letters and words
what is Lissencephaly?
smooth brain, less gyri in the brain; results in lower IQ
when does the swallow and gag reflex develop? what CNs are responsible for this relfex?
(1) 14 weeks
(2) CN 5, 7, 9, 10, 12
when does the visual motor cortex develop? what CNs are responsible for this this?
(1) 25 weeks
(2) 2, 3, 4, 6
when does hearing develop? what CNs are responsible for this? (1)
(1) 28 weeks
(2) 8
when does olfaction develop? what CNs are responsible for this? (1)
(1) 31-32 weeks
(2) 1
what is included within the telencephalon? (3)
(1) cerebral cortex
(2) white matter (subcortical)
(3) basal ganglia
what is included within the diencephalon? (3)
(1) thalamus
(2) hypothalamus
(3) epithalamus
what is included within the mesencephalon? (3)
(1) cerebral peduncles
(2) midbrain tectum
(3) midbrain tegmentum
what is included within the metencephalon? (2)
(1) pons
(2) cerebellum
what is included within the myelencephalon? (1)
(1) medulla
what does the choroid plexus do? where is it located?
(1) creates CSF
(2) ventricles
what are the meninges? what are the 3 parts?
3 layers that line the skull PAD (1) Pia Matter: most inner layer, close to surface of the brain (thin) (2) Arachnoid Matter: middle layer (3) Dura Matter: hard, outer layer
what is the purpose of the falx cerebri?
dura matter structure dips in between the cerebral hemispheres; prevent brain from moving around
what are the 3 types of neurons?
(1) Multipolar: have several dendrites and axons; most neurons in mammals
(2) Bipolar: single dendrite and axon; vision and olfaction neurons
(3) Unipolar: both axon and dendrite from a single process coming off a cell body; (seen in invertebrates)
what is a synapse; where do they typically occur?
(1) communication between neurons
(2) from axon terminal of one nerve to the dendrite of the next neuron
what is the function of myelin sheath?
covers the axons to allow for increased speed of transmission of the AP
what forms myelin in the CNS?
Oligodendrocytes
what forms myelin in the PNS?
Schwann cells
what are the excitatory and inhibitory neurotransmitters of the CNS?
excitatory: glutamate
inhibitory: GABA
what neurotransmitters are used by the PNS?
Acetylcholine
what neurotransmitters are used by the ANS?
Acetylcholine
Norepinephrine
what are characteristics of white matter? (2)
(1) myelinated axons
(2) transmit signals over greater distances than gray matter
what are characteristics of gray matter? (2)
(1) cell bodies
(2) local synaptic communication
where is gray and white matter found within the brain?
(1) gray matter: outer cortex
(2) white matter: middle of the brain
where is gray and white matter found within the spinal cord?
(1) gray matter: in the middle
2) white matter: outer edges of the spinal cord (where ascending and descending tracts are located
where is gray matter found within the CNS? (2)
(1) cerebral cortex
2) nuclei (basal ganglia, thalamus, cranial nerve nuclei
where is white matter found within the CNS? (5)
(1) Tracts
(2) Fascicle
(3) Lemniscus
(4) Bundle
(5) Commissure
where is white matter found within the PNS? (1)
(1) peripheral nerves
where is gray matter found within the PNS? (1)
(1) ganglia
what is the final neurotransmitter for the Sympathetic nervous system
Norepinephrine
what is the final neurotransmitter for the Parasympathetic nervous system
Acetylcholine
what is the differences between sulci, fissures and gyri?
(1) sulci: infoldings
(2) fissures: deep infoldings
(3) bumps or ridges between sulci
what are the 4 main lobes of the brain? what are the hemispheres?
Lobes (1) frontal (2) temporal (3) parietal (4) occipital Hemispheres (1) left (2) right
what is the insular cortex?
convergence of frontal, parietal, and temporal cortexes
what does the Central Sulcus separate?
frontal and parietal lobes
what does the Sylvian fissure separate?
parietal and temporal lobes
what does the Parieto-occipital sulcus separate?
parietal and occipital lobes
what is the corpus callosum made up of? what are the 4 parts?
white matter
(1) Rostrum: front
(2) Genu: bend
(3) Body: largest portion
(4) Splenium: tail end
where does the Calcarine fissure run?
within the occipital lobe
where is the Primary motor cortex located?
precentral gyrus
where is the Primary sensory cortex located?
post central gyrus
where is the Primary visual cortex located?
occipital lobe
where is the Primary auditory cortex located?
transverse gyrus of Heschl (temporal lobe)
what are the 6 layers of the neocortex?
Many Small Men Got Large Penises I – Molecular layer II – Small pyramidal layer III – Medium pyramidal layer IV – Granular layer V – Large pyramidal layer VI – Polymorphic layer
what layer is the molecular layer? what is the main connection for this layer?
Layer 1; connects dendrites and Axons from other layers
what layer is the small pyramidal layer? what is the main connection for this layer?
Layer 2; cortical to cortical connections
what layer is the medium pyramidal layer? what is the main connection for this layer?
Layer 3; cortical to cortical connections
what layer is the granular layer? what is the main connection for this layer?
Layer 4; receive input from thalamus
what layer is the large pyramidal layer? what is the main connection for this layer?
Layer 5; sends output to subcortical structures (other than thalmus)
what layer is the polymorphic layer? what is the main connection for this layer?
Layer 6; sends output to the thalamus
where are Brodmann’s areas 1,2,3 found? what is their function?
(1) Primary Somatosensory Cortex
(2) Touch
where is Brodmann’s area 4 found? what is it’s function?
(1) Primary Motor Cortex
(2) Voluntary movement
where is Brodmann’s area 17 found? what is it’s function?
(1) Primary Visual Cortex
(2) Vision
where is Brodmann’s area 22 found? what is it’s function?
(1) Wernicke’s area
(2) Language Interpretation
where are Brodmann’s areas 28,34,35,36,38 found? what are their functions?
(1) Primary Olfactory Cortex
(2) Smell; emotion
where is Brodmann’s area 41 and 42 found? what is it’s function?
(1) Primary Auditory Cortex
(2) Hearing
where is Brodmann’s area 44 found? what is it’s function?
(1) Broca’s area
(2) Speech; Motor Planning
where are Brodmann’s areas 23-36, 38 found? what are their functions?
(1) Limbic Association Cortex
(2) Emotions
what are the 2 main somatosensory pathways? what sensation do each provide?
(1) Anterolateral Pathway; Pain, Temperature & Crude Touch
(2) Posterior (Dorsal) column pathway; Proprioception, Vibration & Discriminative Touch
what is the tract for the Anterolateral Pathway?
(1) Dorsal Root → (2) Synapses Immediately in Grey Matter → (3) Cross & Ascend in Antero-lateral White Matter → (4) Synapses in the Thalamus → (5) Primary Somatosensory Cortex (Post Central Gyrus)
what is the tract for the Dorsal Column Pathway?
(1) Doral Root → (2) Ipsilateral White Matter/Dorsal Column → (3) Dorsal Column Nuclei Medulla → (4) Synapse & Cross Medulla → (5) Contralateral Ascend to Thalamus → (6) Synapse in Thalamus → (7) Primary Somatosensory Cortex
what is the tract for the stretch reflex arch?
Muscle Spindle (1) → Distal Sensory Neuron (1) → Dorsal Root (1) → Synapse in Grey Matter (2) → Ventral Root (2) → To Muscle
where is Brodmann’s area 18 found? what is it’s function?
(1) Secondary Visual Cortex
(2) Vision
where are Brodmann’s areas 5, 7, 39, 40 found? what are their functions?
(1) Sensory association cortex
(2) Stereogenesis, Perception, Vision, Reading, Speech
where is Brodmann’s area 28 found? what is it’s function?
(1) Parahippocampal gyrus
(2) Smell, emotions
