Neuroscience Primer Flashcards
basic structure
-Brain derived from 5 embryonic regions of Neural Tube
-Telencephalon: cortex and subcortical nuclei – very front edge of the developing neural tube
-Diencephalon: thalamus and hypothalamus
-Mesencephalon: “midbrain”/quad. Plate (Superior calliculi and inferior caliculi which deal with visual and auditory reflexes)
-Metencephalon: pons and cerebellum – consciousness
Myelencephalon: medulla oblongata
primary vs association
- Primary cortex is (in the context of sensory fxn) – receives raw data from the environment
- Ex) what do we see? Light, wavelengths, lines, shapes – this is primary data – received in primary visual cortex
- Then the cortex compares set of primary data to associations to things you have formed over time
- Primary cortex has to communicate with association cortex which is typically nearby
- Is there a single cell that lights up when you are exposed to one stimulus? NO!! Is there a network of cells
- The more exposure you have to a particular stimulus, the stronger the network is that allows you to retrieve the information
occipital, temporal, post-central gyrus, and pre-central gyrus
- Occipital = vision
- Temporal = Auditory/Language
- Post-central Gyrus = Primary Somatosensory Cortex
- Pre-Central Gyrus = Primary Motor Cortex
broca’s/wernicke’s areas
- Brocas = motor (tail end) (The face, larynx, and mouth is located there)
- Wernickes = where we put meaning to words (WORD SALAD if this area is damaged)
- You lose syntax – this may be subtle (i.e. nouns are all messed up)
Aphasia
- “Fluent Aphasia” – Words are easily spoken but are incorrect or unrelated to content of other words. AKA Sensory, receptive or Wernicke’s aphasia.
- “Non-fluent Aphasia” – great difficulty speaking but context and content of the words is correct. AKA motor, expressive or Broca’s aphasia.
- Fluency = ability to form words
- Don’t memorize what sensory or receptive refers to – he will give you fluent or non fluent
vasculature of the brain
- Cortex fed by three major arteries: anterior, middle and posterior cerebral off the Circle of Willis
- “Watershed” areas of vascularization most sensitive to loss of perfusion, even transient (Relies on two areas of perfusion in order to have adequate ventilation)
- Both Wernickes and Brocas areas are in watershed regions which makes them highly susceptible to damage and thus pathology
subcortical nuclei
- Basal Ganglia
- Amygdaloid Nucleus – involved in the aggressive behavior
basal ganglia
- coordination of movement
- Globus Pallidus
- Caudate Nucleus
- Putamen (caudate + putamen = neostriatum)
role of the basal ganglia
- Wilson: the basal ganglia “maintain a postural background for voluntary activities.” (Don’t think of posture as standing still)
- Reflects the primary function of the evolutionarily newer corticospinal system, making the “extrapyramidal” pathways subordinate to the cortex
diencephalon
- Thalamus: afferent relay for virtually all sensory information (except olfaction)
- Hypothalamus: “set points”, control of homeostatic systems of the body through pituitary gland
mesencephalon
- Primary occupant: corpora quadrigemina (ie quadrigeminal plate (Superior colliculus: visual reflexes, Inferior colliculus: auditory reflexes
- The cortex is NOT FAST!!! Has to think about stuff all the time
metencephalon
- Pons: bridge of fibers to the cerebellum and container of pontine nuclei of the RAS and other systems
- Cerebellum: control of balance and coordination of movement
Myelencephalon
-Medulla oblongata: responsible for the maintenance of vital bodily functions, very sensitive to trauma
Spinal cord
- Butterfly-shaped central gray contains cell bodies
- Surrounding white contains bundles of myelinated fibers
- Dorsal and ventral roots emanate from lateral surface (anterolateral and posterolateral sulcus) forming 31 pairs of spinal nerves
Spinal gray matter
-Each spinal segment contains posterior and anterior horns, lateral horns in thoracic region
Spinal white matter
-Three paired funiculi: posterior, lateral, anterior
Posterior funiculus
- long ascending and short (spinal ganglia) descending fibers
- Carry proprioceptive fibers – these are posterior columns
- They carry vibratory sensation as well
Lateral funiculus
- lat. corticospinal, rubrospinal, lat. spinothalamic, spinotectal, spino-olivary, ant. spinocerebellar tracts
- Spinothalamic = spinal cord to thalamus
anterior funiculus
-vestibulospinal, reticulospinal, ant. spinothalamic, tectospinal, ant. corticospinal tracts