Flashcards in Neuro2 Deck (88):
How many neurons are estimated to be in the cortical gray matter?
What 6 layers make up the cortical gray matter?
Name 5 types of important cells in the 6 layers of cortical gray matter.
Horizontal cells of Cajal
cells of Martinotti
What two directional categories does white matter have in relation to cortical gray matter?
Radial fibers - run toward the cortex
Tangential fibers - run parallel to the cortex
What is the smallest division of functionally-grouped activity within the cortex?
Vertical columns form:
Functionally specialized areas
Functionally specialized areas of vertical columns are grouped together into anatomically distinct:
Lobes or Cortices
Lobes/cortices can be further grouped into other connected areas in:
Functional circuits can be connected via what 3 pathways?
Association fibers (intra-hemisphere)
Commissural fibers (contralateral hemisphere)
Projection fibers (thalamocortical - fibers leave cortex and go ANYwhere other than cortex)
What do association fibers connect anatomically?
to the same hemisphere
What do commissural fibers connect anatomically?
to the opposite (contralateral) hemisphere
Where do projection fibers originate?
Name 5 important functional areas of the cortex.
Primary Sensory cortices
Sensory Association cortices
Motor Planning cortices
Primary Motor cortices
Where is the primary somatosensory cortex?
(this is the sensory homunculus)
What does a lesion on the somatosensory cortex cause?
Deficit in sensation from the opposite side of the body
(hemi-anasthesia contralateral to lesion)
Where is the somatosensory association complex?
Superior parietal lobe and supramarginal gyrus
(this identifies the object you are feeling)
Where is the primary visual cortex?
Cuneus and Lingual gyri
(analyzes visual world without association)
Where is the visual association cortex?
Medial and lateral occipital gyri
Where is the primary auditory cortex?
The auditory association cortex?
Superior Temporal Gyrus/Transverse Temporal gyri
Superior Temporal Gyrus
Wernike's area is a specialized part of what?
The auditory association cortex in the superior temporal gyrus.
Spoken language comprehension
What do the uncus, piriform cortex, periamygdaloid, and part of parahippocampal gyrus make up?
The Primary Olfactory Cortex
What is Agnosia?
Inability to recognize an object or to interpret sensory stimuli.
Name 3 types of Agnosia.
Where does executive function reside?
specifically: superior, middle frontal gyri, and medial frontal lobe
What is meant by Executive Function?
refers to all planning (motor, cognitive, emotional)
as well as regulate Affect with sensation
What can be termed a negative sign?
Loss of function (paralysis)
What can be termed a positive sign?
Abnormal function (hallucination)
What does the Limbic association cortex regulate?
Emotions, mood, affect, memory
(closely tied to the sense of smell)
What would a tumor or stroke cause if it was in the limbic system?
visual and auditory hallucinations
What cortex is involved in sensory integration (including interpretation), problem solving, speech, and spatial processing?
Parietotemporal Association Complex
What can a lesion of the non-dominant (usually right) Parietotemporal association complex cause?
Hemineglect Syndrome on the Left
(this won't effect speech because in most people it is localized in the left hemisphere)
Where is the Primary Motor Cortex?
The precentral gyrus
What will a lesion in the primary motor cortex cause?
Paresis (weakness/partial paralysis) in the opposite side.
Where are the Premotor Cortex and the Frontal Eye Fields?
Middle Frontal Gyrus
Where is the Supplemental Motor Cortex?
Superior Frontal Gyrus
Where is Broca's area and what is its function?
Inferior Frontal Gyrus
What are symptoms of Broca's Aphasia?
Normal comprehension of language, but speech expression is limited
disorder of sensory integration causing an inability to plan and perform complex movements
What is the inability to carry out spontaneous movement?
What is the inability to carry out movement on command (due to inability to remember command)?
What is the inability to perform complicated motor tasks called?
What is the inability to demonstrate use of objects called?
What is the most common Apraxia?
the inability to perform facial-oral movements on command (like lick lips)
What one area is consistently an asymmetry in the brain?
Wernicke's speech area
(upper surface temporal lobe)
What hemisphere is usually dominant/non-dominant?
Left usually dominant
What are some functions of the dominant hemisphere?
Praxia (motor formulation)
Analytical skills (in math)
What are some functions of the non-dominant hemisphere?
Prosody (emotion in voice)
Spatial skills (analysis, math, orientation)
The cells of Martinotti tend to be:
What is astereognosis?
(inability to identify what is placed in hand without other sensory input)
What is homonymous hemianopia?
Loss of 1/2 of the visual field
usually affects both eyes at midline
What is visual agnosia?
inability to determine what one is seeing
not a deficit in acuity
Are conscious location of sounds and auditory agnosia located in different areas?
Yes. Agnosia is more anterior
Where do (nearly) all the inputs to the cerebrum first synapse?
Ascending somatosensory pathways from body
Relays somatosensation of body to cortex
(the homunculus processor)
Somatosensory from face/taste (V, VII, IX)
somatosensation from face/taste to cortex
(VPM island in VPL)
Cerebellum and basal ganglia
Motor, Premotor, Supplemental motor cortices
motor from basal ganglia/cerebellum to cortex
Widespread to frontal lobes
motor from basal ganglia/cerebellum to cortex
Sensory pathways from Tectum (visual colliculi)
Parietotemporooccipital association cortex
Behavioral orientation to visual stimulus
Pulvinar - think visual association
Primary visual cortex
visual input to cortex
little tonguelike thingy
Primary auditory cortex
Auditory information to the cortex
(teeny one on the bottom)
Emotional/memory input to cortex
Limbic and Hippocampus
relays info from limbic system
What are the 3 main functions of the Limbic System?
Homeostasis - Hypothalamus
Memory - hippocampus
Emotions - Amygdyla
What regulates Homeostasis?
(includes sex, behavior, autonomics, and endocrine)
What regulates memory in the limbic system?
What regulates emotions in the limbic system?
What does Fornix mean?
What is an important pathway that converges cognitive activities, emotional experience, and expression?
Circuit of Papez
(this is a Fornix circuit)
Outline the pathway of the Circuit of Papez:
Parrahippocampal gyrus > hippocampus > fornix > mammilary bodies (part of hypothalamus) > thalamus > cingulate gyrus > parahippocampal gyrus
What does the Stria Terminalis connect?
Amygdala and Hypothalamus
What connects the Amygdala with the basal ganglia, olfactory cortex, cingulate gyrus, prefontal cortex, hypothalamus, and septal nuclei?
Ventral amygdalofugal pathway
What structure is a diffuse group of axons that carry info between amygdala, brainstem, and hypothalamus?
Medial forebrain bundle
Name 7 pathologies that arise when the limbic system is damaged:
Autonomic and homeostatic dysfunctions
Changes in sexual behaviors and grooming
Where is the Pituitary housed?
What are the two divisions of the pituitary, and what structure connects it to the Hypothalamus?
Pituitary stalk called the Infundibulum
What is the glandular division of the pituitary?
What is the neural tissue division of the pituitary?
Name the 6 hormones secreted/synthesized by the Anterior Pituitary.
What other structure in the brain does the Anterior Pituitary have an endocrine relationship with and how is it connected?
Hypothalamic-Hypophysial portal system
Does the Posterior Pituitary make any hormones?
No! They just store hormones synthesized by neural tissue.
What are 2 hormones secreted by the Posterior Pituitary?
Vasopressin (aka - ADH)
Pretty much every hormone in the Anterior Pituitary is mediated/controlled by hormones in the:
What is the most anterior region of the hypothalamus and what does it contain?
contains medial and lateral preoptic nuclei
What are the 6 nuclei in the Supraoptic (anterior) region of the hypothalamus?
Lateral hypothalamic nuc.
What 5 nuclei make up the middle (tuberal) region of the hypothalamus?
What 3 nuclei make up the Posterior (mammilary) region of the Hypothalamus?
Lateral hypothalamic nucleus