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Flashcards in cerebral hemisphere Deck (34):
1

Achicotex

- part of allocortex (ancient center)

- contains 3 layers of gray matter

- involved in memory and emtions

- HIPPOCAMPAL FORMATION

2

Paleocortex

- Part of allocortex (ancient cortex)

- made up of 3-5 layers of gray matter

- PARAHIPPOCAMPAL GYRUS, uncus and the lateral olfactory gyrus (olfactory system)

3

Mesocortex

- Part of allocrotex (ancient center)

- made up of 3-6 layers of gray matter

- cingulate gyrus and the insula

4

describe Neocortex

- is the evolutionarily newer cortex (makes up 90% of cerebral cortex)

- made up of 6-layers present with regional variation

--> HOMOTYPICAL CORTEX = association areas (all 6 layers are present)

--> HETEROTYPICAL CORTEX = PRIMARY AREAS

1) agranular = primary motor cortex

2) granular = primary sensory cortex

5

define pyramidal cells

- most abundant, 75% of cortical cells

- Long axons FORM WHITE MATTER TRACTS

6

Fusiform

- Modified pyramidal

- Located in the DEEPEST cortical layers

- Axons PROJECT TO THALAMUS

7

define Stellate (granule) cells

- Involved in integration

- Aspiny = INHIBITORY INTERNEURONS

- Spiny = EXCITATORY interneurons, located in layer IV of the gray matter

8

Horizontal cells of cajal

- located in SUPERFICIAL most layer of gray matter

- Seldom seen or completely lacking in adult brain

 

9

Cells of MARTINOTTI

- Interneurons

- located in DEEP LAYERS of the gray matter

10

Association fibers

- Intracortical fibers = superior longitudinal fasciculus, uncinate fasciulus, occipitofrontal fasiculus

- Send projections WITHIN SAME HEMISPHERE (IPSILATERAL)

11

Commissural fibers

- Commissural fibers = corpus callosum, anterior/posterior commissures

- TO/FROM OPPOSITE HEMISPHERE (CONTRALATERAL)

12

Projection fibers

- Ex = crus cerebri, internal capsule

- TO/FROM CORTEX and SPINAL CORD = corticobulbar, corticothalamic, corticopontine

- INTERNAL CAPSULE

13

Molecular layer (I)

- Synaptic area = axons and MOSTLY DENDRITES

- neuroglia and cells of cajal

- INTEGRATION (sends axons horizontally)

14

External granular layer (II)

- Small pyramidal and STELLATE CELLS

- Axons and dendrites from deeper layers

- INTEGRATION (sends cells horizontally)

15

External Pyramidal layer (III)

- Moderate size PYRAMIDAL cells

- EFFERENT LAYER (OUTPUT LAYER)

- Corticocortical fibers = association and commissural fibers

16

Internal granular layer (IV)

- STELLATE CELLS DENSLY PACKED

- outer band of baillarger = myelin staining

- AFFERENT LAYER = CHIEF INPUT LAYER (EXPANDED IN SENSORY CORTEXS)

- thalamic afferents = VPL, VPM-thalmocortical fibers

17

Internal pyramidal layer (V)

- GIANT PYRAMIDAL CELLS of betz, smaller number of stellate cells, cells of martinotti

- Inner band of baillarger- myelin staining

- EFFERENT LAYER (OUTPUT)

- PROJECTION FIBERS = corticofugal (striate), corticobulbar, corticospinal fiber

**EXPANDED IN MOTOR CORTEX**

18

polymorphic (multiform) layer (VI)

- small pyramidal cells, stellate cells, CELLS OF MARTINOTTI, Fusiform cells

- Efferent layer

- corticothalamic fibers

19

Precentral gyrus

- Brodmanns 4 = primary motor cortex

- Lesion = contralateral weakness, spastic paralysis, hyperreflexia (UMN lesion)

20

Premotor and supplementary motor area

- Brodmanns 6 = superior and middle frontal gyri

- Premotor and supplementary motor area = programming necessary for movements

- LESION = APRAXIA (inability to perform purposeful movements)

21

frontal eye field

- brodmanns 8 = superior and middle frontal gyri of pre-frontal cortex

- LESION = disruption of some of the most complex aspecs of behavior (e.g Phinaeus gage)

22

Brocas area

- Opercular and triangular parts of inferior frontal gyrus

- Brodmanns 44

- motor programs necessary for generation of language

- located in DOMINANT HEMISPHERE

- LESION = Brocas aphasia

23

define broca's aphasia

- nonfluent, motor, expressive

- Comprehends language, difficult producing written or spoken words

24

Primary somatosensory area

- Brodmans 3,1,2 = post central gyrus

- Lesion = loss of tactile discriminatory and proprioception on CONTRALATERAL SIDE

- PAIN is not elicited, abolished or relieved

25

Somatosensory association area

- Brodmanns 5,7 = superior parietal lobule

- Tactile and visual information, cognition of body itself and objects surroudning it

- LESION = tactile agnosia, asterognosis, neglect syndrome

26

Primary visual cortex

- Brodmans = 17 = banks of alcarine sulcus

- primary visual cortex:

--> forms on the walls of calcarine fissue

-- initial processing from both eyes

--> distributes to association areas

27

Visual association area

- Brodmans 17, 18, 19

- visual association area receives visual information from area 17

- Motion, color, etc are analyzed

- LESION = visual agnosia, achromatopsia, akinetopsia

28

Primary auditory area

- brodmanns 41 = SUPERIOR temporal gyrus

- Granular cortex

29

Auditory association area

- Brodmans 42

- Superior temporal gyrus

- receives inputs from area 41

30

Wernicke's area

- Brodmanns 39, 22

- Superior temporal gyrus

- Dominant side, the mechanisms for formualtion of language

- LESION = wernicke's aphasia

31

define wernicke's aphasia

- Fluent, sensory, receptive

- PATIENT is ABLE to PRODUCE WRITTEN or SPOKEN WORDS but they string together words and phrases in an order that conveys LITTLE OR NOT MEANING

32

Limbic lobe

- Horseshoe-shape cortex surroudning the junction of diencephalon and each cerebral cortex

- drive related and emotional behavior functions

- Contents = cingulate gyrus (24), Parahippocampus gyrus (27,28), Uncus (34), and Hippocampal formation

33

define aphasia

loss of ability to understand or express speech, caused by brain damage

34

define agnosia

inability to interpret sensations and hence to recognize things, typically as a result of brain damage