Lecture 2 GROSS ANATOMY OF THE CENTRAL NERVOUS SYSTEM Flashcards
Cellular Organization of the Brain
Five layers of cells
comprise the cortex
Brodmann’s areas is devided
Brain is divided into around
50 regions
* Each area is referred to by a
number
* Divisions based on
cytoarchitecture
Brodmann’s Areas delineated by
Brodmann’s areas (delineated by cytoarchitecture
) correspond to functional
differences observed between certain areas of the
brain
* Lesions studies observing relationship between
structure and function following damage
* Paul Broca
* Carl Wernicke
Central Nervous System (CNS)
Mediates all communication in the body
* NO direct communication between any two body
parts
* Mediation may be volitional or reflexive
* Consists of __Brain___________ and __Spinal cord_____________
* Protected by bony shell, three membranous coverings
(called _______Miniges_________), and cerebrospinal fluid
Peripheral Nervous System (PNS
Nervous system not including CNS
* What else is left?
* Motor ( efferent) and sensory ( affarent) nerves from
periphery
* Cranial and spinal nerves
Major Division of the Brain
Cerebrum or cerebral cortex – Telencephalon
* Diencephalon
* Cerebellum
* Brainstem
Cerebral Hemispheres
Part of Telencephalon
* Cerebrum consists of two cerebral hemispheres:
Separated by longitudinal fissure (aka ______Cerebral fissure_________)
* Largest part of brain
* 3.5mm thick layer of neurons: convoluted surface =
cerebral cortex
* Convolutions form ridges (a.k.a. Gyrus)
and valleys (a.k.a. sulci )
* Convoluted surface of cortex allows for . . .?
Cerebral dominance:
Hemispheres have specialized
function
Left Hemisphere
Language, speech, verbal memory, logic, science and math, writing, list
Right Hemisphere
Pragmatics skills, visual concept, spatial awareness, music, emotions, creativity, and imagination.
Cerebral Hemispheres:
Contralateral Sensorimotor Control
Cerebral hemispheres have contralateral sensory and
motor control of the body
Lobes of the Brain
Four primary lobes: named for cranial bone
overlying cortex
* Frontal
* Parietal
* Temporal
* Occipital
- Secondary area:
- Insular: beneath lateral sulcus
Lobes of the Brain
Demarcation of Lobes
Arbitrary
* Variable locations between brains
* Based on location of gyri and sulci
* ROUGH FRAME OF REFERENCE
Central sulcus (aka _________________)
* Marks boundary between ______ and _______ lobes
* Separates primary motor cortex (______________ ) from
primary sensory cortex (_______________)
Central sulcus (aka ___Fissure of Rolando______________)
* Marks boundary between __frontal____ and ___parietal____ lobes
* Separates primary motor cortex (____procentral gyrus__________ ) from
primary sensory cortex (____postcentral gyrus___________)
Lateral fissure (aka _____________)
* anteriorly, marks boundary between _______ and
__________ lobes; posteriorly, marks boundary
between __________ and ________ lobes
Lateral fissure (aka ___Sylvian fussure__________)
* anteriorly, marks boundary between _frontal______ and
____Temporal______ lobes; posteriorly, marks boundary
between ____temporal______ and __parietla______ lobes
Parieto-occipital sulcus
* Separates
Separates ____parietal______ lobe from ____occipital______ lobe
Preoccipital notch
Demarcates temporal lobe from occipital lobe
The Frontal Lobe
Motor functions
Motor functions
* Precentral gyrus (Brodmann’s area 4)
* ____Primary Motor Cortex_______________
* Homunculus (representation of human body)
* Premotor cortex (Brodmann’s area 6)
* Regulates responsiveness of the primary motor cortex, specifically for
complex and skilled movements
body parts scaled
to motor area in brain
Motor homunculus
The Frontal Lobe
* Cognitive functions
Prefrontal cortex (Brodmann’s areas 8, 9, 10)
* Contribute to personality & mood
* Regulate cognitive function
The Frontal Lobe
Cognitive & Motor functions
Superior frontal gyrus
* Middle frontal gyrus
* Inferior frontal gyrus
Inferior frontal gyrus
In dominant hemispheres, constitutes __Broca’s area___________
(Brodmann’s areas 45__and __44)
* Located immediately anterior to primary motor areas
controlling jaw, lip, tongue, and vocal fold movement –
* Why is this important?
* Motor function: Plans and organizes speech movement
* Cognitive function: Processing structure of language
(phonology, syntax)
The Parietal Lobe
* Functions
Spatial orientation
* cross-modality integration
* Memory
* cognition
* perceptual interpretation and
elaboration of somatic sensation
* SOMATOSENSORY perception
(homunculus)
The Parietal Lobe
* Post central gyrus
Post central gyrus (Brodmann’s area 3, 1, 2)
* ____Primary Somatosensory cortex________________: All modalities of bodily
experienced (somatic) sensation are perceived
* How do we recognize sensations?
* Sensations recognized in awareness in the parietal sensory
association cortex (Brodmann’s areas 5, 7)
The Occipital Lobe
Primary visual cortex
(Brodmann’s area 17)
* Receives input from visual fields
* Association visual cortex
(Brodmann’s areas 18, 19)
* elaboration, recognition &
appreciation of visual
information
The Temporal Lobe
___Heschl’s gyri__________ form
Primary Auditory Cortex
(Brodmann’s 41 &42)
* First/Superior temporal
gyrus:
* Contains Wernicke’s area
(Brodmann’s 22)
* ‘auditory verbal comprehension’
* Dominant hemisphere
Gray matter
neuronal cell bodies
White matter:
bundles of axons in myelin sheath
* Account for all interhemispheric and intrahemispheric
communication
* Three types:
* Commissural
* Association
* Projection
Nerve Cells
Gray matter: Cell bodies
* White matter: Axons
