Lecture 2 GROSS ANATOMY OF THE CENTRAL NERVOUS SYSTEM

Question 1

Cellular Organization of the Brain

Answer 1

Five layers of cells
comprise the cortex

Question 2

Brodmann’s areas is devided

Answer 2

Brain is divided into around
50 regions
* Each area is referred to by a
number
* Divisions based on
cytoarchitecture

Question 3

Brodmann’s Areas delineated by

Answer 3

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

Question 4

Central Nervous System (CNS)

Answer 4

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

Question 5

Peripheral Nervous System (PNS

Answer 5

Nervous system not including CNS
* What else is left?
* Motor ( efferent) and sensory ( affarent) nerves from
periphery
*  Cranial and spinal nerves

Question 6

Major Division of the Brain

Answer 6

Cerebrum or cerebral cortex – Telencephalon
* Diencephalon
* Cerebellum
* Brainstem

Question 7

Cerebral Hemispheres

Answer 7

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 . . .?

Question 8

Cerebral dominance:

Answer 8

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.

Question 9

Cerebral Hemispheres:
Contralateral Sensorimotor Control

Answer 9

Cerebral hemispheres have contralateral sensory and
motor control of the body

Question 10

Lobes of the Brain

Answer 10

Four primary lobes: named for cranial bone
overlying cortex
* Frontal
* Parietal
* Temporal
* Occipital

• Secondary area:
• Insular: beneath lateral sulcus
  Lobes of the Brain

Question 11

Demarcation of Lobes

Answer 11

Arbitrary
* Variable locations between brains
* Based on location of gyri and sulci
* ROUGH FRAME OF REFERENCE

Question 12

Central sulcus (aka _________________)
* Marks boundary between ______ and _______ lobes
* Separates primary motor cortex (______________ ) from
primary sensory cortex (_______________)

Answer 12

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___________)

Question 13

Lateral fissure (aka _____________)
* anteriorly, marks boundary between _______ and
__________ lobes; posteriorly, marks boundary
between __________ and ________ lobes

Answer 13

Lateral fissure (aka ___Sylvian fussure__________)
* anteriorly, marks boundary between _frontal______ and
____Temporal______ lobes; posteriorly, marks boundary
between ____temporal______ and __parietla______ lobes

Question 14

Parieto-occipital sulcus
* Separates

Answer 14

Separates ____parietal______ lobe from ____occipital______ lobe

Question 15

Preoccipital notch

Answer 15

Demarcates temporal lobe from occipital lobe

Question 16

The Frontal Lobe
Motor functions

Answer 16

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

Question 17

body parts scaled
to motor area in brain

Answer 17

Motor homunculus

Question 18

The Frontal Lobe
* Cognitive functions

Answer 18

Prefrontal cortex (Brodmann’s areas 8, 9, 10)
* Contribute to personality & mood
* Regulate cognitive function

Question 19

The Frontal Lobe
Cognitive & Motor functions

Answer 19

Superior frontal gyrus
* Middle frontal gyrus
* Inferior frontal gyrus

Question 20

Inferior frontal gyrus

Answer 20

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)

Question 21

The Parietal Lobe
* Functions

Answer 21

Spatial orientation
* cross-modality integration
* Memory
* cognition
* perceptual interpretation and
elaboration of somatic sensation
* SOMATOSENSORY perception
(homunculus)

Question 22

The Parietal Lobe
* Post central gyrus

Answer 22

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)

Question 23

The Occipital Lobe

Answer 23

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

Question 24

The Temporal Lobe

Answer 24

___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

Question 25

Gray matter

Answer 25

neuronal cell bodies

Question 26

White matter:

Answer 26

bundles of axons in myelin sheath
* Account for all interhemispheric and intrahemispheric
communication
* Three types:
* Commissural
* Association
* Projection

Question 27

Nerve Cells

Answer 27

Gray matter: Cell bodies
* White matter: Axons