CNS Ch 12

Question 1

Primary brain vesicles : 4 weeks

Answer 1

Prosencephalon
Mesencephalon
Rhombenephalon
Cephalization

Question 2

Brain embryonic development

Answer 2

Prosenrphalon ( optic vesicles
Telencephalon : cerebral hemispheres
Diencephlon : epithalamus, thalamus, hypothalamus and retina
Mesencephalon / midbrain
Merenicephon- pond and cerebellum
Myelencephalon- medulla oblongata
Central cavity of neural tube - ventricles

Question 3

Brain directional terms and landmarks

Answer 3

Rostral : towards the forehead
Causal : towards the cord

Major part of brain: cerebrum, cerebellum and brain stem

Question 4

Longitudinal fissure

Answer 4

Separates the cerebral hemispheres
Guri are the folds and sulcus the grooves
Surface layer of gray matter called cortex

Deeper masses of gray mater are call nuclei
Bundles of axons ( white matter) are tracts

Question 5

Cranial meninges

Answer 5

Dura mater - outter most tough membrane
Separated from inner meninges like layer in some places, forms rural venous sinuses draining blood from brain

Supportive structure : fall cerebral, cerebellum and tentotoriun cerebellum no epidural space

Question 6

Cranial men cont.

arachnoid vs pia mater

Answer 6

Spider web like filamentous layer

A thin vascular layer adherent to contours of brain

Question 7

Meningitis

Answer 7

Inflammation of the meninges
Serious disease of infancy and childhood ( 3 m -2yrs )
Bacterial and virus invasion of the cns by way of nose and throat
( pia most likely to be affected )
Sings: fever, stiff neck, drowsiness and intense headache
Diagnose by examining the csf ( spinal tap)

Question 8

Ventricles vs cerebrospinal fluid

Answer 8

Internal chambers within the cns ( lateral, third and fourth ventricles )
Ventricles lined with pendymal cells and containing choroid plexus of capillaries that produce CSF

Clear plasma like liquid filled ventricles and canals and bathes external surfaces of brain and spinal cord

Rscsiea the 4th ventricle to surround the brain

Reabsored by arachnoid villi into dural venous sinuses

Question 9

Blood-brain and blood CSF barries

Answer 9

Blood brain barrier- tightly joined endothelium of brown capillaries ( brain tissue)
- all material pass thru cell not between them

Blood CSf Barrie- at choroid plexus is ependymal cells joined by tight junction

Circumventricular organs - in 3rd and 4th ventricles at breaks in the barrier where blood has direct access to brain
Allow monito of ph, glucose and osmolarity , possible route of infection ( HIV)

Question 10

Cerebrum : cross anatomy

Answer 10

Layer of Gray matter with extensive folds to increase surface area, divided into lobes and divide into 3 kinds of functional area : motor, sensory and association areas

Question 11

Cortex : motor control

Answer 11

Motor association area
Where planning of the voluntary movement occurs
Control of learned motor skills of a repetitious or patterned nature ( typing , playing instrument )
Coordination of movement
Sends activating impulses to primary motor cortex

Question 12

Correct motor control con

Answer 12

Primary motor cortext: ( precentral gurus)
Processs order from premotorr cortex then sends motor aid las to spinal cord pyramidal cells called upper motor nuerons
Corticospinal tract
Decussate at medulla

Mother homunculus :
Distorted map of the body alone the orexenrral gurus
Larger area require more motor unite for fine control ( hands , face lips and tongue )

Question 13

Cortex sensory area

Answer 13

Primary somewthric cortex : some static signals travel up gracile and cuneate fascicui and spunothalamic tracts of spinal cord

Somatosensory area is post central gurus

Sensory homunculus
Larger areas of the gurus related to more sensitive areas of body (fingertip , lips, tongue and genitalia ) areas with high # of receptors

Question 14

Cortex ; sensory areas

Answer 14

Somatosensory association cortex

Integration of sensory inputs from primary somatise sort cortex to produce an understanding of object being felt ( size and texture and it’s meaning )

Question 15

Sensory areas cont

Visual areas vs visual association

Answer 15

Primary visual cortex
Posterior tip of occipital lobe
Receives visual info from retinas

Visual association
Most of occipital lobe
Uses part visual experience to interpret visual stimuli

Question 16

Auditory areas

Answer 16

Primary auditory cortex : cochea
Puperior margin of temporal lobe
Interpreted sonic impulses from inner ear in term of pitch , loudness and location

Association areas ;
Perception of the sound stimulus we” hear”these sounds as speech , music , thunder scream etc

Question 17

Cortex : sensory areas

Answer 17

Primary olfactory: medial temp lobe , receives olfactory signals from nasal cavity via olfactory nerves

Olfactory association area : perception and recognition of odors

Gustatory( tastes )
Deep temp lobe insulat

Visceral sensory area : Insula, upset stomach , full bladder etc

Vestibular ( equilibrium )
Posterior insula
Awareness of balance , head position in space

Question 18

Language : includes reading, writing, speaking and understanding words

Answer 18

Wernicke’s area : permits recognition of spoken and written lanaguge and creates plan of speech

Broca’d area : generate motor program for larynx, tongue , cheeks and lips transmit that to primary motor cortex for action

Question 19

Multimodal association areas

Answer 19

Sensory receptors- primary sensory cortex- sensory association cortex - multimodal association cortex ( gives meaning to info we device , tie it to previous experience , stores memory if needed , decide what actions to take
-premotor Cortex- primary Cortex

Question 20

Cognition

Answer 20

Mental processes such as awareness, perception, thinking, knowledge and memory ( 75% of brain is multimodal where integration of sensory and motor information occurs

Eg. Functions of these areas are learned by observing what happens when they are damage

Prefrontal cortex- prob with personality ( inability to plan &execute appropriate behavior )

Partial lobe: contra lateral neglect syndrome

Temp lobe: agnosia ( inability to recognize objects ) prosopagnosia inability to recognize faces

Question 21

Accidentally lobotomy of phi was gage

Answer 21

Accidental destruction of ventromdedial region of both frontal lobe ( pre frontal cortex )

Personality change to irreverent, profane and fitful person

Neuroscientist believe planning, moral judgement and emotional control are functions of the prefrontal cortex

Question 22

Cerebral white matter

Answer 22

Most of volume of cerebrum ( myelinated. Glial cells )

Types of tracts :
Projection tracts : extend vertically between brains and spinal cord forming the internal capsule

Commusural tract : cross from one hemisphere to another

• corpus callousness is wide band of white for we tract
• anterior and posterior commisures are penciled lead size

Association tracts : connects lives and gyri within each hemisphere

Question 23

Basal nuclei

Answer 23

Masses of subcritical gray matter
Recieive I put from substantia nigra and motor cortex a d output to premotor and prefrontal corticosteroids
Inhibit antagonist or unnecessary movement

Question 24

Function of basal nuclei

Answer 24

Influence muscle movements
Tilde in cognition and emotion
Regulate intensity of slow or stereotyped movement
Filter out incorrect/I appropriate responses

Inhibit antagonistic /unnecessary movement

Question 25

Limbus system

Answer 25

Loop of cortical structures surrounding deep brain
Hippocampus : impotent In memory recall
Amygdala : important in emotional learning ( fear and reward condiontining)
Emotion n cognition
Interacts with prefrontal lobes
Reacts emotionally to things we consciously understand to be happening

Question 26

Diencephalon: thalamus

Answer 26

Consists of bilateral egg shaped nuclei deep in cerebral hemispheres that form suoerolatedal walls of 3rd ventricular

Revives nearly all sensory info on its ways to the cerebral cortex ( relay station)

Question 27

Thalamus function :

Answer 27

Fastest to cerebral cortex
Sorts edits and replays ascending input
Impulses from hypothalamus fro regulation of emotion and visceral function
Impulses from cerebellum and basal nuclei to help direct motor cortices,

Mediate sensation , motor activities and cortical arousal , learning and memory

Question 28

Hypothalamus:

Answer 28

Walls and floor of 3rd ventricle 
Functions : 
Harmony secretion and pituitary 
And control center 
Thermoregumation 
Food and water intake 
Sleep and circadian rhythms 
Memory ( mammillary bodies )
Emotional behavior 

( limbic system ( pleasure, fear range )

Question 29

Brain steam: midbrain

Answer 29

Cerebral aqueduct
Can 111 and 1v ( every movement)

Substantia nigra : sends inhibitory signals to basal nuclei and thalamus

( degeneration leads to tremors and Parkinson’s diseases )

Question 30

Brain stem : pone

Answer 30

Bulge in the brain stem , Rostral to the medulla 
Ascending sensory tracts 
Defending motor tract 
Relay center 
     Cerebrum to center you vellum 
      Up to thalamus

Question 31

Medulla oblongata

Answer 31

3 cm extension of spinal cord
Ascending and descend nerve tract
Nuclear cranial nerves ( 9-12)
Cardiac center - adjust rate/force or heat
Vasomotir center : adjust blood vessels diameter
Respiratory centers: control rate and depth of breathing
Reflex center for coughing, sneezing gagging swallowing, vomiting , salivation, sweating and movements of tongue n head

Question 32

Cerebellum

Answer 32

Right and left hemisphere connects vermis
Parallel surface folds called folia are gray matter
White matter ( arbor vitae ) visible in Sagittal section
Muscular coordination: motor control and balance, posture

Question 33

Spinal cord

Answer 33

Info highway between brain/bod
Extends thru vertebral canal from firemen mag to L1
Each pair of spinal nerves receives sensory info and issues motor signal to muscle gland ( mixed)
Component of cns and pns

Question 34

Anatomy of the spinal cord

Answer 34

Cylllindrr of nerves tissues within the center rental canal
31 pairs of spinal nerves
Cetvical, lumbar enlargements
Medullary cone: is tapered tip of spinal cord ( filum terminale)

Cauda equines : l2 to s5 nerve root resemble horse tail

Question 35

Meninges or the spinal cord

Answer 35

3 fibros layer enclosing spinal cord

Dura mater : tough collageneour membrane surrounded by epidural space filled with fat and blood vessels

Arachnoid: layer of simple squamous epithelium lining dura mater and lose mesh of fibers filled with CSf

Pia mater: delicate membrane adherent to spinal cord
Filium terminale and denticulate ligaments anchor the cord

Question 36

Cross sectional anatomy of spinal cord

Answer 36

Centra area of gray matter shaped like butterfly , surrounded by white matter in 3 columns
Gray matter - neuron cell bodies with myelin
White matter - myelinated axons

Question 37

Gray matter in spinal cord

Answer 37

Pair of dorsal or posterior horns
Foral root of spinal nerve is totally sensory fibers

Pair of central and Anterior horns

Connected by gray commissire punctured by ventral canal and continuous above with 4th ventricle

Question 38

White matter in spinal cord

Answer 38

White column- bundle of myelinated axons that carry singable up and down

Dorsal ( posterior ) volume , lateral volume and central ( anterior columns)

Each column filled with names tracts

Question 39

Spinal tracts

Answer 39

Ascending and deserving tray head up and down while decussation means that the fibers cross sides

Contra lateral means origin and destination are on opposite sides while ipsilatetl means on same side

Question 40

Ascending ( sensory ) pathways

Answer 40

Consist of 2 or 3 new irons 
First order neuron: 
 Conducts impulses from cantankerous receptors and proprioceptors 
Enters special cord through dorsal root 
Synapses with second order neuron 
  Immediately at level of entry or 
   Ascends and synapses in medulla 
    Decussates and then ascends

Question 41

Ascending pathways

Answer 41

Second order neuron
Interneurons
Cell body location in dorsal horn of spinal cord at level of entry of 1st order neuron or medullary nuclei
Axons extend to 3rd order neurons in thalamus or terminates in cerebellum

Third: interneurons
Cell body in thalamus
Axon extend to soma stows sort cortex
(No third order neuron In cerebellum)

Question 42

Descending pathways and tracts

Answer 42

Deliver efferent impulses from brain and spinal cord
Two groups
Direct pathways - pyramid tracts
Indirect pathways - all others

Question 43

Descending pathways tracts

Answer 43

Motor pathways invoices two neurons :
Upper motor neuron : pyramidal cells in primary motor cortext

Lower motor neurons
Central horn motor neurons
Inner are skeletal muscles

Question 44

Direct pyramidal pathways

Answer 44

Impulses from pyramidal neurons in precentral gyri pass through pyramidal corticospinal tract

Descend without say passing
Axons synapse with interneurons or central horn motor neurons
Direct pathways regulates fast snd fine ( skilled) movements