Somatic Sensory Cortex Flashcards
بسم الله الرحمن الرحيم وبه نستعين
“فبما نقضهم ميثاقهم لعناهم وجعلنا قلوبهم قاسية”
Define Somatic sensory cortex ?
It is the part of Cerebral cortex responsible for smoatic sensory Functions
احساسات الجسد
Site of Somatosensory cortex ?
behind Central sulcus above Lateral Sulcus
In Post Central Gyrus in Parietal Lobe
Mention divisions and areas of Somatosensory cortex
S1: 3.2.1
s2:40
Sensory association area : 5-7 stero
Primary sensory cortex site ?
Post Central area 3-1-2
S1 Body representation?
Locality+ Spatial Orientation
Spatial orientation in s1 is crossed mean ?
The s1 in right cerebral hemishpere responsible for sensation of left body sensations and vice versa
Spatial Orientation in S1 is Inverted Mean ?
The sensation of Face are localized down in the s1 then the trunk then lower limb as you go up
Spatial Orientaion is changable ?
Mean cortical plasticity i.e the ability of the intact senory areas to take the place of the damadged sensory area making the intact one more sensitive
مهم جدااااااا
S1 spatial Orientaion or body represntation is Dispropotinate to actual size of the body areas
but ?
the More sensitive the area is the more size it occupies in S1
it is propotinate to ?
-Number of sensory Receptors
-Sensory Acuity
Body represenation spatial Orientaion or locality chracteristics mention /
C2ID يا سيد مينفعش كده ياسيد فين ازازة الببسي يا سيد @@ طحالب
Crossed
Changable
Inverted
Disproptrionate
Finger and Lips has Large sensory area at S1 why?
That is becasue they have a lot of receptors
and havd high sensory acuity
1-Anterior Columns of S1 Recive?
2-More posterior column receive?
3-More posterior ones ?
4-Most posterior ?
1-Impulses from propricoceptors of Muscles, tendons, joints
2-From slowly adapting Receptors as Ruffini end Organ
3-Deep pressure sensations
4-sensations of movments across skin and touch
Describe Laminar represntation of S1 ?
High degree Of Localization .
is divided into vertical Cloumns
Functions of Primary Sensory Cortex
Mention Function Of S1
What is the imp of S1 ?
Dorsal column sensation + 2
TV PROPR DS
Fine touch
Vibration
Proprioception
Deep pressure
Sterognosis
________________<2
Fast Pain
Fine degrees of Temperature diversity
Effect of Lesion of S1 ? Mention
Loss of sensations felt by S1
TV PROPR DS 2
Fine touch
Proprioception
Vibration
Deep pressure
Sterognosis
Fast pain
Fine degrees of temperature
If person lost Fine localiztion of snsatioan this measn
Lesion to s1
if person cannot detect the orientation of his body parts this means ?
Loss of Propcception and Damage to s1
If person cannto judge critical degrees of pressure
s1 lesion
If person cannto judge critical degrees of weight ?
loss deep pressure sensation + s1 damage
If person cannto judge critical degrees of temperature And SteroGnosis
Lesion to S1
In case of s1 lesion what happen to pain and temp sensation ?
Poorly affected why ?
Only fast pain lost and remain the whole slow pain
Only fine temperature sensation lost but u can still sense the wide range of different temperature
Crude touch and s1 lesion ?
It is intact as its recevied by thalamus
Sensations that remain intact in case of S1 lesion ?
1-Slow pain
2-Wide range of temp
3-Crude touch
Where is S2 located?
behind and below S1 represnting area 40
Body represntation in Area 40 ?
Body represntaion in S2 ?
Secondary somatosensory area represntation
خريطة واحد نايم
Face is Anterior
Trunk + L.L Posterior
What about Localiztion in s2?>
What about chracters of S2?
The localization is poorer than s1
S2 بتستقبل منـــــــــــــــين؟
s1
Visual Auditory imupuses
Bilateral Spinothalmic tracts+Bilateral Dorsal columns tracts
S2 بتستقبل منـــــــــــــــين؟
s1
Visual Auditory imupuses
Bilateral Spinothalmic tracts+Bilateral Dorsal columns tracts
S2 تبعت اشارات لمين ؟
1-S1 potentining function
2-Motor cortex
3-Sensory association cortical area for higher processing for sterognosis
4-Insula+ Amygdala + Hippocampus for Tactile learning and memory
Tactile Learning and Memory explain
learning by touch becasue sensation from s1 go to s2 then go to
Insula for consuouness emotions
Amygdala Anger and emtions
Hippocampus for Memory
and this helps learning by touch
Lesion to s2 leads to ?
Loss of Tactile learning and Manipulatio
Asterognosis Loss of Stereognosis
Site of Somatic sensory asscocation area
Postcentral Gyrus Behind S1
Representing areas 5,7
Sensory association area recieve from ?
-Collective function area
-S1
-S2
-Audiotry+ Visual Impulses
Thalmus (sensory Nuclei+ other areas of Thalamus ).
to make meaning of Sensory Stimulus
FUNCTION OF SENSORY ASSCOCIATION AREA
-Collective function area
-S1
-S2
-Audiotry+ Visual Impulses
Thalmus (sensory Nuclei+ other areas of Thalamus ).
to make meaning of Sensory Stimulus
List effect of lesion to Sensory association area
or area5,7
1-Asterognosis
2-Neglect syndrome
Negelect syndrome ,,, give definition
-Syndrome results from Lesion to SAA Area 5,7
Characterized by Partial Neglect or Inattention to Visual , auditory, tactile and propioceptive impulses senssations from the contralateral side of body only feeling the ipislateral side to lesion
1-Negelect sensations of The contralateral side to lesion
2-Neglect proprioception of contralateral side to lesion cannot know the site of body parts at space
3-Neglect motor funtions of contralateral side to lesion
4-Only get sensation and porpricepton and Motor function from Ipsilateral side to Lesion of SomatoSensory Association Area
Effect of Neglect syndrome ?
1-Negelect sensations of The contralateral side to lesion
2-Neglect proprioception of contralateral side to lesion cannot know the site of body parts at space
3-Neglect motor funtions of contralateral side to lesion
4-Amorphosynthesis detect ipsilateral side of objects to lesion
4-Only get sensation and porpricepton and Motor function from Ipsilateral side to Lesion of SomatoSensory Association Area
What is Thalamus ?
it is subcortical collection of Gray matter lateral to 3rd Ventricle
anatomic divison of thalamus ?
Ant and post
Medial and Lateral
Ventral Thalamic Nuclei
Physiological divison of Thalamus show
Specific thalamic Nuclei
Non Specfic Thalamic Nuceli
Define specific thalamic Nuceli ?
Pprojects impulses to specific areas of cortex
May be sesnory or motor specific
Describe Non Specific Thalamic Nuclei
Projects impulse non specifically to whole cortex
Receive impulse from Reticular Formation in brainstem
Theres is reticular activating system as pacemaker sends impulses to the non specific thalamic Nuceli to reach whole cortex non specifically
Illustrate Functions of Thalamus !
ssmcc mhb
2s m 2c mhb
-Tranmsit all sensations except olfaction to cerberal cortex
-Perception of protpathic crude sensation contralaterally by intralaminar and midline thalamic Nuclei
-Connects Cerbellum and Basal ganglia to Motor cortex
-Conscoussness how ? RAS activat RF projecting to non specific thalamic Nuclei to reach the whole cortex
-Produce alpah wave EEG
-Memory and Emotions as part of limibc system
-Higher intellectial functions due to connections with assosciation cortical areas
-Behavior and personality due connections with preferontal association Cortex
Trasmits all senastion to cerberal cortex what and are there excpetions ?
Thalamus
Yes except olfaction
Function of Intralaminar and Midline Nuclei mention
Sensation of crude touch contralaterally + Slow pain + wide temp
Thalamus motor function mention
Connects cerebellum and basal ganglia to motor cortex
How thalamus plays a role in conscoussness ?
by it non speiicifc thalamic Nuclei
The Reticular activating system pacemake activates reticular formation sending impulses to the thalamus non spercidi nuclei that sends it non specifically to whole Cortex feeling Consoicsenss radiating alpha wave in EEG
Why thalamus play a role in higher intellectual funtions ?
due to Connections with
Assoication cortical areas
Why thalamus plays a role in Behavior and personality ?
due to connections with prefrontal association areas
فذكر بالقرءان من يخاف وعيـــــــــــــــــــــــــــــد
الحمدلله رب السماوات رب الأرض رب العالمين
وله الكبرياء في السماوات والارض
وهو العزيز الحكيم
