Cerebral Cortex

What is the highly folded outer surface of the brain?

cerebral cortex

Gyri

ridges

Sulci

sunken furrows

Fissures

deeper than sulci

Major lobes of the Cerebral Cortex:

frontal, parietal, occipital, temporal, and limbic

Gyri, Sulci, and fissurews separate what?

regions/lobes and help divide the brain into functional areas

What sulcus separates the frontal and parietal lobes?

central sulcus

What fissure separates the cerebral hemispheres?

longitudinal fissure

What fissure separates the temporal lobes from the frontal parietal lobes?

sylvian/lateral fissure

What sulcus separates the occipital and parietal lobes?

parieto-occipital sulcus

Precentral gyrus

anterior to central sulcus

Postcentral gyrus

posterior to central sulcus

Precentral sulcus

anterior to precentral gyrus

What are the 3 parallel gyri in the lateral frontal lobe?

superior, middle and inferior frontal gyri

What largest lobe in the brain?

frontal lobe

Functions of Frontal lobe:

reasoning, problem-solving, planning, and control

Precentral gyrus of the frontal lobe function ?

primary motor areas

Broca's area of the frontal lobe function?

expressive (motor) aspects of language

Prefrontal association areas of the frontal lobe functions?

emotion, motivation, personality, initiative, judgement, ability to concentrate, social inhibition

What is the most rostral part of the frontal lobe?

prefrontal cortex

Prefrontal cortex

part of frontal lobe responsible for thinking, planning, and language

Main functions of the prefrontal cortex?

- directing and maintain attention

- morality

- problem-solving

- adjusting behavior to social norms

- planning

- working memory

- deliberate decisions

Parietal lobe does the regulation of what?

somatosensory function

Parietal lobe will process what?

sensory information like touch, temp, pain, and position

What is the primary sensory area of the parietal lobe?

postcentral gyrus

What is the receptive (sensory) aspects of language of the parietal lobe?

Wernicke area

Wernicke area spans what two lobes?

parietal and temporal lobes

Posterior parietal cortex has the integration of what?

somatic and visual sensations for higher level interpretation of stimuli

The Posterior Parietal Cortex is interconnected with prefrontal cortex to do what?

filter out distractions and choose which stimuli to focus on

Posterior Parietal Cortex functions:

attention, awareness of self, awareness of extrapersonal space

Contralateral Neglect Syndrome

unaware of objects on opposite side of the body

Occipital lobe is responsible for what?

visual processing

Primary visual area of the occipital lobe is located on where?

either side of calcarine sulcus

Temporal lobe is involved in what actions?

auditory processing, memory, and language comprehension

The temporal and occipital lobe is separated by what?

occipital notch

Occipital Notch

extension of the parietoocipital sulcus

The Temporal Lobe is important in complex aspects of what?

learning, memory, and emotion

What is the primary auditory cortex of the occipital lobe?

basic auditory perception

What is the receptive (sensory) aspects of language of the occipital lobe?

Wernicke area

Limbic Lobe

ring of cortex on the medial surface of the brain that covers parts of the frontal, parietal, and temporal lobes

The Limbic lobe is associated with what?

emotions and memory

Limbic system includes what?

amygdala and hippocampus (both are parts of the temporal lobe)

Primary Area of the Cerebral Cortex

- receives information from peripheral receptors, with little interpretation of the meaning of that information

- sensory and motor areas

- lesion = clearly defined deficit

Association Area of the Cerebral Cortex

- receive input from primary areas and are involved in higher order processing, integrating, and interpreting information

- makes up majority of cortex

- lesions = complex presentation

Brodmann's classification

reference base for the localization of physiologic and pathologic processes

Brodmann's classification is most commonly used based on what?

cytoarchitectonics

Cytoarchitectonics

precise shapes and arrangements of neurons within a given part of the cortex

Primary Motor Cortex (PMC) Area 4 is where?

localized in the precentral gyrus of frontal lobes

Primary Motor Cortex (PMC) Area 4

control voluntary movements (force, direction, extent/distance, speed) of skeletal muscle on the opposite side(contralateral)

Primary Motor Cortex (PMC) Area 4 fibers will do descend to make up what?

corticospinal tract

Somatotopy

neurons clustered in functional areas representing the various target organs they influence/are influenced by

What is the graphic representation of somatotopy?

homonculus

Size of body parts in the homunculus represents what?

size of the neuron pool related to that body part

Motor Homonculus

relatively large amount of primary motor area devoted to face and hands

*large amount of cortex devoted to fine finger control and buccolingual movements

Upper motor neuron lesion signs

is lesion in the primary motor cortex

Lesion in the primary motor cortex presents what?

contralateral weakness/paralysis, hypertonia, and hyperreflexia

Premotor Cortex - Motor Association Areas

- selection of appropriate motor plans

- sensitive to behavior context, visual stimuli

Supplementary Motor Area - Motor Association Areas

- sequencing and coordination of movements

- sensitive to memory

Areas 3, 1, 2 of Primary Somatosensory Cortex is localized in?

postcentral gyrus of parietal lobes

Areas 3, 1, 2 of Primary Somatosensory Cortex the sensory afferents come from?

contralateral peripheral receptors and travel to the thalamus and then to the primary somatosensory cortex

Areas 3, 1, 2 of Primary Somatosensory Cortex detect what?

somatic sensations such as touch, propioception, nociception, and temperature

Sensory Homonculus size is correlated to what?

tactile acuity

Tactile acuity

ability to discriminate different sensory input

Does the hands have high or low tactile acuity?

high

The hand having HIGH tactile acuity means what?

many receptors with small receptive fields

Does the back have high or low tactile acuity?

low

The back having LOW tactile acuity means what?

fewer receptors (skin) with large receptive fields

Cortical plasticity

area of the cortex that represents any particular body area change over time in response to the input or lack of input from a particular area of the body

Somatosensory Association Area is located where?

posterior to primary somatosensory area

Somatosensory Association Area allows what?

interpretation of SIGNIFICANCE of sensory information

Majority of convergence of somatosensory information occurs where?

posterior parietal cortex

Functions of Somatosensory Association Area is?

- input from primary somatosensory areas

- visual system

- attention

- motivation

Visual Areas include what?

primary visual area and visual association area

Primary Visual area is located where?

on either side of calcarine sulcus

Primary visual area pathway

fibers from retina to thalamus to optic rediations to primary visual cortex

Visual association area is located where?

surrounds primary visual cortex on medial surface of occipital lobe

Visual association area does what?

gives meaning and interpretation to visual information

Auditory Areas include what?

primary auditory area and auditory association area

Primary auditory area is located where?

deep within lateral fissure on a strip of cortex in the superior temporal lobe

Primary auditory area pathway:

auditory info to cochlea to thalamus to projecting to primary auditory area

Auditory Association area is located where?

adjacent to primary auditory area

Auditory Association area allows what?

interpretation of sounds and meaning to them

Language areas include what?

Broca's area and Wernicke's area

Broca's Area is located where?

inferior frontal lobe, anterior to premotor association areas

Broca's area allows for what?

production of language

Broca's aphasia

inability to express

Wernicke's Area is located where?

spans the parietal and temporal lobes around the posterior lateral fissure and primary auditory area

Wernicke's Area allows for what?

comprehension of language

Wenicke's aphasia

inability to comprehend

Aphasia

language disorder

Damage to the brain in the Broca's or Wenicke's area can result in what?

inability to communicate properly