W1 - Cerebral Cortex, Cerebral White Matter

Composition of the Brain

• R/L Cerebral Hemispheres (Cerebrum)

• Diencephalon

• Brainstem

• Cerebellum

Cerebrum Composition

• Cerebral Cortex = outer crust of cerebral gray matter, location of conscious mind

• Cerebral White Matter = neuron fiber tracts deep to the cerebral cortex

• Basal Nuclei (Basal Ganglia) = islands of gray matter buried within the white matter

• Limbic System = gray and white matter structures dispersed thruout the cerebrum

Gross Anatomical Features of the Brain

• gyri = folds that increase SA, numerous

• sulci = shallow grooves between the gyri

• fissure = deep grooves that sep larger portions of the cerebrum

Lobes of the Cerebral Hemisphere

• frontal

• parietal

• occipital

• temporal

Frontal Lobe

contains primary motor cortex- voluntary control of skeletal muscles

Parietal Lobe

contains primary somatosensory cortex- conscious perception of touch, pressure, pain, vibration, temp

Occipital Lobe

contains visual cortex- conscious perception of visual stimuli

Temporal Lobe

contains auditory cortex and olfactory cortex- conscious perception of auditory and olfactory stimuli

Fissures of the Brain (Sylvian fissure = Lateral Fissure/Sulcus)

Insula

located deep within the lateral fissure- involved in sensory processing, emotions and self awareness

Hemispheric Functionality

while both hems are involved in most functions, they are specialized

• LT = language, numerical and scientific skills

• RT = complex visual-spatial skills, communicate emotional significance to events and language, music perception

Pre/Post- Central Gyrus aka

primary motor/sensory cortex 

A lesion in the Somatosensory Area

causes contralateral loss of sensations, can perceive sensation but cannot tell the degree or origin

A lesion in the Primary Motor Area

contralateral paralysis

Special Sense Areas of the Cerebral Cortex

• Insula = Gustatory (taste)

• Occipital = Visual

• Temporal = Olfactory, Auditory

Special Cerebral Cortex Areas for Speech and Language

• Broca’s Area = speech muscles

• Wernicke’s Area = permits recognition of spoken and written language, create plan of speech

Types of Tracts within Cerebral White Matter

• association = confined to the same hem

• commissural = run between R/L hems

• projection = project to and from the cerebral cortex and form asc/desc tracts

Corpus Callosum

• important white matter commissural tract

• components: rostrum, genu, body, splenium