Brain Notes

BRAIN Four main parts: Cerebrum – largest portion Diencephalon –superior to brain stem Thalamus Hypothalmus

Brain stem Medulla oblongata Pons Midbrain Cerebellum – “little brain”

CEREBRUM Cortex – dark outer area consists of gray matter; contains cell bodies of 75% of all neurons in the nervous system Gyri (gyrus)– convolutions (bumps) Sulci (sulcus)– grooves Fissures – deeper grooves

Longitudinal fissure – separates brain into Right and left cerebral hemispheres Corpus callosum – connects both hemispheres

Cerebrum is divided into lobes: Frontal - forehead Temporal – above ears Parietal – top sides Occipital – back Lateral fissure divides temporal lobe from frontal & parietal lobes

Central sulcus divides frontal & parietal lobes No distinct boundary between parietal & occipital lobes Transverse fissure – separates cerebrum & cerebellum

White matter of brain lies under cortex and makes up bulk of cerebrum Contain tracts (nerve fibers within the CNS) inside gray matter

Functional Areas of Frontal Lobe Primary motor cortex In front of central sulcus in precentral gyrus Controls voluntary actions of specific muscles or groups of muscles on the opposite side of body

Broca’s area – coordinates muscle movements for speech Association areas – concerned with more complex integrative functions, such as memory, emotions, reasoning, will, judgment and intelligence

Language comprehension

Functional Areas of Parietal Lobe Primary somatosensory cortex Behind central sulcus in postcentral gyrus Receives impulses for touch, proprioception, pain, & temperature

Functional Areas of Occipital Lobe Visual area - vision Visual recognition

Functional Areas of Temporal Lobe Olfactory area – smell Auditory area - hearing