Neural Tube Develops into the central nervous system in embryos.
Ventricles Cavities in the brain filled with cerebrospinal fluid.
Cerebral Hemisphere Speech Memory Logical and emotional response Consciousness Interpretation of sensation Voluntary movement.
Parts of the Brain a)Gyri – elevated ridges of tissue. b)Sulci – shallow grooves that separate the gyri. c)Fissures – deeper grooves that separate large regions of the brain. d)Lobes – parietal, occipital, temporal, and frontal.
Lobes Parietal lobe – somatic sensory area (excluding special senses). Occipital lobe – visual Temporal lobe – auditory and olfactory Frontal lobe – primary motor area
Parts of the Brain e.Cerebral cortex – gray matter f.Cerebral white matter – fiber tracts (bundles of nerve fibers) g.Corpus callosum – connects the cerebral hemisphere h.Basal nuclei – small “islands” of gray matter buried deep within the white matter of the cerebral hemispheres.
Diencephalon or Interbrain a)Thalamus – relay station for sensory impulses passing upward to the sensory cortex. b)Hypothalamus – floor of diencephalons; regulation of body temperature, water balance, and metabolism; center of many drives and emotions. c)Epithalamus – pineal body; choroids plexus – capillaries within each ventricle that forms cerebrospinal fluid.
Dura Mater Periosteal layer – attached to inner surface of skull. Meningeal layer – outmost covering of brain extending to the spinal cord.
Arachnoid Mater Subarachnoid space – between arachnoid mater and pia mater Arachnoid villi – projections that protrude through the dura mater Absorbs cerebrospinal fluid
Pia Mater Clings tightly to the surface of the brain and spinal cord Delicate layer
Cerebrospinal Fluid Formed from blood by the choroid plexus Choroid plexus – cluster of capillaries hanging from the roof of each ventricles. Cushions the brain from trauma or blows Forms and drains at a constant rate – normal volume = 150 mL /half a cup
Circulation of CSF Two lateral ventricles, Third ventricle, Cerebral aqueduct of midbrain, Fourth ventricle, Some will flow down to the central canal of the spinal cord. Most will circulate in the subarachnoid space.
The Blood-Brain Barrier Composed of the least permeable capillaries. Prevents the following from entering the brain – nonessential ions and amino acids, metabolic waste (urea, toxins, proteins, most drugs) Does not prevent against – fats, respiratory gases, other fat-soluble molecules ( alcohol, nicotine, anesthetics)