Cerebral Cortex Cerebral hemispheres Gray white matter Gyri

Cerebral Cortex • Cerebral hemispheres • Gray & white matter • Gyri & sulci (in humans) ▫ Fissures �Longitudinal, central, lateral • Corpus callosum ▫ Connects the 2 hemis

Cerebral Cortex • 4 lobes of the brain 1. Frontal � PFC 2. Parietal 3. Occipital 4. Temporal

4 Lobes of the Brain 1. Frontal ▫ ▫ Motor function PFC � Complex cognitive functions 2. Parietal ▫ ▫ ▫ Somatosensory (touch) Perceiving location of body & objects Attention 3. Occipital ▫ Vision 4. Temporal ▫ Hearing & language

4 Lobes of the Brain

Cells of the Nervous System • Neurons • Glia

Cells of the Nervous System: Neurons • Cells specialized for the reception, conduction & transmission of electrochemical signals • Different classes based on shape/# of projections from cell body ▫ Multipolar �Most neurons are multipolar ▫ Unipolar ▫ Bipolar ▫ Interneurons

Neurons

Parts of the Neuron • Dendrites ▫ Receive input from other neurons • Cell body (soma) ▫ Energy center; contains the nucleus • Axon hillock ▫ Where the soma joins the axon • Axon ▫ Sends signal from the soma towards other neurons • Myelin sheath ▫ Insulation around the axon to increase the speed of the signal • Nodes of Ranvier ▫ Gaps between myelin sections • Terminal Buttons ▫ End of axon branches that release chemicals into the synapse

Parts of the Neuron • Synapse ▫ Gaps between terminal buttons sending neuron & dendrites of receiving neuron ▫ Where chemical signals are released of • Synaptic vesicles ▫ Packages inside the terminal buttons that contain ready-to-release neurotransmitters • Neurotransmitters ▫ Molecules that are released to transmit the chemical signal from one neuron to another

Neurons • Lipid bilayer: neuron cell membrane ▫ Channel proteins • Groups of nerve structures ▫ Mostly cell bodies: �In CNS: nuclei �In PNS: ganglia ▫ Mostly axons: �In CNS: tracts �In PNS: nerves

Cells of the Nervous System: Glia • Long ignored by neuroscience • Glia ≥ neurons • 4 main types 1. 2. 3. 4. Oligodendrocytes Schwann Cells Microglia Astrocytes

Cells of the Nervous System: Glia • Oligodendrocytes: ▫ Make up myelin sheaths that wrap around axons in the CNS to increase the speed of signal conduction ▫ 1 glia: multiple myelin • Schwann Cells: ▫ Similar function but in the PNS ▫ 1 glia: 1 myelin ▫ Can guide regeneration

Cells of the Nervous System: Glia • Microglia: ▫ Act in response to injury or disease; multiply and engulf cellular debris and trigger inflammatory responses • Astrocytes: ▫ Contact blood vessels and neuron cell bodies to allow the transfer of some chemicals