Nervous System
Functions: Homeostasis Memory Senses Components: Brain, Spinal Cord, Nerves, receptors, ganglia, tracts Can be organized anatomically and physiologically
Overview of the Nervous System
Anatomically: Central: Brain Spinal Cord Peripheral: Nerves Receptors Ganglia Physiologically: Afferent (Sensory) receptors Efferent (Motor) somatic autonomic Sympathetic Parasympathetic
There are 2 types of cells in the Nervous System: 1)Neurons 2)Neuroglial cells
The Neuron
Dendrites incoming Cell Body integration Axon output Axon Terminal release of neurotransmitter A Typical Neuron Nodes of Ranvier
Neurons can be categorized by the number of processes and function
All or None Spatial Summation different all at once Temporal summation one many times in concession
The Biochemistry of the Synapse
Neuroglial Cells The Neuroglial Cells
Saltatory Conduction
Tay Sachs Multiple Sclerosis Gray matter White matter
Nervous System Terminology Gray Matter – mostly nerve cell bodies. White Matter – mostly myelinated axons. Nerve fiber – a single axon of a neuron. Tract – a bundle of axon ins the CNS. Ganglion – a cluster of nerve cell bodies in PNS. Nucleus – gray matter in CNS with common function. Nerve – a bundle of axon in the PNS.
Sulci (sulcus) – grooves on surface of cerebrum. 1) Sensory areas 2) Association areas 3) Motor areas Three kinds of cerebral functional area: Gyri (gyrus) – fold of brain tissue between sulci. Fissure - deep groove, separating hemispheres.