Nervous System Delanie Cyr Jacob Butcher JacklynJaronik Claudia Bishop
Nervous system: Central and Peripheral • The Nervous system is stream lined to send rapid signals from cell to cell to maintain homeostasis and coordinate body organs and functions.
Central and Peripheral Systems • There are two basic types of nervous systems: • CNS (Central Nervous System) • PNS (Peripheral Nervous System)
Central Nervous System • Consists of the brain and spinal cord • It coordinates information received from sensory receptors and initiates responses
Peripheral Nervous System • Contains a afferent division composed of sensory receptors and sensory neurons, and an efferent division composed of motor neurons.
Sensory Receptors and Motor Nerves • Sensory receptors detect changes in the environment and transmits this information along sensory or afferent nerves to the CNS • Motor nerves transmits impulses from the CNS to the PNS
Structure of Nervous Tissue • Located in the brain, spinal cord, ganglia, and nerves. • It is composed of two types of cells, Neurons and Neuroglia • Neurons conduct action potentials and are the structural and functional units of nervous tissue • Neuroglia are cells that support, protect, and furnish nutrients to neurons, and augment the speed of neuron transmission
Structure of a Neuron • Can be over 3 feet long (longest nerve in your body) • Three basic parts to a neuron: • Dendrites- receive information from receptors or other neurons and send it back out to the cell body • Cell Body-usually has a triangular or cone shaped area called the axon hillock • Axon- extends from the axon hillock, is the elongated fiber that extends from the cell body to the terminal endings and transmits the neural signal.
Structure of a Neuroglia Cell • Generally smaller and more abundant the neurons. • Six types of neuroglia cells, four located in the CNS, and two located in the PNS. • CNS: • Astrocytes • Oligodendrocytes • Microglia • Ependymal Cells • PNS: • Schwann Cells • Satellite Cells
Classification of a Neuron • Three classifications of a neuron based on their function: • Sensory(afferent)- changes the stimulation into an action potential or nervous impulse that travels along the axon to a spinal cord. • Interneuron- structurally a multipolar neuron and comprises about 90% of the neurons in the CNS. • Motor neuron (efferent)- takes the impulse out of the spinal cord via a spinal nerve to an effector.