The Nervous System Kelsey and Chrissy

The Central Nervous System The CNS is the largest part of the nervous system. Fundamental role in the control of behavior.(2)

Anatomy of CNS Consists of brain and spinal cord. Spinal cord connected to brainstem and runs through spinal canal. Cranial Nerves Peripheral Nerves Cerebrospinal fluid surrounds brain and spinal cord; circulates in ventricles. Leptominenges-2 layers of tissue that covers the brain and spinal cord. Basic unit is neuron.(1)

The Peripheral Nervous System Carries information to and from the Central Nervous System.(3)

Anatomy of PNS Sensory Nervous Cells- carry to CNS Motor Nervous Cells- carry from CNS - Somatic- controls skeletal muscles and external sensory organs -Autonomic-controls involuntary muscles -Sympathetic- controls activities that increase energy expenditures. -Parasympathetic- controls activities that conserve energy expenditures. (3)

Anatomy of the Nerve Cell Contains nucleus 2 or more long fibers (dendrites) Impulses are carried along dendrites. In higher level nervous systems, there is only one fiber(axon.) Held together by connective tissues to form nerves.(4)

Types of Neurons Sensory-run from stimulants to the CNS. Interneuron- only in spinal cord and brain. Stimulated by signals from sensory and other interneurons. (also known as association neurons) Motor- Transmit impulses from the CNS to muscles and glands. Stimulated by interneurons or sensory neurons.(5)

Anatomy of Nerves Nerves are organs that make up PNS Allows Brain and Spinal Cord to communicate with tissues and organs Groups of Neurons organized into bundles called Fascicles The Perineurium (composed flattened cells basement membrane and collagen fibers) holds together each Fascicles(4)

Anatomy continued Inside fascicles nuerons and blood vessals are held in place by the endoneurium (loose connective tissue) The Epineurim (dense connective tissue) holds together the outer surface of the nerves Arteries and veins are between the Fascicles to supply the nuerons with nutrients and gases. (4)

Cranial Nerves There are 12 pairs of Cranial nerves, whose function is to carry motor or sensory information 1.Olfactory Nerve 2.Optic Nerve 3.Oculomotor Nerve 4.Trochlear Nerve 5.Trigeminal Nerve 6.AbducensNerve 7.Facial Nerve 8.Vestibulocochlear Nerve 9.Gassopharyngeal Nerve 10.Vagus Nerve 11.Spinal Accessory Nerve 12.Hypoglossal Nerve (6 and 7)

Spinal Nerves Part of PNS 31 pairs of Spinal Nerves - 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal (8)

Works Cited 1.emedicinehealth.com/anatomy_of_the_centeral_nervous_system/articl e_em.htm 2. sciencedaily.com/articles/C/centeral_nervous?system.htm 3.biology.about.com/od/organsystem/a/aa/061804a.htm 4.britannica.com/EBchecked/topic/410669/neuron 5. users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/Neurons.html daviddarling.info/encyclopedia/S/spinal_nerve.html