Functions of the Nervous System Sensory input – monitor changes occurring inside and outside the body  Changes = stimuli  Done by a sensory receptor (Ex.- Rods and cones of eye, olfactory neurons of nose, touch receptors in integument…)

Functions of the Nervous System  Integration  To process and interpret sensory input and decide if action is needed  Done in brain or spinal cord

Basic Tasks of the Nervous System Sensory Input: Monitor both external and internal environments. Integration: Process the information and often integrate it with stored information. Motor output: If necessary, signal effector organs to make an appropriate response.

Slide 7.17 Functional Properties of Nervous Tissue Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Irritability – ability to respond to stimuli  Conductivity – ability to transmit an impulse synapse.jpg#!oZZ2QQcurrentZZhttp%3A%2F%2Fmedia.photobucket.com%2Fimage%2Fsynaps e%2Fpink_deity%2FSynapse.jpg%3Fo%3D2

Slide 7.2 Structural Classification of the Nervous System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Central nervous system (CNS)  Brain  Spinal cord  Peripheral nervous system (PNS)  Nerves outside the brain and spinal cord

Central Nervous System (CNS) Slide 7.26 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  CNS develops from the embryonic neural tube  The neural tube becomes the brain and spinal cord  The opening of the neural tube becomes the ventricles  Four chambers within the brain  Filled with cerebrospinal fluid

Slide 7.44a Protection of the Central Nervous System Layers Layers Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings 1. Scalp and skin 2. Skull and vertebral column 3. Meninges Figure 7.16a

Slide 7.44b Protection of the Central Nervous System Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cerebrospinal fluid- CSF Produced by which cells?  Blood brain barrier Figure 7.16a

Slide 7.45a Meninges  Dura mater  Double-layered external covering  Periosteum – attached to surface of the skull  Meningeal layer – outer covering of the brain  Folds inward in several areas

Slide 7.45b Meninges Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Arachnoid layer  Middle layer  Web-like  Pia mater  Internal layer  Clings to the surface of the brain

Higher Brain function Vision Speech, memory, hearing Spatial Motor control-Posture & equilibrium Autonomic Functions: breathing, heartbeat, respiration, etc,

Regions of the Brain Slide 7.27 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cerebral hemispheres  Diencephalon  Brain stem  Cerebellum Figure 7.12

Cerebral Hemispheres (Cerebrum ) Slide 7.28a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Paired (left and right) superior parts of the brain  Include more than half of the brain mass Figure 7.13a

Language: aphasias: loss of language ability due to damage to specific areas of the brain Broca’s Area: speaking and forming words- damage = difficulty speaking, not understanding Wernicke’s area: understanding of words damage= “word salad”

 Basal nuclei – receive information from cerebral cortex  Regulates voluntary motor activities by modifying info sent to the motor cortex  Problems = ie unable to control muscles, spastic, jerky  Involved in Huntington’s and Parkinson’s Disease Crossover of Pyramids in Medulla : Each cerebral hemisphere controls voluntary movement in opposite side of the body

Diencephalon

Brain Stem

Traumatic Brain Injury National TBI Estimates Every year, at least 1.7 million TBIs occur either as an isolated injury or along with other injuries. TBI is a contributing factor to a third (30.5%) of all injury-related deaths in the United States. About 75% of TBIs that occur each year are concussions or other forms of mild TBI.

Did you know? yrs Each year, U.S. emergency departments (EDs) treat an estimated 173,285 sports- and recreation-related TBIs During the last decade, ED visits for sports- and recreation- related TBIs, including concussions, among children and adolescents increased by 60%. Overall, the activities associated with the greatest number of TBI-related ED visits included bicycling, football, playground activities, basketball, and soccer. National surveillance in 9 high school sports: TBI represents almost 9% of all injuries reported in the 9 sports Numbers and rates are highest in football (55,007; 0.47 per 1000 athlete exposures) and girl’s soccer (29,167; 0.36 per 1000 athlete exposures) A national survey of all sports- and recreation-related injuries among all ages demonstrates that 31% occurred in a sports facility and 20% in a school facility. 3

Slide 7.52 Spinal Cord Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Extends from the foramen magnum to the region of L 2  Below is the cauda equina (a collection of spinal nerves)  Enlargements occur in the cervical and lumbar regions Figure 7.18

Slide 7.53a Spinal Cord Anatomy Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Exterior white mater – conduction tracts Figure 7.19

Slide 7.53b Spinal Cord Anatomy Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Internal gray matter - mostly cell bodies  Dorsal (posterior) horns  Anterior (ventral) horns Figure 7.19

Slide 7.53c Spinal Cord Anatomy Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Central canal filled with cerebrospinal fluid- continuous with CFS in Brain Figure 7.19

Slide 7.54 Spinal Cord Anatomy Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Meninges  Nerves leave at the level of each vertebrae  Dorsal root- sensory neurons  Ventral root- contains motor neurons