PSYCHOLOGY 0505 LECTURE OBJECTIVES AND OUTLINE Spring 2014 LECTURE STRUCTURAL AND FUNCTIONAL ORGANIZATION OF THE NERVOUS SYSTEM Objectives Terms and concepts to learn Neuraxis imaginary midline that goes through the center of the body from head to tail has special terms that refer to given regions depending on where the neuraxis is placed within the body of a given creature can be on the entire body or just on the head anterior rostral front surface toward nose beak and posterior caudal back surface toward the tail dorsal where the back is like dorsal fin along spine of fish and ventral where the chest abdomen are lateral away from the middle toward the outside of the body and medial towards the middle toward the neuraxis and inside of the body most terms map in the body but in the brain it is a little different as humans are upright and not four legged creatures this changes the positioning of the neuraxis in the brain bends at a 90 degree angle when it gets to the brain if wanted to have a straight neuraxis we must point our nose straight to the sky to have it be like a cat aligned with the neuraxis of the rest of the body Ipsilateral and Contralateral identifies how brain controls a part of body or how information is moved from body to brain more about function then positioning ipsilateral stays on same side of the neuraxis ex left olfactory bulb in nose process sensory information on smell on left same side of the brain contralateral when sensory information crosses the neuraxis ex sensory information from the left hand goes to the right side of brain motor control is also crisscrossed across the body Four Types of Neural Planes Sections sagital plane splits the left side versus the right side is like a mid sagittal if the brain would be perfectly cut in the middle separates the sections frontal plane left to right on the brain horizontal plane parallel to the ground cut dorsal from ventral sections cross section typically used for something that is cylindrical in shape cut across two ends of the tube and look at the inside afferent and efferent neurons brain structures and functions nervous systems structures and functions central nervous system CNS peripheral nervous system PNS autonomic nervous system ANS somatic nervous system SNS sympathetic nervous system branch of ANS parasympathetic nervous system branch of ANS four brain lobes limbic system primary cortexes association cortexes ventricles help support weight of the brain lateral ventricles take up a lot of space one on each hemisphere that is separated by the corpus callosum in the middle of the brain dividing it vertically in tow meninges dura mater pia mater arachnoid membrane subarachnoid space spinal cord structures and functions cranial and spinal nerves cerebral cortex corpus callosum thalamus hypothalamus midbrain tectum tegmentum cerebellum pons medulla I PERIPHERAL NERVOUS SYSTEM somatic and autonomic nervous system can be differentiation from central as having cell bodies that are outside of bone and are not part of brain or spinal cord A Cranial and Spinal Nerves cranial nerves even the ones that originate in the brain are still thought of as somatic nervous system as at least half of them originate outside the brain 12 cranial nerves that have both afferent and efferent nerves and are located under chin under ventral surface of the brain all but 10 vagus nerve for internal organ innervation serve important functions in the head and neck region vagus nerve as vagabond or wandering nerve that leaves head and neck region to innervate the chest and abdominal cavity diaphragm for breathing heart stomach liver etc functions really are rather autonomic nervous system as we cannot directly control our own internal organs some have single pathways that are only afferent sensory or efferent motor and some have both afferent and efferent pathways in the same nerve spinal nerves are made up of 31 pairs of nerves one of a pair of each side of the spinal cord 8 cervial 12 thoracic B Afferent and Efferent Neuronal Pathways in both the somatic and autonomic nervous system correspond to types of neurons and types of neural pathways in that system afferent are input pathways from peripheral to the central is usual path for information sensory information that comes into the brain to tell the brain what is going on with the body efferent are output pathways from the central nervous system to the peripheral nervous system telling the body what type of motion to do etc E for exit like the brain sending info out of brain exiting brain to be a motor pathway and controlling the body in that way C Somatic and Autonomic Nervous Systems somatic nervous system derives from soma or body under voluntary control like muscles in arms and legs where you can initiate movement just by wanting to do something autonomic nervous system is autonomous or self governing where the system runs itself and you have no direct control over it cannot reduce your blood pressure with just your thoughts can still do stuff that will influence it indirectly like closing your eyes and breathe calmly and thus cause changes to come about still not direct control D Sympathetic and Parasympathetic Nervous Systems the efferent nerves of the autonomic nervous system break down to sympathetic and parasympathetic components sympathetic nervous system has circle cell body originating in the spinal cord and v shape nerve terminal at the ganglion a place where we have a lot of nerve synapse connect with one another this is motor control of various nervous systems sympathetic is what is triggered in a fight or flight response excited or terrified so that the system can respond in some way to an external stimuli this can be a good happy activation or something bad too both systems are always on the question is which one is operating more then the other the one that is operating more is aroused in state in a kind of see saw metaphor where one goes up as the other goes down and sometimes they balance awkwardly around the middle the shift happens very rapidly when sympathetic nervous system first activated pupils dilate to allow for more light into eye retina and allows for better vision allows you to access the threat that you are about to fight or flee from next your salivary glands are inhibited get dry mouth no reason to be eating right now when danger is around bronchi will dilate to allow more air into the lungs oxygenate the blood breath harder and faster heart