7/21/2014 Outline Nervous System - PNS and CNS I. II. Two Parts of the Nervous System Central Nervous System vs Peripheral Nervous System Peripheral Nervous System A. B. Brain and Spinal Cord III. Autonomic Nervous System Biol 105 Lecture Packet 10 Chapter 8 A. B. Central Nervous System (CNS) Autonomic Nervous Systems Somatic Nervous Systems Peripheral Nervous System (PNS) Parasympathetic Nervous Systems Sympathetic Nervous Systems Nervous tissue outside brain and spine Sense organs IV. Reflex Actions V. Central Nervous System A. B. C. Protection of CNS Spinal Cord Brain Figure 8.1 The nervous system Peripheral Nervous System Somatic nervous system part of PNS that controls voluntary functions Movement, controls skeletal muscles Autonomic nervous system part of PNS that control involuntary functions Controls cardiac and smooth muscles, and glands Autonomic Nervous System The PNS - Parasympathetic Parasympathetic rest and digest Parasympathetic Nervous System (Cranial and sacral regions of spinal cord) Autonomic Nervous System is divided into two systems: Parasympathetic division rest and digest Sympathetic division stimulatory stress responses (flight or fight responses) Constricts pupil salivation Decreases breathing rate Slows heart rate Widens blood vessels digestive activity digestive activity Synapse between neurons Contracts bladder muscles Constricts eye pupils Stimulate salivation Slows heart rate Constricts breathing Dilates blood vessels Stimulates digestion Constricts bladder Stimulates sex organs Stimulates defecation Figure 8.12 (1 of 2) 1
7/21/2014 PNS Sympathetic Nervous System Dilates pupil Decreases salivation breathing rate heart rate Narrows blood vessels Slows digestive activity Slows digestive activity Ganglion Stimulates secretion of epinephrine and norepinephrine Causes salt and water retention Relaxes bladder muscles Inhibits defecation Sympathetic Nervous System (Thoracic and lumbar Sympathetic fight or flight Reflex Actions regions of spinal cord) dilates eye pupils Inhibits salivation Accelerates heart rate Facilitates breathing Stimulates secretion of epinephrine and norepinephrine Stimulates release of free glucose Inhibits digestion Relaxes bladder Inhibits sex organs Sometime we need a really quick response reacting to a hot stove. We may not have time to send the message up to the brain to process the information. The spinal cord can process the information and send a response back to the motor nerves Figure 8.12 (2 of 2) Reflex Arc The Spinal Cord The pathway consisting of a sensory receptor, a sensory neuron, interneurons, a motor neuron and an effector (muscle) PLAY Animation Reflex Arcs This part of your PNS inhibits digestion Central Nervous System Protection of the CNS 1. Parasympathetic 2. Sympathetic 50% 50% Brain Spinal cord The CNS is protected by: 1. Bone (skull and vertebral column) 2. Meninges 3. Cerebrospinal fluid 4. Blood-Brain barrier Parasympathetic Sympathetic 2
7/21/2014 Meninges Meningitis Function of Cerebrospinal Fluid There are three layers of the meninges: 1. Dura mater outer layer 2. Arachnoid mater middle layer 3. Pia mater inner layer Meningitis - Inflammation of the meninges It is caused by many forms of bacteria, viruses and fungi It can lead to encephalitis, an inflammation of the brain. Functions 1. Shock absorption 2. Support the weight of the brain 3. Nourishment and waste removal Blood-brain barrier Protection of the CNS The innermost layer of the meninges is the: Permits certain substances to enter the brain, while inhibiting others from entering It inhibits many drugs that are not lipid soluble from reaching brain tissue The bones of the skull and vertebral column are hard cases that protect the brain and spinal cord. The meninges are three membranes that protect the brain and spinal cord. Ventricles of the brain 1. Pia mater 2. Dura mater 3. Arachnoid mater 33% 33% 33% Cerebrospinal fluid cushions Pia mater Dura mater Arachnoid mater the brain and spinal cord. Figure 8.2 Spinal Cord Spinal Cord Spinal cord extends from the base of the brain down the back transmits messages between the brain and the rest of the body If you look at a cross section of the spinal cord you will see white matter and grey matter There is cerebrospinal fluid in a central canal The white matter is myelinated axons Grey matter is mainly cell bodies and non-myelinated axons 3
7/21/2014 Spinal Cord Cerebral cortex amygdala White matter Gray matter Dorsal root Dorsal-root ganglion Ventral root Pair of spinal nerves Thalamus Cerebellum Brain stem midbrain, pons, medulla oblongata (Pineal gland and Pituitary gland is in the brain but it is part of the endocrine system) (a) View from front of body Figure 8.11a is the control center Contains sensory areas for skin senses, vision, hearing, olfaction Motor areas for voluntary control of m ovem ent Association areas for interpreting sensations, language, thinking, decision m aking, self-awareness, creativity, and storage of m em ories The cerebral cortex of the cerebrum is the thinking, conscious part of the brain Corpus callosum Allows left and right cerebral hem ispheres to com m unicate with one another Contains: Cerebral cortex Functions as the sensory area for touch, vision, hearing, and olfaction as well as association areas for interpreting sensations, language, thinking, decision making, self-awareness, creativity, and storing memories. Figure 8.3 (2 of 2) Cerebral cortex Cerebral cortex - The thin outer layer of the cerebrum is where most of the higher thinking and processing takes place. Contains sensory areas (post-central gyrus) Contains motor areas (pre-central gyrus) Prefrontal region of the cerebral cortex is responsible for decision making Folding increases surface area by about 3x Sulci are the folds or furrows Gyri are the ridges 4
7/21/2014 Corpus callosum cerebral cortex Beneath the cortex is white matter Corpus callosum band of white matter that connects the two cerebral hemispheres Split Brains The corpus callosum is a band of white matter that allows communication between the cerebral hemisperes. Split Brain Video Gray matter consists of interneurons, cell bodies, and unmyelinated axons that integrate information. Figure 8.4 important in long term memory important in remembering fear and responding to it. White matter consists of myelinated axons that allow communication over long distances. Figure 8.5 Memory Thalamus Thalamus Thalamus Processes sensory information (except smell) and relays it to other areas of brain Olfactory bulb Figure 8.8 5
7/21/2014 Cerebellum Functions of hypothalamus: 1. maintains homeostasis: Controls heart rate, blood pressure, breathing rate, body temperature 2. regulates drives including hunger, thirst, sex 3. controls the pituitary gland secretions Thalamus Processes all sensory inform ation (except olfaction) Relays inform ation to appropriate higher brain centers Cerebellum maintains balance and coordination, refines motor skills, new motor skills (playing piano) Controls heart rate, blood pressure, breathing rate, body tem perature, food intake Is a center for em otions Serves as m aster biological clock Figure 8.3 (2 of 2) Cerebellum Brain Stem Contains: Medulla oblongata Midbrain Pons Cerebellum Coordinates sensory motor voluntary movement Stores memory of learned motor patterns Brain Stem Medulla oblongata Medulla oblongata controls many vital involuntary functions including breathing, heartbeat and blood pressure Where the crossing over point is for many neural tracks Figure 8.3 (1 of 2) Brain Stem - Pons Function of the pons: Assists the medulla oblongata to control involuntary breathing Relays messages between the spinal cord and the cerebellum with the cerebrum, thalamus, and hypothalmus Brain Stem - Midbrain Functions of Midbrain Important in voluntary muscle control Relay station for auditory and visual information Relays information between the cerebellum or spinal cord and the cerebrum Controls eye movement 6
7/21/2014 Glands Pituitary gland and pineal glands are part of the brain but will be covered in the endocrine system Brainstem Midbrain Relays information between the cerebellum or spinal cord and the cerebrum Integrates sensory input Pons A bridge between higher and lower brain centers Medulla oblongata Contains autonomic centers for heart rate and digestive activities Relays sensory information to thalamus Figure 8.3 (1 of 2) What region of the brain is the region where most of the higher thinking and processing takes place What region of the brain is the region important in long term memory What region of the brain regulates drives including hunger, maintains homeostasis, controls the pituitary gland 1. 2. 3. Cerebral cortex 4. 25% 25% 25% 25% 1. 2. 3. Cerebral cortex 4. 25% 25% 25% 25% 1. 2. 3. Cerebral cortex 4. 25% 25% 25% 25% Cerebral cortex Cerebral cortex Cerebral cortex What region of the brain is important in remembering fear and responding to it. 1. 2. 3. Cerebral cortex 4. 25% 25% 25% 25% Important Concepts What are the somatic nervous system and autonomic nervous system, what do they control? What are reflex actions? What are the Parasympathetic division and the Sympathetic division what specifically do they control (increase heart rate, etc) Important Concepts What protects the CNS What are the three layers of the meninges, be able to describe them and their location (which is the inner, middle or outer layer. What is meningitis, what is the cause, what is encephalitis What are the functions of cerebrospinal fluid Cerebral cortex What is the function of the blood-brain barriers, what does it allow to pass? 7
7/21/2014 Important Concepts Major regions of the brain and their functions: (including the cerebral cortex, hippocampus, and amygdala),, Thalamus, Cerebellum, Brain stem (including the midbrain, pons, and medulla oblongata) What parts of the brain are in the cerebrum and in the brain stem What is the corpus callosum and what is its function? Important Concepts What are split brains and how does that effect a person Where are the primary motor and somatosensory areas of the cortex How are body parts represented on the cortex Definitions Long term memory, somatic nervous system, autonomic nervous system, voluntary, involuntary, reflex arc, constrict, dilate, inhibits, accelerates, facilitates, stimulates, relaxes, white matter, grey matter, prefrontal region, 8