The Nervous System The body's speedy electrochemical communication network -consists of all the nerve cells of the central and peripheral nervous systems Cns- The brain and spinal cord Pns- Sensory and motor neurons connected the cns to the rest of the body Types or neurons Sensory- carrying messages from the bodys tissues and sensory receptors to the spinal cord and brain Motor neurons- carrying outgoing instructions from the cns to the body's muscles(outgoing) Interneurons- present in the brain and spinal cord Communicate internally and process information between sensory inputs and motor outputs. Look at figure 2.5 diagram in the textbook, The functional divisions of the human nervous system Sympathetic- someone you can control (Touch something hot, you get it<, grab milk out of the fridge, etc tell your body what to do)butterflies, etc Automatic-things you can't control (getting nervous about a big game, etc.) The Peripheral nervous system Consists of two parts- Somatic ns- controls the body's skeletal muscles Autonomic-glands and muscles Sympathetic nervous system Parasympathetic ns Figure 2.6 The dual functions of the autonomic nervous system in the textbook The central nervous system The brain contains 86 billion neurons that cluster into work groups to form neural networks that givern reflexes Spinal cord- two-way highway connecting the pns and the brain Injury could cause the loss of sensation and voluntary movement Reflexes- simple automatic sensory feelings Figure 2.7 a simple reflex diagram in the textbook Figure 2.8 The endocrine system diagram in the textbook Endocrine system- slow chemical communication system Sets of glands that secrete hormones into the bloodstream Hormones- chemical messengers manufactured by the endocrine glands Travels through the bloodstream and affect other tissues The effects of endocrine messages last longer than those of neural messages Works with cns-maintain balance Manages response to stress, hard work, etc Adrenal glands- pair of glands that sit above the kidneys Secrete epinephrine (adrenaline) and norepinephrine (noradrenaline) that help arouse the body during stress Influence fight or flight response. Pituitary gland- Releases hormones and sends messages to other endocrine glands to release theor hormones, controlled by the hypothamus -grown hormones that control physical development Oxytocin that enables contractions during birth and orgasms Known as the master gland Retrive and remember 6 Why is it called the master gland? Relates to oxytocin release an it releases hormones that trigger other endocrine glands to secrete hormones which in turn influence our behaviour How are the nervous system and endocrine systems alike? And how do they differ The difference is the speed and flow of communication also both produce chemical molecules that act on the bodys receptors to influence our behavuour and emotions. The endocine system which secretes hormones into the bloodstream delivers its messages much more slowly than the speedy nervous system The Brain-Tools of discovery Older vrain sturctuers, the cerebal cortex thinking critically The human brain emergence of brain mapping helped reveal unknown brain areas and their actviiteies Electroecephalograph-(Eeg)- uses electrodes placed on the scalp to record waves of electrical activity sweeping across the brains surface Positron emission tomography (PET)- View of brain activity, depicts where a radioactive form of glucose goes while the brain performs a given task Tools for scanning the brainMRI- uses magnetic fields and radio waves to produce computer generated images of soft tissue Functional MRI-Technique that compares successful MRI scans Reveals blood flow and brain activity Older brain structures A less complex brain in primitive vertebrae's handles basic survival functions (Rats. Mammals etc.) A complex brain in lower mammals such as rodents, enables emotion and greater memory A more complex brain in advanced mammals sich as humans enables the ability to plan ahead4 The brainstem -Oldest and innermost brain region Responsible or automatic survival functions Medulla- base of the brainstem that controls heartbeat and breathing Pons- helps coordinate movement and controls sleep Figure 2.11 The brainstem and Thalamus in the textbooks The thalamus is attached to its top The body's wiring. Brainstem is a crossover point It comprises a peculiar sort of cross wiring to and from each side of the brain connects to one side of the body The thalamus- The brains sensory control center -located at the top of the brainstem Directs sensory messages to the cortex Transmits replies to the cerebellum and medulla Reticular formation: The nerve network running through the brain stem and thalamus -Acts as a filter that relays important information to other brain areas plays an important role in controlling arousal The cerebellum (little brain) situated at the rear of the brainstem Aids in judgment of time, disscrimination of sound and texture and emotional control -Coordinates voluntary movements and life sustaining functions -Helps process and store memories of things that cannot be consciously recalled Figure 2.13 The brains organ of agility in the textbook Pracice question in what brain region would damage likely too 1 disrupt your ability to skip rope- celleberem 2 disrupt your ability to hear and tase-thalamus 3 perhaps leave you in a coma- Medulla 4 cut off the very breath and heartbeat of life- Brainstem The Limbic System Neural system that lies between the oldest and newest brain areas-associated with emotions and drives -includes the amygdala, hypothalamus, and the hippocampus Figure 2.14 Diagram in the textbook The neural system that sits between your brains older parts and its cerebral hemispheres Parts of the limbic system Three key structures of this system and what they serve are the three listed below Amygala-Two lima bean sized neural clusters that enable agression and fear and are linked to emotion Hypothalamuslinked to emotion and reward, neural structure that is positioned below the thalamus, directs several maintenance activities -Helps govern the endocrine system via the pituitary gland The Hippocampus -Helps process Explicit memories of facts and events Figure 2.15 Brain structures and their functions in the textbook. Figure 2.16 The cortex and its basic subdivisions Cerebral cortex: Thin layer of interconnected neurons covering the cerebral hemispheres; the body’s ultimate control and information-processing center. It is the body’s ultimate control and information- processing center. It contains some 20 to 23 billion nerve cells and 300 trillion synaptic connections. Each hemisphere’s cortex is subdivided into four lobes, separated by deep folds. Frontal lobes: Portion of the cerebral cortex lying just behind the forehead Involved in speaking and muscle movements and in making plans and judgments Parietal lobes: Portion of the cerebral cortex lying at the top of the head and toward the rear Receives sensory input for touch and body position Occipital lobes: Portion of the cerebral cortex lying at the back of the head Includes areas that receive information from the visual fields Temporal lobes: Portion of the cerebral cortex lying roughly above the ears Includes areas that receive information from the ears. Functions of the cortex:Motor functions Electrically stimulating parts of the cortex can enable movements of body parts Motor cortex- Cerebral cortex area at the rear of the frontol lobes that control voluntary movement -Discovered by french and Hitzig -Foerster and Penfield mapped the motor cortex Discovered that body areas that required precise control occupied by the greatest amount of cortical space Figure 2.17-Left hemisphere tissue devoted to each body part In the motor cortex Functions of the cortex- sensory functions Somatosensory Cortex: cerebral cortex area at the front of the parietal lobes -Sensitivity of a body region is directly to the size of the somatosensory area that its devoted to it -Registers and processes body touch and movement sensations Visual cortex and auditory cortex Visual cortex -area in the occipital lobes located at the rear of the brain -receives input from the eyes Auditory cortex- -area in the temporal lobes located above the ears -receives info from the ears Figure 2.18 The brain in action As this person looks at a photo the fmri scan shows increased activity in the visual cortex in the occipital lobes -when the person stops looking the region instantly calms down Functions of the cortex: association areas -includes learning, thinking, remembering and speaking. ^ This is Found in all four lobes -prefrontal cortex in the frontal lobes enables judgment, planning, and processing of new memories. Damages could result in the inability to plan ahead Effect of damages to association areas Damage to the frontal lobes can alter a person's personality Damage to the parietal lobes can lead to loss in mathematical and spatial reasoning abillities Damage to the underside of the right temporal lobe can result in the inability to identify a person A blast from the past part 1 Phineas gage’s skull was kept as a medical record A metal bar went through his skull it didn’t go through the part that controls memory, etc but it did damage the personality part of his brain Think critically Using more than 10% of the human brain -electrically probing an association area leads to no observable response -association areas interrupt, intergrade and act on sensory information-link it with stored memory's Retrieve and remember 12 Why are association areas important? Association areas are in higher mental functions-interpreting, integrating, and action on information processed in other areas. The brains plasticity Brain damage effects caused by -severed neurons that usually don’t repair themselves Some brain functions that are forever linked to specific areas Brain attempts to self-repair via Reorganization of existing tissues Neurogenesis- formation of new neurons Figure 2.21 The split brain Corpus Callosum -large band of neural fibers connecting both brain hemispheres and carrying messages between them Split brain- the brain’s hemispheres are isolated by severing the fibers that connect them Figure 2.22 Our divided brain In an intact brain data receive hemisphere are quickly translated to the other side -in a brain with a severed corpus information sharing does not happen Right left differences in intact brains Each hemisphere performs distinct functions The left and right work together The left is good at making quick, exact interpretations of language The right excels in making inferences or reasoned conclusions Helps fine tune human speech Humans possess unified brains with specialized parts Consciousness Awareness of the self and the environment -Enables humans to exert voluntary control and communicate mental states with others -Helps focus one's attention -Conscious awareness is a product of coordinated brain wide activity Altered states of consciousness In addition to normal waking awareness consciousness comes to us in altered states These include meditating, day dreaming, sleeping, and drug induced hallucinating Methods of processing Sequential processing Processing one aspect of a problem at a time Used when one focuses attention on new or complex tasks Parallel processingProcessing many aspects of a problem simultaneously Brains natural mode of information processing for many functions Selective attention Focusing conscious awareness on a particular stimulus Inattentional blindness failure to see visible objects when one's attention is elsewhere ( seeing a squirrel run by while watching your dog Change blindness- failure to notice changes in the enviourment, Selective inattention -viewers who were attending to basketball tosses among the black shirted players failed to notice the umbrella-toting woman sauntering across the screen (watching a vdieo and not noticing something go by_-) Change blindness while a man in red provides directions to a construction worker two experimenters rudely pass between them carrying a door During this interruption the original worker switches shirts and you focus on wat your talking about and not on the change that happened.
