BIO 101 1nd Edition Lecture 6 Outline of Last Lecture II Big themes in Biology III Organization of Animal Bodies IV Different Animal Tissues V Animal Bodies VI Homeostasis VII Wet Cell Song VIII Essential Nutrients IX Illnesses caused by infection X Big Ideas Outline of Current Lecture XI Neurotransmitters XII Action Potential XIII Sensory Receptors XIV Hormones XV Endocrine System Current Lecture If you see a soccer ball coming and move to kick it what is happening in your nervous system consider that your action involves the three interconnected functions of the nervous system These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute First you see it Sensory input Understanding what to do with the information integration Then you kick it motor output Neuron Structure 3 parts Dendrites Bring information into the cell body input Cell Body Integration happens Axon Carries impulses away from the cell body output Controlling and coordinating the body What is a neuron and how do neurons communicate with one another o Neurons produce and transmit nerve impulses o Your body produces electricity Your body also conducts electricity Do electrical impulses jump the synaptic cleft o No Electricity does not jump there has to be a conductor Synapses Chemical Neurotransmitters are released by one cells and received by another The effect on the receiving neuron is to excite it to continue transmitting the signal but also it could inhibit it stop the signal Neurotransmitters in your life Dopamine lack of this causes Parkinson s disease Depression may be caused by low levels of serotonin or norepinephrine o SSRI s they are serotonin reinhibitors Caffeine reduces the effect of inhibitory neurotransmitters Alcohol and legal and illegal drugs also act as impact neurotransmitters A nerve signal involves a temporary reversal of the charge caused by ions flowing into and out of the cell membrane o Ions moved by plasma membrane transport proteins o Resting potentials are negative charges created when sodium Na is moved outside and potassium K inside the plasma membrane o Occur on inactive neurons o Signals are sent along neurons as moving waves of positive charge called action potentials Action Potential notice the type of elements needed for nerves to function properly How many neurons are in your brain o 100 Billion How much energy do neuron action potentials use in a resting human o What is myelin What does it do What is the relationship between action potentials and epilepsy How is epilepsy treated o WATCH ACTION POTENTIAL VIDEO ON POWERPOINT Why are myelin Sheaths Important Can you explain why multiple sclerosis is a disease of the nervous system that also involves the lymphatic system o A disease where your own body attacks you o Auto immune disease Sensory Perception Sensory organs absorb stimuli and turn them into action potentials that are processed by the brain Senses touch vision smell taste hearing balance and proprioception Types of sensory receptors Receptor Mechanorece Stimulus Example Physical force Balance hearing ptor Thermoreceptor Heat Temperature Chemoreceptor Dissolved chemicals Taste smell Photorecepto Light Vision Nociceptor Immune chemicals Pain r Sensory adaptation occurs when receptors adjust to changing stimuli Nociceptors are an exception pain sensation continues as long as stimulus is present Vision The retina contains 2 type of photoreceptors that react to different light stimuli o rods sensitive to low light intensity provide night vision black and white perception only o Cones Sensitive to bright light provide color vision 3 types red blue green Taste is a chemical sense Taste buds detect dissolved chemicals 4 basic taste sensations triggered by different chemicals o Sweet o Sour o Salty o Bitter o Umami savory Olfaction two options for detection of airborne chemicals in the nasal epithelium Nasolfaction detection of volatile airborne chemicals Vomerolfaction detection of non volatile chemicals o Often used in chemical communication between members of a species Hearing occurs when sound waves stimulate mechanoreceptors Visible aspects of sensory structures indicate importance of different senses Contrast the Nervous system with the endocrine system Nervous system o Electrical and chemical signals o Rapid response short duration of action o Signals stay in the system o Only target cells are affected Endocrine system o Chemical signal o Slower response long duration of action o Signals sent through circulatory system o Cells through the body may be affected Hormones messengers of the Endocrine System Steroid Hormones influence the cell by getting into the nucleus and changing chemical production Peptide Hormones peptide means protein influence the cell by binding to a receptor on the cell membrane Endocrine system important players Hypothalamus o Control center of the endocrine system Pituitary o Receives signals from the hypothalamus Parathyroid glands o Help regulate blood calcium levels Thyroid gland o Regulates oxygen consumption metabolism blood calcium levels and body temperature Pancreas o Regulates blood glucose levels through the secretion of hormones Adrenal glands o Regulate metabolism and responses to stress Fight or Flight system Testes and ovaries o Growth and development promote sexual characteristics and regulate reproduction The nervous and endocrine systems respond to feedback loops Without proper regulation by insulin cells cannot obtain enough glucose In a person with diabetes mellitus either the body fails to produce enough insulin as in type 1 or target cells do not respond normally to insulin as in type 2 Uncontrolled diabetes can cause damage to multiple organs and result in premature death