Do Now pg 81 1. What is the fight or flight response? 2. Give an example of when this response would kick in.
Autonomic Nervous System The portion of the PNS that functions independently (autonomously) and continuously without conscious effort. Regulates the actions of smooth muscles, cardiac muscles, glands, heart rate, blood pressure, breathing rate, body temperature, and other mechanisms of homeostasis
2 Divisions
Sympathetic Division Prepares the body for energy-expending, stressful, or emergency situations, as part of the fight or flight response.
Parasympathetic Division Most active under ordinary, restful conditions. Counterbalances the effects of the sympathetic division and restores the body to a resting state following a stressful experience.
Preganglionic Fibers: The axons of neurons leaving the CNS, which synapse with one or more neurons whose cell bodies are housed within an autonomic ganglion. Postganglionic Fiber: The axon of the second neuron that extends to a visceral effector.
Cholinergic Fibers: preganglionic fibers of the sympathetic and parasympathetic divisions that all secrete acetylcholine Adrenergic Fibers: sympathetic postganglionic neurons that secrete norepinephrine
Fight or Flight Response How does the man get out of the way of the car? What does the adrenal gland release? What does epinephrine do to digestion? Is it possible for your body to respond in many ways due to 1 signal?
Both divisions of the nervous system PARASYMPATHETIC NERVOUS SYSTEM SYMPATHETIC NERVOUS SYSTEM Function Counterbalance; restores body to state of calm Body speeds up, becomes more alert. Functions not critical to survival shut down Originates in Spinal cord, medulla Spinal cord, thoracic and lumbar spinal cord Activates response of Rest and Digest Fight or flight Neuron Pathways Longer pathways, slower system Very short neurons, faster system General Body Response Controls the body s response while at rest Controls the body s response during perceive threat Cardiovascular system (heart rate) Decreases heart rate Increases contraction, heart rate Pulmonary System (lungs) Bronchial tubes constrict Bronchial Tubes dilate Musculoskeletal System Muscles contract Muscles relax Pupils Constrict Dilate Gastrointestinal System Increases stomach movement and Decreases stomach movement and secretions secretions Salivary Glands Saliva production decreases Saliva production increases Adrenal Gland No involvement Releases adrenaline Glycogen to Glucose Conversion No involvement Increases; converts glycogen to glucose for muscle energy Urinary Response Increase urinary output Decrease in urinary output
Look back at your notes and textbook chapter 9 to help you answer the following questions. What does visceral mean? Which divisions of the nervous system are responsible for controlling visceral activities? Compare the sensory and motor nervous systems in regards to their functions and their use of efferent and afferent nerves. Describe the difference between the somatic sensory division and the somatic motor division of the nervous system.
Questions What are some symptoms of dysautonomia? When an individual suffers from orthostatic intolerance, what part of the autonomic nervous system is not functioning properly? What are reflexes? Is the sympathetic nervous system involved with reflexes? Explain. Autonomic Nerve Disorders: Read the text and then answer the questions below. Autonomic nerve disorders (dysautonomia) refer to disorders of autonomic nervous system (ANS) function. Dysautonomia is a general term used to describe a breakdown or abnormal function of the ANS. The autonomic nervous system controls much of your involuntary functions. Symptoms are wide-ranging and can include problems with the regulation of heart rate, blood pressure, body temperature, perspiration, and bowel and bladder functions. Other symptoms include fatigue, lightheadedness, feeling faint or passing out (syncope), weakness, and cognitive impairment. Orthostatic intolerance refers to impairment in the body's ability to handle gravity. When a person stands, blood pools in the abdomen and legs. Normally, the autonomic nervous system will compensate by constricting blood vessels and pushing the blood to the brain. When autonomic pathways are damaged, these reflexes, termed baroreflexes, do not function adequately. As a result, the person becomes dizzy, light-headed, and may faint.