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Neuron (Nerve Cell). Myelin Sheath Cell Body Nucleus Axon Carry messages away from the cell body to other neurons Axon Terminal Dendrites Carry messages to the cell body. Myelin Sheath. signal direction. Axon coated with insulation made of myelin cells (Fatty, protein substance)
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Neuron (Nerve Cell) • Myelin Sheath • Cell Body • Nucleus • Axon • Carry messages away from the cell body to other neurons • Axon Terminal • Dendrites • Carry messages to the cell body
Myelin Sheath signal direction • Axon coated with insulation made of myelin cells (Fatty, protein substance) • speeds electrical signal • 330 mph vs. 11 mph myelincoating • Multiple Sclerosis • immune system (T cells) attacks myelin coating • loss of signal
Types of neurons sensory neuron (from senses) interneuron (brain & spinal cord) motor neuron (to muscle)
Types of Neurons • Receptor Cells Receives information from a stimulus • For example - your finger gets hit by a hammer • Sensory Neurons (Monitor Change) • Carry the impulse to the spinal cord • Travels the length of the arm to the spinal cord • Interneuron (Process & Interpret) Impulse is transmitted to the brain and the motor neurons via synapses Travels to the brain to register pain and out to the finger • Motor neurons (Generate Response) • Sends the processed information back to finger • Carries impulse to the effector cells in the fingers, hand and arm
Simplest Nerve Circuit • Reflex, or automatic response • rapid response • automated • signal only goes to spinal cord • no higher level processing • advantage • essential actions • don’t need to think or make decisions about • blinking • balance • pupil dilation • startle http://www.youtube.com/watch?v=2Ko0Zuv4Z64
Synapse Junction between nerve cells • 1st cell releases chemical to trigger next cell (Neurotransmitter) • where drugs affect nervous system synapse
Nervous System • Two MAJOR divisions • Central Nervous System (CNS) • brain and spinal cord 2. Peripheral Nervous System • nerves • Ganglia • Collections of nerves • Two MINORdivisions • Somatic and autonomic
The Peripheral Nervous System Your brain and spinal cord are connected to the rest of your body by the peripheral nervous system. The PNS is made up of 12 pairs of nerves from your brain called cranial nerves, and 31 pairs from your spinal cord called spinal nerves. Spinal nerves are made up of bundles of sensory and motor neurons bound together by connective tissue. For this reason, a single spinal nerve can have impulses going to and from the brain at the same time. Some nerves contain only sensory neurons, and some contain only motor neurons, but most nerves contain both types of neurons. Somatic and Autonomic Systems The peripheral nervous system has two major divisions. The somatic system controls voluntary actions. It is made up of the cranial and spinal nerves that go from the central nervous system to your skeletal muscles. The autonomic system controls involuntary actions-those not under conscious control-such as your heart rate, breathing, digestion, and glandular functions. These two divisions, along with the central nervous system, make up your body's nervous system. Research Visit the Glencoe Science Web site at tx.science.glencoe.com for more information about the nervous system. Make a brochure outlining recent medical advances.
Acupuncture • Traditional Chinese medicine: • Balance Chi ( life force energy) • Points in body allow better flow of Chi • energy flow will re-balance. • Western practitioners • acupuncture points as places to stimulate nerves, & muscles. • boost the activity of your body's natural painkillers • increase blood flow.
Quick Practice • A biochemical compound (i.e. proteins) that readily combines with oxygen and distributes it throughout the human body is • urea • water • acetylcholine • hemoglobin The body cells of most multicellular animals are not in direct contact with the external environment. These cells are supplied with materials from the environment by • a central nervous system • hydrolytic enzymes • sense receptors • a circulatory system
Quick Practice • Which of the following is/are type(s) of neurons? A)sensory B)motor C)interneurons D)all of the above • Sensory nerve cells act as the decision-making cells to sum up all signals for certain stimuli. A)True B)False
Quick Practice • The peripheral nervous system includes mixed nerves that _________. • A)serve the muscular and skeletal system • B)serve the sympathetic system • C)serve the parasympathetic system • D)contain both sensory and motorfibers
Endocrine System: Through chemicals released into the bloodstream, this system regulates overall metabolism, homeostasis, growth, mood, & reproduction. Chemical signals called hormones are created in glands. (see naked person to the right) Works with the nervous system to accomplish regulation. Example: Fear + Adrenaline Chemical Regulation!
http://www.youtube.com/watch?v=NX7QNWEGcNIhttp://www.youtube.com/watch?v=NX7QNWEGcNIhttp://www.youtube.com/watch?v=NX7QNWEGcNIhttp://www.youtube.com/watch?v=NX7QNWEGcNI • Parkour • http://dsc.discovery.com/tv-shows/other-shows/videos/adrenaline-lab-jeff-wise-explains-adrenalines-power.htm • How Adrenaline works
Endocrine glands: “Ductless” glands. Produce & secrete chemicals into blood However, hormones will only affect specific cells with receptors Target tissue: Specific tissue (group of cells) that recognizes each type of hormone. Is either stimulated (start or speed up) or inhibited (stop or slow down).
Rate of secretion varies with the needs of the body Like when your hyperglycemic Endocrine & Nervous system teamwork Hypothalamus Feedback regulates glandular secretions: Negative Feedback Positive Feedback The Regulation of Hormone Secretion What’s happening in the loops? What are the hormones(chemical messengers) involved? Target cells? Are they released all the time? Every day at 1pm? Once a year? Does it vary?
Negative Feedback & Stability: Tends to keep a variable close to some value (set point). Ex: Blood glucose conc., or body temp. MUST MAINTAIN HOMEOSTASIS! Positive Feedback & Rapid Change The response intensifies the original change. i.e: Baby Cry Oxytocin Milk Production
“How Bad Is It Doc?” • Research an endocrine disorder for homework. (citations required) • Pick a gland • What is the normal function of this gland? • Hormone secreted • Target cell • Explain what happens when homeostasis fails? (for example, what over-secretion or under-secretion causes. List and briefly describe any disease names you may find) • What are the clinical symptoms of the disorder? • What treatment is currently available for sufferers? • Find at least 2 images of ppl infected, if possible • Be prepared to get into small groups and create a collaborative table • Gland Options • Pituitary • Hypothalamus • Thyroid • Parathyroid • Adrenal • Pancreas • Testis • Ovaries
Portfolio • To be completed over next 3 weeks • Today, Wednesday, Thursday, Friday your topic is the nervous and Endocrine systems • Homework will also include portfolio work • By Thursday (Class’ end) • Gather information covering all requirements per system • Continue multimedia formatting of evidence • By Friday (Class’ end) • I should be reviewing your multimedia evidence for accuracy and misconception • Finalize evidence of nervous and endocrine systems