2 Section 1 The Nervous System Objectives:Describe the relationship between the central nervous system and the peripheral nervous system.Compare the somatic nervous system with the autonomic nervous system.List one function of each part of the brain.
3 Two Systems Within a System The nervous system acts as the body’s central command post.The two parts of the nervous system include:central nervous system (CNS)peripheral nervous system (PNS)
4 The Central Nervous System consists of the brain and spinal cordprocesses and responds to all messages coming from the peripheral nervous system (PNS)
5 The Peripheral Nervous System consists of all parts of the nervous system except for the brain and spinal cordconnects all parts of the body to the central nervous system (CNS) using specialized structures called nervesA nerve is a collection of axons bundled together with blood vessels and connective tissue.
6 The Peripheral Nervous System Messages about your environment travel through the nervous system along neurons.A neuron is a nerve cell that is specialized to transfer messages in the form of fast-moving electrical energy.These electrical messages are called impulses.
8 Neuron StructureCell body-large region in the center of a neuron that has a nucleus and organellesDendrites-short, branched extensions of the cell that receive information from other cellsAxons-elongated extensions of a neuron that carry impulses away from the cell body
9 Types of NeuronsSensory neurons-gather information about what is happening in and around your body and send to the CNS for processingMotor neurons-neurons that send impulses from the brain and spinal cord to other systemsDivided into two types of nerves:SomaticAutonomic
10 Somatic Nervous System Most neurons are under your conscious controlStimulate skeletal muscles to perform voluntary movements like writing, talking, smiling, and jumping.
11 Autonomic Nervous System These nerves do not need your conscious controlControls body functions that you don’t think about such as digestion and heart rateMain job is to keep the body’s functions in balance (homeostasis)2 divisions: sympathetic & parasympathetic
13 Central Nervous System The largest organ in the nervous system is the brain.It controls both involuntary and voluntary processes.3 Main Parts:CerebrumCerebellumMedulla
14 Brain FunctionsCerebrum – largest part of brain, controls voluntary muscles, thinking, learning, memory, and sensesCerebellum – coordinates muscle movement and balanceMedulla – top of brainstem, controls automatic things like breathing, heart beat, and involuntary muscles (digestion)
16 The Spinal CordMade of neurons and bundles of axons that pass impulses to and from the brain.The nerve fibers in your spinal cord allow your brain to communicate with your PNS.Surrounded by protective bones called vertebrae.
17 Section 2 Responding to the Environment Objectives:List four sensations that are detected by receptors in the skin.Describe how a feedback mechanism works.Describe how light relates to sight.Describe how the senses of hearing, taste, and smell work.
19 Sense of Touch A reflex is an immediate involuntary action. Touch is what you feel when sensory receptors in the skin are stimulated.Four sensations detected by receptors in the skin:vibrationpressurepainheatA reflex is an immediate involuntary action.
20 Feedback MechanismsA feedback mechanism is a cycle of events in which information from one step controls or affects a previous step.
21 Sense of SightSight is the sense that allows you to see the size, shape, motion, and color of objects around you.Photoreceptors are special neurons in your eyes that change light into electrical impulses.Two types: rods (black & white) & cones (color)
22 Sense of Hearing Sound is produced when something vibrates. Ears are organs specialized for hearing; each ear has an outer, middle, and inner portion.
23 Sense of TasteTaste is the sense that allows you to detect chemicals and distinguish flavors.Your tongue is covered with tiny bumps called papillae that contain taste buds.Taste cells in your taste buds react to four basic tastes: sweet, sour, salty & bitter
24 Sense of SmellReceptors for smell are located on olfactory cells in the upper part of your nasal cavity; they respond to chemical molecules in the air.Taste buds and olfactory cells work together to give you sensations of flavor.
25 Section 3 The Endocrine System Objectives:Explain why the endocrine system is important to the body.Identify five glands of the endocrine system, and describe what their hormones do.Describe how feedback mechanisms stop and start hormone release.Name two hormone imbalances.
26 The Endocrine Systemcontrols body functions by using chemicals that are made by the endocrine glandsExamples include:fluid balancegrowthdevelopmentA gland is a group of cells that make special chemicals for your body.
27 The Endocrine SystemA hormone is a chemical messenger made in one cell or tissue that causes a change in another cell or tissue in another part of the body.Hormones flow through the bloodstream to all parts of the body.
28 Major Glands of the Endocrine System Pituitary GlandAnterior and PosteriorPineal GlandHypothalamusThyroid GlandParathyroidThymusAdrenal GlandAdrenal CortexAdrenal MedullaPancreas (Pancreatic Islets)TestesOvaries
29 HypothalamusLocation: lies within the diencephalon, below the thalamus;Primary Hormones: No one specific hormone; called the “gate-keeper” regulating the release and inhibition of hormonesFunctions: “gate-keeper” role; regulates pituitaryMajor Disorders:
33 Pineal GlandLocation: Between the pons and sides of the thalamus; size of a peaPrimary Hormones: MelatoninFunctions: Regulates sleep patterns; mating patterns; migration patterns; day and night rhythmsMajor Disorders: Insomnia
37 Parathyroid Gland Location: 4 glands around the thyroid Primary Hormones: PTH (parathyroid hormone)Functions: Affects the bones and kidneys; maintain calcium levels in the bloodMajor Disorders: Osteoporosis; Hyper- and Hypo- parathyroidism
45 Pancreas Location: Around the stomach and small intestine Primary Hormones: Insulin and Glucagon (secreted by the pancreatic islets or the Islets of Langerhans)Functions: Digestion of enzymes; regulate blood-glucose levels; insulin uptakeMajor Disorders: Diabetes mellitus types I and II
47 Testes Location: Within the scrotum Primary Hormones: Testosterone; ICSHFunctions: Produce sperm and testosterone; primary and secondary sex characteristicsMajor Disorders: Testicular cancer; Germ-cell tumors
48 Ovaries Location: In the abdomen at the end of the fallopian tubes Primary Hormones: Estrogen, Progestins, EstradiolFunctions: Produce female gametes; ova and ovum; oocytes- immature gametesMajor Disorders: Ovarian Cancer;