Chapter 5 (pg. 137-151) 1. Distinguish between neurons and nerves. What are the different types of neurons and what are their specific functions?Neurons: Single cells in the nervous system that are specialized for carrying information rapidly from one place to another and/ or integrating information from various sources. Nerve: A large bundle containing the axons of many neurons within the peripheral nervous system. Nerves connect the central nervous system to the body’s sensory organs, muscles, and glands. Central Nervous System: The brain and spinal cord. Extensions from the central nervous system, called nerves, make up the peripheral nervous system. Peripheral Nervous System: The entire set of cranial and spinal nerves that connect the central nervous system (brain and spinal cord) to the body’s sensory organs, muscles, and glands. -Central and peripheral nervous systems are not two separate systems, but are parts of an integrated whole. Sensory Neurons: neurons, bundled together to make nerves, that carry messages from a sensory organ (eyes, ears, nose, tongue, and skin), through a nerve, into the central nervous system (brainor spinal cord). Motor Neurons: neurons, bundled together to make nerves, that carry messages out from the central nervous system (brain or spinal cord), through a nerve, to a muscle or gland. Interneurons: A neuron that exists entirely within the central nervous system (brain or spinal cord) and carries messages from one set of neurons to another. They collect, organize, and integrate messages from various sources. Vastly outnumber the other two types. They make sense of the input that comes from sensory neurons, generate all our mental experiences, and initiate and coordinate all our behavioral actions through their connects to motor neurons. 2. How are neurons in the central nervous system organized? Use the terms nucleus, tract, white matter, and gray matter.Neurons in the central nervous system are organized into Nuclei and Tracts - Nucleus: a cluster of cell bodies o Called Gray Matter: are darker in looks - Tract: a bundle of axons that course together from one nucleus to another. o Called White Matter: myelin sheaths around axon make tracts appear white- Neurons in a given nucleus and tract have the same or similar functions, and groups of neighboring nuclei generally have closely related functionsChapter 5 (pg. 151-end) 1. What are the inputs to sensory neurons and how do they relate to somatosensation? What is the function of motor neurons and how do they carry out this function? Include the terms skeletal, autonomic, sympathetic and parasympathetic. Input to Sensory Neurons: Input from the ears, eyes, nose, and tongue (sensory organs of head)enter the brain through the cranial nerves. Sensory input from the rest of the body (skin, muscles,tendons, internal organs) enters the central nervous system through the spinal cord and some cranial nerves. Without this input, the Central nervous system would have no information to which to base its behavior –controlling devices. Nerves are divided into two classes that correspond to the portion of the central nervous system which they protrude. 1. Cranial Nerves a. Project directly from the brain 2. Spinal Nervesa. Project from the spinal cord. Relationship of Sensory Neurons to Somatosensation: The sensation conveyed by spinal nerve inputs (which include touch and pain) are collectively called somatosenations. Somatosensation: The set of senses that derive from the whole body (from skin, muscles, and tendons: Spinal nerves) as opposed to those senses that come from the special sensory organs of the head. Function of Motor neurons: Only through motor neurons can the nervous system control behavior. Motor neurons have cell bodies in the central nervous system and send their long axonsout, by way of cranial or spinal nerves, to terminate on muscles or glands. All of the behavioral decisions of the nervous system are translated into patterns of action potentials in the axons of motor neurons and those patterns determine our behavior. How do they carry out this function: Skeletal Motor System: Portion of the peripheral motor system, consists of skeletal muscles, or the muscles that are attached to bones and produce externally observable movements of the bodywhen contracted.- Skeletal motor neurons initiate activity in the skeletal musclesAutonomic Motor System: Portion of the peripheral motor system, consists of muscles that act on visceral muscles and glands. - Autonomic motor neurons typically modulate (modify) rather than initiate activity in the visceral muscles. - Visceral muscles have nonneural mechanisms for generating activity (heart continues to beat in response to local influences even if all the nerves to these organs are destroyed.)- Most visceral muscles and glands receive two sets of neurons, which produce opposite effects and come from two anatomically distinct divisions:o 1. Sympathetic Division o 2. Parasympathetic Division Visceral Muscles: muscles that are not attached to bones and do not move the skeleton when they contract. They from walls of structures like (heart, arteries, stomach, intestines). Glands: structures that produce secretions, such as salivary glands and sweat glands. Sympathetic Division: One of the two sets of neurons that visceral muscles and glands receive. Responds to stressful stimulation and helps prepare for fight or flight. Effects are: 1. Increased heart rate and blood pressure 2. The release of energy molecules (sugars and fats) from storage deposits to permit high energy expenditure3. Increased blood flow to the skeletal muscles 4. Inhibition of digestive process Parasympathetic division: One of the two sets of neurons that visceral muscles and glands receive. Serves for regenerative, growth promoting, and energy conserving functions through effects that include the opposite of effects of Sympathetic Division.2. How can the cerebral cortex be divided into lobes? How can it be divided into functional regions? Describe the functions carried out in each region. How is the prefrontal cortex implicated in the control of behavior?Cerebral Cortex: The outermost, evolutionarily newest, and in humans by far the largest portion of the brain; It is divisible into two hemispheres (right and left), and each hemisphere is divisible into four lobes: 1. Occipital: Contains the visual area of the brain2. Temporal: Contains the auditory area of the brain3. Parietal:
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