Students, this is the place to reflect on what you have learned in a short two to three sentence summar…..On Patho what I have learned so far is………………
Medcom Nursing Assessment The Nervous System, Part 1 Anatomy and Subjective Data
brain spinal cord nerves central nervous system CNS peripheral nervous system PNS Nerves cell body dendrites axons synapse sensory neurons motor neurons interneurons sensory neurons motor neurons spinal cord to foot axons = 1 meter interneurons 100 billion interneurons 1000 synapses each 100 trillion synapses 100 meters per second 200 miles per hour 1/10,000th second
01:00 JIM HARRIGAN Each organ system is crucial to maintaining our lives and completing even the simplest daily activities. The mere wiggle of a finger involves the integimentory(ph), circulatory, muscular and skeletal systems. One system, however, coordinates all the activities of these other systems and without it, we wouldn’t be able to function at all: the nervous system. The organs of the nervous system are few in number: the brain, the spinal cord, and the nerves. The organs are separated into the two divisions: the central nervous system or CNS, which includes the brain and the spinal cord, and the peripheral nervous system or PNS, which includes all the nerves that extend outside the central nervous system and serve the limbs and organs. The nervous system consists of two types of cells: neurons and neuroglia. Neurons are the primary cells of the nervous system, neuroglia are secondary cells involved in nourishment and structural support. What neurons actually do is transmit signals very, very rapidly. This is accomplished in two ways: within the neuron itself and between neurons. A typical neuron is composed of a cell body, dendrites and axons. The dendrites carry impulses towards the cell body, the axons transmit them away from the cell body. The contact between one neuron’s axon and another neuron’s dendrites is called a synapse. You can see how an impulse is transmitted from one nerve cell to another. Some neurons have over 1,000 dendrites apiece, enabling connections to tens of thousands of other neurons simultaneously. There are three main types of neurons: sensory neurons, motor neurons and interneurons. Sensory neurons connect our senses of touch, odor, taste, sound and vision to the central nervous system, that is, the brain and spinal cord. Motor neurons transmit impulses from the central nervous system to the muscles and glands that carry out the response. While most neurons are very short, the axons connecting your spinal cord to your foot can be as much as one meter long although only a few micrometers in diameter. Interneurons are found exclusively within the spinal cord and brain. It is estimated that the human brain contains 100 billion interneurons, averaging 1,000 synapses apiece. That amounts to 100 trillion synapses. Electrical impulses travel through neurons at about 100 meters per second. This is equivalent to over 200 miles per hour, the speed of a bullet train. The nerve impulse crosses a synapse in 1/10,000th of a second. Between catching a ball and throwing it again only a moment later, many millions of neurons may have been activated and hundreds of complicated processes have sent information, processed the information and acted upon it.
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Central Nervous System spinal cord brain encephalon largest, most complex mass of nerve tissue frontal lobe thinking, creating control of body movements parietal lobe sense of direction recognition & uses of objects collection of sensory data hearing speech memory temporal lobe occipital lobe receive & interpret information from the eyes brain stem breathing heartbeat blood pressure cranial nerves spinal nerves transmit impulses to & from the spinal cord & the periphery of the body ventricle meninges arachnoid
04:55 JIM HARRIGAN The central nervous system consists of the brain and spinal cord. Weighing about 3 pounds and roughly the size of a coconut, the brain, also called the encephalon, fills the top half of the head and is the largest and most complex mass of nerve tissue. Composed of multiple interacting parts, the brain regulates widely different bodily functions, from involuntary processes like blood pressure, balance and appetite to voluntary processes like walking, thinking and feeling. Specific brain functions are to some extent localized in various lobes. Thinking, creating and control of body movement occurs in the frontal lobes. Sense of direction, recognition of objects and their uses and collection of sensory data received by the body takes place in the parietal lobes. Located next to our ears, the temporal lobes regulate hearing, speech and memory. The occipital lobes, located at the back of the head, receive and interpret information from the eyes. In general, sensory information from the left side of the body is processed in the right side of the brain and information from the right side of the body is processed in the left side of the brain. Among other things, this means that damage to the right side of the brain caused by a stroke, for example, will affect the left side of the body. The brain stem is the brain’s stalk and connects the brain to the spinal cord. It is responsible for such basic, unconscious functions as breathing, heart beat and blood pressure. 12 pairs of nerves called cranial nerves emerge from the brain stem. These nerves primarily control functions of the head, face, and sensory organs and are part of the peripheral nervous system which connects the brain to the body. The spinal cord consists of nerve cells and is enclosed in and protected by the vertebral column or backbone. 31 pairs of nerves, belonging to the peripheral nervous system, branch out from the vertebrae, in the backbone. The function of all the spinal nerves is to transmit impulses to and from the spinal cord and the periphery of the body. The brain and spinal cord are constantly bathed in a cerebral spinal fluid that originates from circulating blood plasma. Cerebral spinal fluid also cushions the brain and spinal cord and is found in large spaces deep within the brain, called ventricles. The brain and spinal cord are covered by special protective membranes called meninges, which provide support and stabilization of these delicate tissues. The middle layer of the meninges is called arachnoid, which means ‘spider’ in Greek, because it resembles a spiderweb.
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The Peripheral Nervous System somatic (voluntary) autonomic (involuntary) facilitates control of body movements autonomic (involuntary) (visceral) digestion respiration metabolism blood pressure Peripheral Nervous System Somatic Nervous System Autonomic Nervous System Sympathetic Division Parasympathetic Division sympathetic nervous division regulates increase of heartbeat and blood pressure parasympathetic nervous division constriction of pupils slowing of heart dilation of blood vessels
08:15 JIM HARRIGAN The peripheral nervous system consists of nerves that extend outside the central nervous system, to serve the limbs and organs. The peripheral nervous system is divided into two main systems: the somatic or voluntary nervous system and the autonomic or involuntary nervous system. The somatic nervous system facilitates control of body movements. In contrast, the autonomic nervous system is responsible for controlling involuntary functions, also called visceral functions, including digestion, respiration, metabolism, and blood pressure. There are connections between the two systems, however, and thoughts can influence visceral reactions and vice versa, as illustrated by the phrase, ‘The thought of that makes me sick.’ The autonomic nervous system is further subdivided into the sympathetic division and parasympathetic division. The sympathetic nervous system responds to impending danger or stress and is responsible for the increase of one’s heartbeat and blood pressure. The parasympathetic nervous system is evident when a person is resting and feels relaxed and is responsible for such things as the constriction of the pupil, the slowing of the heart, the dilation of blood vessels. Most impulses travel from a sensory node like a fingertip to the spinal cord and then to the brain for processing and response. But some of these impulses terminate in the spinal cord itself. This is called a reflex and it’s one of the body’s defense mechanisms that provides for fast reaction. For example, when you accidentally touch something hot and immediately pull your hand away, the heat sensation travels along the sensory nerve to the spinal cord while the impulse to jerk your hand away travels instantly from the spinal cord back along a motor nerve without engaging your brain at all…………..
Transition to Nursing Assignment
Discussion
Research online and find a recent medical error that made the news. Answer the following questions.
What happened in the incident?
Who was involved?
What were the ramifications for the patient and/or staff?
Reflect on the incident and think about some causes and possible interventions that could have prevented the error.
Refer to the Small Group Discussion guidelines (Links to an external site.) for more information.
