File Name: anatomy and physiology of neurological system .zip
- Peripheral nervous system
- Nervous System
- Nervous System Anatomy and Physiology
- 12.1 Structure and Function of the Nervous System
Peripheral nervous system
The peripheral nervous system PNS is one of two components that make up the nervous system of bilateral animals , with the other part being the central nervous system CNS. The PNS consists of the nerves and ganglia outside the brain and spinal cord. The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system. In the somatic nervous system, the cranial nerves are part of the PNS with the exception of the optic nerve cranial nerve II , along with the retina. The second cranial nerve is not a true peripheral nerve but a tract of the diencephalon. However, the remaining ten cranial nerve axons extend beyond the brain and are therefore considered part of the PNS. The peripheral nervous system is divided into the somatic nervous system , and the autonomic nervous system.
Skip to content. Skip to navigation. Firstly, with the nervous system there are many new terms you will likely come across, whether its in this section, in other anatomy text books and in the fitness industry. Neurons nerve cells are the building blocks of all nerves. Individual nerves are made up of thousands of neurons.
The nervous system is a complex network of nerves and nerve cells neurons that carry signals or messages to and from the brain and spinal cord to different parts of the body. It is made up of the central nervous system and the peripheral nervous system. The central nervous system CNS is made up of the brain and spinal cord. The brain controls most body functions, including awareness, movements, sensations, thoughts, speech and memory. The spinal cord is connected to the brain at the brain stem and is covered by the vertebrae of the spine. Nerves exit the spinal cord to both sides of the body.
This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables. This book is intended to present neuro-anatomy and especially neurophysiology mainly from the standpoint of clinical usefulness. It is divided into twenty-four chapters to include the peripheral nervous system, spinal cord, brain stem, cerebellum, epithalamus, extrapyramidal systems, the brain, the vegetative nervous system, posture and the cerebrospinal fluid. The author has ably described in his introduction changes in the nervous system brought about by evolution.
The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Together, these organs are responsible for the control of the body and communication among its parts. The brain and spinal cord form the control center known as the central nervous system CNS , where information is evaluated and decisions made. The sensory nerves and sense organs of the peripheral nervous system PNS monitor conditions inside and outside of the body and send this information to the CNS. Efferent nerves in the PNS carry signals from the control center to the muscles, glands, and organs to regulate their functions. The majority of the nervous system is tissue made up of two classes of cells: neurons and neuroglia.
Nervous System Anatomy and Physiology
The nervous system is the master controlling and communicating system of the body. Every thought, action, and emotion reflects its activity. Its signaling device, or means of communicating with body cells, is electrical impulses, which are rapid and specific and cause almost immediate responses. The nervous system does not work alone to regulate and maintain body homeostasis ; the endocrine system is a second important regulating system.
12.1 Structure and Function of the Nervous System
The brain and the spinal cord are the central nervous system, and they represent the main organs of the nervous system. The spinal cord is a single structure, whereas the adult brain is described in terms of four major regions: the cerebrum, the diencephalon, the brain stem, and the cerebellum. The regulation of homeostasis is governed by a specialized region in the brain. The coordination of reflexes depends on the integration of sensory and motor pathways in the spinal cord. The iconic gray mantle of the human brain, which appears to make up most of the mass of the brain, is the cerebrum [link]. The wrinkled portion is the cerebral cortex , and the rest of the structure is beneath that outer covering.
The picture you have in your mind of the nervous system probably includes the brain , the nervous tissue contained within the cranium, and the spinal cord , the extension of nervous tissue within the vertebral column. The brain is contained within the cranial cavity of the skull, and the spinal cord is contained within the vertebral canal of the vertebral column. The peripheral nervous system is so named because it is in the periphery—meaning beyond the brain and spinal cord. In addition to the anatomical divisions listed above, the nervous system can also be divided on the basis of its functions. The nervous system is involved in receiving information about the environment around us sensory functions, sensation and generating responses to that information motor functions, responses and coordinating the two integration.
Animals must be able to sense and respond to the environment in which they live if they are to survive. They need to be able to sense the temperature of their surroundings, for example, so they can avoid the hot sun. They must also be able to identify food and escape predators. The various systems and organs in the body must also be linked so they work together. For example, once a predator has identified suitable prey it has to catch it.
ГЛАВА 13 Токуген Нуматака стоял у окна своего роскошного кабинета на верхнем этаже небоскреба и разглядывал завораживающие очертания Токио на фоне ярко-синего неба. Служащие и конкуренты называли Нуматаку акута саме - смертоносной акулой. За три десятилетия он перехитрил, превзошел и задавил рекламой всех своих японских конкурентов, и теперь лишь один шаг отделял его от того, чтобы превратиться еще и в гиганта мирового рынка. Он собирался совершить крупнейшую в своей жизни сделку - сделку, которая превратит его Нуматек корпорейшн в Майкрософт будущего.
Каждый компьютер в мире, от обычных ПК, продающихся в магазинах торговой сети Радиошэк, и до систем спутникового управления и контроля НАСА, имеет встроенное страховочное приспособление как раз на случай таких ситуаций, называемое отключение из розетки. Полностью отключив электроснабжение, они могли бы остановить работу ТРАНСТЕКСТА, а вирус удалить позже, просто заново отформатировав жесткие диски компьютера. В процессе форматирования стирается память машины - информация, программное обеспечение, вирусы, одним словом - все, и в большинстве случаев переформатирование означает потерю тысяч файлов, многих лет труда. Но ТРАНСТЕКСТ не был обычным компьютером - его можно было отформатировать практически без потерь. Машины параллельной обработки сконструированы для того, чтобы думать, а не запоминать.
Поднявшись на подиум, она крикнула: - Директор. На коммутатор поступает сообщение. Фонтейн тотчас повернулся к стене-экрану. Пятнадцать секунд спустя экран ожил.