The Description of the Human Body (French : La description du corps humain) is an unfinished treatise written in 1647 by René Descartes (1596-1650). Descartes felt knowing oneself was particularly useful. This for him included medical knowledge. He hoped to cure and prevent disease, even to slow down aging.
French is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages. French evolved from Gallo-Romance, the spoken Latin in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues d'oïl—languages historically spoken in northern France and in southern Belgium, which French (Francien) has largely supplanted. French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the (Germanic) Frankish language of the post-Roman Frankish invaders. Today, owing to France's past overseas expansion, there are numerous French-based creole languages, most notably Haitian Creole. A French-speaking person or nation may be referred to as Francophone in both English and French.
A treatise is a formal and systematic written discourse on some subject, generally longer and treating it in greater depth than an essay, and more concerned with investigating or exposing the principles of the subject.
René Descartes was a French philosopher, mathematician, and scientist. A native of the Kingdom of France, he spent about 20 years (1629–1649) of his life in the Dutch Republic after serving for a while in the Dutch States Army of Maurice of Nassau, Prince of Orange and the Stadtholder of the United Provinces. One of the most notable intellectual figures of the Dutch Golden Age, Descartes is also widely regarded as one of the founders of modern philosophy.
René Descartes believed the soul caused conscious thought. The body caused automatic functions like the beating of the heart and digestion he felt. The body was necessary for voluntary movement as well as the will. However, he believed the power to move the body was wrongly imagined to come from the soul. A sick or injured body does not do what we want or moves in ways we do not want. He believed the death of the body stopped it from being fit to bring about movement. This did not necessarily happen because the soul left the body.
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, followed by a period of robust contraction and pumping of blood, dubbed systole. After emptying, the heart immediately relaxes and expands to receive another influx of blood returning from the lungs and other systems of the body, before again contracting to pump blood to the lungs and those systems. A normally performing heart must be fully expanded before it can efficiently pump again. Assuming a healthy heart and a typical rate of 70 to 75 beats per minute, each cardiac cycle, or heartbeat, takes about 0.8 seconds to complete the cycle.
Digestion is the breakdown of large insoluble food molecules into small water-soluble food molecules so that they can be absorbed into the watery blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In chemical digestion, enzymes break down food into the small molecules the body can use.
Death is the permanent cessation of all biological functions that sustain a living organism. Phenomena which commonly bring about death include aging, predation, malnutrition, disease, suicide, homicide, starvation, dehydration, and accidents or major trauma resulting in terminal injury. In most cases, bodies of living organisms begin to decompose shortly after death.
René Descartes believed the body could exist through mechanical means alone. This included digestion, blood circulation, muscle movement and some brain function. He felt we all know what the human body is like because animals have similar bodies and we have all seen them opened up.
Muscle is a soft tissue found in most animals. Muscle cells contain protein filaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. Muscles function to produce force and motion. They are primarily responsible for maintaining and changing posture, locomotion, as well as movement of internal organs, such as the contraction of the heart and the movement of food through the digestive system via peristalsis.
The brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. The brain is located in the head, usually close to the sensory organs for senses such as vision. The brain is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons communicate with one another by means of long protoplasmic fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells.
Animals are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 millionths of a metre to 33.6 metres (110 ft) and have complex interactions with each other and their environments, forming intricate food webs. The category includes humans, but in colloquial use the term animal often refers only to non-human animals. The study of non-human animals is known as zoology.
He saw the body as a machine. He believed the heat of the heart somehow caused all movement of the body. Blood vessels he realized were pipes, he saw that veins carried digested food to the heart. (This was brought further by William Harvey. Harvey developed the idea of the circulation of the blood.) Descartes felt that an energetic part of blood went to the brain and there gave the brain a special type of air imbued with vital force that enabled the brain to experience, think and imagine. This special air then went through the nerves to the muscles enabling them to move.
The blood vessels are the components of the circulatory system that transports blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away from the tissues. Blood vessels are needed to sustain life, because all of the body’s tissues rely on their functionality.
William Harvey was an English physician who made seminal contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and properties of blood being pumped to the brain and body by the heart, though earlier writers, such as Realdo Colombo, Michael Servetus, and Jacques Dubois, had provided precursors of the theory. In 1973, the William Harvey Hospital was constructed in the town of Ashford, a few miles from his birthplace of Folkestone.
A nerve is an enclosed, cable-like bundle of nerve fibres called axons, in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials that are transmitted along each of the axons to peripheral organs or, in the case of sensory nerves, from the periphery back to the central nervous system. Each axon within the nerve is an extension of an individual neuron, along with other supportive cells such as Schwann cells that coat the axons in myelin.
Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart.
The human body is the structure of a human being. It is composed of many different types of cells that together create tissues and subsequently organ systems. They ensure homeostasis and the viability of the human body.
The circulatory system, also called the cardiovascular system or the vascular system, is an organ system that permits blood to circulate and transport nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases, stabilize temperature and pH, and maintain homeostasis.
Coronary circulation is the circulation of blood in the blood vessels that supply the heart muscle (myocardium). Coronary arteries supply oxygenated blood to the heart muscle, and cardiac veins drain away the blood once it has been deoxygenated. Because the rest of the body, and most especially the brain, needs a steady supply of oxygenated blood that is free of all but the slightest interruptions, the heart works constantly and sometimes works quite hard. Therefore its circulation is of major importance not only to its own tissues but to the entire body and even the level of consciousness of the brain from moment to moment. Interruptions of coronary circulation quickly cause heart attacks, in which the heart muscle is damaged by oxygen starvation. Such interruptions are usually caused by ischemic heart disease and sometimes by embolism from other causes like obstruction in blood flow through vessels.
Mind–body dualism, or mind–body duality, is a view in the philosophy of mind that mental phenomena are, in some respects, non-physical, or that the mind and body are distinct and separable. Thus, it encompasses a set of views about the relationship between mind and matter, and between subject and object, and is contrasted with other positions, such as physicalism and enactivism, in the mind–body problem.
Discourse on the Method of Rightly Conducting One's Reason and of Seeking Truth in the Sciences is a philosophical and autobiographical treatise published by René Descartes in 1637. It is best known as the source of the famous quotation "Je pense, donc je suis", which occurs in Part IV of the work. A similar argument, without this precise wording, is found in Meditations on First Philosophy (1641), and a Latin version of the same statement Cogito, ergo sum is found in Principles of Philosophy (1644).
Neuropsychology is the study and characterization of the behavioral modifications that follow a neurological trauma or condition. It is both an experimental and clinical field of psychology that aims to understand how behavior and cognition are influenced by brain functioning and is concerned with the diagnosis and treatment of behavioral and cognitive effects of neurological disorders. Whereas classical neurology focuses on the pathology of the nervous system and classical psychology is largely divorced from it, neuropsychology seeks to discover how the brain correlates with the mind through the study of neurological patients. It thus shares concepts and concerns with neuropsychiatry and with behavioral neurology in general. The term neuropsychology has been applied to lesion studies in humans and animals. It has also been applied in efforts to record electrical activity from individual cells in higher primates.
An organ system is a group of organs that work together as a biological system to perform one or more functions. Each organ system does a particular job in the body, and is made up of certain tissues.
The pulmonary circulation is the portion of the circulatory system which carries deoxygenated blood away from the right ventricle of the heart, to the lungs, and returns oxygenated blood to the left atrium and ventricle of the heart. The term pulmonary circulation is readily paired and contrasted with the systemic circulation. The vessels of the pulmonary circulation are the pulmonary arteries and the pulmonary veins.
René Descartes (1596–1650) was one of the first to conceive a model of reciprocal innervation as the principle that provides for the control of agonist and antagonist muscles. Reciprocal innervation describes skeletal muscles as existing in antagonistic pairs, with contraction of one muscle producing forces opposite to those generated by contraction of the other. For example, in the human arm, the triceps acts to extend the lower arm outward while the biceps acts to flex the lower arm inward. To reach optimum efficiency, contraction of opposing muscles must be inhibited while muscles with the desired action are excited. This reciprocal innervation occurs so that the contraction of a muscle results in the simultaneous relaxation of its corresponding antagonist.
A notion in philosophy is a reflection in the mind of real objects and phenomena in their essential features and relations. Notions are usually described in terms of scope and content. This is because notions are often created in response to empirical observations of covarying trends among variables.
The World, also called Treatise on the Light, is a book by René Descartes (1596–1650). Written between 1629 and 1633, it contains a nearly complete version of his philosophy, from method, to metaphysics, to physics and biology.
Balloonist theory was a theory in early neuroscience that attempted to explain muscle movement by asserting that muscles contract by inflating with air or fluid. The Greek physician Galen believed that muscles contracted due to a fluid flowing into them, and for 1500 years afterward, it was believed that nerves were hollow and that they carried fluid. René Descartes, who was interested in hydraulics and used fluid pressure to explain various aspects of physiology such as the reflex arc, proposed that "animal spirits" flowed into muscle and were responsible for their contraction. In the model, which Descartes used to explain reflexes, the spirits would flow from the ventricles of the brain, through the nerves, and to the muscles to animate the latter.
In his final philosophical treatise, The Passions of the Soul, completed in 1649 and dedicated to Queen Christina of Sweden, René Descartes contributes to a long tradition of philosophical enquiry into the nature of "the passions". The passions were experiences – now commonly called emotions in the modern period – that had been a subject of debate among philosophers and theologians since the time of Plato.
Iatrophysics or iatromechanics is the medical application of physics. It provides an explanation for medical practices with mechanical principles. It was a school of medicine in the seventeenth century which attempted to explain physiological phenomena in mechanical terms. Believers of iatromechanics thought that physiological phenomena of the human body followed the laws of physics. It was related to iatrochemistry in studying the human body in a systematic manner based on observations from the natural world though it had more emphasis on mathematical models rather than chemical processes.
The mind–body problem is a philosophical problem concerning the relationship between thought and consciousness in the human mind, and the brain as part of the physical body. It is distinct from the question of how mind and body function chemically and physiologically since that question presupposes an interactionist account of mind-body relations. This question arises when mind and body are considered as distinct, based on the premise that the mind and the body are fundamentally different in nature.
Floating man, flying man or man suspended in air is a thought experiment by Avicenna to argue for the existence of the soul. The argument is used to argue for the knowledge by presence.
The search for a hypothetical soul and its location have been a subject of much speculation throughout history. In early medicine and anatomy the location of the soul was hypothesized and studied to be physically located within the body. Today neuroscientists and other fields of science that deal with the body and the mind, such as psychology, bridge the gap between what is physical and what is corporeal. Aristotle and Plato understood the soul as a corporeal form but closely related to the physical world. The Hippocratic Corpus chronicles the evolution of the evolution of thought, that the soul is located within the body and is manifested in diseased conditions. Later, Galen explicitly used Plato's description of the corporeal soul to physical locations in the body. The logical (λογιστικός) in the brain, the spirited (θυμοειδές) in the heart, and the appetitive (ἐπιθυμητικόν) in the liver.