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Patellar Reflex
The patellar reflex, also called the knee reflex or knee-jerk, is a stretch reflex which tests the L2, L3, and L4 segments of the spinal cord. Many animals, most significantly humans, have been seen to have the patellar reflex, including dogs, cats, horses, and other mammalian species. Mechanism Striking of the patellar tendon with a reflex hammer just below the patella stretches the muscle spindle in the quadriceps muscle. This produces a signal which travels back to the spinal cord and synapses (without interneurons) at the level of L3 or L4 in the spinal cord, completely independent of higher centres. From there, an alpha motor neuron conducts an efferent impulse back to the quadriceps femoris muscle, triggering contraction. This contraction, coordinated with the relaxation of the antagonistic flexor hamstring muscle causes the leg to kick. There is a latency of around 18 ms between stretch of the patellar tendon and the beginning of contraction of the quadriceps femori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interneuron
Interneurons (also called internuncial neurons, association neurons, connector neurons, or intermediate neurons) are neurons that are not specifically motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the central nervous system (CNS). They play vital roles in reflexes, neuronal oscillations, and neurogenesis in the adult mammalian brain. Interneurons can be further broken down into two groups: local interneurons and relay interneurons. Local interneurons have short axons and form circuits with nearby neurons to analyze small pieces of information. Relay interneurons have long axons and connect circuits of neurons in one region of the brain with those in other regions. However, interneurons are generally considered to operate mainly within local brain areas. The interaction between interneurons allows the brain to perform complex functions such as learning and decision-making. Stru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Coshocton Tribune
''Coshocton Tribune'' is a daily newspaper that serves the community of Coshocton, Ohio, United States, and the surrounding Coshocton County. History The ''Coshocton Tribune'' was founded in 1909 by William J. Bahmer, a former teacher. The paper was independently owned until 1960, when it was sold to Thompson Newspapers. In 2000, it was sold to Gannett Gannett Co., Inc. ( ) is an American mass media holding company headquartered in New York City. It is the largest U.S. newspaper publisher as measured by total daily circulation. It owns the national newspaper ''USA Today'', as well as several .... References External links ''Coshocton Tribune'' website ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ systems, individual organ (biology), organs, cell (biology), cells, and biomolecules carry out chemistry, chemical and physics, physical functions in a living system. According to the classes of organisms, the field can be divided into clinical physiology, medical physiology, Zoology#Physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysics, biophysical and biochemical processes, homeostasis, homeostatic control mechanisms, and cell signaling, communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathology, pathological state'' refers to abnormality (behavior), abnormal conditions, including human diseases. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Foster (physiologist)
Sir Michael Foster (8 March 1836 – 29 January 1907) was an English physiologist. He was instrumental in organizing the University of Cambridge, Cambridge Biological School and acted as Secretary of the Royal Society. Biography Foster was born in Huntingdon, Huntingdonshire, in March 1836, the son of Michael Foster, FRCS. He was educated at Huntingdon Grammar school where he played cricket for the first eleven and was described as "a capital cricketer", in his role as wicket-keeper batsman and University College School, London. After graduating in medicine in 1859, he began to practise in his native town, but in 1867 he returned to London as teacher of practical physiology at University College London, where two years afterwards he became professor. In 1870 he was appointed by Trinity College, Cambridge, to its praelectorship in physiology, and thirteen years later he became the first occupant of the newly created chair of physiology in the university, holding it till 1903. O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Friedrich Otto Westphal
Karl Friedrich Otto Westphal (23 March 1833 – 27 January 1890) was a German psychiatrist from Berlin. He was the son of Otto Carl Friedrich Westphal (1800–1879) and Karoline Friederike Heine and the father of Alexander Karl Otto Westphal (1863–1941). He was married to Klara, daughter of the banker Alexander Mendelssohn. Westphal died in Kreuzlingen in 1890. Academic career After receiving his doctorate, he worked at the Berlin Charité, and subsequently became an assistant in the department for the mentally ill under Wilhelm Griesinger (1817–1868) and Karl Wilhelm Ideler (1795–1860). In 1869 he became an associate professor of psychiatry, as well as a clinical instructor in the department for mental and nervous diseases, In 1874 he attained the title of full professor of psychiatry. Achievements in medicine Westphal's contributions to medical science are many; in 1871 he coined the term ''agoraphobia'' when he observed that three male patients of his displayed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wilhelm Heinrich Erb
Wilhelm Heinrich Erb (30 November 1840 – 29 October 1921) was a German neurologist. He was born in Winnweiler, and died in Heidelberg. Academic career In 1864 he received his medical degree from the University of Heidelberg, where for several years he served as an assistant to pathologist Nikolaus Friedreich (1825–1882). As a young man, he also worked for a period of time under Ludwig von Buhl (1816–1880) in University of Munich, Munich. In 1880 Erb attained the chair of special pathology at the University of Leipzig, where he was also appointed head of its policlinic. In 1883 he succeeded Friedreich at the University of Heidelberg, where he worked until his retirement in 1907. Psychiatrist Emil Kraepelin (1856–1926) and neurologists Ernst Julius Remak (1849–1911), Max Nonne (1861–1959) and Paul Julius Möbius (1853–1907) [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infant
In common terminology, a baby is the very young offspring of adult human beings, while infant (from the Latin word ''infans'', meaning 'baby' or 'child') is a formal or specialised synonym. The terms may also be used to refer to juveniles of other organisms. A newborn is, in colloquial use, a baby who is only hours, days, or weeks old; while in medical contexts, a newborn or neonate (from Latin, ''neonatus'', newborn) is an infant in the first 28 days after birth (the term applies to premature, full term, and postmature infants). Infants born prior to 37 weeks of gestation are called "premature", those born between 39 and 40 weeks are "full term", those born through 41 weeks are "late term", and anything beyond 42 weeks is considered "post term". Before birth, the offspring is called a fetus. The term ''infant'' is typically applied to very young children under one year of age; however, definitions may vary and may include children up to two years of age. When a human chi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperthyroidism
Hyperthyroidism is a endocrine disease in which the thyroid gland produces excessive amounts of thyroid hormones. Thyrotoxicosis is a condition that occurs due to elevated levels of thyroid hormones of any cause and therefore includes hyperthyroidism. Some, however, use the terms interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleeping problems, a tachycardia, fast heartbeat, heat intolerance, diarrhea, goitre, enlargement of the thyroid, hand tremor, and weight loss. Symptoms are typically less severe in the elderly and during pregnancy. An uncommon but life-threatening complication is thyroid storm in which an event such as an infection results in worsening symptoms such as confusion and a hyperthermia, high temperature; this often results in death. The opposite is hypothyroidism, when the thyroid gland does not make enough thyroid hormone. Graves' disease is the cause of about 50% to 80% of the cases of hyperthyroidism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Motor Neuron Lesion
An upper motor neuron lesion (also known as pyramidal insufficiency) Is an injury or abnormality that occurs in the neural pathway above the anterior horn cell of the spinal cord or motor nuclei of the cranial nerves. Conversely, a lower motor neuron lesion affects nerve fibers traveling from the anterior horn of the spinal cord or the cranial motor nuclei to the relevant muscle(s). Upper motor neuron lesions occur in the brain or the spinal cord as the result of stroke, multiple sclerosis, traumatic brain injury, cerebral palsy, atypical parkinsonisms, multiple system atrophy, and amyotrophic lateral sclerosis. Symptoms Changes in muscle performance can be broadly described as the upper motor neuron syndrome. These changes vary depending on the site and the extent of the lesion, and may include: * Muscle weakness. known as 'pyramidal weakness' *Sloth sign. Decreased control of active movement, particularly slowness * Spasticity, a velocity-dependent change in muscle tone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebellar Diseases
The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or even larger. In humans, the cerebellum plays an important role in motor control and cognitive functions such as attention and language as well as emotional control such as regulating fear and pleasure responses, but its movement-related functions are the most solidly established. The human cerebellum does not initiate movement, but contributes to coordination, precision, and accurate timing: it receives input from sensory systems of the spinal cord and from other parts of the brain, and integrates these inputs to fine-tune motor activity. Cerebellar damage produces disorders in fine movement, equilibrium, posture, and motor learning in humans. Anatomically, the human cerebellum has the appearance of a separate structure attached to the botto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Motor Neuron Lesion
A lower motor neuron lesion is a lesion which affects nerve fibers traveling from the lower motor neuron(s) in the anterior horn/anterior grey column of the spinal cord, or in the motor nuclei of the cranial nerves, to the relevant muscle(s). One major characteristic used to identify a lower motor neuron lesion is flaccid paralysis – paralysis accompanied by loss of muscle tone. This is in contrast to an upper motor neuron lesion, which often presents with spastic paralysis – paralysis accompanied by severe hypertonia. Signs and symptoms * Muscle paresis or paralysis * Fibrillations * Fasciculations – caused by increased receptor concentration on muscles to compensate for lack of innervation. * Hypotonia or atonia – Tone is not velocity dependent. * Hyporeflexia - Along with deep reflexes even cutaneous reflexes are also decreased or absent. * Strength – weakness is limited to segmental or focal pattern, Root innervated pattern The extensor plantar reflex ( Babin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
