International Standard Serial Number
An International Standard Serial Number is an eight-digit serial number used to uniquely identify a serial publication, such as a magazine. The ISSN is helpful in distinguishing between serials with the same title. ISSN are used in ordering, interlibrary loans, other practices in connection with serial literature; the ISSN system was first drafted as an International Organization for Standardization international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard; when a serial with the same content is published in more than one media type, a different ISSN is assigned to each media type. For example, many serials are published both in electronic media; the ISSN system refers to these types as electronic ISSN, respectively. Conversely, as defined in ISO 3297:2007, every serial in the ISSN system is assigned a linking ISSN the same as the ISSN assigned to the serial in its first published medium, which links together all ISSNs assigned to the serial in every medium.
The format of the ISSN is an eight digit code, divided by a hyphen into two four-digit numbers. As an integer number, it can be represented by the first seven digits; the last code digit, which may be 0-9 or an X, is a check digit. Formally, the general form of the ISSN code can be expressed as follows: NNNN-NNNC where N is in the set, a digit character, C is in; the ISSN of the journal Hearing Research, for example, is 0378-5955, where the final 5 is the check digit, C=5. To calculate the check digit, the following algorithm may be used: Calculate the sum of the first seven digits of the ISSN multiplied by its position in the number, counting from the right—that is, 8, 7, 6, 5, 4, 3, 2, respectively: 0 ⋅ 8 + 3 ⋅ 7 + 7 ⋅ 6 + 8 ⋅ 5 + 5 ⋅ 4 + 9 ⋅ 3 + 5 ⋅ 2 = 0 + 21 + 42 + 40 + 20 + 27 + 10 = 160 The modulus 11 of this sum is calculated. For calculations, an upper case X in the check digit position indicates a check digit of 10. To confirm the check digit, calculate the sum of all eight digits of the ISSN multiplied by its position in the number, counting from the right.
The modulus 11 of the sum must be 0. There is an online ISSN checker. ISSN codes are assigned by a network of ISSN National Centres located at national libraries and coordinated by the ISSN International Centre based in Paris; the International Centre is an intergovernmental organization created in 1974 through an agreement between UNESCO and the French government. The International Centre maintains a database of all ISSNs assigned worldwide, the ISDS Register otherwise known as the ISSN Register. At the end of 2016, the ISSN Register contained records for 1,943,572 items. ISSN and ISBN codes are similar in concept. An ISBN might be assigned for particular issues of a serial, in addition to the ISSN code for the serial as a whole. An ISSN, unlike the ISBN code, is an anonymous identifier associated with a serial title, containing no information as to the publisher or its location. For this reason a new ISSN is assigned to a serial each time it undergoes a major title change. Since the ISSN applies to an entire serial a new identifier, the Serial Item and Contribution Identifier, was built on top of it to allow references to specific volumes, articles, or other identifiable components.
Separate ISSNs are needed for serials in different media. Thus, the print and electronic media versions of a serial need separate ISSNs. A CD-ROM version and a web version of a serial require different ISSNs since two different media are involved. However, the same ISSN can be used for different file formats of the same online serial; this "media-oriented identification" of serials made sense in the 1970s. In the 1990s and onward, with personal computers, better screens, the Web, it makes sense to consider only content, independent of media; this "content-oriented identification" of serials was a repressed demand during a decade, but no ISSN update or initiative occurred. A natural extension for ISSN, the unique-identification of the articles in the serials, was the main demand application. An alternative serials' contents model arrived with the indecs Content Model and its application, the digital object identifier, as ISSN-independent initiative, consolidated in the 2000s. Only in 2007, ISSN-L was defined in the
The patellar reflex or knee-jerk is a stretch reflex which tests the L2, L3, L4 segments of the spinal cord. 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 at the level of L3 in the spinal cord 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. This is a reflex of proprioception which helps maintain posture and balance, allowing to keep one's balance with little effort or conscious thought; the patellar reflex is a classic example of the monosynaptic reflex arc. There is no interneuron in the pathway leading to contraction of the quadriceps muscle. Instead, the bipolar sensory neuron synapses directly on a motor neuron in the spinal cord.
However, there is an inhibitory interneuron used to relax the antagonistic hamstring muscle. This test of a basic automatic reflex may be influenced by the patient consciously inhibiting or exaggerating the response. After the tap of a hammer, the leg is extended once and comes to rest; the absence or decrease of this reflex is problematic, known as Westphal's sign. This reflex may be absent in lower motor neuron lesions and during sleep. On the other hand, multiple oscillation of the leg following the tap may be a sign of cerebellar diseases. Exaggerated deep tendon reflexes such as this can be found in upper motor neuron lesions, anxiety or nervousness; the test itself assesses the nervous tissue between and including the L2 and L4 segments of the spinal cord. The term knee-jerk was recorded by Sir Michael Foster in his Textbook of physiology in 1877: "Striking the tendon below the patella gives rise to a sudden extension of the leg, known as the knee-jerk." The term began to be used figuratively from the early 20th century onwards.
O. O. McIntyre, in his New York Day-By-Day column in The Coshocton Tribune, October 1921, wrote: "Itinerant preacher stemming Broadway on a soap box, and gets only an occasional knee-jerk." Tonic vibration reflex Motor control Jendrassik maneuver Gurfinkel' VS, Lipshits MI, Popov KE. "Is the stretch reflex a basic mechanism in the system of regulation of human vertical posture?". Biofizika. 19: 744–8. PMID 4425696. Pinnock CA, Lin ES, Smith T. "Physiology of the Nervous System". Fundamentals of Anaesthesia, 2nd Edition. Greenwich Medical Media Ltd
The somatosensory system is a part of the sensory nervous system. The somatosensory system is a complex system of sensory neurons and pathways that responds to changes at the surface or inside the body; the axons of sensory neurons connect with, or respond to, various receptor cells. These sensory receptor cells are activated by different stimuli such as heat and nociception, giving a functional name to the responding sensory neuron, such as a thermoreceptor which carries information about temperature changes. Other types include mechanoreceptors and nociceptors which send signals along a sensory nerve to the spinal cord where they may be processed by other sensory neurons and relayed to the brain for further processing. Sensory receptors are found all over the body including the skin, epithelial tissues, muscles and joints, internal organs, the cardiovascular system. Somatic senses are sometimes referred to as somesthetic senses, with the understanding that somesthesis includes the sense of touch and haptic perception.
The mapping of the body surfaces in the brain is called somatotopy. In the cortex, it is referred to as the cortical homunculus; this brain-surface map is not immutable, however. Dramatic shifts can occur in response to injury; the four mechanoreceptors in the skin each respond to different stimuli for long periods. Merkel cell nerve endings are found in hair follicles. Due to having a small receptive field, they are used in areas like fingertips the most. Tactile corpuscles react to moderate light touch, they are located in the dermal papillae. They respond unlike Merkel nerve endings, they are responsible for the ability to feel gentle stimuli. Lamellar corpuscles distinguish rough and soft substances, they react in quick action potentials to vibrations around 250 Hz. They have large receptor fields. Pacinian reacts only to sudden stimuli so pressures like clothes that are always compressing their shape are ignored. Bulbous corpuscles react and respond to sustained skin stretch, they are responsible for the feeling of object slippage and play a major role in the kinesthetic sense and control of finger position and movement.
Merkel and bulbous cells - slow-response - are myelinated. All of these receptors are activated upon pressures that squish their shape causing an action potential. All afferent touch/vibration info ascends the spinal cord via the posterior column-medial lemniscus pathway via gracilis or cuneatus. Cuneatus sends signals to the cochlear nucleus indirectly via spinal grey matter, this info is used in determining if a perceived sound is just villi noise/irritation. All fibers cross in the medulla; the postcentral gyrus includes the primary somatosensory cortex collectively referred to as S1. BA3 receives the densest projections from the thalamus. BA3a is involved with the sense of relative position of neighboring body parts and amount of effort being used during movement. BA3b is responsible for distributing somato info, it projects texture info to BA1 and shape + size info to BA2. Region S2 divides into parietal ventral area. Area S2 is involved with specific touch perception and is thus integrally linked with the amygdala and hippocampus to encode and reinforce memories.
Parietal ventral area is the somatosensory relay to the premotor cortex and somatosensory memory hub, BA5. BA5 is association area. BA1 processes texture info. Area S2 processes light touch, visceral sensation, tactile attention. S1 processes the remaining info. BA7 integrates visual and proprioceptive info to locate objects in space; the insular cortex plays a role in the sense of bodily-ownership, bodily self-awareness, perception. Insula plays a role in conveying info about sensual touch, temperature and local oxygen status. Insula is a connected relay and thus is involved in numerous functions; the somatosensory system is spread through all major parts of the vertebrate body. It consists both of sensory receptors and afferent neurons in the periphery, to deeper neurons within the central nervous system. A somatosensory pathway will have three long neurons: primary and tertiary; the first neuron always has its cell body in the dorsal root ganglion of the spinal nerve. The second neuron has its cell body either in the brainstem.
This neuron's ascending axons will cross to the opposite side either in the spinal cord or in the brainstem. In the case of touch and certain types of pain, the third neuron has its cell body in the VPN of the thalamus and ends in the postcentral gyrus of the parietal lobe. Photoreceptors, similar to those found in the retina of the eye, detect damaging ultraviolet radiation (
Flushing is to become markedly red in the face and other areas of the skin, from various physiological conditions. Flushing is distinguished, despite a close physiological relation between them, from blushing, milder restricted to the face, cheeks or ears, assumed to reflect emotional stress, such as embarrassment, anger, or romantic stimulation. Flushing is a cardinal symptom of carcinoid syndrome—the syndrome that results from hormones being secreted into systemic circulation. Abrupt cessation of physical exertion abdominal cutaneous nerve entrapment syndrome in patients who have had abdominal surgery alcohol flush reaction antiestrogens such as tamoxifen atropine poisoning body contact with warm or hot water butorphanol reaction with some narcotic analgesics caffeine consumption carbon monoxide poisoning carcinoid tumor chronic obstructive pulmonary disease emphysema cluster headache attack or headache compression of the nerve by the sixth thoracic vertebrae coughing severe coughing fits Cushing's syndrome dehydration dysautonomia emotions: anger, embarrassment fever Kratom fibromyalgia high doses of non flush free niacin histamines homocystinuria Horner's syndrome hot flush hyperglycaemia hyperstimulation of the parasympathetic nervous system the vagus nerve hyperthyroidism inflammation iron poisoning Jarisch-Herxheimer reaction keratosis pilaris rubra faceii Limerence mastocytosis medullary thyroid cancer mixing an antibiotic with alcohol pheochromocytoma polycythemia vera powerful vasodilators, such as dihydropyridine calcium channel blockers rosacea severe pain sexual arousal orgasm sexual intercourse sneezing some recreational drugs, such as alcohol, heroin and amphetamines spicy foods sunburn tachycardia vinpocetine Allergies Commonly referred to as the sex flush, vasocongestion of the skin can occur during all four phases of the human sexual response cycle.
Studies show that the sex flush occurs in 50–75% of females and 25% of males, yet not consistently. The sex flush tends to occur more under warmer conditions and may not appear at all under lower temperatures. During the female sex flush, pinkish spots develop under the breasts spread to the breasts, face, soles of the feet, over the entire body. Vasocongestion is responsible for the darkening of the clitoris and the walls of the vagina during sexual arousal. During the male sex flush, the coloration of the skin develops less than in the female, but starts with the epigastrium, spreads across the chest continues to the neck, forehead and sometimes, shoulders and forearms; the sex flush disappears soon after reaching orgasm, but in other cases it may take up to two hours or so, sometimes intense sweating occurs simultaneously. Cholinergic urticaria Erythema Pallor Rash
A dermatome is an area of skin, supplied by a single spinal nerve. There are 12 thoracic nerves, 5 lumbar nerves and 5 sacral nerves; each of these nerves relays sensation from a particular region of skin to the brain. A dermatome refers to the part of an embryonic somite. Along the thorax and abdomen the dermatomes are like a stack of discs forming a human, each supplied by a different spinal nerve. Along the arms and the legs, the pattern is different: the dermatomes run longitudinally along the limbs. Although the general pattern is similar in all people, the precise areas of innervation are as unique to an individual as fingerprints. A similar area innervated by peripheral nerves is called a peripheral nerve field. A dermatome is an area of skin supplied by sensory neurons. Symptoms that follow a dermatome may indicate a pathology. Examples include somatic dysfunction of viral infection. Referred pain involves a specific, "referred" location so is not associated with a dermatome. Certain skin problems tend to orient the lesions in the dermatomal direction.
Viruses that lie dormant in nerve ganglia cause either pain, rash or both in a pattern defined by a dermatome. However, the symptoms may not appear across the entire dermatome. Following is a list of spinal nerves and points that are characteristically belonging to the dermatome of each nerve: C2 - At least one cm lateral to the occipital protuberance at the base of the skull. Alternately, a point at least 3 cm behind the ear. C3 - In the supraclavicular fossa, at the midclavicular line. C4 - Over the acromioclavicular joint. C5 - On the lateral side of the antecubital fossa, just proximally to the elbow. C6 - On the dorsal surface of the proximal phalanx of the thumb. C7 - On the dorsal surface of the proximal phalanx of the middle finger. C8 - On the dorsal surface of the proximal phalanx of the little finger. T1 - On the medial side of the antecubital fossa, just proximally to the medial epicondyle of the humerus. T2 - At the apex of the axilla. T3 - Intersection of the midclavicular line and the third intercostal space T4 - Intersection of the midclavicular line and the fourth intercostal space, located at the level of the nipples.
T5 - Intersection of the midclavicular line and the fifth intercostal space, horizontally located midway between the level of the nipples and the level of the xiphoid process. T6 - Intersection of the midclavicular line and the horizontal level of the xiphoid process. T7 - Intersection of the midclavicular line and the horizontal level at one quarter the distance between the level of the xiphoid process and the level of the umbilicus. T8 - Intersection of the midclavicular line and the horizontal level at one half the distance between the level of the xiphoid process and the level of the umbilicus. T9 - Intersection of the midclavicular line and the horizontal level at three quarters of the distance between the level of the xiphoid process and the level of the umbilicus. T10 - Intersection of the midclavicular line, at the horizontal level of the umbilicus. T11 - Intersection of the midclavicular line, at the horizontal level midway between the level of the umbilicus and the inguinal ligament.
T12 - Intersection of the midclavicular line and the midpoint of the inguinal ligament. L1 - Midway between the key sensory points for T12 and L2. L2 - On the anterior medial thigh, at the midpoint of a line connecting the midpoint of the inguinal ligament and the medial epicondyle of the femur. L3 - At the medial epicondyle of the femur. L4 - Over the medial malleolus. L5 - On the dorsum of the foot at the third metatarsophalangeal joint. S1 - On the lateral aspect of the calcaneus. S2 - At the midpoint of the popliteal fossa. S3 - Over the tuberosity of the ischium or infragluteal fold S4 and S5 - In the perianal area, less than one cm lateral to the mucocutaneous zoneFollowing is a list of sensory cranial nerves: V1 - associated with Herpes zoster ophthalmicus V2 V3 Cutaneous innervation Dorsal root Peripheral nerve field 3D Dermatomes Web App, Instamedic Hand kinesiology at the University of Kansas Medical Center Diagram "Adult Dermatome", The New York Times
Sensory neurons known as afferent neurons are neurons that convert a specific type of stimulus, via their receptors, into action potentials or graded potentials. This process is called sensory transduction; the cell bodies of the sensory neurons are located in the dorsal ganglia of the spinal cord. This sensory information travels along afferent nerve fibers in an afferent or sensory nerve, to the brain via the spinal cord; the stimulus can come from extoreceptors outside the body, for example light and sound, or from interoreceptors inside the body, for example blood pressure or the sense of body position. Different types of sensory neurons have different sensory receptors that respond to different kinds of stimuli; the sensory neurons involved in smell are called olfactory sensory neurons. These neurons contain receptors, called olfactory receptors, that are activated by odor molecules in the air. To Olfactory receptors, taste receptors in taste buds interact with chemicals in food to produce an action potential.
Photoreceptor cells are capable of phototransduction, a process which converts light into electrical signals. These signals are refined and controlled by the interactions with other types of neurons in the retina; the five basic classes of neurons within the retina are photoreceptor cells, bipolar cells, ganglion cells, horizontal cells, amacrine cells. The basic circuitry of the retina incorporates a three-neuron chain consisting of the photoreceptor, bipolar cell, the ganglion cell; the first action potential occurs in the retinal ganglion cell. This pathway is the most direct way for transmitting visual information to the brain. There are three primary types of photoreceptors: Cones are photoreceptors that respond to color. In humans the three different types of cones correspond with a primary response to short wavelength, medium wavelength, long wavelength. Rods are photoreceptors that are sensitive to the intensity of light, allowing for vision in dim lighting; the concentrations and ratio of rods to cones is correlated with whether an animal is diurnal or nocturnal.
In humans, rods outnumber cones by 20:1, while in nocturnal animals, such as the tawny owl, the ratio is closer to 1000:1. Retinal ganglion cells are involved in the sympathetic response. Of the ~1.3 million ganglion cells present in the retina, 1-2% are believed to be photosensitive. Problems and decay of sensory neurons associated with vision lead to disorders such as: Macular degeneration – degeneration of the central visual field due to either cellular debris or blood vessels accumulating between the retina and the choroid, thereby disturbing and/or destroying the complex interplay of neurons that are present there. Glaucoma – loss of retinal ganglion cells which causes some loss of vision to blindness. Diabetic retinopathy – poor blood sugar control due to diabetes damages the tiny blood vessels in the retina; the auditory system is responsible for converting pressure waves generated by vibrating air molecules or sound into signals that can be interpreted by the brain. This mechanoelectrical transduction is mediated with hair cells within the ear.
Depending on the movement, the hair cell can either depolarize. When the movement is towards the tallest stereocilia, the Na+ cation channels open allowing Na+ to flow into cell and the resulting depolarization causes the Ca++ channels to open, thus releasing its neurotransmitter into the afferent auditory nerve. There are two types of hair cells: outer; the inner hair cells are the sensory receptors. Problems with sensory neurons associated with the auditory system leads to disorders such as: Auditory processing disorder – Auditory information in the brain is processed in an abnormal way. Patients with auditory processing disorder can gain the information but their brain cannot process it properly, leading to hearing disability. Auditory verbal agnosia – Comprehension of speech is lost but hearing, speaking and writing ability is retained; this is caused by damage to the posterior superior temporal lobes, again not allowing the brain to process auditory input correctly. Thermoreceptors are sensory receptors.
While the mechanisms through which these receptors operate is unclear, recent discoveries have shown that mammals have at least two distinct types of thermoreceptors. The bulboid corpuscle, is a cutaneous receptor a cold-sensitive receptor, that detects cold temperatures; the other type is a warmth-sensitive receptor. Mechanoreceptors are sensory receptors which respond to mechanical forces, such as pressure or distortion. Specialized sensory receptor cells called mechanoreceptors encapsulate afferent fibers to help tune the afferent fibers to the different types of somatic stimulation. Mechanoreceptors help lower thresholds for action potential generation in afferent fibers and thus make them more to fire in the presence of sensory stimulation; some types of mechanoreceptors fire action potentials. Proprioceptors are another type of mechanoreceptors which means "receptors for self"; these receptors provide spatial information about other body parts. Nociceptors are responsible for processing temperature changes.
The burning pain and irritation experienced after eating a chili pepper, the cold sensation experienced after ingesting a chemical such as menthol or icillin, as well as the common sensation of pain are all a result of neurons with these receptors. Problems with mechanoreceptors lead to disorders such as: Neuropa