By W. Onatas. Central Methodist College. 2019.
Free nerve endings: These afferent nerve endings are dendrites (branched exten- sions) of sensory neurons that act primarily as pain receptors purchase 10 mg lotensin with visa, although some sense temperature lotensin 10mg mastercard, touch, and muscles (including the sensation of “stretch”). Found all over the body, free nerve endings are especially prevalent in epithelial and connective tissue. These small-diameter fibers have a swelling at the end that responds to touch and sometimes heat, cold, or pain. Some of the endings are disc-shaped structures called Merkel discs that function as light-touch recep- tors within the deep layers of the epidermis. Meissner’s corpuscles: These light-touch mechanoreceptors lie within the dermal papillae. They’re small, egg-shaped capsules of connective tissue sur- rounding a spiraled end of a dendrite. Most abundant in sensitive skin areas such as the lips and fingertips, these corpuscles and free nerve endings can sense a quick touch but not a sustained one. Pacinian corpuscles: These deep-pressure mechanoreceptors are dendrites surrounded by concentric layers of connective tissue. Found deep within the dermis, they respond to deep or firm pressure and vibrations. Hair nerve endings: These mechanoreceptors respond to a change in position of a hair. There are two primary temperature receptors, one for heat and one for cold: End-bulbs of Krause: Also known as Krause’s corpuscles, these cold receptors usually activate below 68 degrees F (20 degrees C). They consist of a bulbous capsule surrounding the dendrite and are commonly found throughout the body in the dermis as well as in the lips, the tongue, and the conjunctiva of the eyes. Brushes of Ruffini: Also known as Ruffini cylinders or Ruffini’s corpuscles, these warmth receptors respond to temperatures between 77 degrees and 113 degrees F (25 degrees to 45 degrees C).
For example order lotensin 10mg, in a hypothetical study of the influence of the presence This condition was first described by Sigmund of loud music on the test performances of children generic 10 mg lotensin free shipping, the Freud as conversion hysteria because it involved the control group would consist of the group of children not conversion of a repressed emotional problem to a physi- exposed to the loud music during the test. Today, conversion reaction is classified as scores would be compared with the experimental group, a somatoform disorder in the American Psychiatric As- the group of children who were exposed to loud music sociation’s Diagnostic and Statistical Manual of Men- during the test. Conversion reaction is a very rare condition, ac- counting for about 2 percent of all psychiatric diag- Further Reading noses, and usually first appears during adolescence or Atkinson, Rita L. San early adulthood, generally when an individual is under Diego: Harcourt Brace Jovanovich, 1987. Another source of “secondary gain” is the attraction of attention, sympathy, and sup- port that the patient may need but is unable to obtain in Convergent thinking other ways. The ability to narrow the number of possible solu- tions to a problem by applying logic and knowl- Some of the most common symptoms of conversion edge. Other physical com- ford, a psychologist well-known for his research on cre- plaints include tremors, abdominal pain, and speech im- ativity. Guilford posited that a prime component of cre- pairments such as aphonia, the inability to speak above ativity is divergent thinking, the capacity to arrive at a whisper. Sometimes a person will experience anesthe- unique and original solutions and the tendency to consid- sia in only one part of the body, such as “glove anesthe- er problems in terms of multiple solutions rather than sia,” which affects the hand only up to the wrist, al- just one. Convergent thinking, which narrows all options though such a problem could have no physiological ori- to one solution, corresponds closely to the types of tasks gin since there is no cut-off point between the nerves of usually called for in school and on standardized multi- the hand and arm. In contrast, creativity tests designed to docrine glands or autonomic nervous systems. If the assess divergent thinking often ask how many different symptoms of a conversion disorder are prolonged, they answers or solutions a person can think of to a specific may produce physiological damage by interrupting the question or problem. Some researchers have claimed that normal functioning of the body, and psychological creative achievement actually involves both divergent damage by inducing excessive dependence on family and convergent thinking—divergent thinking to generate members and other persons. The Standard Edition of the Complete Psy- Further Reading chological Works of Sigmund Freud. There are several different types of correlations; the most commonly used is called the Pear- A technique used to measure the likelihood of two son Product-Moment Correlation. See also Research methodology; Scientific method Psychologists are often interested in deciding whether two behaviors tend to occur together. Sometimes two measurements are associated so that when the value of one increases, so does the other— Cortex a positive correlation.
Cytokines Cytokines are chemical mediators of immunity which enhance inflammatory responses purchase lotensin 10mg with amex. They appear to cause various autoimmune disorders: meningitis 10 mg lotensin for sale, systemic lupus erythematosus, malaria, rheumatoid arthritis, Crohn’s disease, cystic fibrosis, asthma, multiple sclerosis, Intensive care nursing 238 atheroma, Alzheimer’s (Grimble 1994). Platelet activating factor In the early stages of shock, platelets release this mediator which ■ increases vascular permeability ■ increases smooth muscle contraction (arteriolarconstriction) ■ activates neutrophils ■ activates platelet surface adherence (accelerating hypercoaguable states) Myocardial depressant factor Released by the pancreas and spleen following lysosomal damage to cell proteins (e. Acute phase proteins Infection initiates the early release of proteins, including fibrinogen, alpha-1 protinase inhibitor, C-reactive protein and serum amyloid associated protein (Nowak & Handford 1996) to assist phagocytosis. Prostaglandin E1 is used therapeutically to reduce platelet adhesion and decrease systemic vascular resistance, so improving tissue perfusion (Appel et al. Complement Activated by endotoxaemia, the complement combination (C5b, 6, 7, 8, 9) forms a Membrane Attack Complex, part of antigen-antibody reactions to foreign proteins (especially gram negative bacteria). With systemic pathologies, such as shock, increased vascular permeability (C5), inappropriate neutrophil activation and gross fluid shifts complicate, rather than resolve, progression. Free radicals are molecules with one or more unpaired electrons in their outer orbit, which makes them inherently unstable, reacting readily with other molecules to pair the free electron. The reaction of two radicals eliminates both, but reactions between radicals and non-radicals produces a further radical. Reactivity is indiscriminate, so that although their lifespan lasts only microseconds, chain reactions may be thousands of events long (Davidson & Boom 1995) causing the autocatalysis underlying most critical illnesses. Oxygen radicals are particularly destructive, with oxidation modifying proteins (Hipkiss 1989), including cell membrane phospholipid. Free oxygen radicals are released with hyperoxia (Davidson & Boom 1995), so that prolonged high FiO2 (above 0. Intensive care nursing 240 Hypoxic vascular epithelium releases endogenous nitric oxide (see Chapter 28); widespread tissue hypoxia (shock) therefore causes widespread nitric oxide release and systemic vasodilation.