Biological High
Biological High
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Student Thermometer, High Range
Sale Price: $2.70 |
DescriptionA 6 3/4" plastic thermometer with red alcohol tube recessed in molded plastic to help prevent breakage. Resistant to both chemicals and heat. High range (10 to 225 degrees F; -25 to 110 degrees C). |

Biological Factors That Contribute to Depression
Many people are pre-disposed to depression because of their own biological makeup making their risk of suffering from this condition much greater then those who do not share these risk factors. There are four main biological factors that can increase a persons risk for depression and these include (1) genetic factors, (2) biochemical factors, (3) alterations in hormonal regulation and, (4) sleep abnormalities.
Genetic Factors
Studies done with twins have shown that genetic factors play a role in the development of depressive disorders. There have been a number of studies done that show that the average rate of shared mood disorders among identical twins is 45% to 60%. This means if one twin suffers from depression, or any other mood disorder, there is a 45% to 60% chance that the other twin will also be affected. Contrast this with fraternal twins where the percentage falls of drastically to only 12%.
Moods disorders are inheritable for some people. This also means that those who are genetically susceptible to mood disorders can have an earlier age of onset, a greater rate of suffering other disorders in addition to depression and an increased risk of recurrent illnesses. However, any genetic factors that are present must interact with environmental factors for depression to develop.
Biochemical Factors
The brain contains billions of neurons and is a highly complex organ. There is a lot of evidence that points to the idea that depression is a biological or chemical disorder where central nervous system neurotransmitter abnormalities are a probable cause of clinical depression. These neurotransmitter abnormalities may be the result of inherited or environmental factors, or even of other Medical conditions, such as cerebral infarction, hypothyroidism, AIDS, or substance abuse.
Specific neurotransmitters in the brain are believed to be related to mood altered states. It was initially believed that the two main neurotransmitters involved were serotonin and norepinephrine. With new research though it is now thought that depression results from the dysregulation of a number of neurotransmitter systems in addition to serotonin and norepinephrine. The dopamine, acetylcholine, and GABA systems are also believed to be involved in the pathophysiology of major depression.
Alterations in Hormonal Regulation
Although there is still inconclusive evidence that hormones can play a role in depression. The most studied neuroendocrine characteristic that relates to depression has been hyperactivity of the hypothalamic-pituitary-adrenal cortical axis. Evidence of increased cortisol secretion is apparent in 20% to 40% of depressed outpatients and 40% to 60% of depressed inpatients. Results of a dexamethasone suppression test are abnormal in about 50% of patients with depression, which indicates hyperactivity of the hypothalamic-pituitary-adrenal cortical axis. However, the findings of this test may also be abnormal in people with obsessive-compulsive disorders and other medical conditions. Significantly, patients with psychotic major depression are among those with the highest rates of nonsuppression of cortisol on the dexamethasone suppression test.
Sleep Abnormalities
Sleep electroencephalogram abnormalities may be evident in 40% to 60% of outpatients and up to 90% of inpatients during a major depressive episode. People prone to depression tend to have a pre-mature loss of sleep, slow delta wave sleep and altered rapid eye movement (REM) latency. The phase of REM sleep associated with dreaming occurs earlier in two thirds of people with bipolar and major depressive illnesses. This sign is referred to as reduced REM latency and is consistent with the expected manifestation of an inherited trait. Reduced REM latency and deficits in slow-wave sleep typical persist following recovery from a depressed episode. Data also suggests that depressed patients without this sign are not likely to respond to treatment with tricyclic antidepressants, which suppress early REM sleep.
There are many factors that contribute to depression, many of which are biochemical in nature. Those that are biologically induced can be treated with different prescription drugs but as with anything relating to human emotion and chemical makeup answering one question as to why brings up more questions that remain unanswered.
About the Author
To learn more about the types of depression please visit the web site Depression and You by Clicking Here.
The puramax Moving Bed Biological Reactor MBBR System for Wastewater Treatment by Bord na Mona
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Student Thermometer, High Range
Sale Price: $2.70 |
DescriptionA 6 3/4" plastic thermometer with red alcohol tube recessed in molded plastic to help prevent breakage. Resistant to both chemicals and heat. High range (10 to 225 degrees F; -25 to 110 degrees C). |
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High-Precision Specific Gravity Hydrometer
Sale Price: $33.25 |
DescriptionGlobe Certified!Plain-form hydrometer Used to measure the density of liquid at 60degrees F. Specific gravity range: 1.000 to 1.070 with 0.0005 graduations. Length, 325 mm. Meets specifications for the Globe Program. |
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Alpine saxifrage (Saxifraga aprica) Photo Mugs |
DescriptionAlpine saxifrage flowers (Saxifraga aprica). Photographed at around 3300 metres in the Sierra Nevada, California, USA, in July.. |
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The Crazies
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DescriptionDuring the 10 years between Night of the Living Dead and Dawn of the Dead, director George Romero had a string of box-office flops--some of which were actually quite good. For example,there's The Crazies, in which a military plane carrying biological-warfare agents crashes near Evans City, Pennsylvania... |
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Pondmaster PMK1250 Pond Filter with 250gph Pump and Bonus Fountain Head
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DescriptionFor ponds up to 600 gallons, 250 gph flow, pumps seven feet high. The complete garden pond filter system includes Pondmaster 1000 with 12" x 12" dual filter elements, Supreme Mag-Drive Pump, two free Fountain Kits, and all the connectors, fittings, and filter media... |
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Biohazard Decorative High Gloss Ceramic Drawer Knob
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DescriptionHandcrafted in the USA to the highest standards using a specialized heat fused, high definition image transfer, that is tripled sealed with a UV resistant glass like gloss finish to ensure durability, easy cleaning, and to obtain an enamel hard like finish... |
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Gloves, High/Low Temperature, Large, Pair
Sale Price: $8.45 |
DescriptionGloves, High/Low Temperature, Large, Pair |
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Heliocare Oil Free Compact SPF 50 light
Sale Price: $24.52 |
DescriptionUltra-smooth, easy-apply facial make-up sunscreens. Providing advanced UV protection with skin tone enhancement and correction. The creamy smooth make-up enables daily use and is ideal when applied after aesthetic procedures or on areas of uneven skin tone where make-up cover is required... |









