clock

(redirected from system clock)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to system clock: Clock speed

clock

(klŏk)
n.
1. An instrument other than a watch for measuring or indicating time, especially a mechanical or electronic device having a numbered dial and moving hands or a digital display.
2. A biological clock.
v. clocked, clocking, clocks
v.tr.
To register or record with a mechanical device: clocked the winds at 60 miles per hour.

clock′er n.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

CLOCK

A gene on chromosome 4q12 that encodes a ubiquitously expressed human homolog of the mouse clock gene, which forms a heterodimer with ARNTL and activates E-box element transcription of several circadian clock proteins (e.g., PER1 and PER2). CLOCK is highly expressed in the suprachiasmatic nucleus.

Molecular pathology
CLOCK-ARNTL double mutations in the PAS domains result in syngernistic desensitisation to high levels of CRY on repression of CLOCK-ARNTL transcriptional activity of PER1, disrupting circadian rhythmicity.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

clock

(klok)
A device for measuring time.

biological clock

1. An internal system in organisms that influences behavior in a rhythmic manner. Functions such as growth, feeding, secretion of hormones, the rate of drug action, the wake-sleep cycle, the menstrual cycle, and reproduction coincide with certain external events such as day and night, the tides, and the seasons. Biological clocks appear to be set by environmental conditions in some animals, but if these animals are isolated from their environment they continue to function according to the usual rhythm. A gradual change in environment does produce a gradual change in the timing of the biological clock. See: circadian; maladaptation to night work; zeitgeber
2. A colloquial term for the decrease in fertility that accompanies aging, particularly as women approach the age of 35.
Medical Dictionary, © 2009 Farlex and Partners

Patient discussion about clock

Q. How do you wake up in the morning if your narcolepsy is so severe you can't hear the alarm clock, phone ring? biggest problem is sleep paralysis, can't wake up. Late for work, everything, life is suffering because of severity. Have tried ritalin, natural supplements, hypnosis therapy, Provigal, antidepressants, nothing seems to work. Employer thinks it's an excuse, friends are irritated, I'm at my wits end. Life is spent sleeping more than awake.

A. Narcolepsy cannot yet be cured. But EDS and cataplexy, the most disabling symptoms of the disorder, can be controlled in most patients with drug treatment. Often the treatment regimen is modified as symptoms change. For decades, doctors have used central nervous system stimulants-amphetamines such as methylphenidate, dextroamphetamine, methamphetamine, and pemoline-to alleviate EDS and reduce the incidence of sleep attacks. For most patients these medications are generally quite effective at reducing daytime drowsiness and improving levels of alertness. However, they are associated with a wide array of undesirable side effects so their use must be carefully monitored. Common side effects include irritability and nervousness, shakiness, disturbances in heart rhythm, stomach upset, nighttime sleep disruption, and anorexia. For full article: http://www.ninds.nih.gov/disorders/narcolepsy/detail_narcolepsy.htm#120393201 Hope this helps.

More discussions about clock
This content is provided by iMedix and is subject to iMedix Terms. The Questions and Answers are not endorsed or recommended and are made available by patients, not doctors.
References in periodicals archive ?
The system clock period is given by the following equation:
Router with SPS Algorithm Input: system clock, start, Lottery Input.
(i) wired distribution of one common system clock among UWB modules by means of conventional coax cables,
To enhance system performance, the new chip offers two built-in clock systems: a 10MHz system clock generator and a 32KHz sub-clock generator.
JIFFY - One of the few words that geekspeak gave to common usage - the jiffy is the duration of one tick of the system clock on your computer (1/60 second in the U.S.
Synchronous DRAM (SDRAM) is "in synch" or synchronized to the system clock that controls the CPU.
Normally the program reads the system clock and displays the Earth's current lighting conditions.
Michelle Johnston, branded motherboard product manager, said that the board had been delayed because of problems with the system clock, which had been rectified, by shipping the component with an external ocisilator.
Like most PCs, the system clock is used to date and time stamp every file that is created or updated, and several of his programs base calculations on its settings.
If a BIOS upgrade won't fix your PC, Calay Systems (the folks who made a turnkey router for PC boards in the 1980s) will sell you a new system clock mounted on a circuit board that plugs into an EISA slot.
Is reversing the system clock a long-term solution?

Full browser ?