Biological Clock Essay

904 Words4 Pages

Abbreviations
SCN Suprachiasmatic nucleus
RTH Retinohypothalamic tract
PER Period homolog
BMAL1 Brain and Muscle Arnt Like Protein 1
CLOCK Circadian locomotor output cycles kaput
CRY Cryptochrome
REV-ERB-α Reverse erythroblastosis virus α
ROR α/γ Retinoid-related orphan receptor α/γ
FAA Food-anticipatory activity
NPY Neuropeptide Y
AgRP Agouti-related protein
MCH Melanin concentrating hormone
CART Cocain amphetamine-regulated transcript
POMC Pro-opiomelanocortin
MSH Melanocortin
HDL High density lipoprotein)
VLDL Very low density lipoprotein).

Abstract
Study objective
This study investigates the possible influence of the biological clock on body weight with regard to the regulation of food intake and energy metabolism.

Methods
Search engine and databases Google Scholar, Wageningen library Global search, PubMed, Web of Science, Scopus, ScienceDirect, were searched for this literature study. Included studies were any term of the circadian clock in relation to weight with the use of human or …show more content…

The biological clock consists of several endogenous clocks. This allows intern biological functions to be in phase with the daily environmental changes such as food intake and light-dark cycle by means of oscillation of the endogenous clocks. The biological clock is composed of peripheral oscillators and a central pacemaker. The central pacemaker also called the master clock or main circadian clock is the SCN. It is a paired neuronal structure located at the base of the hypothalamus above the optic chiasm 1. The SCN orchestrates daily patterns of behavioural and physiological processes. It can generate circadian oscillations because it is composed of multiple cellular clocks that are coupled 2. The SCN neurons are synchronized by direct input from the retina through the retinohypothalamic tract where light activates the photosensitive retinal ganglion cells