Biologicial Rhythyms Flashcards
What is a rhythm
A function which oscillates or cycles at regular frequencies
What is chronobiologiy
A field of science that examines periodic phenomena in living organisms and their adaptation to external environments
What is circadian
A daily rhythmical change in behaviour or in a physiological process
What is infradian
Frequency with less than one cycle in 28 hours
What is ultradian
Periods shorter than circadian rhythm
What is a zeitgeber?
Any external cue that entrains the internal time keeping of the organism
What is an example of an infradian cycle
Breeding/ reproduction cycle
What is an example of ultranian movement
Rapid eye movement in sleep
What is external synchronisation
organisms living in synchro with the rhthyms of nature
What is internal synchronisation
Organisation of endogenous processes (organ systems)
Where are the biological clocks of the body
- Retina (photopigment in ganglion cells)
- Superchiasmatic nucleus
- Pineal gland
How is the retina involved in biological clocks
Sends signal to SCN and thalamus
Where is the suprachiasmtic nucleus?
Above optic chiasm
What is the suprachiasm nucleus function
Circadian functions
Where is the pineal gland
Attached to dorsal tectum
Where is the pineal gland
Above dorsal tectum
What does the pineal gland do
Produces melatonin in response to signals from SCN
What are the inputs of the SCN
Light
What does the SCN control
Sleep/ wakefulness
Feeding/ energy expenditure
Glucose homeostasis
Hormone homeostasis
Body temperature and blood pressure regulation
What is the input of the peripheral clocks
Signal from SCN
Feeding/ fasting
What is the output of peripheral clocks
Lipogenesis
Fat absorption
What are peripheral clocks
Monitors in each organ to external environment
What are the consequences if the circadian rhythm of sleep is disrupted
Poor sleep
Bipolar disorder
Alhezimers
What are the consequences if the circadian rhythm of metabolism is disrupted
Obesity
Type 2 diabetes
Fatty liver disease
