LMBR8: SLEEP Definitions Flashcards
What is the function of the suprachiasmatic nucleus ?
Where is it located ?
What does it control (2) ?
What is the result ?
“The SCN controls the _ & _ “
BR 277
SCN
- main body “clock”, in hypothalamus.
- controls (via nerves) the pineal gland resulting in melatonin secretion (& am cortisol spike)
- creates the circadian rhythm in the body
- “SCN controls the body clock & circadian rhythm”
What is melatonin ?
Where is it made ?
What does it do ?
BR 277
Melatonin
- a natural hormone
- made in the pineal gland
- regulates sleep & wake cycles
In terms of the circadian rhythm
a) What is it ? Also known as __ ?
b) What does it regulate ?
c) What is it regulated by ?
BR 277
Circadian rhythm
a) A biological process which regulates physiologic functions over a 24 hr period that aligns w the light-dark cycles. Known as “body clock”
b) Regulates physiologic functions over a 24 hr period
c) Regulated by endogenous oscillators
In terms of endogenous oscillators
a) What else are they called ?
b) What are they
c) What do they produce ? The result ?
d) Where are they located ?
BR 277
Endogenous oscillators
a) Also called internal circadian oscillators
b) = the molecules, cells & tissues that make up the body’s “internal clock”.
c) Produce oscillatiing (alternating) currents thru self-regulating + and - feedback loops that produce the circadian rhythm.
d) Include both central (in SCN) & peripheral oscillators (in major organs - kidney, liver, heart, adrenals, pancreas).
What are retinal ganglion cells ?
What type of information do they collect/transmit ?
BR 277
Retinal ganglion cells - non-visual light-sensitive retinal neurons that relay light intensity/spectra to the SCN
In the context of sleep, what are:
a) Inputs
b) Modifiers
c) Operators
d) Outputs
BR 277
In the context of sleep, what are:
Inputs - the external and envtl factors that can entrain the circadian rhythm
Modifiers - things that change the amount of ‘input’ that gets to the body’s operators
Operators - the body’s reaction or response to the modified inputs
Outputs - the behavioral & physiological conseqs of the operators.
What is ambient temperature ?
BR 277
Ambient temperature is the temperature of the surrounding environment
What is blood osmolality ?
BR 277
Blood osmolality is a measure of the particles (Na, K, Cl) dissolved in the plasma
In the context of sleep:
1) What is blue light
2) Name to physiologic effects of blue lights
BR 277
Blue light is a specific range (~ 480 nm) within the spectrum of light.
Effects
1) Creates greater melatonin suppression at lower intensities & shorter durations
2) Has disruptive nighttime effects
What is entrainment
BR 261-2
Entrainment - The ability to be brought into the rhythm.
