Final Exam: Chapter 13/14 Flashcards
(73 cards)
Circadian rhythms are produced by an endogenous (internal)
mechanism referred to as —-
a biological clock
a free-running rhythm
one that has a period of the body’s own devising.
Free running period is — than 24 hours, you have a — clock
less
fast
Free running period is — than 24 hours, you have a — clock
more
slow
Zeitgeber
a clock-setting cue
ex: exposed to regular light cues
entrained (2)
+signifigance
When a Zeitgeber resets a biorhythm, the rhythm is said to be entrained. When its biological clock is entrained, an animal is able to organize its daily schedule, including when to eat, exercise, and sleep.
Infradian biological rhythm
More than a daily
Ex: Mentrual cycles
Circadian biological clock
Daily
Ex: Human sleep-wake cycle
Ultradian
Less than a day
ex: human eating eating cycles, respiration
humans have a — clock
slow
What is the best zeitgeber and why?
Light: Most obvious cue as to if its day or night, supress melotonin
light in the —- or —– is the best zeitgeber cue
early morning, late evening
The deeper light falls into the night, the —- the effect (2)
+ maximal
bigger
*Maximal around body temp minimal
This is phase —-
advance
This is a phase —–
delay
suprachiasmatic nucleus (SCN) (4)
What is is considered+ location+optic chiasm+divided in 2 regions
- Master biological clock
- a region of the hypothalamus
- just above the optic chiasm
- can be divided into a rhythmic dorsomedial shell region and a non-rhythmic ventrolateral core region
Although the SCN is considered the brain’s master clock, two other neural structures, the —–, also have a clocklike role in controlling behavior.
intergeniculate leaflet and the pineal gland
Melanopsin-containing ganglion cells use — as their primary neurotransmitter but also contain two cotransmitters: substance P and pituitary adenylate cyclase–activating polypeptide (PACAP)
- glutamate
When stimulated by light, melanopsincontaining RGCs are excited, and in turn they excite —
cells in the SCN
dorsomedial shell region of SCN (2)
- rthymic
- contain cells expressing arginine vasopressin (AVP)
When the SCN is lesioned, animals become —
arrhythmic
Ventrolateral core region in SCN
- Contain cells expressing gastrin releasing peptide (GRP) and vasoactiv intestinal peptide (VIP)
- non-rthymic
- entrain the shell neurons, which are rhythmic
The retinohypothalamic tract activates the
core cells
Single cells within the SCN
are rhythmic on their own, however
They are not all in phase with eachother