Exam 3: Sleep

Question 1

biological rhythms

Answer 1

regular fluctuations in any living process

- control physiological and cognitive processes including sleep, T, alertness, BP, hormone levels

Question 2

circadian rhythms

Answer 2

about every 24 hrs reset

- influences sleep/wake cycle

Question 3

Ultradian Rhythms

Answer 3

repeat more than once a day

ex: eating, going to bathroom

Question 4

Infradian Rhythms

Answer 4

repeat less than once a day

ex: menstrual cycle

Question 5

what is the cue used to synchronize with the environment

Answer 5

zeitgeber

“time clock”

Question 6

the major value of circadian rhythms is that they synchronize ______ to changes in _____

Answer 6

behavior and body states

environment

Question 7

free-running

Answer 7

animal maintains its own cycle without external cues

Question 8

phase shift

Answer 8

shift in activity in response to synchronizing stimulus - light
- ex: night shift people

Question 9

components of biological clock

Answer 9

light sensor, clock, output pathway

Question 10

biological clock

Answer 10

suprachiasmatic nucleus (SCN) 
- located in hypothalamus along third ventricle

Question 11

what happens when you get lesions to the SCN?

Answer 11

• eliminate ALL circadian rhythms including sleep/wake and feeding

Question 12

Transplanted SCN

Answer 12

receiving animal displayed circadian rhythm of donor SCN

- you can transplant clocks but not reset them

Question 13

nocturnal animal biological clock when lesion occurs?

Answer 13

usually no movement in light but movement in dark

- after destroyed they move all the time, no sense of night and day

Question 14

SCN keeps track of…

Answer 14

night and day

Question 15

Ticking of the biological clock within the SCN is due to…

Answer 15

activity within individual neurons

Question 16

Neurons in SCN make what 2 proteins

Answer 16

clock and cycle

Question 17

clock and cycle form ____and promote expression of what 2 genes

Answer 17

dimer

cry (cryptochrome) and per (period)

Question 18

what is the function of cry and per?

Answer 18

bind together and inhibit clock and cycle

• high protein concentration turns off its own production
• levels of protein decline removing the inhibition and starting the cycle again

Question 19

no new clock and cycle proteins made until

Answer 19

per and cry proteins degrade

24hr

Question 20

retinohypothalamic pathway

Answer 20

consists of retinal ganglion cells that project to the SCN

Question 21

what do most of the retinal ganglion cells contain?

Answer 21

melanopsin

Question 22

melanopsin

Answer 22

special photopigment

makes them sensitive to light - blue light