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234 Cards in this Set
- Front
- Back
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1. What are six misconceptions that people have about sleep?
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1. Sleep in order to dream (REM sleep is most important)
2. We incorporate environmental stimuli into our dreams 3. Dreams don't run in real time 4. Some people just don't dream 5. Sleep walking and/or talking is a manifestation of our dream 6. Dreams are an extension of life working out its problems |
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2. Why do some people say they never dream?
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If you don't wake up during a dream or right after it ended, you won't remember the dream and hence say you never dreamed.
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3. When does sleep walking and talking occur and what causes this to happen?
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Both happen during early stages of sleep when you are not dreaming
They are caused by impulsed that activate the cortex during slow wave sleep |
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4. How does the modern activation synthesis theory describe dreaming?
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This theory states that dream content reflects the cerebral cortex's inherent tendency to make sense of, and give form to, the random signals it receives from the brain stem during REM sleep
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5. What are lucid dreams?
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Dreams in which the dreamer is aware that he or she is dreaming and can influence the course of the dream
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6. What are the two major theories regarding the question "why do we sleep?"
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Recuperative Theories of Sleep
Circadian Theories of Sleep |
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7. According to recuperative theories, generally what is the purpose of sleep?
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The purpose of sleep is to recuperate or restore homeostasis
-Daily activity disrupts the body's homeostasis so it must be reset, which is done during sleep |
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8. What is some general evidence for recuperative theories of sleep? How can this evidence be explained
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Sleep more after you've been sleep deprived.
Make up for lost sleep in order to restore balance |
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9. What are two specific recuperative theories of sleep?
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1. The restorative theory of sleep
2. Elimination theory of sleep |
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10. According to the restorative theory of sleep, what is slow-wave sleep necessary for? What is REM sleep necessary for?
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Slow wave sleep is necessary for the body to recuperate
REM sleep is important for brain recovery/recuperation |
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11. What evidence is there for the calms of the restorative theory of sleep?
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1. Data shows that during slow-wave sleep, 80% of tissue synthesis occurs.
2. 80% of total secretion of growth hormone is secreted during slow-wave sleep 3. More brain protein generation occurs during REM sleep (trying to restore balance in CNS) |
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12. What type of people proportionally have a lot more slow-wave sleep?
Three groups of people... |
1. Children during rapid growth periods
2. Adolescents during growth spurts 3. Athletes during times of training |
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13. According to the elimination theory of sleep, what is the purpose of sleep?
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We sleep to allow homeostasis to re-balance by ridding our body and brain of excess stimulation
Daily activity overloads our neural network and the overload has to be purged |
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14. What happens to our memories during sleep according to the elimination theory of sleep?
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During REM sleep there is memory consolidation (get rid of excess)
Hippocampus takes what is important, consolidates it, and store in LTM |
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15. What are the three general predictions of recuperative theories of sleep regarding sleep deprivation?
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1. Long periods of wakefulness will produce physiological and behavioral problems
(cumulative effect will cause break down) 2. Disturbances will worsen as sleep deprivation continues 3. At end of deprivation, you should make up ALL of the lost sleep |
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16. In reality, what does one experience due to sleep deprivation?
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Long periods of wakefulness do produce some physiological and behavioral problems but they are mild
-Not completely incompassitated |
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17. In reality how do we make up lost sleep?
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-Make up sleep in quality not quantity
-Don't make up sleep hour by hour but instead sleep an extra hour or two for two or so nights |
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18. What is the rebound effect?
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Whatever type of sleep you are more deprived of, causes you to have more of that type of sleep
ex. If you miss more REM sleep, than you have more REM sleep |
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19. What is the basis of circadian theories of sleep?
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These theories are based on the premise that sleep is controlled by an internal timing mechanism and is not a reaction to the adverse effects of wakefulness
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20. When subjects went into a cave without any light, what was their determined sleep cycle?
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Without any cues from earth, the body runs on a 25 hour cycle with about 8 hours of sleep
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21. What resets our circadian clock?
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Sunlight
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22. What is sleep according to circadian theories of sleep?
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Sleep is an instinct
An instinctive reaction to sunlight |
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23. What are two circadian theories of sleep?
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Immobilization Theory
Energy-Conservation Theory |
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24. Based upon the immobilization theory, what is sleep and its purpose?
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Sleep is an adaptive response that has evolved to promote safety
Sleep during the times we can't navigate and thus avoid the times of danger |
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25. What is the point of sleep according to the energy-conservation theory? When was this theory more important?
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Sleep provides a period of time when we can conserve our energy
This was more important when we were hunters and gathers because we only ate every 2-3 days |
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26. Looking at metabolic rates, what support is there for the energy-conservation theory of sleep?
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Higher metabolic rates are associated with longer periods of sleep
Those with higher metabolic rates sleep longer to conserve energy or else they'd burn too much energy |
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27. What are circadian rhythms?
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Daily cycles of body functions
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28. What is a free-running cycle?
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Circadian rhythms that do not depend on environmental cues to keep them on a regular schedule
-Don't have to be learned -About 25 hrs in a human |
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29. What are the two effects of REM-sleep deprivation?
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1. With each successive night of deprivation, there is a greater tendency to initiate REM sequences
1. The number of awakenings required to deprive a subject of REM sleep increases as the period of deprivation ensue 3. Following REM-sleep deprivation, there is a REM rebound |
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30. How does sleep deprivation increase the efficiency of sleep?
Four ways.... |
1. Regain most of lost stage 4 sleep
2. Higher proportion of slow-wave sleep 3. Short sleepers get just as must slow-wave sleep and long sleepers 4. Reducing sleep results in less stage 1 & 2 sleep but duration of slow-wave sleep remains the same |
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31. What is Bremer's passive theory of sleep?
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Theory claims that we are totally passive during sleep and pay no attention to sensory input
-The brain just shuts down in the absence of sensory input -There is no active sleep process |
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32. Where did Bremer severe the bain stem in cats? What is this cut called?
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Severed the brain stem between the inferior and superior colliculi (separated forebrain from hindbrain)
Cut is called Cerveau isole |
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33. What was the result of the cerveau isole preparation?
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Cut out all sensory input
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34. What was the pattern of sleep displayed by the cats of Bremer's experiment?
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They displayed continuous slow-wave sleep in their cortical EEGs
Continuous high-amplitude, slow-wave activity |
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35. How could the cats slow-wave EEG be changed into a desynchronized EEG?
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Present strong visual or olfactory stimuli
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36. What is a dsynchronized EEG?
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A low-amplitude, high frequency EEG
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37. Bremer also made an encephale isole preparation which disconnected the brain from what?
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An encephale isole disconnected the brain from the rest of the nervous system
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38. What was the result of an encephale isole?
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It cut most of the same sensory fibers as the cerveau isole transection but did not disrupt the normal cycle of sleep EEG and wakefulness EEG
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39. Based upon the cerveau isole and encephale isole transection where is the structure for maintaining wakefulness?
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It is somewhere in the brain stem between the two transections
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40. Moruzzi and Magoun made a third transection between the first two resulting in what sleep pattern by the cats?
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They were always awake
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41. What did Moruzzi and Magoun's transection cut through?
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The reticular formation
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42. What was found when the reticular formation of cats was electrically stimulated?
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The sleeping cats awakened and produced lengthy periods of EEG desynchronization when their reticular formation was electrically stimulated
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43. Based upon all of these findings, what did Moruzzi and Magoun propose?
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They proposed that low levels of activity in the reticular formation produce sleep and that high levels produce wakefulness
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44. What is Yerkes-Dodson Law?
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A law which states a relationship between arousal and task performance, arguing that there is an optimal level of arousal for performance, and too little or too much arousal can adversely affect task performance
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45. What is one complete sleep cycle?
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A complete descention and ascension through the four sleep stages and also a period of REM
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46. Roughly how long does it take someone to go through one sleep cycle?
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90 minutes
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47. During which part of the night do you have more slow-wave sleep? When do you have more REM sleep?
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Earlier in the night there is more slow-wave sleep
Later in the night more REM sleep is seen |
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48. What type of brain wave is seen on an EEG when someone is fully alert and thinking?
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Beta Waves
-High frequency (15-30 Hz) -Low amplitude -Irregular |
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49. What type of wave is associated with being relaxed but still awake?
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Alpha Waves
-Frequency: 8-12 Hz -Medium Amplitude -More regular -Waxing and waning bursts |
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50. When someone just falls asleep, what type of wave is observed?
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Theta Waves
-Frequency: 6-8 Hz -Medium Amplitude -Slower than beta waves |
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51. What are the waves of stage 1 sleep and what percent of time sleeping is stage 1 sleep?
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Theta Waves
5% of sleep time |
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52. What are the waves of stage 2? What makes these waves different from those of stage 1?
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Theta Waves
Theta waves have sleep spindles and k-complexes |
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53. What causes sleep spindles and k-complexes and what are their hypothesized functions?
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They are caused by external stimuli
Their function is to prevent waking (negate the sensory stimuli) |
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54. What are sleep spindles?
What external stimuli causes sleep spindles? |
Sleep spindles is a short, rapid burst of a 12 to 14 Hz wave
They are caused by noise |
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55. What are k-complexes?
What external stimuli causes k-complexes? |
K-complexes are a single large upward deflection followed y a single large downward deflection
(long, isolated high A wave) They are cause by tactile stimuli |
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56. What percentage of sleep time is spent in stage 2?
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45% of sleep time
*stage 2 sleep happens in 20 minute chunks |
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57. What happens if a person wakes up while in stage 1 or 2 sleep?
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They don't feel like they have slept
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58. What is stage 3 sleep?
What percentage of sleep time is spent in stage 3? |
Stage 3 sleep is a transitional stage where slow-wave sleep begins
It's 5% of sleep time |
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59. What waves characterize stage 3 sleep?
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Mostly Delta Wave
-Low frequency (1-3 Hz) -High amplitude Some Theta Waves |
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50. What is stage 4 sleep?
What percentage of sleep time is spent in stage 4? |
Stage 4 is slow-wave sleep
15% of total sleep time |
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51. What wave(s) characterize stage 4 sleep?
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All Delta Waves
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52. When does stage 4 sleep mostly occur?
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It occurs mostly in the fist 1-3 hours of sleep
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53. How are a person's muscles during stage 4 sleep?
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-Muscle tension is relaxed
-Lose some muscle tone but not all -person might snore -sleep walking can occur |
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54. How can someone be awakened from stage 4 sleep?
How will they feel if awoken from stage 4 sleep? |
Loud noises, real physical contact, saying persons name. stress, and anxiety
Waking up from stage 4 causes grogginess |
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55. What physiological changes are associated with stage 4 sleep?
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Decrease in heart rate, blood pressure, and body temperature
Breathing is slow and rhythmic |
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56. What are nightmares or night terrors?
When can they occur? |
They are short bursts of strong emotional experience that may be accompanied by short visualization
-have no continuity Occur during stages 3 & 4 |
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57. What is slow-wave sleep necessary for?
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Necessary for recuperation (especially for the brain)
Important to restore normal cognitive brain function |
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58. What are the effects of slow-wave sleep deprivation?
Five symptoms.... |
1. Tired
2. Sluggish 3. Motor control problems 4. Irritable 5. Long periods of deprivation can cause minor hallucinations |
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59. What is the main initiating area of the brain for sleep?
Where is this area located? |
Ventrolateral Preoptic Area (VLPA)
In the hypothalamus |
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60. What is the VLPA?
What does it do? |
Starting point for sleep, especially slow-wave sleep
It inhibits the cortex in order for relaxation and thus sleep |
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61. What specifically does the VLPA inhibit?
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Inhibits acetylcholingeric neurons on the basal forbrain area
(basal forbrain does not become stimulated) |
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62. What is associated with the basal forbrain area?
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Arousal and REM-sleep
This area releases neurons when one is starting to wake up |
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63. What is the pathway for arousal?
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Pons to
Basal Forbrain to Cerebal Cortex |
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64. What triggers waking?
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Reticular formation
(reticular activating system) |
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65. What are raphe nuclei?
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Small bundle of neurons in the mid area of the pons in the reticular formation
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66. What is neurotransmitter is released by the raphe nuclei?
What does this neurotransmitter do? |
Releases serotonin to bring on slow-wave sleep (stage 3 & 4)
Serotonin inhibits that areas in the pons responsible for initiating REM-sleep |
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67. What does damage to the raphe nuclei result in?
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Insomnia because one will hit stage 3 of sleep and wake up
(lack of slow-wave sleep) |
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68. What is initial stage 1 EEG?
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The first period of stage 1 EEG during a night's sleep not marked by a striking EOG or EMG changes
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69. What is emergent stage 1 EEF?
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Subsequent periods of stage 1 sleep EEG that are accompanied by REMs and a loss of tone in the muscles of the body core
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70. What is REM (rapid eye movement) sleep?
What is the brain wave activity during REM-sleep referred to as? |
A period of time were instead of reaching stage 1, REM sleep is began
Change in brain wave activity is referred to as paradoxical |
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71. What wave characterized REM-sleep?
Three types.... |
1. Small proportion of delta waves
2. Theta waves 3. Alpha waves *both awake and asleep waves |
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72. What are the characteristics of REM-sleep?
Five things.... |
1. Complete loss of muscle tone
2. Light sleep (wake easily) 3. Awake coherent and alert (better than if awake from slow-wave sleep) 4. Stage for dreaming 5. Increase heart rate and respiration |
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73. What are dreams?
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Dreams are story-like images or emotions that progress like a movie or show
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74. What are four reasons for why we have REM-sleep?
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1. Memory Consolidation
2. Brain Growth 3. Necessary for cortex to have periods of arousal/stimulation 4. Dampen any strong emotions (Freudian work out life's problems) |
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75. Why is it believed that REM-sleep is necessary for memory consolidation?
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Hippocampus (were information is temporarily stored) is active during REM-sleep
If REM-sleep is disrupted, people have poorer memory of the day's events (never formed memory) |
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76. How have sensory deprivation studies provided evidence that REM-sleep is necessary for cortical stimulation?
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Sensory deprivation studies showed that people will have hallucinations if no input is given to the cortex
Thus, if sensory input to the cortex is suppressed, than the cortex will create its own |
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77. What are the effects of REM-sleep deprivation?
Four symptoms.... |
1. Mild changes in behavior and personality
2. Anxious, irritable 3. Concentration problems 4. Increase in appetite (weight gain) |
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78. When will REM-sleep deprivation occur?
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If someone only sleeps 2-3 hours a night
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79. What is the pathway for dreaming and awakening?
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Peribrachial Area to
Locus Coeruleus to Basal Forbrain to Cortex |
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80. What is the primary neurotransmitter of REM-sleep?
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Acetylcholingeric released bby the Peribrachial area
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81. What neurotransmitter does the locus coeruleus release?
What does this neurotransmitter do? |
Releases neuroepinephrine
Neuroepinephrine excites the basal forbrain releasing acetylcholingeric neurons |
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82. How does the peribrachial area regulate rapid eye movement?
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It sends acetylcholine neurons to the the tectum
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83. What does the tectum do again?
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Contains superior colliculi which are a group of neurons that cause one to react to moving objects (tracking with eyes)
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83. How does th peribrachial area regular atonia?
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Release ACh neuron which stimulate the Subcoerulear Nucleus
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84. What is the subcoerulear nucleus' role in inhibiting motor neurons to produce atonia?
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It stimulates the nucleus magnocellularis of the medulla which inhibits motor neurons
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36. What is the active theory of sleep?
How was this theory tested by Moruzzi and Magoun |
Sleep is controlled by a brainstem arousal center
Tested with a transect below the brainstem: Encéphale isolé |
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85. What is the current state of opinion about whether sleep is active or passive?
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Sleep is an active, not a passive state
The brain is active during sleep, it’s just doing different things than when awake (specific neural circuits for sleep in the brain) |
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What is the reticular activating system?
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Neural structure that runs through the brainstem and midbrain
Pons and medulla |
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86. What is the importance of the tuberomammillary nucleus?
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Histamine in the tuberomammillary nucleus (TM) appears important for
wakefulness These neurons excite basal forbrain to release ACh neurons |
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87. What is the role of the suprochiasmatic nucleus?
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Nuclei of the medial hypothalamus that control the circadian cycles of various body functions
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88. What is the difference between hypnotic and anti-hypnotic drugs?
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Hypnotic drugs increase sleep
Anti-hypnotic drugs reduce sleep |
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89. What type of drugs are benzodiazepines?
What can be a result of using them? |
Hypnotic drugs
A tolerance develops to the hypnotic effects of benzodiazephines and cessation of them can cause insomnia |
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90. What are some anti-hypnotic drugs?
How do these drugs reduce sleepiness? |
Stimulants (amphetamines and cocaine) and tricyclic anti-depressants
Increase the activity of catecholamines |
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91. Which type of sleep do anti-hypnotic drugs act upon?
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Act upon REM-sleep
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92. What effect does melatonin have on sleep?
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It influences circadian rhythmicity
Plays role in promoting sleep or in regulating its timing in mammals |
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93. What is imipramine?
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The first tricyclic anti-depressant (anti-hypnotic drug)
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94. What is narcolepsy?
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A neurological disorder where sleep (or components of sleep) occur during wakefulness
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95. What is the primary symptom of narcolepsy?
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Sleep attack (just fall asleep)
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96. What are sleep attacks?
What do they occur most often? |
Sleep attacks are overwhelming urges to sleep anytime
*don't loss muscle tone Occur most often when one is not overly stimulated (i.e. monotonous task) |
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97. What are some other times during which sleep attacks can occur?
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1. Periods of extreme stress
2. Driving, eating, lecture |
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98. What component of sleep are sleep attacks and how long do they last?
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Slow-wave sleep component
1-10 minutes |
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99. What is cataplexy?
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Recurring losses of muscle tone during wakefulness, often triggered by an emotional experience
-collapse -fully conscious and awake, just can't move |
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100. What component of sleep are cataplexies?
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REM-sleep component
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101. What is sleep paralysis?
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It is atonia that happens when a narcoleptic has just fallen asleep or awoken (not dangerous)
-REM-sleep component were can't move for a couple of minutes |
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102. What are hypnagogic hallucinations?
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When a person wakes up but their dream continues so that it becomes superimposed in the room
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103. What component of sleep are hypnagogic hallucinations and with what other symptom do they usually occur?
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REM-sleep component
Usually occur with sleep paralysis |
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104. What medications are used to treat sleep attacks?
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Take amphetamines in the morning (catecholamine agonist)
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105. What medication is used to treat the REM-sleep components of narcolepsy?
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Imipramine
-It enhances serotonin and all other catecholamines by blocking re-uptake -Suppresses REM-slepp |
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106. What is REM without atonia?
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It is characterized by not losing muscle tone during REM-sleep
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107. What causes REM without atonia?
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The subcoerulear nucleus does not react to acetylcholingeric neurons
*failure within two brain areas |
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108. What can happen to someone who has REM without atonia?
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They can get up and walk around and act out their dreams
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109. What is done to treat someone who has REM without atonia?
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Give them some kind of drug to weaken their muscles before going to sleep
Muscles are relaxed so they can't get up and act their dream |
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110. What does the midpontine section do?
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It causes an increase of cerebral wakefulness
ACh neurons from the peribrachial area excite it which stimulates the basal forbrain |
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124. Why is it believed that females may actually determine the sex of the offspring?
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Females may determine sex due to physiological changes at time of conception
-pH of vagina may control which sperm (x or y) -Body fat of woman may control (strong in animal kingdom) |
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125. What gene on the Y chromosome is responsible for making the fetus male?
What does this gene code for? |
SRY gene on Y chromosome is sex determining sex
It codes for testes determining factor (TDF) |
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126. What does the TDF do?
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It is responsible for the development of testes in fetus
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127. What are primordial gonads?
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These are cells that every fetus has that are capable of developing into either reproductive system
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128. What are the male reproductive ducts called?
What are the female reproductive ducts called? |
Male: Wolffian Ducts
Female: Mullerian Ducts |
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129. What do the testes secrete?
What does this hormone do? |
Testes secrete testosterone as they develop
Testosterone helps the Wolffian system to further develop |
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130. Do primordial cells respond to testosterone?
If not what do they respond to? |
Primordial cells do not respond to testosterone directly
They respond a converted form called dihydrotestosterone |
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131. How is testosterone converted into dihydrotestosterone?
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5-alphareductase acts upon testosterone to convert it
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132. What other important chemical do the testes secrete?
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Mullerian-inhibiting substance
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133. Do the Mullerian ducts need hormonal input?
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No, they will develop on their own w/o any hormone input
(default system) |
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134. What is the purpose of Mullerian-inhibiting substance?
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It stops the Mullerian system from developing
It withers away the Mullerian ducts so that they die and are reabsorbed by the body |
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135. What are the gonads?
What hormone levels are highest in each type of gonad? |
Gonads are the testes and ovaries and they produce/release hormones to further develop reproductive systems
Testes: higher levels of test. Ovaries: higher levels of estrogen |
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136. What are the primary sex characteristics?
When do they form? |
Primary sex characteristics are both the internal and external sex organs
They are developed at birth |
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137. What are the secondary sex characteristics?
When do they appear? |
Secondary sex characteristics are physical changes that are a response to increased hormone levels
They appear during puberty |
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138. Are the male and female brains different?
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Hormones do produce some brain differentiations between male and female brains
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139. How are male brains different?
Four ways.... |
1. 15% larger in mass
2. Thalamus (relay station)is larger 3. Corpus collapsum is larger in males 4. Higher level of activity in limbic system and temporal lobe |
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140. What are two general difference between male and female brains?
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-differences in hypothalamus in terms of responding to hormones and their production
-Response to stimulation in cortex is different between male and female brains |
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141. How is the brain "masculinized?"
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Testosterone undergoes aromatization to form estradiol
Estradiol masculinizes the brain |
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142. What isn't the female brain "masculinized" since they have a lot more estradiol than males?
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Genetic females produce alpha fetus protein which deactivates extra circulating estradiol so less estradiol reaches the brain
*there is no alpha fetus protein in males |
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143. What is the definition of a hormone?
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A chemical secreted by a gland that is carried by the blood or lympathic system and affects target organs elsewhere
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144. What does the endocrine system consist of?
What is the important pathway in hormone regulation especially for reproductive development? |
Glands
HPG axis: hypothalamus, pituitary, and gonads |
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145. What role does the hypothalamus have in the HPG axis?
What specific hormone does it release? |
-The hypothalamus is the starting point
-It secretes releasing hormones -Secretes gonadotropin releasing hormone |
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146. What do the gonadotropin releasing hormones do?
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Travel to the pituitary where they stimulate the release of gonadotropin
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147. What are some gonadotropin hormones released by the pituitary?
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FSH (follicle stimulating hormone)
LH (luteinizing hormone) |
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148. In general, what do the gonadotropin hormones do?
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They travel to the gonads to stimulate the production and release of hormones by the gonads
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149. What does LH do in males?
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1. Responsible for maturation and development of sperm
2. Stimulates (increases) the production of testosterone |
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150. What does LH do in females?
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Increases the production of progesterone in females
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161. What is the role of progesterone in females?
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Pregnancy Hormone
-Helps prepare the uterus for pregnancy -High levels of progesterone help keep the egg implanted in the utereus |
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162. When do the progesterone levels begin to rise?
What happens if the levels drop during pregnancy? |
Rise after egg attaches (implants) to the uterus
If levels drop a miscarriage (spontaneous abortion) will occur |
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163. What does FSH do in females?
Two things... |
1. Responsible for increase production of estrogen by the ovaries
2. Stimulates the maturation of the ovum in the ovaries |
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164. What are two other hormones released by the pituitary?
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1. Basocrecin (not gonadotropin)
2. Oxitosin |
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165. What does basocrecin do?
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Responds to gonadotropin releasing hormone
1.Constricts blood vessels 2. Regulates rise in blood pressure 3. Regulates body temperature |
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166. What does oxitosin do?
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1. Responsible for controlling contractions during labor (stimulates labor)
2. Increases milk production |
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167. What does FSH do in males?
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Increases sperm in males
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168. What are the three classes of hormones produced and released by the gonads?
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1. Androgens
2. Estrogens 3. Gestagens |
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169. What does the androgen testosterone do in males?
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Necessary for development of primary sex characteristics and secondary sex characteristics
*also needed for libido and sexual behavior |
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170. What are the secondary sex characteristics in males?
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Further muscle development
Facial Hair Deepen Voice Widen chest/shoulder cavity |
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171. What does testosterone do in females?
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Regulates libido and body hair growth
-produced by ovaries *during puberty, there is increased hair growth due to testosterone |
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172. What is the important estrogen for females?
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Estradiol (most common estrogen)
*produced by both ovaries and testes |
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173. What does estradiol do in females?
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Triggers development of secondary sex characteristics (pelvic widens, breast growth)
Regulates menstrual cycle |
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174. What does estradiol do in males?
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Important for masculinzation of the brain
*if there is no estradiol in males, there is no deficit in sexual reproduction/behavior |
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175. What is an example of a gestagen?
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Progesterone
-both males and females produce it |
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176. What is the role of progesterone in males?
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No idea!!
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177. How are hormones regulated?
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Feedback mechanism (positive and negative)
-hormones monitor the glands that release them and further back in chain |
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178. What happens in a negative feedback mechanism?
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Level of hormone will stimulate decrease in production and release of hormone
-want to maintain an optimal range (homeostasis) through adjustments |
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179. In negative feedback what happens when hormone levels rise?
What happens when hormone levels fall? |
Increase hormone levels, decrease production/release of hormone
Low level of hormone, produce and release more of hormone |
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180. What happens in a positive feedback mechanism?
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Stimulate more change in the direction of the initial change
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181. In positive feedback what happens when hormone level rises?
What happens when hormone level decreases? |
High level of hormone stimulates more production/release of hormone
Low levels, reduce production/release |
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182. In positive feedback what would high levels of estradiol do?
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Stimulate the production and release of FSH and LH which in turn stimulate release of more estradiol
(levels get higher and higher) |
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183. When is a positive feedback mechanism seen?
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During first trimester and during puberty
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184. Why is positive feedback necessary during the first trimester?
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Increase levels of hormones to ensure the internal organs and reproductive system fully develops
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185. What are organizational effects?
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Organization of reproductive system, during fetal development usually
*internal/external organs develop during first trimester |
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186. What are activational effects?
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Happen after birth, usually during puberty
-activating system -regulates menstrual cycle and male sexual behavior |
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187. How are the hormones released in males?
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Acyclic basis
-maintained at steady level within a range |
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188. How do testosterone levels change throughout a male's life?
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There is a slight decrease in testosterone levels, but it is still usually above a threshold so they can still reproduce
-keep above threshold and still have sex drive |
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189. What sexual behaviors are directly related to testosterone?
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1. Intromission (penetration)
2. Pelvic thrusting 3. Ejaculation *testosterone is critical for male sexual behavior |
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190. What has chemical castration in humans shown?
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Chemical castration has shown evidence that if testosterone drops below a threshold there is decrease if not loss of the above mentioned sexual behaviors
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191. What happened in rats if testosterone was re-introduced after castration?
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Sexual behaviors will come back and stay as long as the rats keep being injecting with testosterone
*works in humans too if problem is too low levels of testosterone |
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192. What is the most critical brain area for regulating copulating behavior in males?
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Medial Preoptic Area (MPA)
*in hypothalamus |
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193. What kind of feedback is in the MPA?
How does the feedback mechanism work? |
Positive feedback loop
When stimulated sexual behaviors are produced (arousal,erection) and the behaviors themselves further stimulate the MPA producing more behaviors |
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194. What did lesion studies of MPA in rats show?
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If lesioned MPA, all sexual behavior was abolished but testosterone levels remain normal (high)
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195. How are hormones released in females?
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-Cycle cycle (28 days)
-Menstrual cycle -Starting point is hypothalamus |
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196. What is the difference between an estrous cycle and a menstrual cycle?
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An estrous cycle is not as regular/often as a menstrual cycle
Only humans and some primates have a menstrual cycle |
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197. When does the menstrual cycle begin?
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First day of period
-release of uterus tissue -menstruation Hypothalamus releases FSH so follicle can begin to develop |
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198. How long does menstruation last?
What are hormone levels like during menstration? |
Lasts 3-5 days
Low level of all hormones |
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199. What does the development of the follicle trigger?
How does this mechanism work? |
Triggers release of estrogen (estradiol)
Estradiol levels rise so that just before ovulation, the levels peak feeding back onto the hypothalamus |
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200. What triggers ovulation?
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High levels of LH
-Increasing levels of estradiol feed back onto hypothalamus causing sudden urge of LH |
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201. How long does the peak in LH last?
What happens when they start to drop? |
One day (around day 14)
LH drops off and estrogen starts to decrease b/c LH stops maturing of follicle |
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202. If estrogen levels are not high enough to trigger surge in LH will ovulation occur?
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NO, need high enough estrogen levels for ovulation
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203. What stimulates the release of progesterone?
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An empty follicle stimulates release
-have corpus luteem |
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204. What happens to the estrogen levels? What causes this?
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Estrogen levels rise again (not as high as before) due to corpus luteum
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205. When is the most fertile day? Why?
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Most fertile 4 days after ovulation because progesterone levels are high so egg could potentially inplant
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206. What happens if woman becomes pregnant?
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Fertilization triggers a mechanism in the uterus to continue production of estrogen and progesterone
-levels of these hormones go off the chart and remain high throughout pregnancy |
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207. What happens if the woman does not become pregnant?
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The corpus luteum shrivels and is reabsorbed by the body
*this causes a decrease in progesterone/estrogen levels which stimulates the beginning of the cycle again |
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208. What type of follicle and hormones are present during the preovulatory period?
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Primary and then secondary follicle
FSH, estrogen, surge in LH |
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209. What is present during the ovulatory period?
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corpus luteum
estrogen; progesterone |
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210. What was birth control originally intended to do?
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Introduce high levels of estrogen which would inhibit FSH if given early in menstrual cycle (1st few days)
-prevent follicle from reaching maturation |
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211. How are the birth control pills used presently designed?
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-Some still intro high estrogen level early in cycle
-New pills have combination of hormones (more effective) |
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212. What back up hormone is used in the new pills?
What does this do? |
Back up hormone in case follicle reaches maturity is progesterone
Fools body into thinking its pregnant so shut down LH and follicle isn't released (no ovulation) |
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213. What does plan B deliver?
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Mifeprisone
-steroid hormone that suppresses cortisol levels It blocks progesterone receptors by binding to them so progesterone levels drop off |
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214. What helps with sexual reproduction in female animals?
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Pheromones
Not sure about hormones |
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215. How can pheromones affect pregnant animals?
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If a new male is introduced, it may cause a spontaneous abortion due to new pheromones
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216. What is the Lee-Boot effect?
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When female mice are housed together without a male present, their estrous cycle is disrupted
-stop ovulating (not fertile) |
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217. What happens if a male is introduced?
What does this imply? |
If male is introduced, all the females go into estrous shortly after
The presence of males through pheromones regulate the estrous cycle (not there no need to waste energy) |
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218. What is the Whitten effect (only documented in animals)?
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When a single male is housed with a group of females, their estrous cycles become synchronized and more often
*his pheromones synchronize females cycles |
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219. A woman names McClintock studied the Whitten effect in human females, what did she observe?
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Observed that all females on her dorm floor were synchronized with their periods
-she believes this is the closest to Whitten effect -somewhere in environment that is an alpha male who is in contact with these females |
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220. What is the Bruce effect? (definite in animals, who knows in human females)
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An unfamiliar male coming into a colony will cause the spontaneous abortion of pregnant females
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221. What does the new male do when enters the colony?
What happens if he wins? |
Male fights over heron
If he wins, all the females go into estrous after aborting so they can mate with new controlling male *strategy to increase your genes |
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222. What is the Vandenberg effect?
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The presence of a male in the colony accelerate puberty in pre-pubescent females (go into puberty right then)
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223. What type of colony is necessary in order to see the Vandenberg effect?
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Usually a matriarchy colony
Male only comes around during estrous (mating session) |
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224. What brain area regulates sexual behavior in females?
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Ventromedial nucleus (VMH)
-part of hypothalamus -regulates receptive sexual behavior in females |
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225. How does the VMH regulate sexual receptive behavior in females?
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VMH becomes stimulated and causes her to go into Lordosis posture
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226. What is the lordosis posture?
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Female gets down low, arches her back, and flicks tail out of the way
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227. What have lesioning studies of the VMH in rats shown?
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If lesioned, rats won't show lordosis posture even if they are willing to mate so there is no reproduction
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228. On the other hand what do studies stimulating the VHM show?
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If VMH is stimulated, rats go into lordosis posture immediately
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229. What happens to females with a damaged hypothalamus?
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They do not engage in as much sexual behavior
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230. What is Androgenic Insensitivity Syndrome?
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There is a mutation on the Y chromosome on the androgen receptor gene
*Don't have androgen receptors |
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231. How does lack of androgen receptors affect fetal development?
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Still have intact SRY gene so the testes start to develop but don't fully develop because there are no androgen receptors
*testes still secrete Mullerian-inhibiting substance so female reproductive system is destroyed |
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232. What is the result of a lack of androgen receptors?
Four results.... |
1. Normal male levels of testosterone
2. Have small internal testes 3. External genitals of female since they don't need hormonal regulation 4. No masculization |
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233. Is androgen insensitivity reversible?
How is it treated? |
It's not reversible and it can't be treated with hormonal therapy
Treatment is to suppress levels of testosterone and elevate estrogen (adjust to that of female) |
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234. What role does the adrenal gland have in congenital adrenal hyperplasia?
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There is a deficiency in the release of cortisol by the adrenal gland which results in compensatory adrenal hyperactivity and the excessive release of adrenal androgens (positive feedback)
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235. What effect does congenital adrenal hyperplasia have on males?
What about females? |
In males it accelerates onset of puberty
In females they look like an underdeveloped male at birth (enlarge clitoris and fused labia) *1 in 1400 live births |
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236. How are females with congenital adrenal hyperplasia treated?
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At 6 months they are given meds that increase cortisol to normal levels thus bringing testosterone down (suppress)
-reset the mechanism and everything operates normally -not a long treatment -surgically alter external genitals |
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237. What is Tuner's Syndrome?
How many does it affect and who? |
Its a defect on the X chromosome
1 in every 2000 live births have it Affects only females b/c males with it don't survive (only have Y chromosome) |
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238. What is the defect on the X chromosome?
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50% with it are XO (missing X)
30% with it a have a normal X and half of a second X (X1/2X) The rest have a serious mutation on the 2nd X chromosome |
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239. What are the characteristics of Tuner's Syndrome?
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1. Ovarian failure (1% can get pregnant)
2. Short (under 5"1') 3. Broad chest cavity 4. Receding jaw line 5. Small hands/feet 6. Affect cardiovascular system (disease starting in childhood) 7. Prone to kidney disease or failure (esp at young age) 8. Higher incidence of diabetes *treat usually just symptoms they are prone to |
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240. Who are the Guevedoces of Salinas?
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Genetic males who at birth appear to female (no male genitals, but no vagina either)but during puberty develop into fully functioning males (penis/balls)
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241. What is the genetic disorder they have?
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They lack 5-alphareductase (don't have gene that codes for it)
Wolffian system goes dormant b/c testosterone can't be converted into dihydrotestosterone |
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242. Why do they "turn" male at puberty?
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Testes pump out testosterone which adult cells can respond to so scrotum grows, testes descend, penis forms, and become fertile males
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243. Where is this mostly seen?
Why does this genetic disorder keep being passed on? |
It seen in isolated communities (small villages, islands)
People with genetic mutation are seen as sex symbols b/c they can "change their sex" so they reproduce a lot |
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244. What is ablatio penis mean?
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Accidental destruction of the penis
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