Hormone Production

• When do circadian rhythms make you feel alert?

  In the morning
• What are the two main hormones involved in circadian rhythms?

  Melatonin and Cortisol
• What does the hypothalamus release to influence the anterior pituitary?

  Hormones that stimulate or inhibit
• What is the first step in melatonin synthesis?

  Tryptophan is converted to serotonin
• What are the three types of biological rhythms and their cycle lengths?

  • Circadian: ~24 hours (e.g., sleep-wake cycle)
  • Ultradian: Less than 24 hours (e.g., heartbeat)
  • Infradian: More than 24 hours (e.g., menstrual cycle)
• Where is cortisol synthesized?

  Adrenal cortex
• What is the cycle length of circadian rhythms?

  ~24 hours
• How do circadian rhythms affect sleep?

  They control the sleep-wake cycle
• How do the functions of the anterior and posterior pituitary differ?

  Anterior releases hormones; posterior stores hormones
• What are the two pathways through which the hypothalamus controls the pituitary gland?

  • Anterior Pituitary: Releases hormones indirectly via blood vessels
  • Posterior Pituitary: Stores hormones with direct neural connections
• What are the hormonal activities during the evening/night (6pm-6am)?

  • Peak melatonin
  • Peak neutrophils
  • Peak body temperature
• Where is melatonin produced?

  Pineal gland
• What role does melatonin play in the body?

  Regulates sleep-wake cycle
• What are circadian rhythms?

  Body's internal clock on a 24-hour cycle
• How does the hypothalamus maintain stable body conditions?

  By responding to signals from receptors
• What does the posterior pituitary do with hormones?

  Stores and releases hormones
• Why are these hormonal fluctuations important?

  They maintain optimal biological function
• How does the hypothalamus link the nervous system to the endocrine system?

  By controlling the pituitary gland
• What is the role of the hypothalamus in hormone production?

  It acts as the master control center
• What do circadian rhythms regulate?

  Sleepy and hungry feelings
• How is serotonin converted to melatonin?

  Serotonin is methylated
• What are the hormonal activities during the morning (6-9am)?

  • Peak cortisol
  • Peak testosterone
  • Peak insulin
• What are the consequences of hormonal imbalances on daily life?

  • Affects sleep-wake cycle
  • Impacts mood
  • Influences metabolism
  • Overall health deterioration
• What are the roles and triggers of Melatonin and Cortisol?

  • Melatonin:
  • Role: Regulates sleep-wake cycle
  • Peak Production: At night
  • Trigger: Darkness
  • Cortisol:
  • Role: Stress response, energy levels
  • Peak Production: Early morning
  • Trigger: Stress, activity
• What is the effect of Cortisol on your body?

  It wakes you up and prepares you for the day
• How do the nervous and endocrine systems use feedback mechanisms?

  • Both systems maintain homeostasis
  • They regulate temperature and water levels
• What happens to cortisol levels in the morning?

  Cortisol peaks in the morning
• What types of receptors send signals to the hypothalamus?

  Thermo- and osmoreceptors
• What amino acid is melatonin made from?

  Tryptophan
• What are the hormonal activities during the day (Noon-5pm)?

  • Peak alertness
  • Peak muscle strength
  • Peak lipid levels
• How do Melatonin and Cortisol interact in the circadian rhythm?

  Melatonin promotes sleep, while Cortisol promotes wakefulness
• What are the effects of high or low cortisol levels?

  Fatigue, mood swings, metabolic issues
• What pattern does hormone production follow?

  Circadian pattern
• What is the first transformation in cortisol synthesis?

  Cholesterol to pregnenolone
• What is the starting substance for cortisol synthesis?

  Cholesterol
• What happens to pregnenolone in cortisol synthesis?

  It undergoes enzymatic transformations to cortisol
• What are the synthesis steps for melatonin and cortisol?

  Melatonin:

  1. Tryptophan to serotonin
  2. Serotonin methylated to melatonin

  
  

  Cortisol:

  1. Cholesterol to pregnenolone
  2. Pregnenolone through enzymatic transformations to cortisol
• What are the components of the negative feedback mechanism?

  • Receptor: Detects changes
  • Control center: Processes information
  • Effector: Initiates corrective action
• What is the relationship between hormone production and sleep-wake cycles?

  Hormone production synchronizes with sleep-wake cycles
• What is homeostasis?

  It is the maintenance of stable internal conditions