Endocrine system

• What is the primary role of the endocrine system?

  Communication and control of physiological processes
• How do biochemical reactions affect a cell's appearance and behavior?


  They are the combined effects of biochemical reactions
• How can a cell change its behavior?

  By affecting enzyme activity in biochemical pathways
• Why do multicellular organisms need control over their cells?

  To maintain extracellular environment and homeostasis
• What are the secreted chemicals that control cell behavior called?

  Hormones
• What are the levels of control in the endocrine system?

  • Autocrine: affects same cell
  • Paracrine: affects neighboring cells
  • Endocrine: hormones released into bloodstream
  • Neurohormones: hormones made in neurons
  • Neurotransmitters: released into synaptic gap
  • Pheromones: organism to organism communication
• What type of hormones are the most abundant?

  Peptide hormones
• How are peptide hormones synthesized?

  Similar to other proteins in secretory vesicles
• What is the half-life of peptide hormones?

  Short, several minutes
• How do peptide hormones trigger changes in cells?

  By binding to cell surface receptors
• What are the two tissues that convert cholesterol to active steroid hormones?

  Adrenal cortex and gonads
• What is the nature of steroid hormones?

  Derived from cholesterol
• How do steroid hormones travel in the blood?

  Bound to carrier proteins
• What is the mechanism of action for steroid hormones?

  Bind to intracellular receptors and act as transcription factors
• From which amino acids are amino acid-derived hormones made?

  Tryptophan and tyrosine
• How do catecholamines act in the body?

  Bind to cell membrane receptors
• What is the role of the hypothalamus in the endocrine system?

  Controls the endocrine system via the pituitary gland
• How many important peptide hormones does the hypothalamus release?

  Nine
• What is the function of the anterior pituitary gland?

  Secretes hormones regulated by the hypothalamus
• What hormone stimulates cell growth and replication?

  Growth Hormone (GH)
• What does Prolactin stimulate?

  Development of mammary glands and milk production
• How does the hypothalamus control the release of TSH?

  Through Thyrotropin Releasing Hormone (TRH)
• What does Follicle Stimulating Hormone (FSH) stimulate in females?

  Follicle development and estrogen secretion
• What is the role of Luteinizing Hormone (LH) in males?

  Causes androgen production
• What does Melanocyte Stimulating Hormone (MSH) stimulate?

  Melanin production in melanocytes
• What hormone decreases the amount of water lost by kidneys?

  Antidiuretic hormone (ADH)
• How does the hypothalamus influence the pituitary gland?

  By releasing regulatory hormones into capillaries
• What is the role of the limbic system in relation to the hypothalamus?

  Influences the hypothalamus's functions
• What are neurohormones and their function?

  Hormones made in neurons released into bloodstream
• How do neurotransmitters differ from hormones?

  Neurotransmitters act locally, hormones act systemically
• What is the function of endorphins?

  Act as endogenous peptide 'opioid' neurotransmitters
• How do catecholamines affect target cells?

  Bind to cell membrane receptors
• What hormone stimulates ACTH release?

  Corticotrophin Releasing Hormone (CRH)
• What does Follicle Stimulating Hormone (FSH) do?

  Stimulates follicle development and sperm production
• What is the role of Leutinizing Hormone (LH) in females?

  Causes ovulation and progesterone production
• What promotes the secretion of FSH and LH?

  Gonadotropin Releasing Hormone (GnRH)
• What are the hormones of the adenohypophysis?

  • Follicle Stimulating Hormone (FSH)
  • Leutinizing Hormone (LH)
  • Melanocyte Stimulating Hormone (MSH)
  • Endorphins
• What does Melanocyte Stimulating Hormone (MSH) stimulate?

  Stimulates melanin production in melanocytes
• Where is antidiuretic hormone (ADH) manufactured?

  In the supraoptic nucleus
• What is the effect of antidiuretic hormone (ADH)?

  Decreases amount of water lost by kidneys