Endocrine

• What does the endocrine system produce?

  Hormones
• How do hormones function in the body?

  They regulate various cells, tissues, and organs
• What is the primary difference between the nervous system and the endocrine system?

  The nervous system uses electrical signals, while the endocrine system uses hormones
• Which part of the brain coordinates most endocrine functions?

  The hypothalamus
• How are hormones secreted into the body?

  They are secreted into the vascular system and connective tissue spaces
• What are the main types of hormones produced by the endocrine system?

  • Steroids
  • Small peptides, proteins, and glycoproteins
  • Amino acid analogues and derivatives
• Where are steroid hormones produced?

  Ovaries, testes, and adrenal cortex
• Which organs produce small peptides, proteins, and glycoproteins?

  Hypothalamus, pituitary gland, thyroid gland, parathyroid, pancreas, enteroendocrine cells
• What type of hormones do neurons and adrenal medulla cells produce?

  Amino acid analogues and derivatives
• How are steroid hormones transported to target cells?

  They are secreted into the blood and transported via plasma proteins
• How do catecholamines differ in their mode of release compared to thyroid hormones?

  Catecholamines dissolve readily in blood, while thyroid hormones require specialized proteins
• What is the mechanism of action for hormones like catecholamines?

  They bind to specific receptors on target cells to elicit a response
• What is negative feedback in hormone regulation?

  It occurs when the response diminishes the original stimulus
• What is positive feedback in hormone regulation?

  It occurs when the response enhances the original stimulus
• What is the pituitary gland also known as?

  Hypophysis
• How is the pituitary gland attached to the hypothalamus?

  It is attached via the infundibulum
• What is the average weight of the pituitary gland in males?

  0.5g
• What is the average weight of the pituitary gland in multiparous women?

  1. 5g
• What are the functional components of the pituitary gland?

  • Anterior lobe (adenohypophysis)
  • Posterior lobe (neurohypophysis)
• What type of tissue makes up the anterior lobe of the pituitary gland?

  Glandular epithelial tissue
• From where is the anterior lobe derived?

  It is derived from an evagination of the ectoderm of the oropharynx
• What type of tissue makes up the posterior lobe of the pituitary gland?

  Neural secretory tissue
• From where is the posterior lobe derived?

  It is derived from a down-growth of neuroectoderm of the 3rd ventricle (diencephalon)
• What are the parts of the anterior lobe (adenohypophysis)?


  • Pars distalis
  • Pars tuberalis
  • Pars intermedia
• What are the parts of the posterior lobe (neurohypophysis)?


  • Infundibulum
  • Pars nervosa
• What is the primary function of the anterior lobe of the pituitary gland?

  It regulates other endocrine glands and some non-endocrine tissue
• How are the cells in the anterior lobe organized?

  They are organized in clumps and cords separated by fenestrated sinusoidal capillaries
• What are trophic hormones secreted by the anterior lobe?

  ACTH, TSH, FSH, LH
• What are non-trophic hormones secreted by the anterior lobe?

  GH and prolactin
• What are the types of chromophils found in the anterior lobe?

  • Acidophils
  • Basophils
• What do acidophils in the anterior lobe secrete?

  Prolactin (PRL) and Growth Hormone (GH)
• What do basophils in the anterior lobe secrete?

  ACTH, FSH, LH, and TSH
• What are chromophobes in the anterior lobe?

  They lack stainable cytoplasmic granules and represent undifferentiated or resting chromophobes
• What is the structure of the pars intermedia in the pituitary gland?

  • Surrounds small cystic cavities
  • Contains parenchymal cells surrounding colloid-filled follicles
  • Contains basophils and chromophobes
• What is the function of the pars nervosa in the pituitary gland?


  It stores and releases secretory products from the hypothalamus
• What type of tissue is the pars nervosa?

  Neural lobe
• What are Herring bodies?

  They contain oxytocin and ADH
• What are pituicytes?

  Glial cells associated with fenestrated capillaries in the pars nervosa
• Where is the thyroid gland located?

  In the anterior neck region adjacent to the larynx and trachea
• What surrounds the thyroid gland?

  A connective tissue capsule