FinalCC

• Endocrinology


  The scientific study of the function and pathology of endocrine glands

  
• Components of the Endocrine System


  • A network of ductless glands that secrete hormones directly into the blood
  • Considered to be the regulatory system of the body
  • Regulated by means of control of hormones synthesis rather than by degradation

  
• Characteristics of the Endocrine System

  • Cyclicity: production of hormones occur in cycles or in patterns
  • Pulsatility: production of hormones in pulses or periodic intervals
  • Feedback mechanism
• Positive Feedback System


  An increased in the product also increases the activity of the system and the production rate
• Negative Feedback System


  An increased in the product decreases the activity of the system and the production
• Hormones


  Active chemical substances produced by specialized cells, transported by the blood stream to other tissues where they exert specific metabolic regulatory effects affecting the body as a whole
• Functions of Hormones

  • Regulatory: Maintain constancy of chemical component of plasma, interstitial and intracellular fluids
  • Morphogenesis: To control type and rate of growth of an organism
  • Integrative action: The presence of other hormones is important for efficient functioning
• Types of Hormones

  • Endocrine
  • Paracrine
  • Autocrine
  • Neurocrine
• Hormone Actions


  • Proteins/Polypeptides
  • Glycoproteins
  • Steroids
  • Amino acid derivative
• Hormone Composition or Structure

  • Amines
  • Polypeptides
  • Glycoproteins
  • Steroids
  • Eicosanoids
• Hormone Functions


  • Releasing hormones
  • Inhibiting hormones
  • Trophic hormones
  • Effector hormones
• Hormone Properties


  • Lipophilic
  • Hydrophilic
• Regulation of Hormones


  • The majority of endocrine functions are regulated through the pituitary gland, which in turn is controlled by secretions from the hypothalamus
• Hypothalamus


  • Small organ located below the brain, above the pituitary gland
  • Connected to posterior pituitary gland through infundibular stalk
  • Supraoptic and paraventricular nuclei produce vasopressin and oxytocin
  • Neurons in the anterior portion are responsible for the secretion of all Releasing hormones which targets the pituitary gland

  
• Hormones of the Hypothalamus


  • Releasing: TRH, GHRH, PRF, CRH, GnRH
  • Inhibiting: GHIH, PIH
• Pituitary Gland


  • Also referred to as "hypophysis"- undergrowth
  • Connected to the hypothalamus through the infundibulum or the pituitary stalk
  • Located in a small cavity in the sphenoid bone of the skull called the sella turcica
  • Three distinct parts: Anterior/Adenohypophysis, Posterior/Neurohypophysis, Intermediate lobe

  
• Anterior Pituitary Cell Types


  • Somatotropes
  • Lactotropes or mammotropes
  • Thyrotropes
  • Gonadotropes
  • Corticotropes

  
• Anterior Pituitary Hormones


  • Tropic hormones: TSH, ACTH, GH, FSH, LH
  • Effector hormones: Prolactin
• Growth Hormone

  • Most abundant of all pituitary hormones
  • Vital hormone for normal growth
  • Release is stimulated by GHRH, inhibited by Somatostatin
  • Secreted in pulses
• Actions of Growth Hormone

  • Influences anabolic and catabolic process
  • Indirect effects mediated by insulin-like growth factors (IGFs)
• Growth Hormone Disorders

  • Excess GH: Gigantism, Acromegaly
  • GH Deficiency: Pituitary dwarfism
• Prolactin

  • Otherwise known as the pituitary lactogenic hormone; stress hormone; direct effector hormone
  • Functions in the initiation and maintenance of lactation
  • Acts in conjunction with estrogen and progesterone to promote breast tissue development
• Endocrinology

  The scientific study of the function and pathology of endocrine glands

  
• Components of the Endocrine System


  • A network of ductless glands that secrete hormones directly into the blood
  • Considered to be the regulatory system of the body
  • Regulated by means of control of hormones synthesis rather than by degradation
• Characteristics of the Endocrine System

  • Cyclicity: production of hormones occur in cycles or in patterns
  • Pulsatility: production of hormones in pulses or periodic intervals
  • Feedback mechanism
• Positive Feedback System


  An increased in the product also increases the activity of the system and the production rate
• Negative Feedback System


  An increased in the product decreases the activity of the system and the production
• Hormones


  Active chemical substances produced by specialized cells, transported by the blood stream to other tissues where they exert specific metabolic regulatory effects affecting the body as a whole
• Functions of Hormones


  • Regulatory: Maintain constancy of chemical component of plasma, interstitial and intracellular fluids
  • Morphogenesis: To control type and rate of growth of an organism
  • Integrative action: The presence of other hormones is important for efficient functioning
• Types of Hormones


  • Endocrine
  • Paracrine
  • Autocrine
  • Neurocrine
• Hormone Actions


  • Proteins/Polypeptides
  • Glycoproteins
  • Steroids
  • Amino acid derivative
• Hormone Composition or Structure


  • Amines
  • Polypeptides
  • Glycoproteins
  • Steroids
  • Eicosanoids
• Hormone Functions


  • Releasing hormones
  • Inhibiting hormones
  • Trophic hormones
  • Effector hormones
• Hormone Properties


  • Lipophilic
  • Hydrophilic
• Regulation of Hormones


  • The majority of endocrine functions are regulated through the pituitary gland, which in turn is controlled by secretions from the hypothalamus
• Hypothalamus


  • Small organ located below the brain, above the pituitary gland
  • Connected to posterior pituitary gland through infundibular stalk
  • Supraoptic and paraventricular nuclei produce vasopressin and oxytocin
  • Neurons in the anterior portion are responsible for the secretion of all Releasing hormones which targets the pituitary gland
• Hormones of the Hypothalamus


  • Releasing: TRH, GHRH, PRF, CRH, GnRH
  • Inhibiting: GHIH, PIH
• Pituitary Gland


  • Also referred to as "hypophysis"- undergrowth
  • Connected to the hypothalamus through the infundibulum or the pituitary stalk
  • Located in a small cavity in the sphenoid bone of the skull called the sella turcica
  • Three distinct parts: Anterior/Adenohypophysis, Posterior/Neurohypophysis, Intermediate lobe

  
• Anterior Pituitary Cell Types


  • Somatotropes
  • Lactotropes or mammotropes
  • Thyrotropes
  • Gonadotropes
  • Corticotropes

  
• Anterior Pituitary Hormones


  • Tropic hormones: TSH, ACTH, GH, FSH, LH
  • Effector hormones: Prolactin