NS 3410 1st Edition Lecture 9Outline of Last LectureI. Dermal-Epidermal Junction Zone or Basement Membrane ZoneII. Epidermolysis Bullosa ComplicationsIII. Types of Inherited EBIV. Possible TreatmentsOutline of Current LectureI. Types of Intracellular CommunicationII. Exocrine GlandsIII. Endocrine GlandsIV. Major Endocrine Organs, Glands, TissuesV. Mechanisms of Hormone ActionCurrent LectureI. Types of Intracellular Communication- Direct communication-Transmitted through gap junctions-Chemical mediators are ions, small solutes, lipid-soluble materials-Distribution of Effects: limited to adjacent cells of the same type that are interconnected by connexons- Paracrine communication-Transmitted through extracellular fluid-Chemical mediators are paracrine factors-Distribution of Effects: limited to a local area where paracrine factor concentrations are relatively high. Target cells must have appropriate receptorsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Endocrine communication-Transmitted through bloodstream-Chemical mediators are hormones-Distribution of Effects: target cells are primarily in other tissues and organs and must have appropriate receptors- Synaptic communication-Transmitted across synaptic clefts-Chemical mediators are neurotransmitters-Distribution of Effects: limited to very specific area; target cells must have appropriate receptorsII. Exocrine Glands- Exocrine glands are glands that secrete a substance out through a duct-Includes salivary glands, sweat glands, glands within GI tract- They are more numerous than endocrine glands- Secrete their products onto body surfaces, into body cavities or into lumen of organ- The mucus are unicellular glands of simple columnar epithelial cells that function to secrete mucus using both apocrine and merocrine methods of secretion- Multicellular exocrine glands are composed of a duct and secretory unit- Modes of secretion:-Merocrine: products are contained in vesicles and are secreted by exocytosis. No part ofthe gland is damaged or lost. Example is a sweat gland. Least destructive to gland-Apocrine: a portion of the plasma membrane buds off the cell, containing the secretion.This is pinched off producing membrane bound vesicles in the lumen. Example is lipid secretion from mammary gland-Holocrine: cell ruptures to release contents. Example is sebaceous glands of skin. Most disruptive to gland- Exocrine glands: sweat glands, salivary glands, mammary glands, stomach, pancreas, liverIII. Endocrine Glands- Endocrine glands secret a substance (hormone) for export into bloodstream- A hormone is a substance released by an endocrine gland and transported through the bloodstream to a target tissue where it has its effects on regulating the function of that tissue-A hormone is more broadly defined as any chemical, irrespective of whether it is produced by a special gland or not, for export or cellular use, that controls and regulates the activity of certain cells or organs- Paracrine hormone actions: hormone has its effects locally on cells other than those in which they were produced. Produced within one tissue and regulate a different tissue of the same organ- Autocrine hormone actions: the hormone acts on the same cell type in which it was produced- Intracrine hormone actions: the hormone acts within the specific cell without ever beingreleased- Hormonal Control and Body Functions:-Reproduction-Growth and development-Mobilization of body defenses-Maintenance of electrolyte, water and nutrient balance-Regulation of cellular metabolism-Regulation of energy balanceIV. Major Endocrine Organs, Glands, Tissues- Pineal gland: produces melatonin- Pituitary gland- Pancreas: insulin- Ovaries: estrogen- Testes: testosterone- Thyroid gland: thyroid hormone- Parathyroid glands (4): parathyroid hormone- Adrenal glands (2): aldosterone - Hypothalamus: gonadotropin releasing hormone- Thymus- Placenta- Kidney- GI tract: stomach and intestine- Adipose- Heart- BoneV. Mechanisms of Hormone Action- Hormone binding protein: many hormones have specific plasma proteins that bind hormone and transport throughout the body-Free hormone: not bound to a binding protein-Bound hormone: bound to carrier protein-Free hormone thought to be biologically active- Hormone receptor: found in target tissues. Cell must express the receptor for the hormone in order to be responsive to the hormone. Receptors can be expressed on the cell membrane of within the cell. Hormones that are not lipid soluble bind to receptors on plasma membrane- Hormone response elements: genes that are responsive to a hormone will express hormone response elements that recognize the hormone-receptor complex and can then increase or decrease expression of the target gene- Non-Genomic: primary target is the cell membrane-Activation/repression of pre-existing cell proteins-Set off intracellular second messengers-Rapid onset of action-Rapid adaptation to changes in the milieu- Genomic: primary action through specific intracellular receptors-Gene expression and new protein synthesis-Relatively long latency of onset-Organization of cell networks for complex functions- Non-Genomic Mechanism:-Hormone is primary messenger-It binds to a receptor bound to cell membrane-Activates a G-protein-Activates adenylate cyclase which activates cAMP (a second messenger)-cAMP acts as second messenger to activate kinase, which then activates other enzymes- Genomic Mechanism:-Nonpolar hormone can diffuse through membrane and bind to receptor in cytoplasm-Transported into nucleus where it binds to specific areas of DNA that are specific for that hormone-receptor-Activates target genes-Leads to transcription and then translation-Secrete protein needed for