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Endocrine DrAbrahams
AP2 Endocrine system Dr. Abrahams
Question | Answer |
---|---|
Pineal Gland: Hormone and Main Function | Melatonin and Biological Clock |
Hypothalamus: Hormone(s)and Main Function | Antidiuretic hormone (ADH) Acts on the kidney to preserve fluid and electrolyte balance and Proopiomelanocortin (POMC)Precursor hormone for ACTH and MSH |
Pituitary: Hormone(s) | Luteinizing hormone (LH) Follicle Stimulating hormone (FSH) Adrenocorticotrophic hormone (ACTH) Growth Hormone (GH) Prolactin (PrL) Melanocyte stimulating hormone (MSH) Thyroid stimulating hormone (TSH) |
What is LH? | Luteinizing hormone produced by Pituitary gland. In females this LH acts on the ovary to stimulate the production of estrogens and induce ovulation. In males this LH acts on the testis to stimulate the production of testosterone. |
What is FSH? | Follicle Stimulating hormone produced by Pituitary Gland. In females FSH stimulates the maturation of ovarian follicles. In males FSH acts on Sertoli cells and participates in the regulation of sperm production |
What is ACTH? | Adrenocorticotrophic hormone produced by Pituitary gland. ACTH acts on the adrenal gland to stimulate the production of cortisol. |
What is GH? | Growth Hormone produced by Pituitary gland. GH acts of various tissues to stimulate the growth |
What is Prl? | Prolactin produced by Pituitary gland. Prl activates Milk let down during lactation |
What is MSH? | Melanocyte stimulating hormoneis produced by Pituitary gland. MSH Stimulates skin tone. |
What is TSH? | Thyroid stimulating hormone produced by Pituitary gland. TSH acts on the thyroid gland to signal the production of thyroxin |
Pancreas: Hormone and Main Function | Insulin - Regulates blood sugar levels. |
Thyroid: Hormone and Main Function | Triiodothyronine and thyroxine ( T3 and T4) Development of the brain and reproductive tract, and regulation of metabolism |
Adrenal: Hormone(s) and Main Function | Cortisol - Immune suppression and stress response Dehydroepiand-rostendione (DHEA) |
Ovary: Hormones | Estrogens Progesterone Testosterone Inhibin |
What is E2 or E1 or E3? | Estrogens produced by ovary. estradiol, estrone, estriol(E2 E1 E3) Growth promotion, maintain elasticity of connective tissues, preserve bone mass and, vascular compliance. |
What is P4? | Progesterone is produced by Ovary. P4 Maintain endometrium in preparation for pregnancy |
What is T? | Female: Testosterone produced by Ovary. T is Precursor for estrogen and acts on libido. Male: Testosterone produced by Testis. Growth of male secondary sexual characteristics, sperm production and libido |
What is Inhibin? | Inhibin is produced by Ovary in female and Testis in male. In both it is handles Feedback regulation on pituitary FSH secretion |
Testis: Hormones | Testosterone (T) Dihydrotestosterone (DHT) Inhibin |
What is DHT? | Dihydrotestosterone is produced by the Testis. DHT Some male secondary sexual characteristics. |
Placenta: Hormone(s) and Main Function | Progesterone P4 and Estriol E3 Maintenance of pregnancy |
T or F: Endocrine hormones may be either proteins or steroids. | True |
Intercellular Communication can be Direct or Indirect how? | Direct: -through cellular junctions like connexons or gap junctions Indirect: 1)via paracrines or local hormones like prostaglandins, histamines, local growth hormones 2)via endocrine agents or hormones 3)via Synapes and neurotransmitters. |
Define Exocrine Glands: | Glands with ducts to deliver their secretions a relatively SHORT distance to a target. Deliver secretions onto epithelial surface. |
Examples of Exocrine Glands | Skin glands (apocrine, merocrine sebaceous) Mammary Salivary Pancreatic acini Gastric Glands |
Define Endocrine Glands: | Glands without ducts that rely on diffusion of their chemical messenger into the circulatory system for transport to a more DISTANT target. |
Examples of Endocrine Glands: | Thyroid and Parathyroid Adrenal Pancreatic Islets Gonads (testes and ovaries) Pineal Gland Anterior Pituitary |
Define Hormone: | Hormone is a chemical messenger secreted by a DUCTLESS (endocrine) gland, diffused into the blood and transported some distance to a target. |
Define Target: | Target - any cell, tissue, gland or organ that responds to a hormone. target’s recognition is due to the presence of a RECEPTOR |
Target Receptor is: | -often, but not always a surface protein molecule -part of the cell’s glycocalyx (carbohydrate on the surface) |
Define Paracrine: | Paracrines local hormones that act on nearby cells. do not commonly travel through the blood like circulating hormones. |
Example of a Paracrine: | IL-2 and (NO) IL-2 (Interlekine) can also act as autocrine |
Define Autocrine: | Autocrines are a group of local hormones that act on the same cell that secreted them. |
Autocrine Example: | IL-2 This is positive feedback |
Define Tropic Hormone: | Hormone that targets another endocrine gland. |
Example of Tropic Hormones: | Adrenocorticotropic Hormone (ACTH)stimulates adrenal Thyroid Stimulating Hormone (TSH) Follicle Stimulating Hormone (FSH) - act on gonads Luteinizing Hormone (LH) - act on gonads Hypothalamic Releasing and Inhibiting Factors (Rfs and Ifs) |
Describe the difference between Hormonal Hypersecretion and Hyposecretion: | Hypersecretion - too much hormone secretion endocrine glands tumors often result in hypersecretory syndromes Hyposecretion - not enough hormone secretion |
Describe the Spectrum of Secretion: | Extreme Extreme Hyposecretion --Normosecretion------Hypersecretion <-------- --------> |
Describe Lipid vs Water Soluble Hormone Transport: | Most lipid soluble hormones and thyrohormones, once produced, are secreted into the blood. Once in the blood,the hormone binds to a plasma protein forms an inactive protein hormone complex. Most water soluble hormones are transported in free form. |
Describe a Bound vs Free Hormone: | Bound hormone is inactive Free hormone is active |
Describe what happens when the Hormone reaches the Target: | At the target: free (active) hormone binds to the receptor initiates the target response through transcription This mechanism is primarily used for: lipid soluble hormones some water soluble |
Describe what happens to Excess/spent hormone: | Excess/spent hormone is circulated to the liver for biodegradation to excretable waste products. Waste products can leave the body by GI elimination via bile in feces Kidney excretion(in urine)-waste product reenter the blood + kidney secretes in urine |
Hormone Classification can be according to: | 1)Type [either Action (synergistic, antagonistic)or Chemical composition] Chemical Composition: A. Lipids which include:Steroids and Eicosanoids B. Amino acid derivatives C. Peptides |
T or F Steroids are lipid soluble. | True |
Steroids (lipid soluble)are ALL derived from a single precursor molecule, name it. | Cholesterol |
T or F Steroids do not need surface receptors | True. Cells membranes are heavy in Lipids. Therefore steroids do not need surface receptors They are lipid soluble and diffuse directly into the cytoplasm |
Describe what happens when steriods enter the cell and then the nucleus: | Once inside the cell: They bind to a cytoplasmic receptor and form a complex that can then enter the nucleus. In the nucleus: The complex can directly stimulate genes to activate transcription and make new protiens to alter cellular structure or activity |
List FOUR Examples of Steroids: | 1)Vitamin D 2)Sex Steroids – Estrogens and Progestins, Testosterone 3)Glucocorticoids – hormones of chronic stress: Cortisol, Cortisone, Corticosterone 4)Mineralocorticoids - Aldosterone |
What are Eiconsanoids? | Lipids derived from the 20-carbon fatty acid– arachidonic acid They Include: -Prostaglandins -Leukotrienes which are local hormones which act as paracrines and autocrines mediating: -Inflammation -fever induction -pain |
Amino Acid Derivatives are all derived from the amino acid precursor molecules which include: | Tyrosine - a nonessential (body can make it) amino acid. Tryptophan – converted into melotonin (sleep cycle) SECRETED BY THE PINEAL GLAND |
Examples of Tyrosine derivatives include: | Catecholamines Dopamine Epinephrine (Adrenaline) Norepinephrine (Noradrenaline) Thyrohormones including: T3 - Triiodo- thyronine (3 iodines) T4 - Tetraiodo- thyronine (Thyroxin) (4 iodines) |
Define and give THREE examples of Small Peptides: | small proteins range in length from 2-3 to 9 amino acids They include: 1)Hypothalamic releasing and inhibiting hormones (Rfs and Ifs)<--come from hypothalmus into pituitary gland 2)Oxytocin<--Labor and delivery 3)Antidiuretic Hormone (ADH) |
Define Polypeptides and list EIGHT: | Polypeptides are large protein chains, including: Insulin Glucagon Parathormone MSH Thymosin Melatonin HGH ACTH |
T or F Glycoproteins are a subcategory of peptides | True. Glycoproteins are a subcategory of peptides Glycoproteins - CHO - protein complexes including: FSH LH TSH |
Hormone Production and Secretion can be stimulated by THREE different mechanisms including: | Humoral Neuronal Hormonal |
Define Humoral: | Humorally - through changes in blood composition or concentrations |
THREE examples of Humoral changes - name the hormones and action: | 1)increase in blood calcium-stimulates calcitonin 2)decrease in blood glucose - stimulates glucagon 3)an increase in blood glucose - stimulates insulin |
T or F Epinephrine/Adrenaline release is considered a Neuronal mechanism. | True. Neuronal is via sympathetic motor neurons as in epinephrine/adrenaline release into the curculation in Fight-or-Flight responses to acute stress. |
Define Hormonal mechanism: | Hormonal via tropic hormones |
THREE Examples of Hormonal Mechanim: | via Tropic Hormones including: 1)ACTH stimulating production and secretion of glucocorticoids 2)TSH stimulating production and secretion of T3 and T4 3)FSH and LH stimulating production and secretion of sex steroids |
Nervous and Endocrine Systems function together by and why: | Controling all bodily functions through: -Integration -Coordination -Regulation TO maintain Steady State (Homeostasis). Both systems utilize a communication system toward this goal |
Nervous System uses neurotransmitters to stimulate what? to act on what? | Nervous System uses neurotransmitters to stimulate ACTION POTENTIALS(neuronal impulses) act on EFFECTORS |
Define Effector: | Effector - any cell, tissue, gland or organ that is stimulated by a neuron. |
Name two ways the Endocrince system uses Hormones? | Endocrine System uses hormones as: chemical messengers and to act on targets. |
Define Target: | Target - any cell, tissue, gland or organ that is stimulated by a hormone. |
Central (CNS) Endocrine System includes: | 1)pituitary gland (hypophysis) 2)Hypothalamus 3)pineal gland |
Peripheral Endocrine System Includes: | all other endocrine glands not in CNS Including: Thyroid Thymus Adrenals (medulla and cortex) Pancreatic islets Gonads Parathyroid glands |
T or F Hormone Action at the Target can be Direct or Indirect | TRUE |
Describe Direct Action: | Hormones enjoy free,direct cytoplasmic access inside,combines with a receptor.Hormone-receptor complex enters the nucleus stimulate DNA directly-initiates the process of transcription-leads to translation-makes new proteins alter structure/activity |
Describe Indirect action of Hormone at Target: | Indirect Action Requires a surface receptor. Once the hormone binds to the surface receptor, the process of signal transduction is initiated. |
Steroids often work by this mechanism as do T3 and T4. Name it | Direct Action |
Describe G Protein in Indirect Action once the hormone binds to surface receptor: | The hormone that binds to the surface receptor functions as a first messenger activating a G-protein molecule. G-proteins are the first step in the process of signal transduction. The G-protein then activates the enzyme, Adenylate cyclase. |
Describe Signal Transduction After G Protein activates the enzyme, Adenylate cyclase: | Adenylate cyclase in turn converts ATP into Cyclic AMP, which is refered to as the second messenger-this process is known as signal transduction |
T or F The second messenger is often responsible for stimulating an intracellular enzyme system (kinase activation) which leads to the target response. | TRUE |
What Are Receptors responsible for and Where are they found: | RECEPTORS - structures responsible for recognizing hormones. They can be located on the : Cell Surface - associated with cell’s glycocalyx (are 3-D complimentarity with the hormone) or Cytosolic - found in the cell’s cytoplasm |
T or F Specificity of Receptors: Receptors are 1-D with the hormone | FALSE! Specificity of Receptors Receptors are 3-D complimentarity with the hormone (a type of ligand) |
T or F Receptors associated with each target can NOT vary as body physiology changes. | FALSE!! Receptors associated with each target can vary as body physiology changes. They can vary in: Number - targets are capable of increasing or decreasing their receptor number Affinity (attraction) for hormone binding |
Describe Receptor upregulation vs downregulation: | Receptor Variation in Number via: upregulation – increase receptor number to increase the target’s sensitivity and response downregulation – decrease receptor number to decrease the target’s sensitivity and response |
Describe High Affinity vs Low Affinity Receptors: | Receptor Affinity Variation high affinity receptors - bind hormone strongly to potentate target response low affinity receptors - bind hormone weakly to modulate target response |
Hormones working together is called: | Synergism or Permissivism - hormones working together |
Hormones that work against each other are: | Antagonism - hormones opposing each other |
Prolactin and Oxytocin are examples of Synergistic Hormones - describe why: | Prolactin and Oxytocin Prolactin promotes milk formation Oxytocin makes the milk available. Both are essential for nursing/breast feeding |
Estrogen and Progesterone are synergistic hormones - describe why: | Estrogen and Progesterone - work together to prepare the uterus for pregnancy. Estrogen restores the uterine endometrium in the Proliferative phase progesterone makes it thick, spongy and promotes glycogen-rich secretions during the Secretory phas |
Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) have what type of relationship and why? | Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) are synergistic. FSH promotes preliminary egg development LH completes development and stimulates ovulation. |
T or F Estrogen and Testosterone are Synergistic | FALSE!!! Estrogen and Testosterone in gender determination are ANTAGONISTIC Estrogen promotes female development Testosterone promotes male development. |
Insulin and Glucagon are Antagonistic - why? | Insulin and Glucagon in serum (blood) glucose regulation – Insulin lowers blood glucose Glucagon raises it. |
T or F PTH increases serum calcium CT lowers serum calcium Thus this is an Antagonistic relationship | True! Antagonistic relationship: Parathormone (PTH) and Calcitonin (CT) in blood calcium _regulation Parathormone (PTH) Increases serum calcium Calcitonin (CT) lowers serum calcum |
What Factors Determining Target Response to Hormone? | Presence of receptors Number of receptors (up to 100’s of thousands) Relationship between hormones (synergistic, antagonistic, permissive) Receptor affinity:decreased-weaker response or increased-aggressive response Quantity of hormone in circulation |
Target Cell Responses do what? | Stimulate or inhibit secretory activity Alter membrane permeability Open sodium or other ion channels Alter membrane polarity. Activate or deactivate enzyme activity |
Pituitary is located where? | Pituitary is located in the sella turcica of the sphenoid bone. It is a small, pea-like gland suspended from the hypothalamus by a pituitary stalk or infundibulum. |
The pituitary or Hypophysis is divided into: | The pituitary or Hypophysis is divided into: Anterior Pituitary or Adenohypophysis– the TRUE, glandular portion of the pituitary Posterior Pituitary or Neurohypophysis – NOT an endocrine gland but part of the CNS (Forebrain). |
Hypothalamus contains 2 important endocrine Nuclei. Describe nuclei and name the them: | Endocrine nuclei(collections of cell bodies in CNS) Paraventricular nucleus – produces and secretes oxytocin (OT) or Pitocin (Pit) Supraoptic nucleus – produces and secretes Anti Diuretic Hormone (ADH) |
What produces and secretes oxytocin (OT) or Pitocin (Pit)? | Paraventricular nucleus in the Hypothalmus |
What produces and secretes Anti Diuretic Hormone (ADH)? | Supraoptic nucleus in the Hypothalmus |
The Anterior Pituitary Histology consists of what 3 cell types: | Acidophils Basophils Chromophobes |
Define Acidophils: | Found in the anterior Pituitary: acid-loving, stain PINK with acidic stains; produce and secrete: Human Growth Hormone - HGH Prolactin - PRL or Lactogenic Hormone |
Human Growth Hormone - HGH and Prolactin - PRL are examples of? Produced where? | Acidophils in the Anterior Pituitary |
Define Basophils(found in the Anterior Pituitary): Give Examples. | base-loving; stain purple with basic dyes produce and secrete: FSH - Follicle Stimulating Hormone LH - Luteinizing Hormone or ICSH TSH - Thyroid Stimulating Hormone ACTH - Adrenocorticotropic Hormone MSH - Melanocyte Stimulating Hormone |
T or F Chromophobes (fear color, won’t stain)and help produce and secrete ACTH. | TRUE!!! Chromophobes are found in the anterior Pituitary. Chromophobes (fear color, won’t stain)and help produce and secrete ACTH. |
T or F Since the anterior pituitary produces and secretes at least 7 different hormones it is considered an endocrine gland. | TRUE! Since the anterior pituitary produces and secretes at least 7 different hormones it is considered an endocrine gland. |
Hypothalamus produces and secretes tiny neurohormone releasing and inhibiting hormones (Rfs and Ifs) that diffuse into a collection of : | Capillaries. These capillaries converge to form a collection of veins which passes down through the infundibulum to the Anterior Pituitary before diverging into a capillary bed once again. PORTAL |
The Hypothalamico-hypophyseal (HTH) Portal system, which interconnects the ______and the _____ It permits _________communication. | the Hypothalamico-hypophyseal (HTH) Portal system, which interconnects the HYPOTHALMUS and the ANTERIOR PITUITARY. It permits DIRECT communication. |
The Hypothalamico-hypophyseal (HTH) Portal system is what type of feeback? | POSTIVE Ex: TRH releasing hormone travels to Ant Pit-> TSH hormone1 is then released ->Thyroid Gland is target then Thyroid Hormone is hormone2 |
T or F The Hypothalamus monitors blood levels of hormones produced and secreted by the Ant. Pit. and/or the products that result from the Ant. Pit. Hormones. | TRUE! The Hypothalamus monitors blood levels of hormones produced and secreted by the Ant. Pit. and/or the products that result from the Ant. Pit. Hormones. It can respond by producing specific Releasing or Inhibiting Hormones or Factors (Rfs or Ifs). |
What are Specific Releasing or Inhibiting Hormones or Factors (Rfs or Ifs)? | Specific Releasing or Inhibiting Hormones or Factors (Rfs or Ifs)are neuropeptide hormones that can travel down through the portal system to stimulate or inhibit the production and secretion of their specific anterior pituitary |
What is a tract? | A collection of Axons |
Posterior Pituitary consists of: | -collections of synaptic knobs that: are located at the distal ends of axons that originate in the hypothalamic nuclei. -contain synaptic vesicles that contain either ADH or OT. (storage) |
T or F Since the Posterior Pituitary stores and releases the neuro-hormones (ADH and OT)it is considered an endocrine gland. | FALSE!!! Since the Posterior Pituitary simply stores and releases these neuro-hormones and does NOT produce them it is NOT considered an endocrine gland. |
What is OT and what else is it called? | Oxytocin (OT) or Pitocin (Pit) or syntocinin |
Define where Oxytocin (OT) is produced, secreted, stored and released: | Produced and secreted by the paraventricular nucleus Stored and released by the posterior pituitary. |
Oxytocin (OT) or Pitocin (Pit) or syntocinin Targets are? | Smooth muscle of: Uterus -the myometrium Mammary’s alveoli - its myoendotheli-um Prostate and Vas deferens |
On mammary OT stimulates : | On mammary OT stimulates contraction of smooth muscle muscularis: to eject milk from the mammary in the Milk Letdown Reflex which makes milk available to the nursing infant. |
On the uterus OT: | On the uterus OT: initiates, sustains, and potentiates the rhythmic contractions of parturition (labor). increases both frequency and amplitude of contractions toward the goal of delivery. |
On the prostate OT: | On the prostate and vas deferens it stimulates smooth muscle contraction to contribute to emission (ejection sperm and secretions). |
OT Release can be Stimulated by: | -increased stretch receptor firing in response to uterine/cervical distention -decreased progesterone, its antagonist -Any form of nipple stimulation including suckling reflex and nipple rolling -Preconditioned stimuli (Sight/sound of a hungry baby) |
OT Release can Inhibited by: | increased progesterone, its antagonist Ethyl alcohol Stress |
Hyposecretion of OT can result in: | Retarded, prolonged, difficult labor. Nursing frustration – inability to experience Milk Letdown |
Hypersecretion of OT can result in: | Rapid delivery increased risk of fetal distress syndrome leading to hyoxia causing deafness, blindness, retardation, cerebral palsy, etc. |
Antidiuretic Hormone (ADH),is also called: | Vasopressin |
List 3 facts about Antidiuretic Hormone (ADH): | Antidiuretic Hormone (ADH), Vasopressin -In large doses, it constrict blood vessels -Produced and secreted by the supraoptic nucleus of hypothalamus -Stored/released from posterior pituitary. |
What are the Targets for ADH? | Kidney tubules (distal convoluted tubule and collecting duct of the kidney’s nephrons) |
What are the Physiologic Effects of ADH? | Acts to promote increased facultative osmosis or reabsorption of electrolyte-free water by stimulating increased production of aquaporin channel proteins in kidney tubule membranes to: decrease urine volume increase Blood Volume and Pressure. |
ADH Release is Stimulated by: | Any increase in serum osmolarity (Major stimulus) decreased blood volume (hypovolemia associated with dehydration or hemorrhage) decreased blood pressure increased pain cholinergics including ACh increased chronic stress |
Describe the Action of ADH: | -Increased Blood Osmotic Press. hypothalamic osmoreceptors -Osmoreceptors activate hypothatamic neurosecretory cells to release ADH -Neurosecretory cells to release ADH into the bloodstream in the posterior pituitary |
ADH causes: | -Kidney water retention and decreased urine output -Decreased sweat production -Arteriolar constriction -Low blood osmotic pressure inhibits hypothalamic osmoreceptors -Osmoreceptor inhibition reduces ADH secretion |
ADH Release is Inhibited by | Ethyl Alcohol and any reversal of a stimulation |
Hyposecretion of ADH causes: | -Polyuria - increased urine volume (>3,000 ml/day) -Hypotension -Lack of ADH diagnosed as Diabetes insipidus with: gross polyuria with 8-10 +L urine produced each day -Polydipsia - increased thirst |
Hyposecretion of ADH can be caused by: | pathology or head trauma |
T or False Hypersecretion of ADH is Very Common. | FALSE!!!!Hypersecretion of ADH (RARE) Results in oliguria - urine output < 800 ml/day Can be caused by a tumor or SIADH (Syndrome of Inappropriate ADH production and secretion) Found in pneumonia, encephalitis, bronchogenic carcinoma (lung cancer) |
T or F Anterior Pituitary Hormones include hGH, TSH, ACTH, FSH, LH (ICSH), PRL, MSH | TRUE Anterior Pituitary Hormones hGH, TSH, ACTH, FSH, LH (ICSH), PRL, MSH |
What is HGH or GH? | HUMAN GROWTH HORMONE - hGH - Somatotropic Hormone (STH) or Growth Hormone (GH) Produced and secreted in its inactive form by anterior pituitary acidophils promotes formation of somatonedins like insulin growth factors (IGFs) in many organs. |
T or F Targets for hGH are specific. | FALSE! Targets for hGH are GENERAL and widespread - many cells have surface receptors for hGH or IGFs. |
Physiologic Effects of hGH as a growth factor: | -increased amino acids uptake from blood -increased protein synthesis (tissue building) Especially skeletal muscle and cartalage -increases uptake of sulfur containing compounds -increases production chondroitin sulfate especially at epiphyseal zone |
As a hormone of chronic stress, HGH: | -Inhibits glucose uptake by cells -promotes glucose storage as glycogen when in cells (glycogenesis) -Stimulates increased fat mobilization and utilization by cells spares glucose for the more vital organs -Increases serum lipids |
hGH Release is Stimulated by hGH Rf (releasing factor) from the hypothalamus in response to: | decreased serum hGH decreased serum glucose increased chronic stress increased serum amino acids decreased serum lipids increased physical activity increases in stages 3&4 of non-REM sleep (rest) |
hGH is Inhibited by hGH If (inhibiting factor) from the hypothalamus in response to: | a reversal of any of the stimulating factors increased REM sleep weightlessness |
Hyposecretion of hHGH causes: | Prepubescent - dwarfism (midgetism) - perfectly proportioned normal miniature (Pituitary Dwarf) Postpubescent - no significance |
Hypersecretion of hHGH causes: | could be caused by an anterior pituitary tumor in the prepubescent - causes gigantism in the postpubescent - causes acromegaly, marked by:increased bone growth,widening of hands thickening of bone especially skull and facial bones |
T or F Thyroid Stimulating Hormone (TSH) a tropic hormone - Produced and secreted by the anterior pituitary Acidophils | FALSE! Thyroid Stimulating Hormone (TSH) a tropic hormone - Produced and secreted by the anterior pituitary BASOPHILS |
T or F Target for TSH: Follicular cells of thyroid gland | TRUE! Target for TSH: Follicular cells of thyroid gland |
Physiologic Effects of TSH: | Stimulation of active iodide pumps in follicular cell membranes to increase I uptake (active transport) increases production and secretion of thyrohormone including T3 and T4 Stimulates increased follicular and thyroid growth |
TSH Release is Stimulated by: Increased TSH Rf (releasing factor) from the hypothalamus. This is in response to: | decreased T3 and T4 decreased ambient temperature increased chronic stress |
Inhibited by increased TSH If (GHIf) (inhibiting factor) from the hypothalamus. This is in response to: | Increased T3 and T4 (what type of mech.- NEGATIVE) increased ambient temperature decreased chronic stress |
ADRENOCORTICO TROPIC HORMONE (ACTH, aka Corticotropin) | Produced and secreted by anterior pituitary basophils and chromophobes Stimulates the release of steroid hormones from the Adrenal cortex. |
Targets for ACTH | Adrenal cortex - outer portion of adrenal gland which consists of 3 zones: zona glomerulosa - outer, thin zone *zona fasciculata - middle, wide zone zona reticularis - thin, inner zone * indicates Major Target |
Adrenal cortex - outer portion of adrenal gland which consists of 3 zones: Name them and which one is major. | Adrenal cortex - outer portion of adrenal gland which consists of 3 zones: zona glomerulosa - outer, thin zone *zona fasciculata - middle, wide zone zona reticularis - thin, inner zone * indicates Major Target |
Physiological Effects of ACTH on the zona glomerulosa: | Physiological Effects of ACTH on the zona glomerulosa - acts to increase production and secretion of Aldosterone, a mineralocorticoid |
Physiological Effects of ACTH on the zona fasciculata: | Physiological Effects of ACTH on the zona fasciculata - acts to increase production and secretion of glucocorticoid These include: cortisol cortisone corticosterone |
Physiological Effects of ACTH on the zona reticularis: | Physiological Effects of ACTH on the zona reticularis - acts to increase production and secretion of sex steroids. These include: Estrogens testosterone |
ACTH Release is Stimulated by: ACTH Rf (CRf) (releasing factor) from the hypothalamus in response to: | decreased serum glucocorticoids increased chronic stress |
ACTH Is Inhibited by: Decreased ACTH Rf (CRf) and increased glucocorticoids (inhibiting factors) This is in response to: | Is Inhibited by: Decreased ACTH Rf (CRf) and increased glucocorticoids (inhibiting factors) This is in response to: increased serum glucocorticoids decreased chronic stress |
Hormones found only in the circulation of pubescent individuals | Gonadotropic Hormones: FSH and LH (female) or ICSH (male) |
T or F Follicle Stimulating Hormone (FSH) Produced and secreted by anterior pituitary basophils | TRUE! Follicle Stimulating Hormone (FSH) Produced and secreted by anterior pituitary basophils |
Targets for FSH: | Gonads, specifically the Ovarian Follicles in the female and the Sustentacular cells of testes |
Physiologic Effects of FSH in the female | Stimulates preliminary growth and development of a “handful” of primary follicles containing immature eggs (primary oocytes) As follicular growth and development occurs, estrogen production increases resulting increased serum estrogen |
Physiologic Effects of FSH in the male | Stimulates production and secretion of androgen binding proteins (ABPs) by sustentacular cells of the testes. ABPs bind to seminiferous tubule cells to increase the binding of testosterone This increases spermatogenesis |
FSH release in the female Is Stimulated by: | Gonadotropin releasing hormone (GnRH) from the hypothalamus in response to: increased estrogen in pre-ovulatory period (positive feedback) decreased estrogen and progesterone in the post ovulatory period decreased inhibin - an ovarian hormone |
FSH Release in the male Is Stimulated by: | Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: decreased testosterone decreased sperm number decreased inhibin - from sustentacular cells |
FSH Release in the female Is Inhibited by decreased Gonadotropin releasing hormone (GnRH) from the hypothalamus. This is in response to: | increased estrogen and progesterone in post-ovulatory period increased inhibin - from ovarian cells |
FSH Release in the male Is Inhibited by decreased Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: | increased testosterone increased inhibin increased sperm number |
What are sustentacular cells? | Cells that surround the sperm. |
T or F Hyposecretion of FSH can cause Reproductive frustration - sterility in both sexes | TRUE! Hyposecretion of FSH can cause Reproductive frustration - sterility in both sexes |
Hypersecretion of FSH causes? | Hypersecretion of FSH unclear significance in both genders |
What are LH and ICSH? | Luteinizing Hormone (LH) - Female Interstitial Cell Stimulating Hormone (ICSH) - Male Produced and secreted by the anterior pituitary basophils |
Targets for LH/ICSH: | gonads specifically: the ovarian follicle in the female the Interstitial cells or Cells of Leydig of the male testes |
LH acts in a synergistic relationship with FSH to single out one of the handful of developing follicles. This single follicle continues its growth, development, and maturation as the Graafian follicle all other follicles undergo atresia/atretic then: | LH now acts on the ruptured follicle transforming it into the corpus luteum(yellow body)which begins its production and secretion of progesterone(serum progesterone increases)LH acts with residual FSH to stimulate ovulation,rupture of follicle,release egg |
What does it meant to undergo atresia or become atretic? | regress in development |
Physiologic Effects of ICSH in the male: | ICSH stimulates the interstitial cells of the testes they increase production and secretion of testosterone |
LH Release in the female is stimulated by: increased Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: | increased estrogen in pre-ovulatory period (positive feedback) decreased inhibin |
ICSH in the male is stimulated by: increased Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: | decreased testosterone decreased inhibin |
LH in the female is inhibited by: is inhibited by: | decreased Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: increased estrogen and progesterone in post-ovulatory period increased inhibin |
ICSH in the male is inhibited by: | decreased Gonadotropin releasing hormone (GnRH) from the hypothalamus This is in response to: increased testosterone increased inhibin |
Hyposecretion of LH/ICSH causes sterlity in both sexes (Why?) | Not enough stimulating androgens |
Hypersecretion of LH in female causes multiple ovulations/multiple births (Why?) | Over stimulation causes more eggs to develop |
Hypersecretion of ISCH in males causes: | No significant effects |
T or F Prolactin (PRL) or Lactogenic Hormone Produced and secreted by the anterior pituitary basophils | FALSE!! Prolactin (PRL) or Lactogenic Hormone Produced and secreted by the anterior pituitary ACIDOPHILS |
Target for PRL is the Myoepithelium of mammary’s alveoli - what does this mean? | The smooth muscle cells of the the mammary's alveoli or milk glands |
Physiologic Effects of PRL in males and females | Physiologic Effects of PRL restricted to females, since PRL is inhibited in males Stimulates increased, venous-lymphatic engorgement of the breasts increased milk production and secretion by the epithelium of the alveoli slight inhibition of FSH |
PRL is stimulated by: increased PRF (releasing factor) from the hypothalamus This is in response to: | decreased progesterone as in termination of pregnancy natural degeneration of corpus luteum about a week before menstruation (part of PMS) the suckling reflex or any nipple stimulation |
PRL is inhibited by: Increased Prolactin inhibiting hormone (PIH - the neurotransmiter dopamine) from the hypothalamus This is in response to: | increased progesterone increased estrogen decreased suckling |
T or F Hyposecretion causes nursing frustration by preventing milk formation | TRUE~Hyposecretion causes nursing frustration by preventing milk formation |
Hypersecretion of PRL results from the most common of the anterior pituitary tumors This results in: | Irregular menses (why?-due to decreased prolactin), infertility, galactorrhea (excessive milk production) in female Impotence, infertility, gynecomastia (inappropriate breast development) in male |
What is galactorrhea? | (excessive milk production) in female |
What is gynecomastia? | (inappropriate breast development) in male |
Melanocyte Stimulating Hormone (MSH) Produced and secreted by anterior pituitary basophils and ??? | pars intermedia |
Targets for MSH: | Melanocytes of stratum basale-deepest layer in skin Neurons in CNS |
Physiologic Effects of MSH | increased melanin production by melanocytes of stratum basale of epidermis increased Neurotransmitter in CNS |
MSH Release Is stimulated by: Increased ACTHRH or CRH (releasing hormone) from the hypothalamus This is in response to: | genetic expression increased exposure to UV light probably mediated through SCN (suprachiasmatic nucleus) of hypothalamus or perhaps the pineal-hypothalamic axis |
MSH release Is inhibited by: Decreased ACTHRH (CRH) and dopamine (inhibiting factor) from the hypothalamus This is in response to: | genetic expression decreased exposure to UV light |
Hyposecretion of MSH causes Hypopigmentation and Lack of Melanin called..... | albinism |
T or F Hypersecretion of MSH causes Hyperpigmentation | True! Hypersecretion of MSH causes Hyperpigmentation |
A bi-lobed mass with an isthmus located at base of neck immediately inferior to the laryngeal, thyroid cartilage is the | Thyroid Gland |
Describe the Histology of the Thyroid | Very, highly vascular Consists of numerous, sac-like, thyroid follicles (thyrofollicles) containing a gel-like substance known as thyrocolloid |
Cytology of the Thyroid Consists of 2 major cell types: | 1. Follicular Cells - with active Iodide pumps to actively take in Iodide 2. Parafollicular Cells (C cells) which produce and secrete Thyrocalcitonin (TCT) or calcitonin (CT) |
Follicular Cells produce and secrete: | T3 - Triiodothyronine T4 – tetraiodothyronine (thyroxine) A protein - TG – Thyroglobulin |
T3 and T4 are conjugated to TG and stored as thyrocolloid in the lumen of the thyroid follicle. When T3 and T4 levels decrease in blood, | follicular cells take in thyrocolloid by endocytosis. |
Follicular cells take in thyrocolloid by endocytosis and then | They separate T3 and T4 from TG: T3 and T4 are dumped into blood and the TG is dumped back into lumen Once in the blood T3 and T4 bind to TBG (Thyroid Binding Globulin, a blood protein) for transport to target in INACTIVE FORM |
T or F T3 is the more active of the two and Most targets can split an Iodide from the T4 once it binds to the target and convert T4 into T3. Thyroid hormone activity refers to the activity of T3 Targets for T3 and T4 Generalized and widespread | TRUE!!! T3 is the more active of the two and Most targets can split an Iodide from the T4 once it binds to the target and convert T4 into T3. Thyroid hormone activity refers to the activity of T3 Targets for T3 and T4 Generalized and widespread |
Physiologic Effects | Increases overall metabolic rate: to increase O2 uptake and CO2 generation to increase heat generation (Calorigenic effect) to increase vital signs including temp, BP, HR and respiration |
Heat Generation or Calorgenic effect is acheived by: | Increased mitochondrial production of ATP Increased production of Na+/K+ Pumps |
T3 and T4 As a hormone of chronic stress: | it increases fat catabolism and utilization by stimulating Beta oxidation of fatty acids it increases cholesterol production and secretion by the liver serum cholesterol decreases because it is more actively taken up by cells |
Release of T3 and T4 are stimulated by:increased TSH from the ant. pit. in response to increased TSH RH from hypothalamus. in response to: | decreased serum T3 and T4 (negative feedback) increased chronic stress decreased ambient temperatures (calorigenic effect) |
Release of T3 and T4 are inhibited by: decreased TSH from the ant. pit. in response to increased TSH IH from the hypothalamus in response to: | increased serum T3 and T4 decreased chronic stress increased ambient temperatures |
Hyposecretion = Hypothyroidism In Prepubescent/neonates can cause.. | Hyposecretion = Hypothyroidism In Prepubescent/neonates - cretinism - can result in profound mental and physical retardation since T3 and T4 are essential for neuronal development and synaptic wiring in the CNS. All newborns are tested for low T3 and T4 |
Adult - Hypothyroidism Signs and Symptoms include: | Myxedema (puffiness of the face/hands) Dry scaly skin, dull brittle hair Always cold due to low metabolic rate Tend to be overweight to obese Dull witted Muscular lethargy Goiter (enlarged thyroid) Hyperlipidemia with increased risk of CAD |
Causes for Hypothyroidism | Depressed HTH/Thyroid axis (low TSH RH activity from the hypothalamus or low TSH production) Hashimoto’s disease–an immune disorder marked by the production of an abnormal antibody that blocks the TSH receptor Endemic Goiter or treatment of |
Hypersecretion = Hyperthyroidism Signs & Symptoms include: | Underweight/thin (high metabolic rate) Always hot/Diaphoresis (profuse sweating) Hyper, anxious - always complaining Voracious appetite Goiter or enlarged (hypersecretory) thyroid increased vital signs Exophthalmos-bulging eyes-due to fat/fluids |
Causes for Hypersecretion of T3 and T4 | HTH axis upset due to excess TSHRH from the hypothalamus or increased TSH production and secretion from the anterior pituitary. Result of Grave’s Disease |
Grave’s Disease is | Grave’s Disease - an immune disorder marked by the production of an abnormal antibody known as LATS (long acting thyroid stimulator) aka TSA (Thyroid stimulating antibody) which promotes excessive thyroid growth by binding to the TSH receptor |
Treatment for Hypersecretion T3 and T4 | Iodine 131 (radioactive isotope of iodine) the more common treatment which destroys the thyroid gland and minimizes the risk of life threatening, post surgical complications including Thyroid Storms. Thyroid supplements must be taken. Radical Thyroidecto |