chapter 12 key terms 1 hormonesmelatonin homeostasisaldosterone thymus glandhyperglycemia...
TRANSCRIPT
1Chapter 12 Key Terms
HormonesMelatoninHomeostasisAldosteroneThymus GlandHyperglycemiaHypophysisHypothalamusInfundibulumAcidosisAdrenal GlandAlpha CellsBeta CellsChief CellsInsulin
AndrogensOvariesTestes
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ANATOMY & PHYSIOLOGYCHAPTER 12: ENDOCRINE SYSTEM
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Introduction
PurposeHomeostasis: maintaining the body’s internal environment
within certain narrow ranges Involves growth, maturation, metabolism, and reproduction
Works closely with the nervous systemHypothalamus sends chemical signals (neurotransmitters)
to the endocrine system Endocrine Glands
Ductless glands that secrete hormones directly into bloodstream
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Hormones
Negative feedback loopMechanism by which hormones function
3 chemical categoriesModified amino acidsProtein hormonesSteroid hormones
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Hypothalamus
Controls the pituitary gland Infundibulum
Funnel shaped extension from hypothalamus to pituitary gland
Produces chemical signalsReleasing hormonesReleasing inhibitory hormones
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Endocrine Glands
Pituitary Gland (A) Thyroid Gland (B) Parathyroid Gland Adrenal Gland (C) Testes (D) Ovaries (E) Pancreas (F) Thymus Gland (G) Pineal Gland (H)
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Pituitary Gland
Also known as the Hypophysis, and also the “Master Gland”
Divided into two lobesAnterior Pituitary GlandPosterior Pituitary Gland
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Anterior Pituitary Gland
Growth Hormone (GH)Stimulates cell growth and divisionStimulates bone and muscle growthPituitary Dwarfism: result of too little GHGigantism: result of too much GH
Thyroid Stimulating Hormone (TSH)Stimulates thyroid to release its hormone
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Anterior Pituitary Gland
Adrenocorticotropic Hormone (ACTH)Stimulates adrenal cortex to secrete its hormone
(Cortisol)Helps reduce inflammation
Melanocyte-stimulating Hormone (MSH)Stimulates production of melanin in the skin
Follicle-stimulating Hormone (FSH)Stimulates the production of sperm in malesStimulates development of follicles in ovaries
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Anterior Pituitary Gland
Luteinizing Hormone (LH)Stimulates production of progesterone and ovulation
in ovaryStimulates production of testosterone in males
Lactogenic Hormone (LTH)AKA ProlactinStimulates milk production in a pregnant femaleMay cause decrease in male sex hormones
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Posterior Pituitary Gland
Antidiuretic Hormone (ADH)AKA VasopressinMaintains body’s water balance by promoting water
reabsorption in the kidneys Oxytocin
Stimulates contraction of smooth muscles in the uterus
Sometimes given to help induce labor if the uterus does not contract sufficiently on its own during childbirth
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Thyroid Gland
Consists of two lobes connected by a smaller band called the isthmus
Stimulated by TSH from the Pituitary Gland Requires Iodine to function properly
Iodine deficiency causes goiters
Releases T3 and T4
Contain 3 and 4 Iodine atoms Regulate metabolism of carbs, fats, proteins for
proper growth and development
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Thyroid Gland
CalcitoninLowers calcium and phosphate concentrations in the blood Inhibits release of ions from bones, and increases
excretion of ions by the kidneys Hypothyroidism
Low levels of thyroid hormonesCretinism
HyperthyroidismToo much secretion of thyroid hormones
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Parathyroid Gland
4 small glands on posterior surface of thyroid gland Made of chief cells and oxyphil cells Releases Parathyroid Hormone (PTH)
Raises blood calcium levels by causing bone matrix to break down, releasing calcium and phosphate ions into bloodstream
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Adrenal Gland
Located on top of the kidneys Adrenal Medulla
Epinephrine (adrenaline) and Norepinephrine (noradrenaline)
Released as a response to signals of the autonomic nervous system
Fight or flight hormonesCauses a breakdown of glycogen to glucoseStimulates release of fatty acids from fat cells
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Adrenal Cortex
AldosteroneRegulates Na reabsorption and K excretion by kidneysReleased by outer layer of cortex
Cortisol (Hydrocortisone)Helps maintain blood glucose levels between mealsSynthesizes glucose from amino acids
CortisoneSteroid often give as medication to reduce
inflammation
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Adrenal Cortex
AndrogensPromotes development of male characteristics
Addison’s diseaseNot enough hormones secreted by adrenal cortexCauses change of electrolyte balance in blood
Cushing’s syndromeBlood glucose concentrations remains high, causing
puffy skin and obesity because of excess tissue fluid
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Pancreas
Part of digestive and endocrine systems Alpha Cells
Secretes GlucagonRaises blood sugar level
Beta CellsSecretes InsulinLowers blood sugar level
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Diabetes Mellitus
Deficiency in insulin production Type 1
Previously called juvenile diabetesBody does not produce insulin5% of diabetics
Type 2Body does not use insulin properly (insulin resistance)Previously called adult onset diabetes
Balanced diet, exercise, proper body weight
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Testes and Ovaries
OvariesReleases estrogen and progesteronePromote development of female characteristicsControl menstrual cycle
TestesReleases testosteronePromotes development of male reproductive
structures and male characteristics Both controlled by LH and LTH from Pituitary gland
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Thymus Gland
Located in the mediastinum Helps in development of the immune system Thymosin
Promotes production of T lymphocytes
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Pineal Gland
MelatoninSecreted directly into cerebrospinal fluid Inhibits secretion of LH and LTHRegulates circadian rhythms (feeling of tired and
onset of sleep)Bright light inhibits secretion of melatonin
SerotoninActs as neurotransmitter and vasoconstrictorStimulates smooth muscle contractions