Chapter 31 ENDOCRINE CONTROL DIFFERENCE BETWEEN ENDOCRINE AND
Chapter 31 ENDOCRINE CONTROL
DIFFERENCE BETWEEN ENDOCRINE AND EXOCRINE The endocrine system controls the body activities by producing chemical substances called _______which are secreted by ductless glands known as _________ Exocrine gland secrete their products into ducts or channels, that carry them either to the outside of the body or into ___________. © Cengage Learning 2015
WHAT ARE ANIMAL HORMONES? Animal hormones: ______________ that are secreted by _________ Distributed by the ________; Typically act at __________from their source Only cells with the appropriate ________ (target cells) can respond to a specific hormone © Cengage Learning 2015
CATEGORIES OF HORMONES Two major categories of hormones: ___________-derived hormones (____) ___________-derived hormones (____) © Cengage Learning 2015
CATEGORIES OF HORMONES (CONT’D. ) Amino acid-derived hormones: bind to receptors at the _________of a target cell Initiates _________ signaling cascade that brings about the target cell’s response Often results in the activation of an ______ Example: glucagon binds to receptor; causes activation of © Cengage Learning 2015 glycogen-degrading enzyme
CATEGORIES OF HORMONES Steroid hormones: synthesized from __________ Directly affects gene expression Diffuses into a target cell (why? ) and forms a hormone–receptor complex Hormone–receptor complex: ____________________________ _____ © Cengage Learning 2015
HORMONE RECEPTOR FUNCTION Many hormones target more than one type of cell Elicit a ________response in each cell type Example: antidiuretic hormone (ADH) Affects urine formation in the ________ Triggers smooth muscle contraction in __________ © Cengage Learning 2015
WHAT ARE THE COMPONENTS OF THE HUMAN ENDOCRINE SYSTEM? Endocrine glands: aggregations of epithelial cells that produce and secrete ____into the ______ Collectively make up the _____________ Portions of the ______system and ____ system are closely linked Most organs respond to hormones and signals from the ____________ © Cengage Learning 2015
ENDOCRINE SYSTEM © Cengage Learning 2015
WHAT ARE THE COMPONENTS OF THE HUMAN ENDOCRINE SYSTEM? © Cengage Learning 2015
HOW DOES THE HYPOTHALAMUS INTERACT WITH THE PITUITARY GLAND? Hypothalamus: main center that controls the __________________ Lies deep inside the forebrain and connects with the ______________ hypothalamus anterior lobe of pituitary © Cengage Learning 2015 posterior lobe of pituitary
POSTERIOR PITUITARY FUNCTION Neurosecretory cells in the hypothalamus synthesize _______ hormones These hormones are transported along _____in the posterior pituitary An action potential triggers the release of hormone into the _______ Posterior pituitary releases two hormones: ______________(____) ______________ © Cengage Learning 2015
PITUITARY FUNCTION © Cengage Learning 2015
ANTERIOR PITUITARY FUNCTION The anterior pituitary makes ______ hormones and secretes them in response to hormones from the _____________ Anterior pituitary hormones: ____________________________________________ _____ © Cengage Learning 2015 ______________________
HORMONAL GROWTH DISORDERS Growth hormone production surges during _______, causing a growth spurt, then declines with _______secretion of growth hormone during childhood leads to pituitary __________ ______growth hormone during childhood can cause pituitary ________ © Cengage Learning 2015
WHAT IS THE ROLE OF THE PINEAL GLAND? Pineal gland: lies deep inside the brain; secretes the hormone ______under low-light or dark conditions ______: _____________________ © Cengage Learning 2015
WHAT ARE THYROID AND PARATHYROID GLANDS? Thyroid gland: endocrine gland located in the base of the neck Thyroid hormone (triiodothyronine and thyroxine): increases metabolic activity The anterior pituitary gland hypothalamus regulate thyroid hormone secretion Decline in thyroid hormone causes hypothalamus to secrete thyroid-releasing hormone (TRH) TRH causes the anterior pituitary to secrete thyroidstimulating hormone (TSH) TSH stimulates secretion of thyroid hormone © Cengage Learning 2015
WHAT ARE THYROID AND PARATHYROID GLANDS? STIMULUS TH declines below a set point RESPONSE Hypothalamus 1 TRH Anterior Pituitary 2 TSH Thyroid Gland 3 © Cengage Learning 2015 TH secretion increases and metabolic rate rises. 4
HORMONAL REGULATION OF BLOOD CALCIUM LEVEL There are four parathyroid glands on the thyroid’s ___________surface Parathyroid hormone (PTH): _________________________________ Calcitonin: ____________________________________________; opposes the actions of PTH © Cengage Learning 2015
WHAT ARE THE ROLES OF THE ADRENAL GLANDS? Adrenal gland: endocrine gland that is located atop the _________ Adrenal cortex: _________________ Examples: Aldosterone: acts in ________and makes urine more concentrated Cortisol: affects _______and ___________ Adrenal medulla: responds to stimulation by releasing _________and _______into the blood Brings on ______________ © Cengage Learning 2015
WHAT ARE THE ROLES OF THE ADRENAL GLANDS? (CONT’D. ) STIMULUS Blood level of cortisol declines. adrenal cortex adrenal medulla RESPONSE Hypothalamus 1 CRH 4 Anterior Pituitary 2 ACTH Adrenal Cortex Rise of cortisol level in the blood inhibits the secretion of CRH and ACTH. 3 Cortisol secretion increases and has the following effects: Cellular uptake of glucose from blood slows in many tissues, especially muscles (but not in the brain). Protein breakdown accelerates, especially in muscles. Some of the amino acids freed by this process get converted to glucose. © Cengage Learning 2015 kidney Fats in adipose tissue are degraded to fatty acids and enter blood as an alternative energy source, indirectly adrenal cortex adrenal medulla kidney conserving glucose for the brain.
HORMONES, STRESS, AND HEALTH Long-term elevation of cortisol is unhealthy (example: Cushing’s syndrome): Interferes with _____________, and _______function Raises the risk of _________________ Abnormally low levels of cortisol (example: Addison’s disease) ___________, and ___________________ © Cengage Learning 2015
WHAT ARE SEX HORMONES? Sex hormones: ______hormones produced by the _________ Essential to ______________function Influence secondary sexual characteristics __________________________________________________ © Cengage Learning 2015
WHAT ARE SEX HORMONES? Testosterone: responsible for development of _____________and secondary sexual characteristics Estrogens: function in ________and cause development of _______secondary sexual characteristics Progesterone: prepares a female body for _______and helps ___________ © Cengage Learning 2015
WHAT ARE SEX HORMONES? © Cengage Learning 2015
HOW DOES THE PANCREAS REGULATE BLOOD SUGAR? Pancreas: lies in the _______cavity, behind the _______ Exocrine cells: secrete _____________ into the small intestine Endocrine cells: grouped in clusters called pancreatic islets (e. g. , ______cells and _______cells) © Cengage Learning 2015
HOW DOES THE PANCREAS REGULATE BLOOD SUGAR? (CONT’D. ) Beta cells secrete _____when blood glucose levels ______ Insulin causes its target cells to _________________ Encourages synthesis of fats and proteins and inhibits their breakdown _____________________ Alpha cells secrete ______when blood glucose levels ______ Glucagon binds to receptors on liver cells: activates enzymes that break _____ into ____subunits ______________________ © Cengage Learning 2015
HORMONES AND GLUCOSE METABOLISM © Cengage Learning 2015
HOW DOES THE PANCREAS REGULATE BLOOD SUGAR? The regulation of blood glucose is disrupted in diabetes mellitus Type 1 diabetes: ____________________________________ Symptoms usually appear in ______and _______ Type 2 diabetes: ______________________________ Symptoms typically start in __________ © Cengage Learning 2015
HOW DOES THE PANCREAS REGULATE BLOOD SUGAR? (CONT’D. ) Insulin pump. This device delivers insulin into a diabetic’s body to maintain blood glucose within normal levels. © Cengage Learning 2015
DO INVERTEBRATES HAVE HORMONES? Some components of the endocrine system occur in invertebrates Example: _____, ______, and _____ make ______hormones Invertebrates do not have the same glands as vertebrates do, but they produce the homologous hormones in other glands Example: octopi produce _____, and ______ in a gland near their eye © Cengage Learning 2015
DO INVERTEBRATES HAVE HORMONES? Hormone-signaling systems unique to invertebrates have also evolved Example: a hormone unique to arthropods called ecdysone controls molting (periodic shedding of the exoskeleton) © Cengage Learning 2015
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