Hole’s Human Anatomy and Physiology Tenth Edition Chapter 13 Copyright © The McGraw-Hill...
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Transcript of Hole’s Human Anatomy and Physiology Tenth Edition Chapter 13 Copyright © The McGraw-Hill...
Hole’s HumanAnatomy and Physiology
Tenth Edition
Chapter 13
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 13-1
Endocrine System
Chapter 13Endocrine System
• __________ glands are ductless• __________ glands have ducts
13-2
Endocrine Glands
Endocrine glands• release hormones• ______________ through blood to targets
Paracrine secretions• act locally• ____________________
Autocrine secretions• affect only the __________
13-3
Comparison of Nervous System and Endocrine System
• Neurons release neurotransmitters into a synapse, affecting postsynaptic cells• Glands release _______________ bloodstream • Only target of ________________
13-4
Chemistry of Hormones
Steroid Hormones• derived from ___________• sex hormones• adrenal cortex hormones
Nonsteroid Hormones• amines• ________• peptides• _____________• most hormones
13-5
Structural Formulas of Hormones
13-6
Types of Hormones
13-7
Actions of Steroid Hormones
• hormone crosses membranes
• hormone combines with receptor in nucleus
• ________________ activated
• mRNA enters cytoplasm to direct synthesis of protein
13-8
Actions of Nonsteroid Hormones
• _____________________
• hormone binds to receptor on cell membrane
• ATP converted to cAMP
• cAMP promotes a series of reactions leading to cellular changes
13-9
Prostaglandins
• paracrine substances• ___________• __________________• regulate cellular responses to hormones • can activate or inhibit adenylate cyclase• wide variety of functions
13-10
Control of Hormonal Secretions
• primarily controlled by negative feedback mechanism
13-11
Negative Feedback
13-12
Major Endocrine Glands
13-13
Pituitary Gland
Two distinct portions• ________________ (adenohypophysis)• __________________ (neurohypophysis)
13-14
Pituitary Gland Control
• Hypothalamic releasing hormones stimulate cells of anterior pituitary to release hormones• Nerve impulses from hypothalamus stimulate nerve endings in the posterior pituitary gland to release hormones
13-15
Hypothalamic Hormones
13-16
Anterior Pituitary Hormones
Growth Hormone (GH)• stimulates increase in size and rate of body cells• enhances movement of amino acids through membranes• promotes growth of long bones• ______________________________• secretion stimulated by growth hormone-releasing hormone
Prolactin (PRL)• sustains milk production after birth• __________________________• secretion inhibited by prolactin release-inhibiting hormone
13-17
Anterior Pituitary Hormones
__________________________________• controls secretions of hormones from the thyroid gland• controlled by thyrotropin-releasing hormone
Adrenocorticotropic Hormone• controls secretions of some hormones of adrenal cortex• _______________________-releasing hormone
13-18
Anterior Pituitary Hormones
Follicle-Stimulating Hormone (FSH)• stimulates development of egg-containing follicles in ovaries• stimulates follicular cells to secrete estrogen• ______________________________• controlled by gonadotropin-releasing hormone
_____________________• promotes secretions of sex hormones• ________________________• promotes growth of long bones• _____________________________________
13-19
Posterior Pituitary Hormones
Antidiuretic Hormone (ADH)• _________________________________• in high concentration, raises blood pressure• controlled by hypothalamus in response to changes in blood water concentration and blood volume
Oxytocin (OT)• stimulates uterine contractions• ___________________________________• controlled by hypothalamus in response to stretch in uterine and vaginal walls and stimulation of breasts
13-20
Thyroid Gland
13-21
Thyroid Gland Hormones
Thyroxine (T4) and Triiodothyronine (T3)• ________________________________ carbohydrates• increases rate of protein synthesis• accelerates growth• stimulates activity in the nervous system• __________________
Calcitonin• __________________ and phosphate ion concentrations by inhibiting release of calcium and phosphate from bones• increases rate at which calcium and phosphate are deposited in bones 13-22
Thyroid Gland Disorders
Cretinism• ______________ in infants• leads to small stature and mental retardation
General Hyperthyroidism• high metabolic rate• ___________• weight loss• protruding eyes
13-23
Thyroid Gland Disorders
Myxedema• ________________• low metabolic rate• sluggishness
Simple Goiter• deficiency of iodine• leads to deficiency of thyroid hormones• gland enlarges
Grave’s disease• overstimulation of gland by antibodies• hyperthyroidism
13-24
Parathyroid Glands
13-25
Parathyroid Hormone
• PTH• increases blood calcium levels• decreases blood phosphate levels• _________________________________• ____________________• stimulates kidneys to retain calcium and excrete phosphate• promotes calcium absorption into intestine
13-26
Parathyroid Glands
Mechanism by which PTH promotes calcium absorption in the intestine
13-27
Parathyroid Gland Disorders
Hyperparathyroidism• caused by tumor• ________• __________________• altered mental functions• bone weakening
Hypoparathyroidism• caused by injury or removal of gland• muscle cramps• seizures• _______________levels
13-28
Adrenal Glands
13-29
Adrenal Medulla Hormones
______________________________• release controlled by sympathetic nervous system• increases heart rate and blood pressure• dilates respiratory airways• promotes breakdown of glycogen• activates reticular formation• __________________
13-30
Adrenal Cortex Hormones
Aldosterone• _________________________ and pressure by promoting conservation of sodium ions and water
13-31
Adrenal Cortex HormonesCortisol
• _____________________________• increases fatty acid release• stimulates glucose synthesis from noncarbohydrates• controlled by _______________ and ACTH from anterior pituitary
13-32
Adrenal Cortex Hormones
Adrenal androgens• supplement sex hormones from the gonads• __________________________
13-33
Pancreas
13-34
Pancreatic Hormones
Glucagon• secreted by alpha cells of pancreatic islets• _________________________________________• stimulates liver to convert noncarbohydrates into glucose• stimulates break down of fats• controlled by blood glucose concentrations
Somatostatin• secreted by delta cells of pancreatic islets• ___________________
13-35
Pancreatic Hormones
Insulin• secreted by beta cells of pancreatic islets• promotes formation of glycogen from glucose• inhibits conversion of noncarbohydrates into glucose• enhances movement of glucose into adipose and muscle cells• decreases blood glucose concentrations• _______________________________• _____________________________• ____________________________________
13-36
Insulin and Glucagon
Insulin and glucagon function together to stabilize blood glucose concentrations
13-37
Other Endocrine Glands
Pineal Gland• secretes ___________• _______________________• may control onset of puberty• helps regulate female reproductive cycle
Thymus Gland• secretes thymosins• ________________________________________
13-38
Other Endocrine Glands
Reproductive Glands• _______ secrete estrogen and progesterone• ______________________• placenta secretes estrogen, progesterone, and gonadotropins
13-39
Stress
Types of Stress• ___________• ________________
Responses to Stress• hypothalamus triggers sympathetic impulses to various organs• epinephrine is released• cortisol is released to promote longer-term responses
13-40
Responses to Stress
13-41
Life-Span Changes
• endocrine glands shrink• ___ levels even out, muscular strength decreases• ADH levels increase due to slow break down• calcitonin levels decrease• _____ increases, osteoporosis risk increases• insulin resistance may develop• changes in melatonin secretion affect the body clock• thymosin production declines increasing risk of infections
13-42
Clinical Application
Growth Hormone Ups and Downs
• __________ - hypersecretion of GH in children • Acromegaly – hypersecretion of GH in adults• ___________ – hyposecretion of GH in children
13-43