Post on 15-Jan-2016
Hormones & Endocrine Systems
Chapter 40: pp. 735 - 754
1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
(Caterpillar): © Doug Wechsler/Animals Animals/Earth Scenes; (Moth): © Richard Kolar/Animals Animals/Earth Scenes
OutlineEndocrine Glands
PheromonesSteroid HormonesPeptide Hormones
Hypothalamus and Pituitary GlandOther Endocrine Glands and Hormones
ThyroidParathyroid AdrenalPancreasGonads
2
Endocrine Gland
• The endocrine system functions differently from the nervous system.
• An endocrine system consists of glands that coordinate body activities through hormones
• Chemical signals are used between individuals, between body parts, and between cells
• Both the nervous system and the endocrine system rely on negative feedback mechanisms.
3
The Human Endocrine System
4
ovary (female)
HYPOTHALAMUS
Releasing and inhibiting hormones: regulate the anterior pituitary
PITUITARY GLAND
Posterior Pituitary
Antidiuretic (ADH): water reabsorption by kidneys
Oxytocin: stimulates uterine contraction and milk letdown
Anterior PituitaryThyroid stimulating (TSH): stimulates thyroid
Adrenocorticotropic (ACTH): stimulates adrenal cortex
Gonadotropic (FSH, LH): egg and sperm production; sex hormone production
Prolactin (PL): milk production
Growth (GH): bone growth, protein synthesis, and cell division
THYROID
Thyroxine (T4) and triiodothyronine (T3): increase metabolic rate; regulates growth and development
Calcitonin: lowers blood calcium level
ADRENAL GLAND
Adrenal cortex
Glucocorticoids (cortisol): raises blood glucose level; stimulates breakdown of protein
Mineralocorticoids (aldosterone): reabsorption of sodium and excretion of potassiumSex hormones: reproductive organs and bring about sex characteristics
Adrenal medullaEpinephrine and norepinephrine: active in emergency situations; raise blood glucose level
parathyroid glands(posterior surfaceof thyroid)
PINEAL GLAND
Melatonin: controls circadian and circannual
PARA THYROIDS
Parathyroid hormone (PTH): raises blood
THYMUS
Thymosins: production and maturation of T lymphocytes
PANCREAS
Insulin: lowers blood glucose level and promotes glycogen buildup
Glucagon: raises blood glucose level and promotes glycogen breakdown
GONADS
TestesAndrogens (testosterone):male sex characteristics
OvariesEstrogens and progesterone:female sex characteristics
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
testis(male)
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Modes of Action of the Nervous and Endocrine Systems
6
receptor
receptor
neurotransmitter
pancreas
arteriole
liverinsulin
liver cell
axon terminal
vesicle
b. Reception of insulin, a hormone
a. Reception of a neurotransmitter
axon ofnerve fiber
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Chemical Signals
• Pheromones– Chemical signals that work at a distance between
individuals
– A woman’s axillary extract can alter another woman’s menstrual cycle
• Hormones– Chemical signals that work
• At a distance between organs, or
• Locally between adjacent cells
7
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Target Cell Concept
9
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
hormone
capillary
nontarget cell
receptors
target cells
Action of Hormones
HormonesChemical signals produced by one cell that regulate
the metabolism of other cellsSteroid Hormones
Can cross cell membranes
Peptide HormonesMost bind to receptor in plasma membrane
First Messenger
Causes internal release of cAMP Second Messenger
10
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Peptide Hormone
13
capillary
receptor protein
glycogen
1. Hormone binds to a receptor in the plasma membrane.
activatedenzyme
2. Binding leads to activation of an enzyme that changes ATP to cAMP.
cAMP(second messenger)
3. cAMP activates an enzyme cascade.
4. Many molecules of glycogen are broken down to glucose, which enters the bloodstream.
glucose(leaves celland goesto blood)
ATP
peptide hormone(first messenger)
plasmamembrane
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Steroid Hormone
15
ribosome
protein
nucleus
cytoplasm
1. Hormone diffuses through plasma membrane because it is lipid soluble.
steroidhormone
plasmamembrane
nuclearpore
2. Hormone binds to receptor inside nucleus.
DNAreceptorprotein
mRNA
3. Hormone-receptor complex activates gene and synthesis of a specific mRN molecule.
4. mRNA moves to ribosomes, and protein synthesis occurs.
mRNA
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Human Endocrine System
• Endocrine glands– Ductless glands that secrete hormones directly into
the bloodstream• Most endocrine hormones are peptides
• Only gonads and adrenal cortex produce steroid hormones
– Effects of hormones are moderated in two ways• Negative feedback opposes release
• Antagonistic hormones oppose each other’s actions
18
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Hypothalamus and Pituitary GlandHypothalamus regulates internal environmentActs through autonomic systemAlso controls glandular secretions of pituitary gland
Posterior PituitaryAntidiuretic Hormone (ADH)
Controlled by negative feedbackOxytocin
Controlled by positive feedback
Anterior PituitaryHypothalamus controls by producing
Hypothalamic-releasing hormones, andHypothalamic-inhibiting hormones
20
Hypothalamus and the Pituitary
21
hypothalamus
Posterior pituitary Anterior pituitary
portal system
1. Neurosecretory cells produce ADH and oxytocin.
2. These hormones move down axons to axon endings.
3. When appropriate, ADH and oxytocin are secreted from axon endings into the bloodstream.
1. Neurosecretory cells produce hypothalamic-releasing and hypothalamic-inhibiting hormones.
2. These hormones are secreted into a portal system.
3. Each type of hypothalamic hormone either stimulates or inhibits production and secretion of an anterior pituitary hormone.
4. The anterior pituitary secretes its hormones into the bloodstream, whereby they are then delivered to specific cells, tissues, and glands.
Thyroid:thyroid-stimulatinghormone (TSH)
Adrenal cortex:adrenocorticotropichormone (ACTH)
Kidney tubules:antidiuretichormone (ADH)
Smooth musclein uterus:oxytocin
Mammary glands:oxytocin
Mammary glands:prolactin (PRL)
Bones, tissues:growth hormone(GH)
Ovaries, testes:gonadotropichormones (FSH, LH)
opticchiasm
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Anterior Pituitary Hormones
Anterior pituitary hormones that affect other glands:Thyroid-Stimulating Hormone (TSH)Adrenocorticotropic Hormone (ACTH)Gonadotropic Hormones
Anterior pituitary hormones that do NOT affect other glandsProlactin (PRL)Melanocyte-Stimulating Hormone (MSH)Growth Hormone (GH)
22
Effect of Growth Hormone
23
a: © AP/Wide World Photos; b: © Ewing Galloway, Inc.
a. b.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Acromegaly
24
From Clinical Pathological Conference, "Acromegaly, Diabetes, Hypermetabolism, Proteinura and Heart Failure", American Journal of Medicine, 20 (1956) 133. Reprinted with permission from Excerpta Medica Inc.
Age 9 Age 16 Age 33 Age 52
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Thyroid Glands
• Composed of large number of follicles filled with– Triiodothyronine (T3), and
– Thyroxine (T4)
• Thyroid hormones increase metabolic rate
• Thyroid-induced abnormalities– Simple goiter - Poor hormone production
– Cretinism - Poor thyroid development
– Myxedema - Hypothyroidism
– Exophthalmic goiter - Hyperthyroidism
25
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Abnormalities of the thyroid
27
a: © Bruce Coleman, Inc./Alamy; b: © Medical-on-Line/Alamy; c: © Dr. P. Marazzi/Photo Researchers, Inc. a. Simple goiter b. Congenital hypothyroidism c. Exophthalmic goiter
affected eye
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Calcitonin• Regulates blood calcium level (in part)• Secreted by thyroid gland when blood calcium level
rises• Brings about deposit of calcium in the bones• Low calcium level in blood stimulates the release of
parathyroid hormone (PTH)– Parathyroid hormone causes
• Phosphate level in blood to decrease, and• Calcium level in blood to increase
– Insufficient production of parathyroid hormone leads to tetany
28
Regulation of Blood Calcium Level
29
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
calcitonin
Homeostasis (normal blood Ca2+)
high blood Ca 2+
Thyroid glandsecretes
calcitonininto blood. Bones
take up Ca2+
from blood.
low blood Ca 2+
Blood Ca2+
lowers.
Blood Ca2+
rises.Parathyroid
glandsrelease PTHinto blood.
activatedvitamin D
parathyroidhormone
(PTH)
Intestinesabsorb Ca2+
from digestivetract.
Kidneysreabsorb Ca2+
from kidneytubules.
Bonesrelease Ca2+
into blood.
Adrenal Glands• Paired – One sits atop each kidney (ad-renal)• Each consists of outer cortex and inner
medulla– Inner portion, the adrenal medulla
• Produces– Epinephrine, and– Norepinephrine
• Short-term response to stress (fight or flight)– Outer portion, adrenal cortex
• Produces– Mineralocorticoids, and– Glucocorticoids
• Long-term response to stress
30
Adrenal Glands
31
epinephrine
norepinephrine
sympathetic fibers
adrenal medulla
Blood glucose level rises.
adrenal cortex
ACTH
Glucocorticoids
Mineralocorticoids
stress
glucocorticoids
mineralocorticoids
hypothalamus
spinal cord(cross section)
neurosecretorycells producehypothalamic-releasinghormone
Stress Response:Long Term
path of nerveimpulses
Protein and fat metabolisminstead of glucosebreakdown.
Reduction of inflammation;immune cells aresuppressed.
Sodium ions and waterare reabsorbed by kidney.
Blood volume andpressure increase.
Stress Response:Short Term
Heartbeat and bloodpressure increase.
Muscles becomeenergized.
anteriorpituitarysecretesACTH
neuroncell body
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glucocorticoids
• Cortisol– Raises blood glucose level– Promotes breakdown of muscle proteins to amino
acids– Promotes metabolism of fatty acids– Counteracts inflammatory response
32
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Mineralocorticoids
AldosteronePromotes two renal functions:
Absorption of sodium, andExcretion of potassium
Renin-angiotensin-aldosterone systemRaises blood pressureAngiotensin II constricts arteriolesAldosterone causes kidneys to reabsorb sodium (causing water
retention)
Atrial natriuretic hormone (ANH) is antagonistic to aldosterone
34
Regulation of Blood Pressure and Volume
35
renin
aldosterone
Homeostasis (normal blood pressure)
low blood Na +
atrial natriuretichormone (ANH)
Kidneys excreteNa+ and water
in urine.
Heart secretesatrial natriuretichormone (ANH)
into blood.
Blood pressurelowers.
Blood pressurerises.
Kidneys secreterenin into blood.
Kidneysreabsorb Na+
and water fromkidney tubules.
Adrenal cortexsecretes
aldosteroneinto blood.
angiotensinI and II
high blood Na+
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Addison Disease
36
a. b.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
a: © Custom Medical Stock Photos; b: © NMSB/Custom Medical Stock Photos
Cushing Syndrome
37
(Both): Atlas of Pediatric Physical Diagnosis, Second Edition by Zitelli & Davis, 1992. Mosby-Wolfe Europe Limited, London, UK
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Pancreas• Made up of exocrine and endocrine tissue
– Endocrine Portion of the Pancreas:• Consists of pancreatic islets• Produce and secrete
– Insulin» Secreted during high blood glucose level» Stimulates uptake of glucose by cells
– Glucagon» Secreted during low blood glucose level» Stimulates liver to break down glycogen
– Exocrine Portion of the Pancreas:• Secretes enzymes and buffers into intestine
38
Regulation of Blood Glucose Level
39
high blood glucose
low blood glucose
insulin
glucagon
Liver storesglucose from
blood asglycogen.
Pancreatic isletof Langerhans
After eating,pancreas
secretes insulininto blood.
Muscle cellsstore glycogen
and build protein.
Adipose tissueuses glucosefrom bloodto form fat.
Homeostasis (normal blood glucose)
Blood glucoselevel lowers.
Before eating,pancreas secretes
glucagon intoblood.
Liver breaksdown glycogen
to glucose.Glucose enters
blood.
Adipose tissuebreaks down fat.
Pancreatic isletof Langerhans
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© Peter Arnold, Inc./Alamy
Animation
Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.
Other Endocrine Glands
• Gonads– Testes
• Produce testosterone
• Secondary sex characteristics
– Ovaries• Produce estrogen and progesterone
• Reproduction
• Secondary sex characteristics
41
The Effects of Anabolic Steroid Use
42
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
deepening of voice in women severe acne
balding in men and women; hair on face and chest in women
breast enlargement in menand breast reduction in women
liver dysfunctionand cancer
kidney disease andretention of fluids,called "steroid bloat"
reduced testicularsize, low sperm count,and impotency
'roid mania–delusions and hallucinations;depression upon withdrawal
high blood cholesterol andatherosclerosis; high bloodpressure and damage to heart
in women, increasedsize of ovaries;cessation of ovulationand menstruation
stunted growth inyoungsters by pre-maturely halting fusionof the growth plates
Other Endocrine Glands
Pineal GlandProduces melatoninInvolved in Circadian rhythms
Thymus GlandSecrete thymosinsAid in differentiation of lymphocytes
ProstaglandinsProduced within cells Not distributed in blood
43
Melatonin Production
44
6 P.M. 6 A.M.
b. winter
a. experimental
c. summer
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© The McGraw-Hill Companies, Inc./ Evelyn Jo Johnson, photographer
ReviewEndocrine Glands
PheromonesSteroid HormonesPeptide Hormones
Hypothalamus and Pituitary GlandOther Endocrine Glands and Hormones
ThyroidParathyroid AdrenalPancreasGonads
45