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Chapter 16: The Endocrine System. Arnold Adolph Berthold 1803 – 1861 Founder of Endocrinology. Berthold’s Experiment in Roosters…. Castration & Reimplantation of testis. Castration. Castration & Transplantation of testis. Berthold’s Conclusion. - PowerPoint PPT Presentation
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Chapter 16:The Endocrine System
Arnold Adolph Berthold 1803 – 1861Founder of Endocrinology
Berthold’s Experiment in Roosters….
Castration Castration &Reimplantationof testis
Castration &Transplantationof testis
Berthold’s Conclusion...
-A secretory, blood-borne product of the transplanted testesis responsible for the normal development of the birds in thesecond and third group
Today, it is called TESTOSTERONE
-’problem’: no one knows why Berthold did the experiment in the first place…. No clear rationale for it.
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.1: Location of the major endocrine organs of the body, p. 605.
Pineal glandHypothalamusPituitary glandThyroid gland
Parathyroid glands(on dorsal aspectof thyroid gland)Thymus gland
Adrenal glands
Pancreas
Ovary(female)
Testis(male)
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.3: PIP second-messenger mechanism of amino acid-based hormones, p. 608.
PIP2
IP3
ReceptorGTP
GTP
CatecholaminesTRHADHGnRHOxytocin
Triggers responses of target cell
GDP
Extracellular fluid
Cytoplasm
Inactiveprotein kinase C
Activeprotein kinase C
Phospholipase C
Gq
Ca2+ Ca2+-calmodulin
Hormone
Endoplasmicreticulum
DAG
GTP
1
2 34 5
5
6
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.4: Direct gene activation mechanism of steroid hormones, p. 609.
Steroidhormone
Steroidhormone
Cytoplasm
Receptor-chaperonincomplex
Molecularchaperones
Receptor-hormonecomplex
Hormoneresponseelements
Binding
Transcription Chromatin
mRNA
Nucleus
New protein
TranslationRibosome
mRNA
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.5: Three types of endocrine gland stimuli, p. 612.
Capillary blood contains lowconcentration of Ca2+, whichstimulates… Capillary
(low Ca2+ in blood)
Parathyroidglands
Thyroid gland(posterior view)
PTH
Parathyroidglands
…secretion of parathyroid hormone (PTH) by parathyroidglands
Humoral
CNS(spinal cord)
Medulla ofadrenalgland
Preganglionic SNS fiber stimulatesadrenal medulla cells…
PreganglionicSNS fiber
…to secrete catecholamines
Capillary
Neural
Hypothalamus
Thyroidgland
Adrenalcortex
The hypothalamus secretes hormones that…
…stimulatethe anteriorpituitary glandto secretehormonesthat…
Hormonal
Gonad(Testis)
Pituitarygland
…stimulate other endocrine glandsto secrete hormones
(a) (b) (c)
1 1 1
2
32
2
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.6: Relationships of the pituitary gland and hypothalamus, p. 613.
Neuronsin the ventralhypothalamus
Hypothalamicneurons in thesupraoptic nuclei
Hypothalamicneurons in theparaventricular nuclei
Hypophyseal portal system
Anterior lobe
Venule
Infundibulum(connecting stalk)
Neurohypophysis(storage area forhypothalamichormones)
Posteriorlobe
Venule
Hypothalamic-hypophyseal tract
Inferiorhypophysealartery
OxytocinADH
TSH, FSH, LH, ACTH, GH, PRL
Superiorhypophysealartery
Secretory cells ofadenohypophysis
• Primary capillary plexus• Hypophyseal portal veins• Secondary capillary plexus
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.7: Metabolic actions of growth hormone (GH), p. 615.
Growth hormone
Feedbackmechanism Inhibits GH synthesis
and release
Anteriorpituitary
Liver andother tissues
Insulin-like growthfactors (IGFs)
Indirectgrowth-promotingactions
Anti-insulinactions
ExtraskeletaleffectsSkeletal effects Fat Carbohydrate
metabolism
Increased cartilageformation andskeletal growth
Increased proteinsynthesis, andcell growth andproliferation
Increasedlipolysis
Increased bloodglucose and otheranti-insulin effects
Direct effects
Hypothalamussecretes growthhormone – releasinghormone (GHRH), andsomatostatin (GHIH)
Key:Increases, stimulatesReduces, inhibits
Initial stimulusPhysiological response
Result
Inhibits GHRH releaseStimulates GHIH release
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.8: Gross and microscopic anatomy of the thyroid gland, p. 620.
(a) (b)
Hyoid boneThyroid cartilage
Internal carotidartery
Common carotidartery
Epiglottis
External carotidarterySuperior thyroidartery
Isthmus ofthyroid gland
Left subclavianarteryLeft lateral lobeof thyroid gland
Inferior thyroidartery
TracheaBrachiocephalicarteryAorta
Colloid-filledfollicles Follicle cells
Parafollicular cell
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.11: The parathyroid glands, p. 624.
(a) (b)
Pharynx(posterioraspect)
Thyroidgland
Parathyroidglands
Trachea
Esophagus
Capillary
Chiefcells
Oxyphilcells
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.12: Effect of parathyroid hormone on bone, the intestine, and the kidneys, p. 625.
Hypocalcemia (low bloodcalcium) stimulatesparathyroid glands
PTH release fromparathyroid glands
Rising Ca2+ inblood inhibitsPTH release
Activatesosteoclasts;calcium andphosphateions releasedinto blood
Increasescalciumabsorptionfrom food
Promotes activationof vitamin D
Increasescalciumreabsorption
Bone
Intestine
Kidney
PTH:
Blood-stream
= Ca2+ ions
= PTH molecules
Key:
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.13: Microscopic structure of the adrenal gland, p. 626.
(a) (b)
• Cortex
Kidney
• Medulla
Adrenal gland
CapsuleZona
glomerulosa
Zonafasciculata
Zonareticularis
Adrenalmedulla
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.16: Stress and the adrenal gland, p. 631.
Short term More prolongedStress
Hypothalamus
Nerve impulses
Adrenalcortex
CRH (corticotropin-releasing hormone)
Corticotrophcells ofanteriorpituitary
To target in blood
ACTH
Mineralocorticoids Glucocorticoids
1. Retention of sodium and water by kidneys2. Increased blood volume and blood pressure
1. Proteins and fats converted to glucose or broken down for energy2. Increased blood glucose3. Suppression of immune system
Long-term stress response
Short-termstress response
Spinal cord
Adrenalmedulla
Preganglionicsympatheticfibers
Catecholamines(epinephrineand norepinephrine)
1. Increased heart rate2. Increased blood pressure3. Liver converts glycogen to glucose and releases glucose to blood4. Dilation of bronchioles5. Changes in blood flow patterns leading to decreased digestive system activity and reduced urine output6. Increased metabolic rate
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.18: Regulation of blood glucose levels by insulin and glucagon, p. 633.
Stimulatesglycogenbreakdown
Glycogen Glucose
Liver
Stimulatesglycogenformation
Stimulatesglucose uptakeby cells
Tissue cells
Stimulus:Rising blood glucose level
Homeostasis: Normal blood glucose level (about 90 mg/100 ml)
Stimulus:Declining bloodglucose levelBlood
glucoserises tonormalrange
Bloodglucosefalls tonormalrange
Glucagon
Pancreas
Insulin
GlycogenGlucose
Liver
Pancreas
Imbalance
Imbalance
Human Anatomy and Physiology, 7eby Elaine Marieb & Katja Hoehn
Copyright © 2007 Pearson Education, Inc.,publishing as Benjamin Cummings.
Figure 16.1: Modified to emphasize the relationship between the adrenal glands and the testes and ovaries.
Adrenal glands
Ovary(female)
Testis(male)
Testes & Ovaries
These gamete producing glands produce the lion’s share of sex hormone for each sex. Ovaries are in females and Testes are in
males. There is, however, an important role for the adrenal
glands…