Hi everyone, This endocrine system ppt has not been modified for the new text. Tomorrow, I will modify as we go through it. Professor Brooks

The Endocrine System

I. The Endocrine System: An Overview Overall Function = B. CONTROL: By altering __________ C. Uses Chemicals = D. Endocrine Glands E. Neuroendocrine Gland = F. Other Organs that Produce Hormones Chemicals similar to Hormones: Autocrines: Paracrines:

II. Hormones Charateristics A. The Chemistry of Hormones Types Amino acid: Steroids: Eicosanoids: Example: Prostaglandins paracrines & autocrines

B. Mechanisms of Hormone Action Target cells: most affect 1 or few Organ systems: Different targets: Typical Affects: Text Page ____ Receptor: Location depends on: Lipid Hormones Non=Lipid Hormones

B. Mechanisms of Hormone Activity … Two Main Mechanisms Plasma Membrane Receptors: a. Type Chemical: - except: Second Messenger (indirect): 2. Intracellular Receptors: a. Type Chemical: Intracellular Receptors (Direct Gene Activaion): hormone receptor lipid hormone receptor 6

1. Plasma Membrane Receptors and Second-Messenger System a. The Cyclic AMP Signaling Mechanism Hormone binds to: Receptor activates: Second messenger produced: cAMP activates: Cell Effects Hormone removal: Phosphodiesterase– Effectiveness: Hormones that act via cAMP: Epinephrine ACTH FSH LH Glucagon PTH TSH Calcitonin

Hormone (1st messenger) binds receptor. 1. Plasma Membrane Receptors and Second-Messenger Systems … a. The Cyclic AMP Signaling Mechanism … Hormone (1st messenger) binds receptor. 1 Extracellular fluid Receptor Cytoplasm Figure 16.2, step 1

Hormone (1st messenger) binds receptor. Extracellular fluid Adenylate cyclase Receptor cAMP (2nd messenger) is produced. 4 GDP Cytoplasm Figure 16.2, step 4

Which triggers responses 1 Hormone (1st messenger) binds receptor. Extracellular fluid Adenylate cyclase 5 cAMP activates protein kinases. G protein (GS) Receptor cAMP (2nd messenger)is produced. 4 GDP Inactive protein kinase Active protein kinase Which triggers responses Cytoplasm Figure 16.2, step 5

1. Plasma Membrane Receptors and Second-Messenger Systems … b 1. Plasma Membrane Receptors and Second-Messenger Systems … b. There are others– The PIP2-Calcium Signaling Mechanism

Protein produced changes: B. Mechanisms of Hormone Activity … 2. Intracellular Receptors and Direct Gene Activation Entrance of Hormone: H attaches to: H-Receptor binds to: Activated Gene: Protein produced changes: Lipid Hormone Receptor 1

Receptor-hormone enters nucleus. Steroid hormone Plasma membrane Extracellular fluid 1 Cytoplasm Receptor protein Receptor- hormone complex 2 Receptor-hormone enters nucleus. Nucleus Figure 16.3, step 2

binds to a specific DNA sequence). Steroid hormone Plasma membrane Extracellular fluid Cytoplasm Receptor protein Receptor- hormone complex Hormone response elements Nucleus 3 binds to a specific DNA sequence). DNA Figure 16.3, step 3

transcription. Steroid hormone Plasma membrane Extracellular fluid 1 Cytoplasm Receptor protein Receptor- hormone complex 2 Hormone response elements Nucleus 3 DNA transcription. 4 mRNA Figure 16.3, step 4

– an enzyme, structural protein, a secretion, etc… Steroid hormone Plasma membrane Extracellular fluid 1 Cytoplasm Receptor protein Receptor- hormone complex 2 Hormone response elements Nucleus 3 DNA 4 mRNA protein synthesis.  new protein – an enzyme, structural protein, a secretion, etc… 5 New protein Figure 16.3, step 5

C. Target Cell Specificity 1. Activity Affected By a. Hormone Blood levels: b. Receptor Numbers Up-regulation: ↑ Hormones  Down-regulation: c. Binding Affinity

D. Half-Life, Onset, and Duration of Hormone Activity 1 D. Half-Life, Onset, and Duration of Hormone Activity 1. Duration of Hormone Activity Half-Life = 2. Removal of Hormones

II. Hormone Characteristics … E. Interactiion of Hormones at Target Cells Permissiveness: Example: Synergism: Antagonism:

F. Control of Hormone Release 1. Negative Feedback Loops A Stimulus: Control Center: Effector: Results: Feedback to Endocrine Gland  Calcium homeostasis of blood 9–11 mg/100 ml Rising blood Ca2+ levels Thyroid gland releases calcitonin Osteoclasts degrade bone matrix and release Ca2+ into blood PTH Calcitonin Calcitonin stimulates calcium salt deposit in bone Parathyroid glands release parathyroid hormone (PTH) Thyroid gland Parathyroid glands Falling blood Ca2+ levels Imbalance

F. Control of Hormone Release 2. Endocrine Gland Stimuli–3 a. Humoral Stimuli (simplest) Humoral = Ends when: Hormones: Parathyroid hormone Calcitonin Insulin

2. Endocrine Gland Stimuli … b. Neural Stimuli = Examples = c. Hormonal Stimuli (most complex) i) Hormones:

1. Endocrine Gland Stimuli … d. Hypothalamic-Pituitary-Target Feedback Loop Hypothalamus Hormones: Function: Anterior Pituitary Hormones: Final Hormone of feedback loop: As it increase it will negatively feeds back to stop the Hypothalamus and Pituitary from releasing their hormones  Rhythmic hormone release:

NS modifies endocrine activity: adjusts Can overrides F. Control of Hormone Release … 2. Nervous System Modulation: Hormone interaction w/ NS NS modifies endocrine activity: adjusts Can overrides Example: Severe Stress

Major Endocrine Glands and Hormones Suggestion: Make notecards with Endocrine Gland Images – include targets, affects, and regulation (control loops)

Major Endocrine Glands and Hormones Table 9.1 (1 of 4) 26

Major Endocrine Glands and Hormones Table 9.1 (3 of 4) 27

Major Endocrine Glands and Hormones Table 9.1 (4 of 4) 28

MAJOR ENDOCRINE GLANDS III. Pituitary Gland and Hypothalamus A MAJOR ENDOCRINE GLANDS III. Pituitary Gland and Hypothalamus A. HYPOTHALAMUS 1 Hormones from Hypo. Released from the Posterior Pituitary Origin: Cell body location: Axons Terminal location: Hormones considered from: Hypo. Hormones that go to the Anterior Pituitary - Production Site: - Path to Ant. Pit. Via: Hypophyseal Portal System: NEXT SLIDE 2 3. Hormones: Releasing Hormones Inhibiting Hormones

Relationships of Posterior Pituitary & HYPO. Hypothalamas synthesizes oxytocin and ADH. 1 Paraventricular nucleus Hypothalamus Supraoptic nucleus Oxytocin and ADH transported along hypothalamic-hypophyseal tract to pituitary. 2 Optic chiasma Infundibulum (connecting stalk) Inferior hypophyseal artery Hypothalamic- hypophyseal tract Oxytocin and ADH stored in axon terminals in posterior pituitary. 3 Axon terminals Oxytocin and ADH released into blood when neurons fire. 4 Posterior lobe of pituitary Oxytocin ADH (a) Relationship between the posterior pituitary and the hypothalamus

- Hypophseal Portal System (Portal = Capill.VeinCapill.) III. Pituitary Gland and Hypothalamus… A. Hypothalamus… 2. Hypo. Hormones That Go to The Ant Pit. … - Hypophseal Portal System (Portal = Capill.VeinCapill.) 1st Capillary Plexus in: HP Veins go through 2nd Capillary Plexus in: Hormones leave and travel to: Type of Hormones: Releasing Hormones: Inhibiting Hormones: Naming of Hormones: 1st Capillary Plexus Hypophseal Portal Veins 2nd Capillary Plexus

III. Pituitary Gland and Hypothalamus… B. Pituitary Gland Location Lobes Anterior Lobe: tissue = (adenohypophysis) Posterior Lobe: tissue = Figure 9.3

1. Posterior Pituitary Hormones from Release stimulated by: Neurohypophysis = Hormones: (Direct Affect) a. ADH: Target: Stimulus Type & ADH release: Osmoreceptors of Hyp.: function Increasing solute concentration = Water is and Blood Pressure is: Effect: Inhibition: via

1. Posterior Pituitary… Hormones … Oxytocin Stimulus: Initiation: Target & Acttions: Regulation: Inhibition:

B. Pituitary Gland … 2. Anterior Pituitary a. Biochemical: All b. Hormone Mechanism: c. Stimulus: Releasing Hormones Inhibiting Hormones d. Pathways: Hypothalamus Hormone  ii) Hypothalamus Hormone  iii) Regulation: Usually the last hormone in the chain inhibits production of the other hormones in the chain

Anterior Pituitary Hormones Non-stimulating Hormones Stimulating Hormones

e. Non-stimulating Hormones i) Growth Hormone Target: Action: growth of Metabolic Effects: Regulation: Stimulation: Inhibition GH GHIH = Somatostatin Synergism:

Growth hormone disorders ** Students Do ** Pituitary dwarfism - Gigantism Acromegaly age 16 age 33 age 9 age 52

2. Anterior Pituitary … e. Non-stimulating Hormone … Prolactin (PRL) Normal: Target: Action: Stimulus: Regulation Path: Inhibition:

i) Thyroid-Stimulating Hormone = Thyrotropic Hormone Target: Stimulus: 2. Anterior Pituitary … Stimulating Hormones = Tropic Hormones Function: i) Thyroid-Stimulating Hormone = Thyrotropic Hormone Target: Stimulus: Action: Regulation: Stimulation: Inhibition:

iii) Gonadotropins: FSH and LH FSH = Follicle-Stimulating Hormone corticotropin f. Stimulating Hormones of Ant. Pit. ii) Adrenocorticotropic Hormone = ACTH Target: Adrenal Glands Action: Regulation: Stimulation: CRH = Stress: Inhibition: iii) Gonadotropins: FSH and LH FSH = Follicle-Stimulating Hormone Target: Synergism w/ LH:

f. Stimulating Hormones iii) Gonadotropins: FSH … Regulation: Stimulation: Inhibition: LH = Lutenizing Hormone Target: Stimulus: Action: Synergism w/ FSH: Gonadal Hormones

IV. Thyroid Gland Location & Structure: Microscopic: Follicles - Parafollicular cells: C. Thyroxine 1. Active forms: T4 & T3 2. Actions: 3. Regulation: Release: Inhibition:

D. Hormone Disorders Students Do 1. Goiters: 2. Myxodema C. Thyroxine … 4. Production Important: D. Hormone Disorders Students Do 1. Goiters: 2. Myxodema 3. Grave’s Disease 4. Cretinism

E. Calcitonin (insignificant) Production at: Target: IV. Thyroid Gland … E. Calcitonin (insignificant) Production at: Target: Actions: Antagonistic to Regulation: Stimulation: Inhibition:

V. Parathyroid Glands & Parathyroid hormone A. Location: B. Antagonistic to Histology & Production Site: D. Target: Thyroid Gland Parathyroid Gland

Thyroid and Parathyroid

V. Parathyroid Gland & Hormone … Actions Activates Stimulate Vitamin D: F. Regulation: Humoral Release: Inhibition: G. Importance:

VI. Adrenal Glands A. Overview 1. Location: Parts Adrenal Tissue: Hormones: - Mineralocorticoids area - Glucocorticoids area - Sex hormone area Layers: 3 (next slide) b. Adrenal Catechcholamines Tissue:

Parts & Layers of Adrenal Gland Hormones Layers = Capsule = Zona Glomerulosa = Zona Fasiculata Adrenal Cortex = Zona Reticularis

B. ADRENAL CORTEX 1. Mineralocorticoids a. Target b. Aldosterone Potency & Amount: Target: Juxtaglomerular Complex of Kidney Actions: Direct Cause:

i) Layer: Zona Glomerulosa Stimulus: 1) and 2) b. Aldosterone … Most common stimuli i) Layer: Zona Glomerulosa Stimulus: 1) and 2) Actions: ↑ blood volume & BP Mechanism (1) Renin-Angiotensin-Aldosterone Mechanism Stimulus: Juxtaglomerular Complex: angiotensin II Zona glomerulosa cells  i) Regulation: Humoral Inhibition:

i) Regulation: Humoral Aldosterone … i) Regulation: Humoral Stimulation: pressure receptors for low blood pressure & kidney for K+ concen. Inhibition ii) Stress Response Short term More prolonged Stress Hypothalamus Nerve impulses Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH Mineralocorticoids Glucocorticoids Retention of sodium and water by kidneys Increased blood volume and blood pressure 1. Proteins and fats converted to glucose or broken down for energy 2. Increased blood sugar 3. Suppression of immune system Long-term stress response Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate

Adrenal Cortex (Glomerulosa and fasciculata)

2. Glucocorticoids Function: b. Cortisol (significant amounts) i) Target: ii) Actions: Blood Sugar maintenance Gluconeogenesis: mechanism = BP maintenance Mechanism: iii) Synergistic with:

iii) Under Stress (prolonged): Negative Affects of Chronic Stress - 2. Glucocorticoids … iii) Under Stress (prolonged): Negative Affects of Chronic Stress - iv) Regulation: CRH (hypo)  ACTH (ant. pit.) Cortisol Cycles: Inhibition: - increasing  ↓ CRH & ↓ ACTH

2. Glucocorticoids ... Hormones involved in Stress 3. Gonadocorticoids Insignificant levels normally Short term More prolonged Stress Hypothalamus Nerve impulses Adrenal cortex Releasing hormone Corticotropic cells of anterior pituitary ACTH Mineralocorticoids Glucocorticoids Retention of sodium and water by kidneys Increased blood volume and blood pressure 1. Proteins and fats converted to glucose or broken down for energy 2. Increased blood sugar 3. Suppression of immune system Long-term stress response Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate 2. Glucocorticoids ... Hormones involved in Stress

Adrenal Cortex – zona fasciculata

4. Adrenal cortex disorders Students Do Cushing’s syndrome– Masculinization– Addison’s disease– 61

C. Adrenal Medulla 1. Cells of: Chromaffin Cells = Modified Symp. Ganglionic neurons 2. Hormones: Catecholamines = Target: Actions: - “Fight or Flight” - brief repone Epinephrine: 80%, greater effect on Norepinephrine: 20%, greater effect on

Zona reticularis and medulla

C. Adrenal Medulla … - ‘fight or flight’ Short term Stress Hypothalamus Figure 9.13, step 1

Figure 9.13, step 2 Short term Stress Hypothalamus Nerve impulses Spinal cord Figure 9.13, step 2

Figure 9.13, step 3 Short term Stress Hypothalamus Nerve impulses Spinal cord Adrenal medulla Preganglionic sympathetic fibers Figure 9.13, step 3

Under neural control Figure 9.13, step 4 Short term Stress Hypothalamus Nerve impulses Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) Under neural control Figure 9.13, step 4

Adrenal Medulla … ‘fight or flight’ … Short term Stress Hypothalamus Nerve impulses Short-term stress response Spinal cord Adrenal medulla Preganglionic sympathetic fibers Catecholamines (epinephrine and norepinephrine) 1. Increased heart rate 2. Increased blood pressure 3. Liver converts glycogen to glucose and releases glucose to blood 4. Dilation of bronchioles 5. Changes in blood flow patterns, leading to increased alertness and decreased digestive and kidney activity 6. Increased metabolic rate Figure 9.13, step 5

VII. Pancreas A. Location: Pancreatic Islets – endocrine B. Hormones/Cells: β and α cells  C. Regulation: D. Target: Insulin producers Glucagon producers

Homeostasis: Normal blood glucose levels (90 mg/100ml) Insulin Action Insulin-secreting cells of the pancreas activated; release insulin into the blood Uptake of glucose from blood is en- hanced in most body cells Blood glucose levels decline to set point; stimulus for insulin release diminishes Elevated blood sugar levels Liver takes up glucose and stores it as glycogen Stimulus: rising blood glucose levels (e.g., after eating four jelly doughnuts) Homeostasis: Normal blood glucose levels (90 mg/100ml) Figure 9.15, step 7

1. Regulation (only this hormone does this) Pancreas … Insulin 1. Regulation (only this hormone does this) Stimulation: _________________ Inhibition: __________________ 2. Actions: Enhances Inhibits Inhibit Once glucose is in cells Energy needs met: Glucose   ATP Excess 

Homeostasis: Normal blood glucose levels (90 mg/100ml) Glucagon Action Stimulus: declining blood glucose levels (e.g., after skipping a meal) Homeostasis: Normal blood glucose levels (90 mg/100ml) Low blood sugar levels Rising blood glucose levels return blood sugar to homeostatic set point; stimulus for glucagon release diminishes Glucagon-releasing cells of pancreas activated; release glucagon into blood; target is the liver Liver breaks down glycogen stores and releases glucose to the blood Figure 9.15, step 12

Stimulates: as above for stimulus Inhibition: ___________________ Pancreas … F. Glucagon 1. Stimulus: 2. Regulation: Stimulates: as above for stimulus Inhibition: ___________________ 3. Glucagon Action: raises blood glucose Gluconeogenesis Glycogen  ____________________ 4. Synergistic with:

G. Disorders of the Pancreas 1. Diabetes mellitus (Hyperglycemia) Type 1– no insulin, autoimmune disorder Type 2 – insulin affects deficient; insulin resistance Effects: excessive hunger High blood fatty acid levels  High glucose in urine    Dehydration 2. Hypoglycemia

VIII. Pineal Gland – tiny gland of the brain Location: Secretes: Actions: Coordinates Believed to Excess Melatonin: Depression in the dark

IX. Gonads & Placenta 2 groups of steroid hormone A. Ovaries – produce _____ 2 groups of steroid hormone B. Testes – produce _______ Hormones: C. Placenta – hormones produced (like hCG) to _______________________________________________

X. Hormone Secretion By Other Organs Parts of small intestine, stomach, kidneys, heart Nearly all cells release hormones or hormone-like chemicals if damaged A. Kidneys & Blood Production-- Erythropoietin Reduced O2 levels in blood Erythropoietin stimulates Kidney releases erythropoietin Enhanced erythropoiesis Red bone marrow More RBCs Normal blood oxygen levels

X. Hormone Secretion By Other Organs … HEART– Atrial Naturietic Factor Gastrointestinal Tract Thymus Gland-- Thymosin

END of PPT Extra Slides Review Questions

Review Qestions The endocrine system makes chemical message molecules known as ____________ . Which of the following are at least partially under hormonal control? hormones A. Reproduction B. Growth and development C. Mobilization of body defenses D. Water and electrolyte balance E. Metabolism rates

Review Questions Identify the following components of the 2nd messenger system… A Hormone B Receptor Extracellular fluid Adenylate cyclase D C G protein (GS) GDP responses

Review Questions … The most common stimuli for hormone release is the presence or absence of other ___________ . When ion or nutrient concentrations in the blood stimulate hormone release, the stimulus is referred to as ___________ . ________ stimuli of endocrine glands occur when nerve impulses stimulate hormone release directly. hormones humoral Neural

Review Questions Lipid soluble hormones are transported by ___________ proteins and stimulate responses via direct ________ activation. Hormones are degraded by ___________ of the target cells or by the _________ or __________. plasma gene enzymes liver kidneys

Review Questions The ________ ________ gland makes and releases 6 different hormones. Release of these hormones is controlled by other hormones of the _____________ region of the brain. The 2 hormones of the posterior pituitary are controlled by Neural stimulation hypothalamus Other hormones Nothing in particular Estrogen anterior pituitary hypothalamus

Review Questions Lack of iodine prevents the __________ gland from making __________ hormone. As a result, TSH from the _____________ continues to stimulate colloid production causing a condition known as __________ . thyroid thyroid pituitary gland goiter

Review Questions Match the following glands with their hormones or functions. Estrogen, progesterone: female reproductive cycles melatonin: sleep cycles Testosterone: male reproductive features Norepinephrine, epinephrine: fight or flight insulin, glucagon: blood sugar control Pineal Gland Pancreatic Islets Testes Ovaries Adrenal Medulla

Relationships of pituitary and hypothalamus. releases hormones. 1 Hypothalamus Hypothalamic neuron cell bodies Superior hypophyseal artery Hypophyseal portal system Hypothalamic hormones travel via portal veins to pituitary. 2 • Primary capillary plexus • Hypophyseal portal veins • Secondary capillary plexus Anterior lobe of pituitary Anterior pituitary hormones released or inhibited… 3 TSH, FSH, LH, ACTH, GH, PRL (b) Relationship between the anterior pituitary and the hypothalamus

FROM 2013 PPT Relationships of pituitary and hypothalamus. Hypothalamas synthesizes oxytocin and ADH. 1 Paraventricular nucleus Hypothalamus Supraoptic nucleus Oxytocin and ADH transported along hypothalamic-hypophyseal tract to pituitary. 2 Optic chiasma Infundibulum (connecting stalk) Inferior hypophyseal artery Hypothalamic- hypophyseal tract Oxytocin and ADH stored in axon terminals in posterior pituitary. 3 Axon terminals Oxytocin and ADH released into blood when neurons fire. 4 Posterior lobe of pituitary Oxytocin ADH (a) Relationship between the posterior pituitary and the hypothalamus