1. Endocrine Gland Stimuli … d. *Hypothalamic-Pituitary-Target Feedback Loop When a hormone is the stimulus for the release of another hormone, the Hypothalamus and/or the Pituitary Gland hormones are involved Hypothalamus: has Releasing & Inhibiting Hormones which travel directly to the Anterior Pituitary via special blood vessels affect the release of 4 Anterior Pituitary Hormones Anterior Pituitary: Some of its hormones are Stimulating Hormones which Regulates the secretion of the hormones of many other endocrine glands

1. Endocrine Gland Stimuli … d. *Hypothalamic-Pituitary-Target Feedback Example: Thyroid Releasing hormone of the hypothalamus travels to Anterior Pit. Causing it to release Thyroid Stimulating Hormone. Then TSH travels to Thyroid Gland causing it to release the Thyroid Hormone. Finally the Thyroid Hormone travels to its target organs. Final Hormone of Feedback Loop: As it’s levels Increase it will feeds back to Hypothalamus and Ant. Pituitary causing them to decreases hormone secretion  Rhythmic hormone release: levels rise and fall in a pattern SEE OPENSTAX TEXT PP. 696 & 704 Tables

MAJOR ENDOCRINE GLANDS III. Pituitary Gland and Hypothalamus A MAJOR ENDOCRINE GLANDS III. Pituitary Gland and Hypothalamus A. HYPOTHALAMUS - Nervous Sys Control 1. *Hormones that go to the Anterior Pituitary - Releasing & Inhibiting Hormones Produced and Released in Hypothalamus - Hormones carried by blood in the Hypophyseal Portal System directly to Anterior Pituitary Releasing & Inhibiting Hormones 1st Capillary Plexus Hypophseal Portal Veins 2nd Capillary Plexus

A. HYPOTHALAMUS … Hypo. Hormones that go to the Posterior Pituitary Posterior Pituitary is made of nervous tissue and is really an extension of the hypothalamus The hormones are made in the hypothalamus and then move down the axons into the axon terminals. There they are stored and released into the capillaries of the posterior pituitary whenever an action potential travels down the neurons 1

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

III. Pituitary Gland and Hypothalamus… B. Pituitary Gland Location Hormones: 8 Lobes Anterior Lobe: (adenohypophysis) Posterior Lobe: Infundibulum Hypophyseal Tract: Hypophseal Portal Veins Infundibulum Figure 9.3

1. Posterior Pituitary Hormones made by: Hormones released into capillary bed of Post. Pit. Hormones: (Direct Affect) a. ADH: Target: Stimulus Receptors: sense osmolarity  nerve impulse to neurons with ADH

b. Oxytocin Problem: as H2O decreases, Blood Pressure _________ 1. Posterior Pituitary … a. ADH … Problem: as H2O decreases, Blood Pressure _________ Osmoreceptors send nerve impulse to neurons storing ADH to cause its release Affect of ADH: Inhibition via Neg. Feedback: normal H2O & solute levels b. Oxytocin Target: Stimulus: Occurs during Child Birth. Occurs during child birth.

1. Posterior Pituitary… Hormones … b. Oxytocin … Information is sent to hypothalamus via nervous system and Oxytocin is released. Regulation: Inhibition: Birth ends the stretching and stops + cycle

i) Biochemical: All 6 are proteins (or peptides) 2. Anterior Pituitary Overview: i) Biochemical: All 6 are proteins (or peptides) ii) Hormone Mechanism: second-messenger systems iii) Stimulus: iv) 2 of the Ant. Pit Hormones go directly to target organs = Non-stimulating Hormones Hypothalamus Hormone  Ant. Pit. Hormones (2 hormones)  Target Organ v) 4 of the Anterior Pituitary Hormones: act as the hormonal stimulus for other Endocrine Glands = Stimulating hormones Hypothalamus Hormone Ant. Pit. Stimulating Hormones  Endocrine Gland  Target Organ & Cells Regulation: Via Neg. Feedback– usually the last hormone in the chain inhibits production of the other hormones

Anterior Pituitary Hormones Non-stimulating Hormones Stimulating Hormones

b. Non-stimulating Hormones Hypothalmic hormone  non-stimulating hormone  target i) Growth Hormone Target: Action: Protein synthesis & tissue building: growth of Metabolic Effects: Regulation: Stimulation: Inhibition GH feeds back to Hypothalamus Synergism: Thyroid Hormone

Growth hormone disorders ** Students Do ** p. 708 Pituitary dwarfism - Gigantism Acromegaly age 16 age 33 age 9 age 52

2. Anterior Pituitary … e. Non-stimulating Hormone … Prolactin (PRL) Target: Action: Stimulus: Regulation: Hormonal Inhibition: PIH = Dopamine

i) Thyroid-Stimulating Hormone = Thyrotropin 2. Anterior Pituitary … c. Stimulating Hormones = Tropic Hormones Function: i) Thyroid-Stimulating Hormone = Thyrotropin Target: Stimulus: Action: Regulation: Hormonal Stimulation: Inhibition: increasing Thyroid Hormone feed back to Hyp. & Pituitary

iii) Gonadotropins: FSH and LH FSH = Follicle-Stimulating Hormone f. Stimulating Hormones of Ant. Pit. ii) Adrenocorticotropic Hormone (corticotrophin)= ACTH Target: Action: Regulationn: Stimulation: CRH = Stress: Inhibition: increasing Cortisol iii) Gonadotropins: FSH and LH FSH = Follicle-Stimulating Hormone Synergism w/ LH: Ovarian Follicle maturation

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

IV. Thyroid Gland B. Thyroxine Overview 1. Location & Structure: 2. Microscopic: Follicles b)Parafollicular cells: B. Thyroxine 1. Active forms: T4 & T3 Production Important: Iodine deficiencey

Inhibition: increasing Thyroid H. on Pit & Hy IV. Thyroid Gland … B. Thyroxine … 3. Actions: ↑ ↑ Growth 4. Regulation: Release: Inhibition: increasing Thyroid H. on Pit & Hy

Histology of the Thyroid Gland Follicle Colloid

D. Thyroid Hormone Disorders Students Do Goiters: 2. Hypothyroidism C. Thyroxine … D. Thyroid Hormone Disorders Students Do Goiters: 2. Hypothyroidism 3. Hyperthyroidism Grave”s Disease:

E. Calcitonin (insignificant) Production at: Target: Actions: IV. Thyroid Gland … E. Calcitonin (insignificant) Production at: Target: Actions: Inhibits: ↑ Antagonistic to Regulation: Stimulation: Inhibition: decreasing blood levels of Ca+2

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

Thyroid and Parathyroid

V. Parathyroid Gland & Hormone … Actions Activates Stimulate 3. Vitamin D: F. Regulation: Humoral Release: Inhibition: increasing Ca+2 blood levels G. Importance:

VI. Adrenal Glands A. Overview 1. Location: Parts Adrenal Cortex Tissue: Hormones: Aldosterone (Mineralocorticoids), Cortisol (Glucocorticoids), Sex hormones Layers: 3 (next slide) b. Adrenal Medulla Tissue: Hormones: Epinephrine & Norepinephrine

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

Lab Tips: Appearance of cells Round clusters Columns Irregular Columns with white spaces Round clusters, blood vessels Lab Tips: Appearance of cells

Adrenal Cortex (Glomerulosa and fasciculata)

B. ADRENAL CORTEX 1. Mineralocorticoids a. Target: b. Aldosterone i) Layer: iii) Target: Juxtaglomerular Complex iv) Stimulus: 1) increasing 2) low blood

Regulation: Multiple Factors Release: b. Aldosterone … v) Actions: Direct Indirectly: Regulation: Multiple Factors Release: Humoral: decreased Na+ and increased K+ Stress  Hormonal: CRH  ATCH  Aldosterone

b. Aldosterone … iv) Regulation … Most common stimuli Release … Kidney: Renin-Angiotensin- Aldosterone Mechanism Juxtaglomerular Complex: angiotensin II formed  Stimulates: Inhibition: when decreasing K+ and increasing blood volume and BP

2. Glucocorticoids a. Layer: b. Cortisol (significant amounts) i) Target: II) Stimulus: Hormonal Long-term Stress  CRH  ACTH iii) Actions: Break-down of: Decrease Immune System Activity

Adrenal Cortex – zona fasciculata

iv) Regulation: CRH (hypo)  ACTH (ant. pit.) Cortisol 2. Glucocorticoids … iv) Regulation: CRH (hypo)  ACTH (ant. pit.) Cortisol Inhibition: Hormonal via rising Cortisol levels -

3. Gonadocorticoids Layer: Hormone: Androgens–levels normally low Females: sex drive maybe

4. Adrenal cortex disorders Masculinization– hypersecretion of sex hormones Beard and male distribution of hair growth Students Do Cushing’s syndrome– 37

C. Adrenal Medulla 1. Cells of: Chromaffin Cells = Modified Sympathetic Ganglionic neurons 2. Hormones: Catecholamines epinephrine & norepinephrine Target: Actions: “Fight or Flight” - brief response

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

Zona reticularis and medulla

VII. Pancreas A. Location: B. Hormones/Cells: β and α cells  Insulin producers Glucagon producers

Inhibition: Low blood glucose 2. Actions: Enhances membrane transport VII. Pancreas … C. Regulation: D. Target: Insulin 1. Regulation: Humoral Stimulation: Inhibition: Low blood glucose 2. Actions: Enhances membrane transport Inhibits glycogen breakdown Once glucose is in cells Energy needs met: Excess  Glycogen and then fat

Homeostasis: Normal blood glucose levels (90 mg/100ml) Actions … Other Actions: Fat storage & Protein synthesis 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

Homeostasis: Normal blood glucose levels (90 mg/100ml) Glucagon - Actions 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

G. Disorders of the Pancreas STUDENTS DO 1. Diabetes mellitus (Hyperglycemia) Type 1– Type 2 – Effects:

VIII. Pineal Gland Location: Secretes: Stimulus: Actions: Depression in the dark

IX. Gonads & Placenta steroid hormone Estrogens Progesterone A. Ovaries – produce: steroid hormone Estrogens Progesterone B. Testes – produce: Produce androgens (testosterone) C. Placenta – hormones produced (like hCG) to maintain pregnancy and manage delivery

X. Hormone Secretion By Other Organs Parts of small intestine, stomach, kidneys, heart Nearly all cells release hormones if damaged Kidneys Erythropoietin Renin  Angiotensin II 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 1. Atrial Natriuretic Peptide (ANP) Gastrointestinal Tract 3 Thymus Gland Produces thymosin Helps develop immune system E. Liver 1. Thriombopoetin

END of PPT Extra Slides Review Questions