Chemical substances secreted by endocrine (ductless) glands. These chemicals are carried by blood to their respective target cells.

What would be a slow long-term process?

Tend to control slow long-term activities in the body.

• Homeostasis• Growth and Development• Reproduction• Energy Metabolism• Behavior

Lipid soluble:

• Steroids

• Thyroid

• NO

Water soluble:

• Proteins/Polypeptides

• Amines

response

endocrine cell

target cell

hormones receptor

protein

Water soluble

response

endocrine cell

target cell

hormones intracellul

ar receptor

Lipid soluble

GlucagonInsulin

OxytocinADH

Calcitonin

tyrosine

thyroxine

epinephrine

Prostaglandins

Leukotrines

• Activate inflammatory response

• Stimulate clotting• Induce labor• Inhibit acid in GI tract,

blood flow in kidneys

• promote constriction of bronchi (asthma)

Fatty acids

blood glucose lowstimulates

glucagon from

pancreas

glucose release

from liver stimulates

blood glucose high inhibits

Control of Hormone Release

Humoral Stimulus

PTH

Capillary (low Ca2+ in blood)

Control of Hormone Release

Neural Stimulus

cortexmedulla

Control of Hormone Release

Hormonal Stimulus

Tropic hormones- stimulate the production and secretion of hormones by other endocrine glands; ex. TSH

Nontropic hormones- stimulates cellular growth, metabolism, or other functions; ex. thyroxine

pineal glandhypothalamus

pituitary gland

• Secreted directly in CSF to blood

• High levels at night make us sleepy; low level during day

• Pineal gland is stimulated by darkness and inhibited by light

• Function in regulating circadian rhythms (sleep, body temp, appetite) biological clock

Produces melatonin (synthesized from seratonin, a derivative of tryptophan)

hypothalamus

anterior pituitary

posterior pituitary

Antidiuretic Hormone (ADH)

Oxytocin (+ feedback)

Fig. 18.09

• Growth Hormone (GH)• Thyroid Stimulating Hormone (TSH)• Adrenocorticotropic Hormone (ACTH)• Gonadotropins (FSH, LH)• Prolactin (PRL)• Melanocyte-stimulating Hormone (MSH)

• Acts on the liver, stimulating it to release several polypeptide hormones.

• Stimulates amino acid uptake and protein synthesis in target cells.

• Ultimately stimulates cell growth (cell size and number), especially in muscle and bone.

• Also stimulates fat breakdown.

Fig. 18.07

GH GH LevelsLevels

awake sleep

strenuous exercise

hyposecretion of GH

DwarfismDwarfism

Kenadie - worlds smallest girl due to primordial dwarfism

Little People Big World

hypersecretion of GH

GigantismGigantism

Bao Xishun, a 7ft 8.95in herdsman from Inner Mongolia

AcromegalAcromegalyy

hypersecretion of GHhypersecretion of GH

7 ft 1 ¼ inches

• Acts on the thyroid gland, stimulating it to release T3 & T4

• These thyroid hormones increase glucose catabolism and body heat production.

• Negative feedback mechanism involved in regulating levels.

• Acts on the adrenal cortex, stimulating it to secrete glucocorticoids (e.g., cortisol).

• Glucocorticoids promote the synthesis of glucose from noncarbohydrate sources such as amino acids, and fatty acids

• Negative feedback mechanism involved in regulating levels.

thyroid

trachea

larynx

• Thyroxine (T4)• Triiodothyronine (T3)Both control metabolic rate and cellular oxidation

• Calcitonin (from parafolicular cells)- lowers blood Ca ++ levels and causes Ca++ reabsorption in bone

Thyroid gland selectively uptakes iodine to produce T3 & T4

Fig. 18.12

Parathyroid Glands

Parathyroid Glands

GoiterGoiterLack of iodine in diethyposecretion of T3 & T4

hyposecretion of T3 & T4

CretinismCretinism

MyxedemaMyxedemahyposecretion of T3 & T4

myxedemaAfter thyroid treatment

ExophthalmoExophthalmos-s-

hyperthyroidism

PTH release:1) stimulates osteoclasts2) enhances reabsorption of Ca++ by kidneys3) increases absorption of Ca++ by intestinal

mucosal cells

Hyperparathyroidism- too much Ca++ drawn out of bone; could be due to tumor

Hypoparathyroidism- most often follow parathyroid gland trauma or after removal of thyroid--- tetany, muscle twitches, convulsions; if untreatedrespiratory paralysis and death

• Regulates glucose uptake by cells

• Controlled via negative feedback:

insulin & glucagon

• Blood sugar level: 90 mg/mL

• Produced by the cells of the Islets of Langerhan• Catalyze oxidation of glucose for ATP production• Lowers blood glucose levels by promoting transport of

glucose into cells. • Stimulates glucose uptake by the liver and muscle

cells.• Stimulates glycogen synthesis in the liver and muscle

cells (glycogenesis).• Stimulates amino acid uptake and protein synthesis• Stimulate lipogenesis• Decreases glycogenolysis• Decreases gluconeogenesis

• Produced by the cells of the Islets of Langerhans

• Stimulates change of glycogen to glucose in the liver (glycogenolysis).

• Synthesis of glucose from lactic acid and non carbohydrate molecules such as fatty acids and amino acids (gluconeogenesis)

• Causes in blood glucose concentration

   hypoglycemic- low blood sugar; deficient in glucagon

Type I Diabetes hyposecretion of insulininsulin dependantjuvenile onset

Type II Diabeteslate onset (adult)insensitivity of cells to insulinmanage by exercise & diet

• Hypergylcemia

• Glucosauria

• Polyuria

• Polydipsia

• Polyphagia

• Ketoacidosis

Symptoms (Type I):

• Arteriosclerosis

• Cardiovascular problems

• Gangrene

• Eye problems

• Kidney damage

Type I (IDDM):

• Insulin replacement

• Pancreas transplant

• Pancreatic cell transplant

• Fetal pancreatic islet cell transplant

Treatment:

Adrenal Adrenal GlandsGlands

Fig. 18.06

Fig. 18.16Regulation of Aldosterone secretion by renin-angiotensin-aldosterone (RAA) pathway

Hormones of the Hormones of the Adrenal MedullaAdrenal Medulla

• Adrenalin (epinephrine): converts glycogen to glucose in liver

• Noradrenalin (norepinephrine): increases blood pressure

(sympathetic nervous system)

• Corticosteroids: glucose levels)

Hormones of the Hormones of the Adrenal CortexAdrenal Cortex

Glucocorticoids- cortisol1. Decrease protein synthesis2. Increase release and use of fatty acids3. Stimulates the liver to produce glucose from non carb’s

Mineralcorticoids- aldosterone1. Stimulates cells in kidney to reabsorb Na+ from filtrate2. Increases water reabsorption in kidneys3. Increases blood pressure

Sex Steroids- small amts (androgens)1. Onset of puberty2. Sex drive

Cushing’s Cushing’s SyndromeSyndrome

Hypersecretion of cortisone; may be caused by an ACTH releasing tumor in pituitary

Symptoms: trunkal obesity and moon face, emotional instability

Treatment: removal of adrenal gland and hormone replacement

Addison’Addison’s s

DiseaseDiseaseHyposecretion of glucocorticoids and mineral corticoids;

Symptoms- wt loss, fatigue, dizziness, changes in mood and personality, low levels of plasma glucose and Na+ levels, high levels of K+

Treatment- corticosteroid replacement therapy

Located anterior to the heart

Produces- thymopoetin and thymosin helps direct maturation and specialization of T-lymphocytes (immunity)

ThymusThymus

Ovaries- produce estrogen and progesteroneresponsible for maturation of the reproductive organs and 2ndary sex characteristics in girls at puberty

GonadsGonads

Female Reproductive System

Testes- produce sperm and testosterone (initiates maturation of male repro organs and 2ndary sex characteristics in boys at puberty)

GonadsGonads

Male Reproductive System

1. A disease in which too much T3 and T4 are produced.

2. The posterior pituitary produces which two hormones and what is their function?

3. What is acromegaly?4. What organ does glucagon target?5. The target tissue for lutenizing hormone

is ____.6. Where are epinephrine and

norepinephrine produced?7. If your adrenal cortex produced low

levels of aldosterone, your urine would be _____?

8. What effect does parathyroid hormone have on your bones?