1. HORMON

2. What is hormon?
Many organs in the body secreted biologically active compound called endocrine hormones, which are transported via blood stream to other tissues or organs where they exert a biological effect
As classically defined, is a substance that is synthesized in one organ and transported by the circulatory system to act on another tissue
Hormones can act on adjacent cells (paracrine)
Hormones can act on the cell in which they were synthesized without entering the sistemic circulation (autocrine)

3. Long-Distance Regulators
Animal hormones are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
Hormones reach all parts of the body, but only target cells are equipped to respond
Hormones convey information via the bloodstream to target cells throughout the body

4. What is the importance of hormones?
Several hormones may control one, process or one hormon may control several process
Provide communication beetween cells, tissues and organs
This comunication is responsible for the regulation of wide range of functions including growth, reproduction, development, homeostasis, and response to external stimuli. Failure in this comunication channels are common and lead to many diseases of the endocrine system

5. How do hormones act?
In order to act , hormones must interact with other loci on or in the target cell
These sites are termed receptors
A receptor is a locus to which the hormone binds in order to elicit its action

6. RECEPTOR A receptor has two function :
First, it must be able to distinguish the hormone from all the other chemicals present in the circulation and bind it.
The hormone binding sites on receptors have evolved to have unique configurations that are complementary to the hormones they bind.
Generally, hormone-receptor interactions are noncovalent in nature and are reversible.

7. RECEPTOR
- Second, the receptor must able to transmit the information gained from the binding to trigger a cellular response. Thus, subtances that bind hormones, even tightly, but do not trigger subsequent responses are not receptors.

8. Types of Hormones
Hormon can be clasisified in several ways, according:
1-Chemical composition :
Cholesterol derivates– this include : glucorticoid, mineralocorticoid, esterogen, progestin
Amino acid -tyrosine
Polypeptyde-ACTH,TRH
Glycoprotein-TSH, FSH, LH
2-Solubility properties-lipophilic dan hidrophilic
3-Location of reseptor
4-Nature of signaling used to mediate hormonal action within the cell

9. Clasification of hormones by mechanism of action
Group I hormones
Hormon that bind to intracellular receptors
Androgens
calcitriol
esterogens
glucocorticoids
mineralocorticoids
progestins
retinoic acid

10. Group II Hormones Hormones that bind to cell surface receptors
A.The second messenger is cAMP
Calcitonin, glucagon, LH, Somatosatin,
B.The second mesenger is cGMP
Nitric oxide, atrial natriuretic factor
C.The second messenger is calcium or phosphatidyl inositols (or both)
Gastrin, oxitocyn, cholecistokinin, TRH, Acetilcholin
D.The second messenger is a kinase or phosphatase cascade
Adponectin, insulin , leptin, GH, Prolactin, IGF-I , IGF-II, EGF

11. General features of hormon classes
Group I
Group II
Types
Steroid, iodothyronines,calcitriol, retinoids
Polypeptides, protein, glycoproteins, cathecolamines
Solubility
Lipophilic
Hydrophilic
Transport protein
Yes No
Plasma halflife
Long ( hours to days)
Short (minutes)
Receptor
Intracellular
Plasma membran
Mediator
Receptor-hormone complex
cAMP.cGMP, Ca2+,metabolites complex phosphoinositols, kinase cascade

12. WHERE HORMONES ARE SYNTHESIZED?
Hormones are synthesized in discrete organs designed solely for spesific purpose
Pituitary: TSH, FSH, LH, GH, Prolactin, ACTH
Some organs are disigned to perform two distinct but closely related function
Ovaries produce mature oocyte and reproductive hormones estradiol and progesteron
The testes produce mature spermatozoa and testesterone
Hormones are also produced in specialized cells within other organs
Small intestine : glucagon like peptide
Thyroid : calcitonin
Kydney : angiotensin II
The synthesis of some hormones requires the parenchimal cells of more than one organ
Skin, liver, kidney : calcitriol.

13. Hormon are synthesized and modified for full activity in a variety of ways
Some hormones are synthesized in final form and secreted immediattely , included in this class are the hormon derived from cholesterol
Others are synthesized in final form and stored in producing cells, example catecholamine
The others hormone synthesized and from precursor molecules in the producing cell, then are processed and secreted upon a physiologic cue, examples insulin
Converted to active forms from precurssor molecules in the periphery, examples: T3, DHT

14. Control Pathways and Feedback Loops
The endocrine system secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth, and behavior
A common feature is a feedback loop connecting the response to the initial stimulus
Negative feedback regulates many hormonal pathways involved in homeostasis

15. Signaling by any of these hormones involves three key events:
Reception
Signal transduction
Response

16. SECRETORY
CELL
SECRETORY
CELL
Hormone
molecule
Hormone
molecule
VIA
BLOOD
VIA
BLOOD
Signal receptor
TARGET
CELL
TARGET
CELL
Signal
transduction
pathway
Signal
receptor OR
Cytoplasmic
response
DNA
Signal
transduction
and response
mRNA
DNA
Nuclear
response
NUCLEUS
Synthesis of
specific proteins
NUCLEUS
Receptor in plasma membrane
Receptor in cell nucleus

17. The same hormone may have different effects on target cells that have
Binding of a hormone to its receptor initiates a signal transduction pathway leading to responses in the cytoplasm or a change in gene expression
The same hormone may have different effects on target cells that have
Different receptors for the hormone
Different signal transduction pathways
Different proteins for carrying out the response

18. Different receptors
different cell responses
Epinephrine
Epinephrine
Epinephrine
a receptor
 receptor
 receptor
Glycogen
deposits
Vessel
dilates
Glycogen
breaks down
and glucose
is released
from cell
Vessel
constricts
Intestinal blood
vessel
Skeletal muscle
blood vessel
Liver cell
Different intracellular proteins
different cell responses

19. Paracrine Signaling by Local Regulators
In paracrine signaling, nonhormonal chemical signals called local regulators elicit responses in nearby target cells
Types of local regulators:
Neurotransmitters
Cytokines and growth factors
Prostaglandins help regulate aggregation of platelets, an early step in formation of blood clots

20. The hypothalamus and pituitary integrate many functions of the vertebrate endocrine system
The hypothalamus and the pituitary gland control much of the endocrine system
Tropic hormones, hormones that regulate endocrine organs
Tropic hormones are secreted into the blood and transported to the anterior pituitary

21. Hypothalamus
Neurosecretory
cells of the
hypothalamus
Axon
Posterior
pituitary
Anterior
pituitary
HORMONE
ADH
Oxytocin
TARGET
Kidney tubules
Mammary glands,
uterine muscles

22. Neurosecretory cells of the hypothalamus Portal vessels Hypothalamic
Tropic Effects Only
FSH, follicle-stimulating hormone
LH, luteinizing hormone
TSH, thyroid-stimulating hormone
ACTH, adrenocorticotropic hormone
Neurosecretory cells
of the hypothalamus
Nontropic Effects Only
Prolactin
MSH, melanocyte-stimulating hormone
Endorphin
Portal vessels
Nontropic and Tropic Effects
Growth hormone
Hypothalamic
releasing
hormones
(red dots)
Endocrine cells of the
anterior pituitary
Pituitary hormones
(blue dots)
HORMONE
FSH and LH
TSH
ACTH
Prolactin
MSH
Endorphin
Growth hormone
TARGET
Testes or
ovaries
Thyroid
Adrenal
cortex
Mammary
glands
Melanocytes
Pain receptors
in the brain
Liver
Bones

23. Posterior Pituitary Hormones
The two hormones released from the posterior pituitary act directly on nonendocrine tissues
Oxytocin induces uterine contractions and milk ejection
Antidiuretic hormone (ADH) enhances water reabsorption in the kidneys

24. Anterior Pituitary Hormones
The anterior pituitary produces both tropic and nontropic hormones

25. Tropic Hormones The four strictly tropic hormones are
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Thyroid-stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Each tropic hormone acts on its target endocrine tissue to stimulate release of hormone(s) with direct metabolic or developmental effects

26. Nontropic Hormones
Nontropic hormones produced by the anterior pituitary:
Prolactin stimulates lactation in mammals but has diverse effects in different vertebrates
MSH influences skin pigmentation in some vertebrates and fat metabolism in mammals
Endorphins inhibit pain

27. Growth Hormone Growth hormone (GH) has tropic and nontropic actions
It promotes growth directly and has diverse metabolic effects
It stimulates production of growth factors

28. The thyroid gland produces calcitonin, which functions in calcium homeostasis

29. Parathyroid Hormone and Calcitonin: Control of Blood Calcium
Two antagonistic hormones, parathyroid hormone (PTH) and calcitonin, play the major role in calcium (Ca2+) homeostasis in mammals. Calcitonin stimulates Ca2+ deposition in bones and secretion by kidneys, lowering blood Ca2+ levels

30. Two Glands of Hormon Thyroid and parathyroid Located
Produce hormone (PTH)

31. Calcitonin
Thyroid gland
releases
calcitonin.
Reduces
Ca2+ uptake
in kidneys
Stimulates
Ca2+ deposition
in bones
STIMULUS:
Rising blood
Ca2+ level
Blood Ca2+
level declines
to set point
Homoeostasis:
Blood Ca2+ level
(about 10 mg/100 mL)
Blood Ca2+
level rises
to set point
STIMULUS:
Falling blood
Ca2+ level
Stimulates
Ca2+ release
from bones
Parathyroid
gland
PTH
Increases
Ca2+ uptake
in intestines
Active
vitamin D
Stimulates Ca2+
uptake in kidneys

32. Insulin and Glucagon: Control of Blood Glucose
The pancreas secretes insulin and glucagon, antagonistic hormones that help maintain glucose homeostasis
Glucagon is produced by alpha cells
Insulin is produced by beta cells

34. Alpha cells of pancreas release glucagon into the blood. Liver breaks
Body cells
take up more
glucose.
Insulin
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Rising blood glucose
level (for instance, after
eating a carbohydrate-
rich meal)
Blood glucose level
declines to set point;
stimulus for insulin
release diminishes.
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)
Blood glucose level
rises to set point;
stimulus for glucagon
release diminishes.
STIMULUS:
Dropping blood glucose
level (for instance, after
skipping a meal)
Alpha cells of pancreas
release glucagon into
the blood.
Liver breaks
down glycogen
and releases
glucose into the
blood.
Glucagon

35. Target Tissues for Insulin and Glucagon
Insulin reduces blood glucose levels by
Promoting the cellular uptake of glucose
Slowing glycogen breakdown in the liver
Promoting fat storage

36. Glucagon increases blood glucose levels by
Stimulating conversion of glycogen to glucose in the liver
Stimulating breakdown of fat and protein into glucose

37. Diabetes Mellitus
Diabetes mellitus is perhaps the best-known endocrine disorder
It is caused by a deficiency of insulin or a decreased response to insulin in target tissues
It is marked by elevated blood glucose levels

39. Adrenal Hormones: Response to Stress
The adrenal glands are adjacent to the kidneys
The adrenal medulla secretes epinephrine (adrenaline) and norepinephrine (noradrenaline)
They are secreted in response to stress-activated impulses from the nervous system
They mediate various fight-or-flight responses

40. Melatonin and Biorhythms
The pineal gland, located in the brain, secretes melatonin
Light/dark cycles control release of melatonin
Primary functions of melatonin appear to relate to biological rhythms associated with reproduction

42. Invertebrate regulatory systems also involve endocrine and nervous system interactions
Diverse hormones regulate homeostasis in invertebrates
In insects, molting and development are controlled by three main hormones:
Brain hormone stimulates release of ecdysone from the prothoracic glands
Ecdysone promotes molting and development of adult characteristics
Juvenile hormone promotes retention of larval characteristics

45. Hormones Released from the Anterior Pituitary or Adenohypophysis
Somatotrophs
Human Growth Hormone (hGH)
Hypothalamic control
hGH releasing hormone
hGH inhibiting hormone
Target Tissues:
General body cells, particularly bone, muscle, cartilage, and the liver.

46. Hormones Released from the Anterior Pituitary or Adenohypophysis
Hormone affects:
promotes the synthesis of insulin-like growth factors
Controls normal growth patterns by increasing protein synthesis, lipolysis, ATP production, and carbohydrate metabolism
In adults, it help maintain muscle and bone mass and promote healing and tissue repair

47. Hormones Released from the Anterior Pituitary or Adenohypophysis
Hypo-secretion:
During childhood causes Dwarfism
Hyper-secretion:
During childhood causes
Gigantism (up to 8 – 9 ft.)
During Adulthood causes
Acromegaly:
Enlargement of the small bones of the hand and feet
Enlargement of the cranium, nose, and lower jaw
Tongue, liver, and kidneys become enlarged

48. Hormones Released from the Anterior Pituitary or Adenohypophysis
Thyrotrophs:
Thyroid Stimulating Hormone (TSH)
Hypothalamic Control
Thyrotropin Releasing Hormone (TRH)
Target Tissue
Follicular cells of the Thyroid gland
Hormone affects:
controls the production of T3 and T4

49. Endocrine activity of the Thyroid Gland
Follicular cells:
T3 and T4
Target Tissue;
Almost all body tissues
Hormone effects:
Increases body metabolism
Increases gluconeogenesis
Increases glycolysis
Increases lipolysis
Increased basal metabolic rate (BMR)
Increases heart rate and force of contraction

50. Endocrine activity of the Thyroid Gland
Hypothyroidism:
endemic goiter: (due to I2 deficiency)
Myxedema: bagginess under the eyes and swelling of the face.
Arteriosclerosis: due to increase in blood cholesterol
Cretinism: extreme hypothyroidism during infancy and childhood

51. Endocrine activity of the Thyroid Gland
Hypothyroidism:
Cretinism: Physical and mental growth and development is greatly retarded
Hyperthyroidism
Toxic goiter
Graves Disease with exophthalmos

52. Hormones Released from the Anterior Pituitary or Adenohypophysis
Corticotrophs
Adrenocorticotropic hormone (ACTH)
Hypothalamic Control
Corticotropic releasing hormone (CRH)
Target Tissue
Adrenal cortex, Zona Fasciculata
Hormone affects:
control production of glucocorticoids such as cortisol

53. Endocrine activity of the Adrenal Cortex
Zona glomerulosa
Mineralocorticoids such as Aldosterone
Hormonal control
renin-angiotensin pathway
permissive effect of ACTH
Target tissue:
Principle cells of the DCT and collecting duct
Hormone affects:
increases reabsorption of Na+ and water

54. Endocrine activity of the Adrenal Cortex
Hyper-secretion:
Aldosteronism:
Hypokalemia, increase in extracellular fluid and blood volume,and hypertension, may also have period of muscular paralysis
Hypo-secretion:
Addison’s disease
Mineralocorticoids deficiency, death occurs in four days to two weeks if untreated

55. Endocrine activity of the Adrenal Cortex
Zona Fasciculata
Glucocorticoids such as cortisol and cortisone
Hormone control:
ACTH
Target tissue:
Liver and general body cells
Hormone affects:
Stimulates gluconeogenesis by the liver
Decreased glucose utilization by cells

56. Endocrine activity of the Adrenal Cortex
Hormone affects:
Elevated blood glucose levels
Reduction of protein stores in all body cells except the liver
increased plasma protein levels
promote lipolysis and beta oxidation of fat
Helps body recover from stress
Prevention of inflammation

57. Endocrine activity of the Adrenal Cortex
Hypo-secretion
Addison’s disease - glucocorticoid deficiency
person becomes highly susceptible to disease and deteriorating effects of stress
Hyper-secretion:
Cushing’s Syndrome
mobilization of fat from lower body to the thoracic and upper abdominal regions giving raise to “Buffalo Torso”

58. Interactions of hormones in response to stress

59. Endocrine activity of the Adrenal Cortex
Zona reticularis
Produces small amounts of androgens, mostly dehydroepiandosterone (DHEA), DHEA may be converted into estrogens
Hormone Control:
Believed to be ACTH
Target tissue:
General body cells

60. Endocrine activity of the Adrenal Cortex
Hyper-secretion:
Adrenogenital Syndrome
in females causes beard growth, deeper voice, masculine distribution of body hair, and growth of the clitoris to resemble a penis.
Picture: In pre-pubertal males it causes the rapid develop of secondary sexual conditions

61. Endocrine Activity of the Adrenal Cortex
Hyper-secretion:
Adrenogenital Syndrome
in females causes beard growth, deeper voice, masculine distribution of body hair, and growth of the clitoris to resemble a penis.
Picture: Virilizing adrenal hyperplasia in a newborn female baby, DHEA was converted to testosterone

62. Endocrine Activity of the Adrenal Cortex
Hyper-secretion:
Picture: micropenis in a newborn baby boy.
micropenis is a result of hypopituitarism and lack of production of LH and therefore testosterone by the cells of Leydig

63. Other Thyroid Hormones
Parafollicular cells
Calcitonin

64. Parathyroid Hormones
Principle Cells
PTH

65. PTH and Calcitonin Interaction

66. Both Pancreatic Hormones interaction