1

Chapter 17 Endocrine System

Hormones, the other side of the nervous system

2

Two systems (side by side)Working together to maintain homeostasis

• NERVOUS SYSTEM• FAST• Uses nerves• reacts quickly and stops

quickly • adapts quickly and

response declines (adaptation)

• effects are targeted and specific (one organ)

• ENDOCRINE SYSTEM• SLOW• Uses hormones• reacts slowly, effect may

continue for weeks • more persistent responses

(thyroid during winter) • may have general,

widespread effects on many organs, ex. GH

3

Two Systems for Fluid Transport

• Exocrine glands- (Exits) secretes fluids into ducts that go to the outside of the body (DUCTS)

• Endocrine glands- secretes fluids into (Ento) the body (DUCTLESS)

• XO

4

• Endocrine glands– produce hormones

• Hormone– chemical messenger secreted into bloodstream,

stimulates response in another tissue or organ

• Target cells– have specific receptors for specific hormones

– Ex. TSH- stimulates the ___________

• Endocrine system– includes endocrine organs (thyroid, pineal, etc)

– includes “occasional” endocrine organs such as the kidneys, placenta, skin

Components of Endocrine System

5

Endocrine Organs and Their Function (in a word)

• Hypothalamus- link

• Pituitary- master

• Pineal- sleep

• Thymus- immune

• Thyroid- metabolism

• Parathyroid- calcium

• Adrenals- stress

• Pancreas- sugar

• Gonads- reproduction

6

Hypothalamus

The “Master of the master gland” (Pituitary) -Many functions of the hypothalamus is carried out by the pituitary• The major link between the two systems of the body- the NERVOUS

AND ENDOCRINE SYSTEM• Controls the autonomic nervous system• Regulates primitive functions: body temperature, thirst, hunger, sexual

behavior, fear and rage.

7

Pituitary Gland AKA: Hypophysis (hy-POFF-ih-sis)

• Suspended from hypothalamus by stalk called the infundibulum (“funnel”)

• Pea shaped

• Sits in the sella turcica of the _____ ______

• The MASTER GLAND- it secretes several hormones that controls other endocrine glands

8

The Two Parts of the Pituitary

• Anterior and Posterior parts

• Anterior Pituitary produces Hormones

• The Anterior Pituitary has hormones (your Aunt is in the Pits and moans about it)

• Posterior Pituitary- under Neurological control, no hormones are created here– But… 2 are stored that come from the

hypothalamus.

9

• Prolactin (PRL)– Pro- lactation, makes milk

• Adrenocorticotropic Hormone (ACTH)– Controls the release by the adrenal cortex

• Thyroid Stimulating Hormone (TSH)– Stimulates the release of Thyroid hormone (TH)

• Follicle Stimulating hormone (FSH)– Develops oocyte in females and sperm in males

• Luteinizing Hormone (LH) – In females- Releases the egg and prepares the uterus and breasts for a kid– In males- causes testes to release testosterone

• Growth Hormone (GH)

Anterior Pituitary Hormones

10

PAT• PAT, Fantastic Looking Girl• P- Prolactin (PRL)• A- ACTH• Tall- TSH• FantaStic- FSH• Looking- LH• Girl- GH• Remember: PAt also stands for Pituitary Anterior

hormones• KNOW HORMONE ABBREVIATIONS

11

Anterior Pituitary Hormones

• Live Thy Best, Ace Our Tests

12

Growth Hormone

• GH is the abbreviation for Human Growth Hormone• GH is the most plentiful anterior pituitary hormone• GH acts indirectly on tissue to causes them to grow • IGF (Insulin Growth Factor) is the hormone that really

causes growth• Too much GH can have a diabetogenic (causes diabetes)

effect by causing beta-cell burn out of the pancreas. – Pathogenesis: GH causes hyperglycemia (high blood glucose).

The pancreas tries to lower the blood sugar by increasing insulin to the point where it gets burned out.

• IGF increases the influx of amino acids into the cells to increase the synthesizing of proteins

13

Protein Synthesis

• DNA gets read by m-RNA (messenger RNA)– This is called: transcription

• m-RNA goes to the rough ER of the cell

• Rough ER is rough due to ribosomes – Ribosomes are also called r-RNA (ribosomal RNA)

• t-RNA attaches to m-RNA and “translates” the message on m-RNA into a protein– This is called: translation

14

15

How to stay young

– Naturally Increase levels of GH by:

– LOW SWEET- GH is decreased with high carbohydrate diets

– SLEEP- GH is higher during first 2 hours of deep sleep,

– EAT- GH is higher after high protein meals,– BEAT FEET- GH is higher after vigorous exercise

16

• Posterior pituitary stores Oxytocin (OT) and Anti-diuretic hormone (ADH)– OT and ADH are made in hypothalamus

• Remember: The posterior pituitary produces no hormones of its own.

• Pituitary hormones are only made in the ________ _________.

Posterior Pituitary Hormones

17

Posterior Pituitary Hormones

• Oxytocin- ejecting and effecting hormone– The ejecting hormone: ejects kid, ejects milk

• A target organ of this hormone is the ____ and the breast

– The effecting hormone: parental feeling, pleasure from sex

• ADH– Causes the kidneys to return water to the blood– Some drugs inhibits ADH so more ______ is produced,

the reason for a hangover

• Pee or POP! (Posterior Pituitary- pee (from ADH) or POP (from Oxytocin)

18

Control of Pituitary: Feedback from Target Organs

• Negative feedback target organ

hormone levels inhibits release of tropic hormones

• Positive feedback – stretching of uterus

OT release, causes stretching of uterus OT release, until delivery

19

Endocrine disorders:

• Too much or too little hormone

20

Disorders of the Pituitary

• Pituitary dwarfism- too little GH during childhood– the epiphyseal plates close before normal height is

reached

• Giantism- too much GH during childhood– Long bone are abnormally long– Goliath may have suffered from a pituitary tumor

• Acromegaly- too much GH in an adult-thickening of the bones and soft tissues

21

Acromegaly

Too much ____ , When?

22

Disorders of the Pituitary

• Diabetes Insipidus (DI)- – Patient with DI may Die

• Excess urination with life threatening dehydration in days

• Not a pancreas problem

– TWO WAYS TO DI:– Lack of ADH called neurogenic DI, etiology is trauma,

brain tumor– Or ADH is normal and is ignored by the kidney called

nephrogenic DI, net effect is to little ADH

23

Pineal Gland

• Pineal = pine cone shaped• Anatomy- small gland on the roof of the 3rd Ventricle• Physiology- The action of the hormone MELATONIN

represents both HORMONAL AND NEUROLOGICAL interaction

Pineal gland

24

Sleep Physiology

• 1. Light stimulates retina

• 2. Retina stimulates Hypothalamus

• 3. Hypothalamus stimulates Cervical ganglion

• 4. Cervical ganglion stimulates pineal gland

• Increase light = decrease melatonin, decrease light = increased melatonin

• Help with sleep- get sunlight, helps circadian cycle

25

PINEAL DISORDERS

• Too much melatonin has caused atrophy of the gonads “Not tonight, I am so tired.”

• SAD- Seasonal affective disorder = depression from lack of sunshine– Treatment = full spectrum lighting

• Jet lag- full spectrum lighting or one melatonin pill

26

Thymus• Important for immunity• Location: sternal angle, level of 2nd rib• Involution after puberty but still active• Secretes hormones that regulate development and later

activation of T-lymphocytes• Stimulate in patient with poor immune function by thymus

thump

27

Thyroid Gland

• Located- in the neck behind and below the thyroid cartilage

• Gross anatomy- two lateral lobes and a central isthmus

• Micro anatomy- Thyroid follicles contain follicular cells which produce thyroid hormone

• Hormones- T4 and T3 (thyroxine, triiodothyronine) abbreviated as TH (Thyroid Hormone)

28

About T4 and T3

• Both thyroid hormones

• Iodine is the key nutrient of these hormones

• T4 is called thyroxine which contains four iodide ions (I-)

• T3 is Triiodothyronine which contains three atoms of iodide ion (I-)

• The thyroid gland is unusual in that it stores its hormones. It has a 100 day supply.

29

Thyroid GlandThyroid hormone:

body’s metabolic rate and O2 consumption– This causes increased protein synthesis and increased

ATP production

• Calorigenic effect - heat production heart rate and contraction strength respiratory rate• Stimulates appetite and breakdown of CHO, lipids &

proteins

30

ATP Creation

• Refer to Chapter 26, page 997-1002

• 1) Glycolysis

• 2) Krebs Cycle

• 3) FINAL PHASE: Electron Transport/ ATP creation

31

GLYCOLYSIS

• 1 six carbon glucose enters glycolysis and is divided into 2 three carbon molecules called PYRUVATE (fire molecule)

• The two pyruvates take a go into the mitochondria and create ACETYL-CoA, a two carbon molecule

32

KREB CYCLE

• The two Acetyl CoAs enter the mitochondria with it’s two carbons and goes into the Krebs cycle (also called the Citric Acid Cycle)

• The Krebs cycle makes NADH and FADH2• NADH and FADH2 are hydrogen donors• The purpose of the Krebs cycle is to produce NADH and

FADH2• The purpose of the Krebs cycle is NOT to produce

ATP!• NADH will yield 3 ATPs in the final phase • FADH2 will yield 2 ATPs in the final phase (FADH2)

33

KREBS CYCLE (cont.)

• The purpose of the Krebs cycle is to produce NADH and FADH2

• The purpose of the Krebs cycle is NOT to produce ATP!

• NADH will yield 3 ATPs in the final phase • FADH2 will yield 2 ATPs in the final phase

(FADH2)

34

FINAL PHASE of ATP Production

• The NADHs and FADH2s produced in the Krebs cycle go to the final phase

• In the final phase NADH and FADH2 contribute positive hydrogen ions by ELECTRON TRANSPORT

• Electron are taken from the hydrogen atoms of NADH and FADH2 to make positive hydrogen ions

35

ATP Creation

• The mitochondria membrane has high concentration of hydrogen ions outside and low concentration of hydrogen ions inside

• Nature always goes from an area of ____ concentration to an area of ____

• The hydrogen ions go through the membrane with such force that ADP is combined with one phosphate creating ATP

36

Why do we need OXYGEN?

• Oxygen is involved in the final phase.• Oxygen maintains the concentration of hydrogen

ions low inside and high on the outside• When oxygen combines with hydrogen ______ is

formed• Without oxygen 36 ATPs would not be created!

37

Thyroid Hormone Secretion

T H Y R O IDT H R e le a se d

(T h yro id H o rm o ne = T 3 a nd T 4 )

A N T E R IO R P IT U IT A R YT S H R e le a se d

(T h yro id S tim ula ting H o rm o ne )

H Y P O TH A LM U STR H R eleased(Thyroid R eleas ing H orm on e)

38

Thyroid Gland Disorders

• Myxedema (adult hypothyroidism, TH)– low metabolic rate, sluggishness, sleepiness, weight gain,

constipation, dry skin and hair, cold sensitivity, blood pressure and tissue swelling

• Goiter (goiter = enlarged thyroid gland)– Endemic goiter is from dietary iodine deficiency

• Cretinism- Congenital hypothyroidism ( TH)– infant brain development stops causing retardation

• Graves disease- Causes a toxic goiter, hereditary – antibodies mimic TSH, TH, exophthalmos = eyes bulge,

(usually easily treated so it is not a Grave disease)

39

Endemic Goiter

40

Thyroid Disorders

• Myxdema (mix-edema)

• Goiter

• Cretinism

• Graves

• Remember- A bad thyroid says, “My goal: create graves”

41

Basal Metabolism Rate Thyroid Test

• Basal Metabolism Rate is the body’s base, or lowest, rate of metabolism

• Barnes BMR test is used to determine thyroid and other hormone imbalances

• Axillary temperature is taken FIRST thing in the AM before anything else is done– Remember this is the BASAL rate

• Normal Temp. will be one degree less in the axilla than oral

• Low temp- hypothyroid, high temp- hyperthyroid

42

How the BMR Test Works

• Determines the rate of O2 consumption used by the cells overnight

• Thyroid hormone stimulates increased use of Oxygen by the cells to step up ATP production

• Increased ATP production causes body heat • This CALORIGENIC effect of thyroid hormone

maintains body heat• We measure the ability of the thyroid to generate

body heat through the Barnes BMR axillary temperature test

43

Calcitonin- Thyroid hormone

• Calcitonin is also a thyroid hormone- for bones

• Function- osteoclast inhibition, osteoblast stimulation

• Keeps Calcium in bone

• Antagonist to Parathyroid function

• Greatly active in children, less effect in adults

44

The Parathyroid Glands

• Location- posterior thyroid gland (piggy horseback)

• Gross anatomy- Small round tissue, usually four in total, two on the left thyroid lobe and two on the right

• Micro anatomy- Epithelial cells called Principal cells produce PTH (Parathyroid Hormone)

45

Parathyroid Hormone Action

• 1) Increases Osteoclasts (FILL THE BUCKET)– Causes bone destruction

• This causes calcium to be released into the blood

• 2) Effects kidneys function (PLUG THE HOLES)– Decreases kidney excretion of calcium into the urine

• This increased calcium retained in the blood

• 3) Makes kidneys an endocrine gland (ADD TO THE BUCKET)– Kidneys release the hormone CALCITRIOL (CAL-sih-TRY-ol)

which is active Vitamin D• Effect is to increase Calcium into the blood by increased absorption of

calcium from the GI tract

46

Sunlight and Vitamin D

• Sunlight produces vitamin D in our skin

• Vitamin D in this form (CALCITRIOL) is really a hormone for mobilizing calcium

• Vitamin D mobilizes calcium from the tissue into the blood

• This is one reason why sunbathing will causes you to relax– Increased sunlight could cause calcium deficiency in

tissue, fever blister could result from decrease tissue calcium

47

The path of calciumCalcitonin (Calcium bone in) from the Thyroid

Vs.Parathyroid Hormone

CALCITONIN: KEEPS CALCIUM IN BONE (SO DECREASES BLOOD

CALCIUM)(CalcitonIN bone)

PTH: CALCIUM FROM BONEBLOOD

48

Parathyroid Disorders

• Hyperparathyroid = excess PTH secretion– tumor in gland– Symptoms of BONES, GROANS and MOANS– causes soft, fragile and deformed bones (BONES) blood Ca+2 (GROANS) causes less tissue Ca+2

– renal calculi (MOANS)– Hypercalcemia is rare

• Hypoparathyroid– surgical excision during thyroid surgery– fatal tetany 3-4 days. WHY?

49

Causes of Hypocalcemia

• PTH

• Vitamin D defiance

• Thyroid tumor

• Decrease stomach hydrochloric acid (HCl)

• Diarrhea

• Kidney dysfunction

• Pregnancy

50

ADRENAL GLANDS

• Located- On top of the kidneys (renal) so we call the adrenals the suprarenal glands

• Anatomy- two parts, Medulla (middle), Cortex (covering)

• Adrenal hormones- cortex hormones are essential for life. Why?– Without adrenocortical hormones death is caused by

dehydration and electrolyte imbalance

51

Adrenal Gland Anatomy

• CORTEX (3 Zones)– Zona Glemerulosa- mineralcorticoids (aldosterone),

Na+, K+– Zona Fasciculate- glucorticoid (cortisol), glucose

homeostatis– Zona Reticularis- Androgens (Andrew’s genes)-

hormones that masculinize

• MEDULLA– Chromaffin (crow-ma-fin) cells- epinephrine,

norepinephrine

52

53

Adrenal Hormones

• Three Adrenal cortex hormones:• 1. Mineralcorticoids

– Principal hormone is aldosterone

– Function: keeps Na+ in the body by the Renin-Angiotensin pathway, regulates blood pressure, blood volume

• 2. Glucocorticoids– Principal hormone is cortisol

• 3. Androgens– DHEA (dehydroepiandrosterone)

• Adrenal medulla hormones:– Epinephrine, norepinephrine

54

Mineralocorticoids

• From Adrenal cortex

• Hormones that control water and electrolyte balance of sodium and potassium ions (Na+ and K+)

• Principal hormone = aldosterone

• Aldosterone effects kidney:

• 1. Increase Na+ absorption, kicks K+ out

• 2. Hydrogen ions out to prevent acidosis

55

Glucocorticoids

• From Adrenal cortex

• Regulates metabolism and resistance to stress

• The principal hormone = Cortisol (hydrocortisone)– Lesser hormones- corticosterone, cortisone

56

Glucocorticoids (continued)

• Functions- Energy creation:– 1. Catabolism of protein to create ATP or enzymes – 2. Gluconeogenesis- new sugar creation, conversion of

something other than stored carbohydrates into into glucose. Example: amino acids concerted to glucose

– 3. Lipolysis- breakdown of fat

• Anti-inflammatory effects

• Depression of immune response

57

More Hormones

• Androgens are sex hormones, DHEA is one of them formed in the adrenal cortex– In male and female causes growth spurt and body hair

• Adrenal medulla: the middle of the adrenal gland releases hormones in response to the ANS, the autonomic nervous system

• Two hormones responsible for the “Fight or Flight response”:– Epinephrine (on top the kidney) also called adrenaline.– Norepinephrine also called noradrenaline

• Q. What other endocrine organ is wired to the nervous system? A.________________

58

Androgens

• In males, androgens come from the testicles

• In females, androgens comes from the adrenals

• Libido is related to the levels of androgens

• In females, androgens are converted to estrogens

• In menopause, the female’s major source for estrogens is the adrenals– This is because the _____ no longer produce adequate

estrogen

59

Adrenal Disorder Cushing’s Disease

• Cushing’s disease is excess adrenal cortical secretion

• Sign:– Moon face= edematous appearance of

the face– buffalo hump= fat

deposition between shoulders

60

Adrenal Diseases

• Cushing's- Hyperadrenalism- principally too much cortisol, tumor or use of drugs like steroids

• Addison’s- Hypoadrenalism- autoimmune destruction of cortex, Signs = extreme fatigue, excessive skin pigmentation especially at folds of skin (a suntan with out sun bathing)– Cortisone treatment causes the Lazarus effect, instant recovery– Remember this disease decreases hormones so we need to ADD

some.• Pheochromocytomas- tumor of medulla, prolonged “fight

or flight response”• Syndrome X, waist 40”, <40 HDL, subclinical, tissues are

insulin resistant puts strain on adrenals• CAPS – the adrenals are caps on the kidneys

61

Pancreas

• Pan= All, creas= flesh

• Location: Retroperitoneal, inferior and dorsal to stomach in central abdomen

• Shape: flat

• TWO FUNCTIONS: Endocrine and Exocrine

62

Pancreas

63

Pancreatic Hormones• 2% of the pancreatic islets produce hormones

(endocrine)• 98% of organ produces digestive enzymes

(exocrine)• Insulin hormone comes from Beta () cells

– secreted after meal with carbohydrates lowers glucose blood levels

– antagonizes glucagon• Glucagon comes from Alpha () cells

– secreted in very low carbohydrate and high protein diet or fasting– stimulates glycogenolysis, fat catabolism – Remember: Gluc-A-gon comes from Alpha cells

64

A c in i C e llsD ige s tiv e E nzym es

G a stro in te s ina l S ys tem

E X O C R IN E

A lph a C e llsG lucag on

In c re a se s B loo d G lu co se

B e ta C e llsInsu lin

D e cre ase s B loo d G luco se

E N D O C R IN EH o rm on es

Is le ts o f La n ge rha ns

P A N C R E A S F U N C T IO N

Pancreas Function

65

The Ups and Down of Glucose Levels in the Blood

• Remember that glucose is important for ATP production• UP: As glucose in the blood increases the pancreas

inhabits alpha cells this decreases _________

• DOWN: If there is decreased glucose in the blood then the pancreas increases glucagon from the alpha cells (Glucagon makes glucose gone from the liver and muscles)

• INSULIN from the beta cells allows for transport of glucose from the blood into the cells by facilated diffusion.

66

Pancreas Abnormality DIABETES MELLITUS

• Diabetes = overflow as in diarrhea in the urine mellitus = melon sweetened urine

• Fourth leading cause of death today, in 1900 few cases reported.

• Two types: • Type I = insulin dependent 10% • -some cases have autoimmune destruction of beta cells,

diagnosed about age 12• Treated with diet, exercise, monitoring of blood glucose

and periodic injections of insulin or insulin pump

67

DIABETES MELLITUS (cont.)

• Type II = Non-Insulin dependent 90% –tissue is insulin resistance • Failure of target cells to respond to insulin –3 major risk factors are heredity, age (40+) and obesity Treated with weight loss program of diet and exercise - Bitter melon and vitamins with minerals improve

insulin secretion or target cell sensitivity May need drugs to inhibit glucose fascinated transport in

intestines

68

Pathology of Diabetes

• Remember that insulin from the pancreas effects ALL cells

• Chronic pathology– chronic hyperglycemia leads to neuropathy (commonly

of the lower extremities), eye changes (vessel problems), kidney problems (vessel problems) and cardiovascular damage from atherosclerosis (local ischemia and systemic high blood pressure)

SYMPTOMS OF DIABETES

THREE POLYSMany DUmPs

POLYDIPSIAlots of thirst

POLYURIAlots of urine

POLYPHAGIAlots of eating

THREE CLINCICAL SIGNS: Hyperglycemia (blood), Glycosuria

(urine), ketouria (urine)What is the difference between clinical symptoms and clinical signs?

70

Hyperinsulinism

• From excess insulin injection or pancreatic islet tumor

• Causes hypoglycemia, weakness and hunger– triggers secretion of epinephrine, GH and glucagon

• side effects: anxiety, sweating and HR

• Insulin shock– uncorrected hyperinsulinism with disorientation,

convulsions or unconsciousness

71

Gonads- Ovaries and Testes

• FEMALE: Two Ovaries produce hormones: estrogen and progesterone– Secondary sex characteristics, regulates reproductive

cycle, pregnancy, lactation, oogenesis– RELAXIN- hormone created in the last months of

pregnancy causes ligaments to relax, especially symphyis pubis,

• frequent cause for lower back pain of pregnancy

• MALE: Two Testes produces testosterone– Spermatogenesis and secondary sex characteristics

72

How Hormones work

73

Hormone Mode of Action• Hydrophobic hormones

(steroids and thyroid hormone) penetrate plasma membrane – enter nucleus

• Hydrophilic hormones can not pass through membrane so must bind to cell-surface receptors

74

Thyroid Hormone Effects• TH binds to

receptors on mitochondria (rate of aerobic respiration), on ribosomes ( protein synthesis)

75

Hormone Clearance

• Hormone signals must be turned off

• Take up and degraded by liver and kidney

• Excreted in bile or urine

76

UP and DOWN Regulation

• Increased hormone can decrease receptors this is called DOWN-REGULATION– This makes the target cells less sensitive to a hormone

• Decreased hormone can increase receptors this is called UP-REGULATION– This makes the target cells more sensitive to a hormone

• Possible mechanism of drug addiction

77

Hormone Interaction• Antagonistic- One hormone opposes the action of

another– Insulin promotes glycogen formation, glucagon

breaks down glycogen• Synergistic- Two hormones working together

have a greater effect then if they worked alone.– Both estrogen and Follicle Stimulating Hormone

(FSH) are needed for normal production of eggs by the ovary

• Permissive- One hormone primes the target organ’s response to a second hormone that is secreted later.– Ex. Estrogen has a permissive effect on the uterus by

up-regulation of progesterone receptors so progesterone will have a great effect on the uterus

78

Stress and Adaptation

• Any situation that upsets homeostasis causes stress.

• A perceived or real threat to one’s physical or emotional well-being causes stress.

• A stressor can be good (eustress) which is productive or bad stress (distress) which is destructive, causes decreased resistance to dis-ease – Can increase colds, infections and allergies

79

C H E M IC A LJunk food , d rugs, po llu tion

E M O T IO N A LT ests, Job , R ela tionsh ips, $

P H Y S IC IA LN o exercise , too m uch exerc ise

traum a

S T R E S S(S T R E S S O R S )

Three Categories of Stress

80

STRESS and GAS• Hans Selye is the father of stress, he described the stages

of the body response to stress as: GAS= General Adaptive Syndrome

• Stress effects the adrenal glands• Unlike regular homeostasis GAS doesn’t maintain the

normal internal environment, it re-sets the level higher– for example it increases blood pressure and blood sugar

• GAS has three progressive phases:– Alarm

– Resistance

– Exhaustion

81

First Phase of GAS: Alarm

• Initial response:• Hypothalamus stimulates adrenals to:

epinephrine and norepinephrine levels HR and BP blood glucose levels, open pupils• Decreased gastroinstinal tract activity• This is a fast response so it is ______ ______ mediated

initially then it is hormonal.

82

Second Phase of GAS: Resistance

• After a few hours of prolonged stress:

• Hypothalamus signals pituitary to stimulate adrenals to: ACTH and cortisol levels

• This is a prolonged response so it is ______ mediated.

83

Third Phase of GAS: Exhaustion

• Stress that continues and causes hypoadrenia

• Loss of glucose homeostasis

• Hypoadrenia symptoms are chronic disease such as increased blood pressure, ulcers, infections, chronic fatigue

84

Paracrine Secretions

• Chemical messengers that diffuse short distances and stimulate nearby cells– unlike neurotransmitters not produced in neurons– unlike hormones not transported in blood

• Examples and their functions– histamine from mast cells in connective tissue causes

relaxation of blood vessel smooth muscle– nitric oxide from endothelium of blood vessels causes

vasodilatation

85

Eicosanoids: a Paracrine Secretion

• Derived from arachidonic acid (fatty acid)• 2 enzymes convert it into eicosanoids, one enzyme

called:– lipoxygenase

• converts arachidonic acid to leukotrienes that mediate allergic and inflammatory reactions

86

Inflammation

• Hormones from non-endocrine glands can cause inflammation

• Hormones produced by local cells such as prostaglandins (not from the prostate gland) act as local hormones

• These are created from acachidonic acid• Prostaglandins have been implicated in chronic diseases

due to their inflammatory and pain causing effects.• NSAIDs (na-saids) Non-steroidal anti-inflammatory

drugs- block the production of prostaglandins

87

Hormone Assisted Abortion

• RU 486 (mifepristone) is a drug that causes abortion

• RU 486 binds to the female’s receptors for Progesterone (a hormone involved in PRO- GESTATION, pro means “in favor”, gestation means “pregnancy”)

• The body is tricked into thinking that it is not pregnant and menstruation resumes

• The uterine lining is shed carrying the fertilized human embryo out of the womb