The Endocrine System

Front 1

Mechanisms of Intercellular Communication (DIRECT)

Back 1

By ions via gap junctions (when cells are in contact w/each other)

Front 2

Mechanisms of Intercellular Communication (PARACRINE)

Back 2

By paracrine factors via the extracellular fluid (cells farther apart)

Front 3

Mechanisms of Intercellular Communication (ENDOCRINE)

Back 3

By hormones via the circulatory system (enters blood stream)

Front 4

Mechanisms of Intercellular Communication (SYNAPTIC)

Back 4

By neurotransmitters across synaptic clefts (carried by nerve endings - nervous system)

Front 5

Endocrine Glands

Back 5

-Hypothalamus
-Pituitary Gland
-Thyroid Gland
-Pineal Gland
-Suprarenal Gland
-Parathyroid Gland
-Pancreas

Front 6

Endocrine Tissues In Organs

Back 6

-Kidneys
-Heart
-Intestines
-Thymus
-Gonads
-Adipose Tissue

Front 7

Hormones

Back 7

Chemical regulators of various body functions such as growth and reproduction

Front 8

Where are hormones secreted and and why are they transported?

Back 8

Blood; To affect the functions of their target cells

Front 9

What do hormones bind to?

Back 9

Specific receptors on their target cells

Front 10

What are hormones specific for?

Back 10

Certain target cells

Front 11

Steroids

Back 11

Derived from lipds or cholesterol

Front 12

Monoamines

Back 12

Derived from a single amino acid

Front 13

Oligopeptides

Back 13

Made from 3-10 amino acids

Front 14

Glycoproteins

Back 14

Carbohydrates/proteins complexes with α & β acid chains

Front 15

Polypeptides

Back 15

14-199 amino acids

*All other hormones

Front 16

Hormone Secretion

Back 16

-Stimulus
-Gland

{Hormone}

*Hormone secretion goes into blood stream*

-Blood
-Receptor
-Target Cells
-Action

Front 17

Hormone Receptors

Back 17

Protein molecules located on the cell membrane, cytoplasm, or nucleus

Front 18

Steroid Hormones

Back 18

Bind to nuclear receptors associated with DNA transcription

Front 19

Thyroid Hormones

Back 19

Bind to cytoplasmic receptors on mitochondria, ribosomes or nucleus

Front 20

All Other Hormones

Back 20

Bind to cell membrane receptors and activate second messenger systems

Front 21

Negative Feed Back

Back 21

Blood level of the endocrine gland hormone reach an optimum value, it inhibits secretion of the hypothalamic and anterior pituitary hormones that stimulate the gland

Front 22

Postive Feed Back

Back 22

The response to an endocrine gland hormone reach an optimum level, it increases secretion of the hormone that stimulates that response

Front 23

Hypothalamus

Back 23

A central area of the basal brain limbic system

Front 24

The hypothalamus consist of a large number of what?

Back 24

Nuclei

Front 25

What do the nuclei in the hypothalamus do?

Back 25

Modify and control the body functions via the hypothalamic hormones

Front 26

Hypothalamic Hormones

Back 26

-Growth hormone releasing hormone (GHRH)
-Growth Hormone Inhibiting Hormone (GHIH) - Somatostatin
-Prolactin Releasing Hormone (PRH)
-Prolactin Inhibiting Hormone (PIH) - Dopamine
-Corticotopin Releasing Hormone (CRH)
-Gonadotropin Releasing Hormone (GnRH)
-Thyrotropin Releasing Hormone (TRH)
-Antidiuretic Hormone (ADH)
-Oxytocin (OT)

Front 27

Corticotropin Releasing Hormone (CRH)

Back 27

Suprenal Gland

Front 28

Gonadotropin Releasing Hormone (GnRH)

Back 28

Gonads Gland

Front 29

Thyrotropin Releasing Hormone (TRH)

Back 29

Thyroid Gland

Front 30

Hypothalamic Hormones that are released from the hypothalamus

Back 30

-Growth hormone releasing hormone (GHRH)
-Growth Hormone Inhibiting Hormone (GHIH) - Somatostatin
-Prolactin Releasing Hormone (PRH)
-Prolactin Inhibiting Hormone (PIH) - Dopamine
-Corticotopin Releasing Hormone (CRH)
-Gonadotropin Releasing Hormone (GnRH)
-Thyrotropin Releasing Hormone (TRH)

Front 31

Hypothalamic Hormones that are released from the posterior pituitary

Back 31

-Antidiuretic Hormone (ADH)
-Oxytocin (OT)

Front 32

Pituitary Gland

Back 32

A small gland that is connected to the hypothalamus by the infundibulum

Front 33

Anterior Pituitary (NAME)

Back 33

Adenohypophysus

Front 34

Posterior Pituitary (NAME)

Back 34

Neurohypophysis

Front 35

Posterior Pituitary

Back 35

Derived from neural brain tissue and connects to hypothalamus by the stalk-like hypothalamus hypophyseal tract

Front 36

Anterior Pituitary

Back 36

Derived from ectodermal tissue in the roof of the embyonic mouth and connects to the hypothalamic hypophyseal portal system

Front 37

Oxytocin (OT)

Back 37

-Target tissues are smooth muscles of reproductive systems of both females and males
-Stimulates uterine contractions during labor
-Stimulates milk ejection during suckling
-Stimulates semen propelling during ejaculation

Front 38

Antidiuretic Hormone (ADH) - Vasopressin)

Back 38

-Target tissues are kidneys and blood vessels
-Increases water reabsorption in the kidneys to increase blood volume
-Causes vasocontriction of blood vessels to increase blood pressure

Front 39

Human Growth Hormone (hGH)

Back 39

-Targets all cells especially skeletal and muscle tissue
-Directly stimulates stem cells division and differentiation
-Stimulates liver synthesis and release of somatomedins
-Somatomedins indirectly mediates growth hormone functions by increasing protein synthesis and cell division

-Results in growth to adulthood and maintenance of skeleton and muscles in adults

Front 40

Pituitary Dwarfism

Back 40

Caused by hyposecretion in children and adolescents resulting in small body

Front 41

Gigantism

Back 41

Caused by hypersecretion in infants and children resulting in heigh of over 8 feet

Front 42

Acromegaly

Back 42

Caused by hypersecretion in adults resulting in distorted facial features

Front 43

Thyroid Stimulating Hormone (TSH)

Back 43

-Targets thyroid gland
-Stimulates secretion of the thyroid hormones

Front 44

Adrenocorticotropic (ACTH)

Back 44

-Targets adrenal cortex
-Stimulates secretion of glucocorticoids from the adrenal cortex

Front 45

Prolactin (PRL)

Back 45

-Targets mammary glands
-Stimulates milk synthesis in mammary glands

Front 46

Gonadotropins

Back 46

-Follicle stimulating hormone (FSH)
-Luteinizing hormone (LH)
-Target the ovaries
-Control female and male reproductive physiology

Front 47

What stimulates secretion?

Back 47

Releasing hormones (RH)

Front 48

Where are releasing hormones and inhibiting hormones released from?

Back 48

Hypothalamus through hypophyseal portal system

Front 49

What supresses secretion?

Back 49

Inhibiting hormones (IH)

Front 50

What controls the anterior pituitary hormone secretion and inhibition?

Back 50

Negative or positive feedback

Front 51

Thyroid Gland

Back 51

-Large butterfly-shaped gland in neck below voice box (larynx)-Has two lobes connected by an isthmus
-Made of follicles filled with a colloid

Front 52

Thyroid Hormone Synthesis

Back 52

1. Iodide trapping by follicular cells and transport into follicular lumen
2. Synthesis of thyroglobulin by follicular cells and transport into follicular lumen
3. Oxidation of iodide to iodine in lumen by thyroid peroxidase enzyme
4. Iodination of tyrosine molecules in the thyroglobulin chain to form T1 and T2
5. Coupling of T1 and T2 to make T3 or T4
6. Pinocytosis of thyroglobulin chain by the follicular cells and digestion by lysosomal enzymes to produce free T3 and T4
7. Secretion of T3 (Triiodothyronine) and T4 (Tetraiodothyronine/Thyroxine) into the blood
8. Transport of T3 and T4 in blood in the free form or bound to thyroid-binding-globulin (TBG)

Front 53

Parafollicular C cells

Back 53

Produce Calcitonin

Front 54

T3 & T4

Back 54

-Increase the basal metabolic Rate (BMR) of all cells
-Increase ATP production in mitochondria of all cells by aerobic cell respiration
-Promote normal growth synergistically with growth hormone

Front 55

Calcitonin

Back 55

Decreases blood calcium levels

Front 56

Thyroid Dwarfism (Cretinism)

Back 56

-Hypothyroidism during fetal development or early infancy
-Severe forms of mental and physical retardation in the newborn child
-Retardation is reversible only if hormonal replacement therapy is started during the first four months of life

Front 57

Hypothyroidsim (in adults)

Back 57

-Too little T3 & T4

-Symptoms:
-Decreased basal metabolic rate
-Bradycardia
-Decreased body temperature
-lethargy
-goiter
-weight gain
-cold intolerance
-myxedema

Front 58

Hyperthyroidism (in adults)

Back 58

-Too much T3 & T4
-Grave's disease is the most common form

-Symptoms:
-Increased basal metabolic rate
-Tachycardia
-Increased body temperature
-Anxiety & irritability
-Goiter
-Weight Loss
-Heat intolerance
-Exophthalmia (Exopthalmos)

Front 59

Endemic Goiter

Back 59

-Caused by iodine deficiency
-Insufficient dietary iodine to make T3 & T4
-Occur mostly in arid, dry, inland regions
-Lack of negative feedback from T3 & T4 causes over stimulation and overgrowth of the thyroid gland
-Goiter results (enlarged thyroid gland)

Front 60

Parathyroid Glands

Back 60

-Four small glands on the posterior surface of the thyroid gland
-Contain principal cells that secrete parathyroid hormone
-Parathyroid hormone & calcitonin regulate blood calcium levels

Front 61

How does calcitonin decrease blood calcium?

Back 61

-Increasing calcium excretion by the kidneys
-Increasing calcium deposition in the bones

Front 62

How does the parathyroid hormone increase blood calcium?

Back 62

-Releasing calcium from bones into blood
-Increasing calcium reabsorption by kidneys
-Activating vitamin D that increases calcium absorption from the intestines

Front 63

Suprarenal Glands

Back 63

-Adrenal glands
-Located on top of the kidneys

-Gross Anatomy:
-Enclosed by a fibrous capsule
-Outer Cortex
-Inner Medulla

Front 64

Zona Glomerulosa

Back 64

-Outer zone secreting mineralocoids
-ALDOSTERONE is the major mineralocoid
-Increase retention of sodim by kidneys
-Increase excretion of potassium by kidneys
-Increase water retention and blood volume

Aldosterone secretion is regulated by sodium and potassium blood levels

Front 65

Zona Fasciculata

Back 65

-Middle zone secreting glucocorticoids
-CORTISOL is the major glucocorticoid
-Increase glucose and glycogen synthesis
-Increase fatty acids and proteins breaking
-Reduce inflammation and allergic rashes

Cortisol secretion is regulated by hypothalamic CRH and anterior pituitary ACTH

Front 66

Zona Reticularis

Back 66

-Innner zone secreting ANDROGENS
-Stimulate pubic hair growth in puberty
-Promote muscle mass, formation of the blood cells and libido in females

Androgens regulated by hypothalamic CRH and anterior pituitary ACTH

Front 67

Addison's Disease

Back 67

-Insufficient glucocorticoids secretion
-Lack of energy
-Weight loss
-Loss of sodium and water in urine
-Inability to resist stress
-John F. Kennedy

Front 68

Cushing's Disease

Back 68

-Excessive glucocorticoids secretion
-Muscle wasting
-Body fat redistribution
-Spindly thin arms and legs
-Rounded face (moon face)
-Fatty hump between shoulders (buffalo hump)
-Large abdomen with stretch marks

Front 69

Suprarenal Medulla

Back 69

-Develops from the same nervous tissue as the sympathetic nervous system
-Chromaffin cells receive direct innervations from the sympathetic nervous system
-Sympathetic stimulation increases hormone secretion by the adrenal medulla
-Adrenal medulla hormones are exactly the same in structure and function as the sympathetic nervous system neurotransmitters.

-Their effects mimic those of sympathetic NS
-They cause fight-flight behavior

Front 70

Catecholamines

Back 70

-Epinephrine and norepinephrine
-(adrenaline and noradrenaline)
-Targets all body cells

-React quickly to stress by:
-Increasing heart rate and strength
-Increasing blood flow to skeletal muscles, heart and brain
-Increases dilation of airways
-Increases fuel for energy
-Increases blood pressure

Front 71

The Pineal Gland

Back 71

-Located in the roof of the third ventricle of the brain
-Contains neurons, neuroglia and the pinealocytes that secrete melatonin hormone
-Melatonin secretion lowest during daytime and highest at night

Front 72

Melatonin Functions

Back 72

-Timing of sexual maturity:
Melatonin deficiency causes premature puberty in children

-Protection:
Against damage by free radicals in the CNS

-Circadian Rhythm Setting:
Increased melatonin secretion may cause seasonal affective disorder (sad) during winter

Front 73

The Pancreas

Back 73

-Five inches long, consists of head, body and tail
-Most cells are exocrine producing digestive enzymes
-Endocrine cells in pancreatic islets produce hormones

Front 74

Pancreas (Structure)

Back 74

-Exocrinne acinar cells surround a small duct
-Endocrine cells secrete near a capillary
-1 to 2 million pancreatic islets of langerhans
-Contains 4 types of endocrine cells

Front 75

Pancreatic Islets (alpha cells)

Back 75

-20%
-Produces Glucagon

Front 76

Pancreatic Islets (beta cells)

Back 76

-70%
-Produces insulin

Front 77

Pancreatic Islets (delta cells)

Back 77

-5%
-Produce somatostatin

Front 78

Pancreatic Islets (F - cells)

Back 78

-5%
-Produce pancreatic polypeptide (PP - cells)

Front 79

Insulin Actions

Back 79

-Decreases blood glucose by:
-Increasing uptake of glucose into cells
-Increasing synthesis of glycogen in the liver for storage

-Increases protein synthesis in cells
-Increases fat synthesis in cells

Front 80

Glucagon Actions

Back 80

-Increases blood glucose by:
-Increasing synthesis of glucose from amino acids in liver
-Increasing breakdown of liver glycogen into glucose
-Increasing the release of glucose from liver into blood

Glucagon increases fat breakdown in adipose tissue to free fatty acids (Lypolysis)

Front 81

Regulation of glucagon and insulin secretion

Back 81

-High blood glucose after a meal stimulates secretion of insulin and inhibits secretion of glucagon
-Low blood glucose when fasting stimulates release of glucagon and inhibits secretion of insulin

Front 82

Diabetes Mellitus

Back 82

-A metabolic disorder that produce high glucose levels in the blood (hyperglycemia)
-Caused by genetic defects that decrease insulin secretion or produce defective insulin molecule or defective insulin receptors
-Insulin receptors defects make the cells unable to respond to normal insulin
-Carbohydrates, proteins and fat metabolisms are all affected

Front 83

Type I (IDDM) or Juvenile DM

Back 83

-Beta cells destroyed by own immune system
-Insulin levels low or absent
-Insulin injections required
-Usually develops in people younger than 10

Front 84

Type II (NIDDM) or Maturity onset DM

Back 84

-Most common type (90%)
-Insulin may still be secreted but the body cells are less sensitive to insulin actions
-Insulin injections may not be required
-Mostly in people over 35 who are obese
-May be controlled by diet

Front 85

Polyuria

Back 85

Excessive urination

Front 86

Polydypsia

Back 86

Excessive water drinking

Front 87

Polyphagia

Back 87

Excessive eating

Front 88

Intestines

Back 88

Intestinal hormones coordinates activities of the digestive system. Most important ones are CHOLECYSTOKININ (CCK), GASTRIN and SECRETION

Front 89

Kidneys

Back 89

CALCITRIOL is the active form of vitamin D that increases calcium absorption from the intestine

ERYTHRPOIETIN stimulates RBC production

RENIN - ANGIOTENSIN - ALDOSTERONE system affect blood volume and blood pressure

Front 90

Heart

Back 90

NATRIURETIC PEPTIDE increase sodium and water excretion by the kidneys

Front 91

Thymus

Back 91

THYMOSINS promote development and maturation of lymphocytes

Front 92

Adipose Tissue

Back 92

LEPTIN suppress appetite

Front 93

Gonads

Back 93

TESTOSTERONE and INHIBIN in males

ESTROGENS and PROGESTERONE in females

Front 94

Chromaffin Cells receive direct innvervation from where?

Back 94

Sympathetic Nervous System

Front 95

Sympathetic stimulation increases the hormone secretion by the what?

Back 95

Adrenal Medulla

Front 96

Adrenal medulla hormones are the exact same in structure and function as the what?

Back 96

Sympathetic nervous system neurotransmitters

Front 97

What type of behavior do the medulla hormones cause?

Back 97

Fight-Flight

Front 98

What type of cells do Human Growth Hormone (hGH) target?

Back 98

All, especially skeletal and muscle tissue

Front 99

The human growth hormone directly stimulates what?

Back 99

-Stem cells division and differentiation

-Stimulates liver synthesis and release of somatomedins

Front 100

Somatomedins INDIRECTLY mediates growth hormone functions by increasing what?

Back 100

Protein synthesis and cell division

Front 101

What is the result of the human growth hormone (hGH)?

Back 101

Growth to adulthood and maintenance of skeleton and muscles in adults

Front 102

FSH

Back 102

Follicle stimulating hormone

Front 103

LH

Back 103

Luteinizing Hormone

Front 104

(Thyroid Hormones Synthesis)

What do the follicular cells trap? And where is it transported?

Back 104

Iodide; follicular lumen

Front 105

(Thyroid Hormones Synthesis)

What do the follicular cells synthesize? And where is it transported/

Back 105

Thyroglobulin; follicular lumen

Front 106

(Thyroid Hormones Synthesis)

The oxidation of iodide in the lumen makes it turn into what?

Back 106

Iodine

Front 107

(Thyroid Hormones Synthesis)

What enzyme causes the oxidation of iodide in the lumen?

Back 107

Thyroid Peroxidase

Front 108

(Thyroid Hormones Synthesis)

What goes through iodination in the thyroglobulin chain to form T1 and T2?

Back 108

Tyrosine Molecules

Front 109

(Thyroid Hormones Synthesis)

T1 and T2 couple to make what?

Back 109

T3 and T4

Front 110

(Thyroid Hormones Synthesis)

What do follicular cells do to the thyroglobulin chain to produce free T3 and T4?

Back 110

Pinocytosis

Front 111

(Thyroid Hormones Synthesis)

What digests the thyroglobulin chain to produce T3 and T4?

Back 111

Lysosomal Enzymes

Front 112

(Thyroid Hormones Synthesis)

Where is T3 and T4 secreted after the thyroglobulin chain has gone through pinocytosis and digestion?

Back 112

Blood

Front 113

(Thyroid Hormones Synthesis)

When T3 and T4 is transported in the blood, it stays in the free form or is bound to what?

Back 113

Thyroid-binding-globulin

Front 114

What do T3 and T4 increase?

Back 114

Basal metabolic rate (BMR) of all cells

Front 115

The lack of negative feedback from T3 and T4 causes over stimulation and overgrowth of which gland?

Back 115

Thyroid

Front 116

What type of region does Endemic Goiters mostly occur in?

Back 116

Arid, dry, inland

Front 117

What causes Endemic Goiter?

Back 117

Iodine Deficiency and Insufficient dietary iodine to make T3 and T4

Front 118

Where is the location of the parathyroid glands?

Back 118

Posterior surface of thyroid gland

Front 119

What do Principal cells of the parathyroid secrete?

Back 119

Parathyroid Hormone

Front 120

What regulates blood calcium levels?

Back 120

Parathyroid hormone and calcitonin

Front 121

Where are the adrenal glands located?

Back 121

On top of the kidneys

Front 122

What's the gross anatomy of the adrenal glands?

Back 122

-Enclosed by a fibrous capsule
-Outer Cortex
-Inner Medulla

Front 123

Which zone is the Zona Glomerulosa located?

Back 123

Outer

Front 124

(Zona Glomerulosa)

What does the outer zone secrete?

Back 124

Mineralocorticoids

Front 125

What is the major mineralocorticoid?

Back 125

Aldosterone

Front 126

How is aldosterone secretion regulated?

Back 126

Sodium and potassium blood levels

Front 127

What zone is the Zona Fasciculata located?

Back 127

Middle

Front 128

What is the major glucocorticoid?

Back 128

Cortisol

Front 129

How is cortisol secretion regulated?

Back 129

Hypothalamic CRH and anterior pituitary ACTH

Front 130

What zone is the Zona Reticularis located?

Back 130

Inner

Front 131

What does the inner zone secrete?

Back 131

Androgens

Front 132

What do Zona Reticularis stimulate?

Back 132

Pubic hair growth in puberty

Front 133

What do Zona Reticularis promote?

Back 133

-Muscle mass
-Formation of blood cells
-Libido in females

Front 134

How are androgens regulated?

Back 134

Hypothalamic CRH and anterior pituitary ACTH

Front 135

Where is the pineal gland located?

Back 135

Roof of the third ventricle of the brain

Front 136

What does the pineal gland contain?

Back 136

-Neurons
-Neuroglia
-Pinealocytes that secrete melatonin hormone

Front 137

Melatonin secretion is lowest during when?

Back 137

Daytime

Front 138

Melatonin secretion is highest during when?

Back 138

Night time

Front 139

What type of cells in the pancreatic islets produce hormones?

Back 139

Endocrine

Front 140

Most cells in the pancreas are described as what?

Back 140

Exocrine producing digestive enzymes

Front 141

What do exocrine acinar cells surround in the pancreas?

Back 141

Small duct

Front 142

Endocrine cells secrete near what?

Back 142

Capillary

Front 143

After a meal stimulates secretion of insulin and inhibits secretion of glucagon

Back 143

High Blood Glucose

Front 144

When fasting stimulates release of glucagon and inhibits secretion of insulin

Back 144

Low blood glucose

Front 145

Hyperglycemia

Back 145

Metabolic disorder that produce high glucose levels in the blood

Front 146

What causes Diabetes Mellitus?

Back 146

Genetic defects that:

-Decrease insulin secretion
-Produce defective insulin molecule
-Defective insulin receptors

Front 147

What are affected from diabetes mellitus as far as diet?

Back 147

-Carbohydrates
-Proteins
-Fat metabolisms