MEDICAL-SURGICAL NURSING
ENDOCRINE SYSTEM
ENDOCRINE SYSTEM
ENDOCRINE SYSTEM
 The endocrine system is one of the two important
control systems of the body
 The endocrine system is composed of endocrine
glands and specialized endocrine cells located
throughout the body
 Group of ductless glands that secrete hormones
 Includes:
o Hypothalamus
o Pituitary gland
o Thyroid and Parathyroid Gland
o Adrenal Gland
o Ovaries and Testes
o Pancreas
FUNCTIONS OF THE ENDOCRINE SYSTEM
1. Regulation of metabolism. The endocrine system
controls the rate of nutrient utilization and energy
production.
2. Control of food intake and digestion. The endocrine
system regulates the level of satiation (fullness) and the
breakdown of food into individual nutrients.
3. Modulation of tissue development. The endocrine
system influences the development of tissues, such as
those of the nervous system.
4. Regulation of ion levels. The endocrine system helps
monitor blood pH, as well as Na+, K+, and Ca2+
concentrations in the blood.
5. Control of water balance. The endocrine system
regulates water balance by controlling the solute
concentration of the blood.
6. Changes in heart rate and blood pressure. The
endocrine system helps regulate the heart rate and blood
pressure and prepare the body for physical activity.
7. Control of blood glucose and other nutrients. The
endocrine system regulates the levels of glucose and
other nutrients in the blood.
8. Control of reproductive functions. The endocrine
system controls the development and functions of the
reproductive systems in males and females.
9. Stimulation of uterine contractions and milk
release. The endocrine system regulates uterine
contractions during delivery and stimulates milk release
from the breasts in lactating females.
10. Modulation of immune system function. The
endocrine system helps control the production of
immune cells.
ENDOCRINE GLANDS
 Endocrine glands secrete very small amounts of
chemical messengers called hormones into the
bloodstream, rather than into a duct.
HORMONES
 Hormones circulate through the bloodstream to
specific sites called target tissues, or effectors.
chemical signals produced by specialized cells
secreted into the blood stream
 The hormones’ transport, interaction with its target,
and removal from the body is dependent to their
chemical structure. There are two major types of
hormones: lipidsoluble and water-soluble.
 necessary for normal growth, development,
reproduction, and homeostasis
 The hormones’ transport, interaction with its target,
and removal from the body is dependent to their
chemical structure. There are two major types of
hormones: lipidsoluble and water-soluble.
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MEDICAL-SURGICAL NURSING
ENDOCRINE SYSTEM
ACTION
OTHER
PROPERTI
ES
Glycoprotei
n
1
2
3
4
5
6
HORMONE ROLES
Stress response
HORMONES SUCH AS:
1 Cortisol
 Known as fight
or flight hormones
2 Epinephrine
Homeostasis
HORMONES SUCH AS:
1 Insulin
 For glucose
homeostasis
2 Glucagon
3 Cortisol
4 Antidiuretic
 Involved in
Hormone (ADH)
regulating blood
volume
Sexual maturation and reproductive process
HORMONES SUCH AS
1 Testosterone
2 Estrogen
Growth and development of the body
HORMONES SUCH AS
1 Growth Hormone
2 Tropic
 such as atropine,
hormones
corticotropin
Energy production and stabilize metabolic rate
Promote or inhibit other hormones
HORMONES SUCH AS
1 Growth Hormone Releasing Hormone
(GHRH)
2 Dopamine
COMPOSITION AND STRUCTURE
(1
)
(2
)
(3
)
TYPES OF HORMONES
Peptide/Protein Hormones
Steroid Hormones
Amino Acid Derived Hormones
PEPTIDE/PROTEIN HORMONES
SYNTHESI
 synthesized in the rough ER, in the
S
ribosomes as a prehormone or a
preprohormone (which means they are
not yet activated)
STORAGE
 stored in vesicles of the cells of
respective endocrine gland
RECEPTOR  in the cell membrane of the target
SITE
cell
Polypeptides
 destined for secretion outside the cell
 hydrophilic in nature
EXAMPLES
 carbohydrate-protein complex
o Follicle stimulating hormone
(FSH)
o Human chorionic
gonadotropin (hCG)
o Thyroid-stimulating
hormone (TSH)
o Erythropoietin
 made entirely of protein
o Adrenocorticotropic hormone
(ACTH)
o Insulin
o Glucagon
o Somatostatin
o ADH
o Angiotensin
o Parathyroid Hormone (PTH)
o Calcitonin
o Growth Hormone
o Cholecystokinin
o Gastrin
o Oxytocin
o Prolactin
STEROID HORMONES
 synthesized in the smooth ER
 derived from cholesterol as their
precursor substance
STORAGE
 no storage form
RECEPTOR  nucleus of the target cell
SITE
ACTION
 onset of action is slower than the
peptide hormones and lasts longer
OTHER
 hydrophobic in nature
PROPERTI
ES
EXAMPLES
Include
 Mineralocorticoids
o aldosterone
 Glucocorticoids
o cortisol
 Androgens
o testosterone
 Estrogens
SYNTHESI
S
AMINO ACID DERIVED HORMONES/ AMINES
SYNTHESI
 function similar to steroid or peptides
S
 synthesized in the cytoplasm
 derived mainly from amino acid such
as:
o Tyrosine
o Tryptophan
EXAMPLES
Include
 Epinephrine
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MEDICAL-SURGICAL NURSING
ENDOCRINE SYSTEM
 Norepinephrine
o Peptide-like AA derived
 Triiodothyronine (T3)
 Thyroxine (T4)
o Steroid-like AA derived
INHIBITORY
REACTION
EXAMPLE
 increase in prolactin
stimulates the secretion of
oxytocin
 The presence of 1 hormone
inhibits the secretion of another
hormone
EXAMPLE
 increase in prolactin inhibits
FSH/GnRH (Gonadotropin
releasing hormone)
PATTERNS OF HORMONE COMMUNICATION
NOTE
 Hormones in the endocrine cell can only act on their
target cell via the receptors either in the cytoplasm or on
the nucleus
PATTERNS OF HORMONE COMMUNICATION
AUTOCRIN hormone secreted by a cell and acts on
E
that cell
EXAMPLE
 Insulin when secreted by the beta
cells of the pancreas, it will also act on
the receptor of the beta cells itself
HORMONAL INTERACTION
TYPES OF HORMONAL INTERACTION
SYNERGISTIC
 2 or more hormones are additive
or complementary in effect
EXAMPLE
 FSH and Luteinizing
hormone (LH) complementary
effect on the development of the
ovaries
ANTAGONISTI
C
PERMISSIVE
 1 hormone offsets another
hormone
EXAMPLE
 Insulin and Glucagon
 increase in concentration of
insulin attenuates secretion of
glucagon and vice versa like a
“see saw”
 1 hormone enhance the
responsiveness of a target to another
hormone
EXAMPLE
 T3/T4 enhances the target
cells of epinephrine
POTENTIATIO
N REACTION
 1 hormone increases the action of
another hormone
EXAMPLE
 Testosterone enhances the
activity of the FSH
STIMULATOR
Y REACTION
 The presence of 1 hormone
stimulates the secretion of another
hormone’’
PARACRIN
E
 hormones secreted by a cell and acts
on nearby cells
EXAMPLE
Estrogen secreted by ovaries
 Testosterone secreted by the Leydig
cells
ENDOCRIN
E
 hormone secreted by glandular cell
into blood and acts on distant cells
NEUROENDOCRIN
E
EXAMPLE
 Tropic hormones and
Gonadotropins (FSH and LH)
secreted by the distant pituitary gland
and may act as far as the ovary
 hormone secreted by nerve cell
(neuron) into blood and acts on distant
target cells
EXAMPLE
 Hypothalamic hormones
(releasing hormones)
THYROID GLAND
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MEDICAL-SURGICAL NURSING
ENDOCRINE SYSTEM
 A shield-shaped organs located inferior to the larynx.
 Typically, it has two lobes, located laterally to the
trachea.
 In 50% of the cases, it has a third lobe called
pyramidal lobe that extends superiorly to the isthmus.
 Divided into two portions: adrenal cortex (outer) and
adrenal medulla (inner).
WHAT HORMONES AND WHAT FOR?
Follicular cells
T3 and T4 (thyroid hormone)
Parafollicular cells
calcitonin
T3 (Triiodothyronine)
Potent thyroxine
T4 (Tetraiodothyronine)
Actual thyroxine
Calcitonin
increase calcium absorption
by stimulating osteoblasts in
the bones.
PARATHYROID GLAND
 Four, small, round structures that are partially
embedded in the posterior surface of the lateral lobes of the
thyroid gland.
 Chief/principal cells in the parathyroid gland produce
the parathyroid hormone (PTH) or parathormone.
 Parathormone is responsible for regulating the serum
levels of calcium, magnesium, and phosphate.
 It increases the calcium resorption by stimulating
osteoclast activity.
 PTH also increases the excretion of phosphate by the
kidneys while decreasing the elimination of calcium and
magnesium in the urine.
 ↑Ca and ↑Mg while ↓HPO4 in the blood.
Moreover, parathyroid hormone stimulates the kindey to
produce calcitriol (active vitamin D) that increases the
absorption of calcium by the intestines.
ADRENAL GLAND
 Two, flattened pyramidal glands located superior to
each kidneys.
WHAT HORMONES AND WHAT FOR?
Adrenal 1. Zona glomerulosa = mineralocorticoids
cortex 2. Zona fasciculata = glucocorticoids
3. Zona reticulata = androgens
1. Mineralocorticoids, mainly aldosterone,
regulates the homeostasis of two mineral ions:
sodium and potassium. It also promotes excretion
of hydrogen via urination; thereby, preventing
acidosis. Its secretion is govern by the RAA
pathway.
2. Glucocorticoids, mainly cortisol
(hydrocortisone), regulates metabolism and
resistance to stress. Functions include: protein
and lipid breakdown, glucose formation
(gluconeogenesis), stress resistance, antiinflammatory response, and
immunosuppression.
3. Androgens, mainly
dehydroepiandrosterone (DHEA), stimulates
axillary and pubic hairs formation, female
libido, and is responsible for post-menopausal
estrogen production. All female estrogen
comes from androgen. ACTH governs the
regulation of androgens.
Adrenal  modified sympathetic ganglion of the SNS.
medulla  Instead of producing neurotransmitters, the
chromaffin cells of the adrenal medulla secrete
hormones: Epinephrine and Norepinephrine.
 Autonomic Nervous System (ANS) has a
direct control over the secretion of epinephrine
and norepinephrine that enhance the effect of
SNS.
 During stressful situation or exercise, the
hypothalamus stimulates the sympathetic
preganglionic neurons to stimulate chromaffin
cells to produce epinephrine and norepinephrine.
PANCREAS
 Both endocrine and exocrine gland
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MEDICAL-SURGICAL NURSING
ENDOCRINE SYSTEM
 Located in the first curve of the duodenum and is
consist of head, tail, and body
Endocrine tissues are called endocrine islets which
include: A cells, B cells, D cells, and F cells.
WHAT HORMONES AND WHAT FOR?
A (alpha) produce glucagon to increase glucose level in
cells
the blood and to stimulate insulin production.
B (beta)
cells
D (delta)
cells
F cells
produce insulin to increase glucose uptake of
cells; thereby, lowering blood glucose level. It
also inhibits glucagon production.
produce somatostatin that inhibits glucagon
and insulin secretion. It also slows down
nutrients absorption in the intestines.
produce pancreatic polypeptide which inhibits
somatostatin secretion.
Female: ovaries produce estrogen and progesterone
Male: testes synthesize testosterone
 Estrogen and progesterone is responsible for
development and function of the female reproductive
organs and other female sexual characteristics
 Cyclical release of estrogen and progesterone regulates
the menstrual cycle.
 These two hormones promote development of
mammary glands and deposition of adipose tissue in
breast, hips, and thighs during puberty.
PINEAL GLAND
 A small, pinecone-shaped structure located superior and
posterior to the thalamus of the brain.
 It produces the hormone melatonin.
 Melatonin is thought to have two functions:
1. Sleep-wake cycle
2. Inhibits the functions of the reproductive system
THYMUS
 A bilobed gland, roughly triangular in shape, located
in the superior mediastinum, behind the sternum between
the lungs.
 It produces the hormones: thymosin, thymi humoral
factor (THF), thymic factor (TF), and thymopoietin. All of
which promotes the maturation of T cells
COMMON ENDOCRINE DISORDER AND
NURSING MANAGEMENT
GONADS
 Gonads are organs that produce gametes and secretes
sex hormones.
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