The document provides an overview of the endocrine system, including: 1) It describes the endocrine system as made up of glands that secrete hormones like the pituitary, thyroid, parathyroid, adrenals and reproductive organs. 2) It explains hormones regulate important bodily functions such as growth, metabolism, mood, and reproduction. Disruptions in hormone levels can cause disorders. 3) Key glands and their hormone secretions involved in growth, calcium regulation, metabolism, stress response, and sexual development/functioning are detailed.

1. Nursing Study Contents

2. What is the
endocrine
system?
The endocrine system is made up of glands and the
hormones they secrete. Although the endocrine
glands are the primary hormone producers, the
brain, heart, lungs, liver, skin, thymus,
gastrointestinal mucosa, and placenta also produce
and release hormones.

3. What is the endocrine system?
The primary
endocrine glands are
the pituitary (the
master gland),
pineal, thyroid,
parathyroid, islets of
Langerhans,
adrenals, ovaries in
the female and testes
in the male.
The function of the endocrine system is the
production and regulation of chemical
substances called hormones.

4. Hormones…
A hormone is a chemical transmitter. It is released
in small amounts from glands, and is transported
in the bloodstream to target organs or other cells.
Hormones are chemical messengers, transferring
information and instructions from one set of cells
to another.

5. Hormones… Hormones regulate growth,
development, mood, tissue
function, metabolism, and
sexual function.
Hyposecretion or
hypersecretion of
any hormone can
be harmful to
the body.
Controlling
the production
of hormones
can treat
many
hormonal
disorders in
the body.

6. Hormones…
The endocrine system and nervous system work
together to help maintain homeostasis… balance.
The hypothalamus is a collection of specialized
cells located in the brain, and is the primary link
between the two systems. It produces chemicals
that either stimulate or suppress hormone
secretions of the pituitary gland.
The pituitary gland has 2
lobes…

7. Secretions from the anterior
pituitary gland…
Growth Hormone (GH):
Essential for the growth
and development of
bones, muscles, and
other organs. It also
enhances protein
synthesis, decreases the
use of glucose, and
promotes fat
destruction.

8. Oversecretion of growth
hormone:
Giantism in childhood
Acromegaly in adults
(with large bones of
face, hands and feet )
Undersecretion of growth
hormone:
Dwarfism in childhood

9. Secretions from the anterior
pituitary gland…
Adrenocorticotropin (ACTH):
Essential for the growth of the
adrenal cortex.
Thyroid-Stimulating Hormone
(TSH): Essential for the
growth and development of the
thyroid gland.

10. Secretions from the anterior
pituitary gland…
It stimulates the growth
ovarian follicles in the
female and the
production of sperm in
the male.
Follicle-Stimulating Hormone
(FSH): is a gonadotropic
hormone.

11. Secretions from the anterior
pituitary gland…Luteinizing Hormone (LH):
is a gonadotropic hormone
stimulating the
development of corpus
luteum in the female
ovarian follicles and the
production of testosterone
in the male.
The yellow corpus luteum
remains after ovulation; it
produces estrogen and
progesterone.

12. Secretions from the anterior
pituitary gland… Prolactin (PRL):
stimulates the
development and growth
of the mammary glands
and milk production
during pregnancy.
The sucking motion of the
baby stimulates prolactin
secretion.

13. Secretions from the anterior
pituitary gland…
Melanocyte-stimulating
hormone (MSH): regulates skin
pigmentation and promotes
the deposit of melanine in the
skin after exposure to sunlight

14. Antidiuretic Hormone (ADH):
stimulates the reabsorption
of water by the renal tubules.
Hyposecretion of this
hormone can result in
diabetes insipidus.
Secretions from the posterior
lobe of the pituitary gland…

15. Oxytocin: stimulates the
uterus to contract during labor,
delivery, and parturition. A
synthetic version of this
hormone, used to induce labor,
is called Pitocin. It also
stimulates the mammary
glands to release milk.
Secretions from the posterior
lobe of the pituitary gland…

16. Secretions from the pineal
gland… The pineal gland is pine-cone-shaped
and only about 1 cm in diameter.
Melatonin:
communicates
information about
environmental lighting
to various parts of the
body. Has some effect
on sleep/awake cycles
and other biological
events connected to
them, such as a lower
production of gastric
secretions at night.

17. Secretions from the pineal
gland…
Serotonin: a neurotransmitter
that regulates intestinal
movements and affects
appetite, mood, sleep, anger,
and metabolism.

18. Secretions of the thyroid gland…
Calcitonin: influences
bone and calcium
metabolism; maintains
a homeostasis of
calcium in the blood
plasma
The thyroid gland plays a
vital role in metabolism
and regulates the body’s
metabolic processes.

19. Located inferior to larynx
2 lobes connected by isthmus
Thyroid follicles produce thyroid hormones
Thyroxine or tetraiodothyronine (T4)
Triiodothyronine (T3)
Both increase BMR, stimulate protein synthesis, increase use of
glucose and fatty acids for ATP production
Parafollicular cells or C cells produce calcitonin
Lowers blood Ca2+ by inhibiting bone resorption
thyroid gland
Thyroid Gland

20. Secretes two nonsteroid hormones
Triiodothyronine (T3)
Thyroxine (T4)
Regulates metabolism
increases protein synthesis
promotes glycolysis, gluconeogenesis,
glucose uptake
Calcitonin: calcium metabolism

21. Secretions of the thyroid gland…
Thyroxine (T4) and
Triodothyronine (T3):
essential to BMR – basal
metabolic rate (the rate at
which a person’s body burns
calories while at rest);
influences physical/mental
development and growth
Hyposecretion of T3 and T4 = cretinism,
myxedema, Hashimoto’s disease
Hypersecretion of T3 and T4 = Grave’s disease,
goiter, Basedow’s disease
Myxedem
a
Grave’s
disease

22. Secretions of the parathyroid
gland…
The two pairs of parathyroid
glands are located on the
dorsal or back side of the
thyroid gland.
They secrete parathyroid
(PTH) which plays a role in
the metabolism of
phosphorus. Too little results
in cramping; too much
results in osteoporosis or
kidney stones.

23. The islets of Langerhans…
The islets of Langerhans are small clusters of
cells located in the pancreas.

24. Secretions from the islets of
Langerhans… Beta cells secrete the
hormone insulin, which is
essential for the maintenance
of normal blood sugar levels.
Inadequate levels result in
diabetes mellitus.
Delta cells suppress
the release of
glucagon and insulin.
Alpha cells facilitate
the breakdown of
glycogen to glucose.
This elevates the
blood sugar.

25. The adrenal glands…
The triangular-shaped
adrenal glands are
located on the top of
each kidney. The
inside is called the
medulla and the
outside layer is called
the cortex.

26. Secretions from the
adrenal cortex…
Cortisol: regulates
carbohydrate, protein, and fat
metabolism; has an anti-
inflammatory effect; helps
the body cope during times of
stress
Hyposecretion results
in Addison’s disease;
hypersecretion
results in Cushing’s
disease
Corticosterone: like
cortisol, it is a
steroid; influences
potassium and
sodium metabolism

27. Secretions from the adrenal
cortex… Aldosterone: essential in regulating
electrolyte and water balance by
promoting sodium and chloride
retention and potassium excretion.
Androgens: several
hormones including
testosterone; they
promote the
development of
secondary sex
characteristics in
the male.

28. Adrenal Cortex
Secretes over 30 different steroid hormones (corticosteroids)
Mineralocorticoids
Aldosterone: maintains electrolyte balance
Glucocorticoids
Cortisol:
Stimulates gluconeogenisis
Mobilization of free fatty acids
Glucose sparing
Anti-inflammatory agent
Gonadocorticoids
testosterone, estrogen, progesterone

29. Adrenal Cortex Imbalances
 Hypersecretion leads
to Cushing’s disease
 ACTH-releasing tumors
or side effects of
corticoid drugs.
 Hyposecretion leads
to Addison’s Disease
 Deficits in
glucocorticoids and
mineralcorticoids

30. Adrenal Medulla
Situated directly atop each kidney and stimulated
by the sympathetic nervous system
Secretes the catecholamines
Epinephrine: elicits a fight or flight response
Increase H.R. and B.P.
Increase respiration
Increase metabolic rate
Increase glycogenolysis
Vasodilation
Norepinephrine
House keeping system

31. Secretions from the
adrenal medulla…
Dopamine is used to treat
shock. It dilates the
arteries, elevates systolic
blood pressure, increases
cardiac output, and
increases urinary output.

32. Secretions
from the
adrenal
medulla…
Epinephrine is also called adrenalin. It elevates
systolic blood pressure, increases heart rate and
cardiac output, speeds up the release of glucose
from the liver… giving a spurt of energy, dilates
the bronchial tubes and relaxes airways, and
dilates the pupils to see more clearly. It is often
used to counteract an allergic reaction.

33. Secretions from the
adrenal medulla…
Norepinephrine, like epinephrine, is released when
the body is under stress. It creates the underlying
influence in the fight or flight response. As a drug,
however, it actually triggers a drop in heart rate.

34. Adrenal Gland Secretion
 Cortex
 Activity stimulated by
ACTH
 Controls prolonged
responses by secreting
corticosteroids.
 Mineralcorticoids
 Aldosterone regulate salt and
water balance
 Glucocorticoids
 Cortisol regulate glucose
metabolism and the immune system.
 Gonadocorticoids
 Androgens
 Estrogens
 Medulla
 The adrenal medulla mediates
short–term responses by
secreting catecholamine
hormones.
 Cells are modified neurons
(lack axons)
 Epinephrine (adrenaline)
 Norepinephrine (noreadrenaline)
 enable a rapid ( fight-or-flight )
responses to stress by
increasing blood glucose and
blood pressure and directing
blood to the heart, brain, and
skeletal muscles.

35. Secretions of the ovaries…
The ovaries produce several
estrogen hormones and
progesterone. These
hormones prepare the uterus
for pregnancy, promote the
development of mammary
glands, play a role in sex drive,
and develop secondary sex
characteristics in the female.
Estrogen is essential for the growth, development,
and maintenance of female sex organs.

36. The testes produce the
male sex hormone called
testosterone. It is
essential for normal
growth and development
of the male sex organs.
Testosterone is
responsible for the
erection of the penis.
Secretions of the testes…

37. During pregnancy, the
placenta serves as an
endocrine gland.
Secretions of the placenta…
It produces
chorionic
gonadotropin
hormone,
estrogen, and
progesterone.

38. The mucosa of the
pyloric area of the
stomach secretes the
hormone gastrin,
which stimulates the
production of gastric
acid for digestion.
Secretions of the
gastrointestinal mucosa…

39. The mucosa of
the duodenum
and jejunum
secretes the
hormone
secretin, which
stimulates
pancreatic juice,
bile, and
intestinal
secretion.
Secretions of the
gastrointestinal mucosa…

40. The thymus gland has
two lobes, and is part
of the lymphatic
system. It is a
ductless gland, and
secretes thymosin.
This is necessary for
the Thymus’ normal
production of T cells
for the immune
system.
Secretions of the
thymus…

41. Feedback Loop
•A rise in blood glucose
causes release of insulin
from beta cells the
pancreas, promoting
glucose uptake in cells
and storage as glycogen
in the liver.
•A fall in blood glucose
stimulates alpha cells in
the pancreas to secrete
glucagon, which causes
the liver to break down
glycogen and release
glucose.

42. Non-Endocrine Gland Hormones
 Stomach (gastrin)
 Small intestine (duodenumintesetinal
gastrin, secretin, cholecystokinin)
 Heart (atrial natriuretic peptide)
 Kidneys (erythropoietin, active vitamin D3)
 Adipose tissue (leptid, resistin)
 Skin
 Placenta (human chorionic gonadotropin,
human placental lactogen, relaxin)

43. Functions of Endocrine System
 Growth
 Healing
 Water balance & Blood Pressure
 Calcium Metabolism
 Energy Metabolism
 Stress
 Regulation of other Endocrine
Organs