ENDOCRINE SYTEM

Group 5
BSMLS-1B
Mr. Exodus Marcus S. Leocadio

LEADER: PABLO, Krinrose L.

MEMBERS
CAPITAN, Mia Grace
DONEZA, Clarita
LAYOLA, Riyanni Sophia
PALANA, Daphne Ann
REDONDO, Euline Ernhea
FUNCTIONAL ORGANIZATION OF ➢ influences the activity of the same cell from
ENDOCRINE SYSTEM which it was secreted
❖ PARACRINE
PRINCIPLE OF CHEMICAL
➢ Produced by a wide variety of tissues and
COMMUNICATIONS
secreted into extracellular fluid;
• Chemical messengers from both the
➢ has a localized effect on nearby tissues
nervous system and the endocrine system
are the primary regulators of this ❖ NEUROTRANSMITTER

coordination. ➢ produced by neurons

➢ secreted into a synaptic cleft by presynaptic
COMPARISON OF NERVOUS SYSTEM nerve terminals;
AND ENDOCRINE SYSTEM ➢ influences postsynaptic cells
❖ ENDOCRINE
Nervous system and Endocrine system regulate
➢ Secreted into the blood by specialized cells;
and coordinate the activities all over our body in
➢ results in coordinated regulation of cell
order to achieve homeostasis. Nervous system
transmit messages directly to target cells through function

action potential that stimulate chemical

messengers (neurotransmitters). Endocrine ENDOCRINE
• derived from greek word endo, meaning
broadcasts information to the whole body through
chemical messengers called (hormones). “within” and krino, meaning “to secrete”
• endocrinology – study of endocrine

CHEMICAL MESSENGER
• allow cells to communicate with each CHARACTERISTICS OF ENDOCRINE

other to regulate body activities SYSTEM

• composed of endocrine glands and
• most are produced by a specific
collection of cells or by a gland specialized endocrine cells
• hormones – chemical messenger

CLASSES OF CHEMICAL MESSENGER secreted by endocrine glands

• target tissues, or effectors – specific

AUTOCRINE sites where hormones circulate through

the bloodstream
➢ Secreted by cells in a local area
 • amplitude-modulated signals – influence any cell, even those located far
hormones secreted by most endocrine from they were produced
glands • binding proteins – hormones
• amplitude - total amount of a requiring a transport chaperone
signal that is produced • bound hormones – hormones
• frequency-modulated signals – all-or- attach to a binding protein
none action potentials carried along • free hormones – hormones
axons detach from the binding protein
• frequency - how often a signal is • some hormones are “always
sent free” ; other hormones are
“sometimes free.”
HORMONES
• derived from greek word hormon”, CHEMICAL NATURE OF HORMONES
meaning “set into motion” (1) lipid-soluble hormones
• is “very powerful molecules, which all (2) water-soluble hormones
share same characteristics
REGULATION OF HORMONE LEVELS IN
CHARACTERISTICS OF HORMONE THE BLOOD
• STABILITY – hormone concentrations • Negative feedback: Most hormones are
are stable in the bloodstream; however, controlled by negative feedback,
some hormones are more stable than meaning when hormone levels get high
others. enough, the hormone itself stops its own
• half-life – hormone’s life span; release.
amount of time it takes for 50% • Positive feedback: some hormones
of the circulating hormone to be cause more of the hormone to be made
removed from the circulation and released. When a hormone is
and excreted. stimulated, it increases the secretion of
• COMMUNICATION – must be able to the hormone that caused it to be released,
interact with their target tissue in a creating a cycle that amplifies the
specific manner in order to activate a process.
coordinated set of events. CONTROL OF HORMONE SECRETION
• DISTRIBUTION – Hormones travel Three types of stimuli regulate hormone release:
through the bloodstream to various parts (1) humoral
of the body, giving them the ability to (2) neural
(3) hormonal. • Modulation of immune system function

HORMONE RECEPTORS AND PITUITARY GLAND

MECHANISM ACTIONS ❖ secretes nine major hormones that regulate
• RECEPTORS – hormones exert their numerous body functions and the secretory
actions by binding to target cell proteins activity of endocrine glands connected to the base
• RECEPTOR SITE – specific portion of of the brain
each receptor molecule ❖ infundibulum – connects the pituitary gland
• SPECIFICITY – tendency of hormone
to the hypothalamus
to bind
❖ sella turcica – where pituitary gland rest
• AGONIST – drug that binds to a
hormone receptor and activates it
2 LOBES OF PITUITARY GLAND
• ANTAGONIST – drug that binds to a
• POSTERIOR PITUITARY GLAND
hormone receptor and inhibits it
• is called the neurohypophysis because it
is continuous with the hypothalamus in
RECEPTOR NUMBER
the brain
• DOWN REGULATION – when the
• its hormones are called neuropeptides, or
receptors rapidly decreases
neurohormones
• UP REGULATION – increase in the
• ANTERIOR PITUITARY GLAND
rate of receptor synthesis
• develops as an out pocketing of the roof
of the embryonic oral cavity called the
MAIN REGULATORY FUNCTIONS OF
pituitary diverticulum, or Rathke pouch
ENDOCRINE SYSTEM
• as it nears the posterior pituitary, the
• Regulation of metabolism
pituitary diverticulum loses its
• Control of food intake and digestion
connection with the oral cavity and
• Modulation of tissue development
becomes the anterior pituitary, which
• Regulation of ion levels
includes an area called the pars
• Control of water balance
intermedia
• Changes in heart rate and blood pressure
• its hormones are traditional hormones
• Control of blood glucose and other
nutrients
HYPOTHALAMUS
• Control of reproductive functions
• regulates the secretory activity of the
• Stimulation of uterine contractions and
pituitary gland in response to other
milk release
 hormones, sensory information, and • stimulates the secretion
emotions adrenocorticotropic hormone
• some of these hypothalamic hormones GONADOTROPIN - RELEASING
are delivered to the anterior pituitary via HORMONE
a circulatory system called a portal • stimulate the secretion of both luteinizing
system hormone and follicle-stimulating
• hypothalamo hypophyseal hormone
portal system – one of the major PROLACTIN - RELEASING HORMONE &
portal systems in the body PROLACTIN - INHIBITING HORMONE
• hypothalamic hormones can either • regulate the secretion of prolactin
stimulate or inhibit release of anterior
pituitary hormones HORMONES OF THE PITUITARY GLAND
• releasing hormone – stimulate anterior • hormones secreted from the pituitary
pituitary secretion gland are separated into two categories:
• inhibiting hormone – decrease anterior posterior pituitary hormones and anterior
pituitary hormone secretion pituitary hormones
POSTERIOR PITUITARY HORMONES
HYPOTHALAMUS RELEASING AND The posterior pituitary, composed of neural
INHIBITING HORMONES tissue, stores and secretes two neurohormones:
GROWTH HORMONE - RELEASING • ANTIDIURETIC HORMONE
HORMONE • water conservation hormone
• stimulates the secretion of growth • ADH prevents (anti-) the output
hormone of large amounts of urine
GROWTH HORMONE - INHIBITING (diuresis).
HORMONE • An alternate name for ADH is
• also called somatostatin vasopressin
• inhibits growth hormone secretion • The secretion rate for ADH
THYROTROPIN - RELEASING changes in response to
HORMONE alterations in blood osmolality
• stimulates the secretion of thyroid- and blood volume. The
stimulating hormone osmolality of a solution
CORTICOTROPIN - RELEASING increases as the concentration of
HORMONE solutes in the solution increases.
Specialized neurons, called
 osmoreceptors, synapse with • THYROID-STIMULATING
the ADH neurosecretory neurons HORMONE
in the hypothalamus. • also called thyrotropin
• OXYTOCIN • stimulates the synthesis and
• reproductive hormone secretion of thyroid hormones
• transported to the posterior • TSH is a glycoprotein dimer
pituitary for storage. consisting of two subunits, α and
• stimulates labor in pregnant β, which bind to membrane-
mammals bound receptors of the thyroid
• responsible for milk letdown in gland.
breastfeeding moms and • The α subunit is common
lactating mammals among the glycoprotein
ANTERIOR PITUITARY HORMONES hormones, TSH, luteinizing
Regulated by hypothalamic releasing and hormone, and follicle-
inhibiting hormones. The hormones secreted stimulating hormone.
from the anterior pituitary are proteins, • It is the β subunit that dictates
glycoproteins, or polypeptides. the specificity of each of the
• GROWTH HORMONE glycoprotein hormones.
• also called somatotropin • TSH secretion is controlled by
• stimulates growth in most tissues two mechanisms: (1) TRH
• determining how tall a person (Thyrotropin-releasing
becomes hormone) from the
• regulates metabolism hypothalamus and (2) negative
• hyposecretion – dwarfism feedback by thyroid hormones.
• hypersecretion – gigantism,
acromegaly
• PROLACTIN • ADRENOCORTICOTROPIC
• plays an important role in milk HORMONE
production • ACTH is one of four smaller
• It binds to a membrane-bound molecules derived from a large
receptor, which is linked to a precursor protein called
kinase that phosphorylates proopiomelanocortin.
intracellular proteins. • synthesized in the anterior
pituitary and is subsequently
 broken down into multiple, function of the gonads, the
smaller peptides. ovaries, and the testes.
• stimulate secretion of the • The two major gonadotropins
hormone cortisol secreted from the anterior
▪ release response to pituitary are (1) luteinizing
stress hormone (LH) and (2) follicle-
▪ regulate blood pressure stimulating hormone (FSH).
• LH and FSH are released from
anterior pituitary cells under the
• LIPOTROPINS influence of the hypothalamic-
• secreted from the anterior releasing hormone
pituitary binds to membrane- gonadotropin-releasing
bound receptor molecules on hormone (GnRH).
adipocytes.
• they cause lipid breakdown and THYROID GLAND
release acids into the blood • synthesizes and secretes three (3)
• B ENDORPHINS hormones
• play a role in analgesia (pain • Located just below the larynx, lateral to
relief) in response to stress and the trachea.
exercise • composed of two lobes connected by a
• the regulation of body narrow band of thyroid tissue called the
temperature, food intake, and isthmus.
water balance. • weight of approximately 20 g, butterfly-
• MELANOCYTE-STIMULATING shaped.
HORMONE • Highly vascular, and appears darker in
• stimulates increased melanin color.
deposition • contains numerous follicles
• studies have shown that MSH is • Function: Produces thyroid hormones
also important in regulating (T3, T4) and calcitonin.
appetite and sexual behavior. KEY STRUCTURES OF THE THYROID
• LUTEINIZING HORMONE AND GLAND
FOLLICLE HORMONE • Thyroid Follicles: Small spheres filled
• glycoprotein hormones capable with colloid.
of promoting the growth and
 • Parafollicular (C) Cells: Produce Iodine Intake: Iodine, an essential component of
calcitonin, regulating calcium levels. thyroid hormones, is absorbed from the diet
• Thyroglobulin: A protein in the colloid, (commonly found in iodized salt and seafood)
precursor to T3 and T4. and transported to the thyroid for hormone
colloid synthesis.
• gelatinous materials filled in the center of Thyroglobulin Formation: Thyroglobulin is
each thyroid follicle produced within the thyroid follicles and serves
• composed of a highly concentrated as the foundation upon which thyroid hormones
protein called thyroglobulin are synthesized.
• building block or raw material used to
make T3 and T4 Synthesis Process: Iodine atoms bind to tyrosine
• Without thyroglobulin, the thyroid residues on thyroglobulin within the colloid,
wouldn't be able to produce T3 and T4. forming T3 and T4, which are then stored until
THYROID HORMONES needed.

TSH Signal: Thyroid-stimulating hormone

• SECRETED BY THYROID (TSH) is released from the pituitary gland in the
FOLLICLES: brain, signaling the thyroid to release T3 and T4
• T3 – triiodothyronine into the bloodstream, where they circulate to
• active form of thyroid hormone, regulate metabolism.
containing three iodine atoms.
• crucial for regulating metabolism by EFFECTS OF THYROID HORMONES (T3
speeding up energy consumption in cells, AND T4)
thus influencing how the body uses
energy.
• T4 – tetraiodothyronine thyroxine • Metabolism Boost
• precursor hormone with four iodine • Growth and Development
atoms, produced in higher quantities than • Temperature Control
T3. T4 is converted into T3 in the tissues,
becoming the active form that directly REGULATION OF THYROID HORMONE
affects metabolism. LEVELS

SYNTHESIS AND RELEASE OF T3 AND T4 TRH and TSH: Thyrotropin-releasing hormone

(TRH) from the hypothalamus stimulates the
release of TSH (thyroid-stimulating hormone)
from the pituitary gland, which in turn prompts CALCITONIN
the thyroid to release T3 and T4. • hormone produced by the parafollicular
cells (C cells) of the thyroid gland.
Negative Feedback Mechanism: High levels of • helps regulate blood calcium levels by
T3 and T4 signal the hypothalamus and pituitary reducing calcium concentration in the
gland to reduce the release of TRH and TSH, thus blood.
preventing the thyroid from overproducing • Mechanism of Action: Calcitonin works
hormones. by inhibiting the release of calcium from
bones and promoting calcium excretion
External Influences: Factors such as stress and through urine, which aids in maintaining
temperature changes can impact TRH levels, bone health and preventing excessive
indirectly influencing the release of T3 and T4. blood calcium levels.

THYROID HORMONE DISORDERS PARATHYROID GLAND

Hypothyroidism
• condition where the thyroid produces • Location: Embedded in the posterior
insufficient hormones, leading to a slow part of each thyroid lobe.
metabolic rate. • 2 structures:
• Symptoms: Often characterized by • Chief Cells: responsible for
fatigue, weight gain, and sensitivity to making and releasing
cold. parathyroid hormone (PTH).
• Causes: Common causes include iodine • Oxyphils: Function is still
deficiency and autoimmune diseases. unknown.

Hyperthyroidism Function of Parathyroid Hormone (PTH)

• condition where the thyroid produces • Main role is to regulate calcium levels in
excess hormones, resulting in an the blood and other body fluids.
accelerated metabolic rate. • The primary target tissues are bone,
• Symptoms: May include weight loss, kidneys, and small intestine.
rapid heartbeat, and heat intolerance.
• Causes: Often due to autoimmune How PTH Works on Bones and Kidneys
conditions.
 • Bone Cells Activated: PTH indirectly
increases osteoclast activity, releasing
calcium into the blood. • part makes epinephrine (adrenaline)
• Kidneys: Reduces calcium loss in urine and norepinephrine (noradrenaline).
and activates vitamin D for calcium
• The overall effect is increased blood
calcium levels while regulating
phosphate levels.
• adrenal cortex
Hypocalcemia • like the maintenance team. It helps with
• is when the calcium levels in the blood daily functions.
are too low • outer part with three layers:
• can be caused by hypoparathyroidism • zona glomerulosa – secretes aldosterone
(low PTH) or a lack of vitamin D. • zona fasciculata – secretes cortisol
• zona reticularis – secretes androgens;
Hyperparathyroidism deepest layer; thin layer of irregularly
• With excess PTH, leading to high arranged cords of cells.
calcium levels.
Hypoparathyroidism HORMONES OF ADRENAL
• With low PTH, leading to low calcium MEDULLA
levels. • EPINEPHRINE – 80% of adrenal
medulla hormones
ADRENAL GLANDS • Prepares the body for the "fight or flight"
• Composed of two main parts: the response.
medulla (inner) and cortex (outer). • NOREPINEPHRINE – 20% of adrenal
• small, triangular-shaped glands that sit medulla hormones
on top of the kidneys.
HORMONES OF THE ADRENAL CORTEX
Structure of the Adrenal Glands • MINERALOCORTICOIDS –
hormones that help control the balance of
sodium (Na+) and potassium (K+) in the
• adrenal medulla - the inner part made body.
of polyhedral cells, produces epinephrine • GLUCOCORTICOIDS – like cortisol,
and norepinephrine. are stress hormones that help the body
 respond to stress and maintain energy • SATIETY CANCER – collection of
levels during tough situations. neurons in the hypothalamus that
controls appetite
• INSULIN – increases the uptake of
• Have other jobs related to metabolism. glucose and amino acids by cells
• ADRENAL ANDROGENS – sex • GLUCOSE – used for energy or is
hormones produced by the adrenal stored as glycogen
cortex, but they're not as powerful as the • AMINO ACIDS – used for energy or are
sex hormones made by the gonads converted to glucose or proteins
▪ ovaries in females and the testes • GLUCAGON – causes the breakdown
in males. of glycogen and lipids for use as an
• mostly weak versions of male sex energy source ; glucagon’s target tissue
hormones like testosterone. is mainly the liver

PANCREAS REGULATION OF PANCREATIC

• Both an exocrine gland and an endocrine HORMONE SECRETION
gland.
• Between 500,000 and 1 million
pancreatic islets are dispersed among the • HYPERGLYCEMIA – or low blood
ducts and acini of the pancreas. Each islet levels of glucose, directly slows insulin
is composed of alpha (α) cells (20%), secretion.
which secrete glucagon, a small • INSULIN SECRETION – increases
polypeptide hormone, and beta (β) cells because of elevated blood glucose levels.
(75%), which secrete insulin, a small an increase in some amino acids,
protein hormone consisting of two (2) parasympathetic stimulation, and
polypeptide chains bound together. gastrointestinal hormones. Sympathetic
stimulation decreases insulin secretion.
EFFECTS OF INSULIN AND GLUCAGON • GLUCAGON SECRETION –
ON THEIR TARGET TISSUES stimulated by low blood glucose levels,
• Insulin's target tissues are the liver, certain amino acids, and sympathetic
adipose tissue, muscle, and the satiety stimulation.
center in the hypothalamus. • SOMATOSTATIN – inhibits insulin
and glucagon secretion
HORMONES OF REPRODUCTIVE the reproductive system in some
SYSTEM animals
• puberty, menstruation, gamete ❖ PHOTOPERIOD – the amount of
formation, and pregnancy, are under daylight and darkness that occurs
control of reproductive hormones each day and changes with the
• secreted primarily from the ovaries, seasons of the year
testes, placenta, and pituitary gland
• TESTES – main endocrine glands of the OTHER HORMONES AND OTHER
male reproductive system CHEMICAL MESSENGERS
• TESTOSTERONE – regulates the • HORMONES OF THYMUS
production of sperm cells by the testes • thymus is important for immune
and the development and maintenance of function; the thymus secretes the
male reproductive organs and secondary hormone thymosin. Both the
sexual characteristics thymus and thymosin play a role
• INHIBIN – inhibits the secretion of FSH in the development and
from the anterior pituitary gland maturation of the immune
• OVARIES – main endocrine glands of system
the female reproductive system
• ESTROGEN & PROGESTERONE –
main hormones secreted by the ovaries; • HORMONES OF DIGESTIVE
these hormones control the female TRACT
reproductive cycle, prepare the • several hormones are released
mammary glands for lactation, and from the digestive tract; they
maintain pregnancy regulate digestive functions by
• RELAXIN – increases the flexibility of influencing the activity of the
the connective tissue of the symphysis stomach, intestines, liver, and
pubis and helps dilate the cervix of the pancreas
uterus
HORMONELIKE CHEMICALS
HORMONES OF PINEAL GLANDS • AUTOCRINE CHEMICAL
❖ MELATONIN – help regulate sleep cycles by MESSENGER
increasing the tendency to sleep • are released from cells that
❖ ARGININE VASOTOCIN – works with influence the same cell from
melatonin to regulate the function of which they are released
 • PARACRINE CHEMICAL 4. Stress Response: The adrenal glands
MESSENGER release cortisol and adrenaline to help
• are released from one cell type, the body respond to stress. These
diffuse short distances, and hormones increase heart rate and
influence the activity of another alertness, preparing the body for action
cell type, which is the target (the "fight or flight" response).
tissue 5. Maintains Balance: The endocrine
CONCLUSION ON THE ENDOCRINE system helps keep the body’s internal
SYSTEM environment stable, like controlling
The endocrine system is a network of glands that blood sugar levels, fluid balance, and
release hormones into the blood to control calcium levels, which are essential for
important body functions. These hormones act good health.
like "messengers," telling different parts of the 6. Works with Other Systems: The
body what to do. endocrine system works closely with the
1. Regulates Energy and Metabolism: nervous system to control body
Hormones like insulin and glucagon functions. The hypothalamus and
from the pancreas control how the body pituitary gland are the main control
uses and stores energy, like glucose. centers for releasing hormones.
Thyroid hormones also help regulate 7. Feedback System: The body has a
metabolism, making sure the body has feedback loop that keeps hormone levels
enough energy to function. in balance. If there’s too much or too
2. Growth and Development: Hormones little of a hormone, the body adjusts to
such as growth hormone, estrogen, and bring things back to normal.
testosterone control physical growth, PROBLEMS WITH THE ENDOCRINE
sexual development, and the body's SYSTEM
ability to mature. These are especially The endocrine system can have problems when it
important during childhood, puberty, and doesn't make the right amount of hormones,
pregnancy. which can lead to conditions like diabetes,
3. Controls Reproduction: The endocrine thyroid issues, or PCOS (polycystic ovary
system controls the menstrual cycle, syndrome). Sometimes lifestyle factors like poor
sperm production, and pregnancy diet or stress can affect how well the system
through hormones like estrogen, works.
progesterone, and testosterone. SUMMARY
The endocrine system is essential for many
functions in the body, from energy use and
growth to reproduction and stress management.
Keeping this system balanced is important for
overall health. When something goes wrong, it
can cause health problems, but with proper care
and treatment, most issues can be managed.