Endocrine
Gland Functions
● Hypothalamus: brain
○ Body temp regulation, sleep, appetite
○ Dopamine, GH-Releasing hormone, Corticotropin
releasing hormone, gonadotropin releasing hormone,
thyrotropin releasing hormone
● Adrenal: top of kidneys
○ Regulate sodium and electrolyte levels
○ Steroid hormones: aldosterone and cortisol
■ Aldosterone: regulates BP, retention of Na and
secretion of K
■ Cortisol: released in response to stress,
increases blood glucose, breaks down
fat/protein/carbs, electrolyte regulation
○ Responsible for androgens (sex hormones) that cause
development of pubic hair, oily skin, oily hair, body
odor
● Thyroid: neck
○ Metabolism
○ TSH which stimulates release of thyroxine
● Parathyroid: behind thyroid
○ Control calcium and phosphorus metabolism
● ***Pituitary: master gland, brain
○ Growth and development
○ Stimulates or inhibits release of hormones
○ If pituitary doesn’t work → hormone problems
○ Anterior: TP FLAG (TSH, Prolactin, FSH, LSH, ACTH, GH)
○ Posterior: (ADH/Vasopressin, Oxytocin) — DI lacks ADH
Hormone Target Organ Effects/Function
Follicle Stimulating Hormone (FSH) Female: Ovaries Stimulates production of estrogen (F) and
GONADOTROPIN Male: Testes testosterone (M).
Luteinizing Hormone (LH) Female: Ovaries Stimulates production of estrogen (F) and
GONADOTROPIN Male: Testes testosterone (M).
Adrenocorticotropic Hormone (ACTH) Adrenal Cortex Stimulates release of cortisol
Thyroid Stimulating Hormone (TSH) Thyroid Gland Stimulates release of thyroxine
, Prolactin Mammary Glands Stimulates the production of breast milk
Endorphins Act on opioid receptors Make you happy!
(made primarily in CNS)
Growth Hormone (GH) Liver Stimulates the production of Insulin-like
Growth Factor (IGF-1)
Major Six Hormones of Endocrine System
● ACTH (Adrenocorticotropic hormone
● TSH (Thyroid Stimulating Hormone)
○ Responsible for growth and development → kids can have developmental delays (loss of IQ)
○ Hypothyroidism → mental retardation
● FSH (Follicle Stimulating Hormone) and LH (Luteinizing hormone)
○ Gonadotropins = reproduction aka stimulate follicular growth and ovulation
● GH (Growth hormone)
Pathophysiology Overview
● Negative feedback loop
○ Hypothalamus stimulates pituitary → pituitary secretes TSH → TSH stimulates thyroid to secrete T3 and
T4 → when enough T3 and T4 released, feedback mechanism alerts hypothalamus + pituitary to halt
release of TSH
● Primary hypothyroidism
○ pituitary works, thyroid doesn’t → pituitary makes lots of TSH but thyroid can’t produce T3/T4
■ HIGH TSH - LOW T4
● Secondary hypothyroidism
○ Pituitary doesn’t work, thyroid works → LOW TSH-LOW T4
● Thyroid function tests: TSH, Free T4, thyroid antibodies
● HPA Axis – Hypothalamus, Pituitary, Adrenal Axis
○ Hypothalamus releases corticotropin releasing hormonestimulates
pituitary to release adrenocorticotopic hormonestimulates adrenal
cortex to release cortisol.
Terminology
● Primary and secondary disorder
○ Primary – Gland is not working!
■ For example: primary hypothyroidism is when the thyroid is malfunctioning so T3 and T4 are
low but the pituitary gland is producing alot of TSH to stimulate the thyroid (like compensating)
○ Secondary – Gland is fine but it is not stimulating anything!
■ For example: secondary hypothyroidism is when pituitary isn't making TSH so the thyroid isn’t
being stimulated to make T3 and T4.
● First and Second Messenger
○ First Messenger – Extracellular
○ Second Messenger – Intracellular
, Panhypopituitarism
● PATHO: does not make ANY pituitary hormones
● **Children w/ panhypo should wear medical identification bracelets
● Order of pituitary hormone failure:
a. Growth Hormone
■ Growth failure: crossing growth percentile after 18mo-2yrs
■ Normal: does not cross percentile
b. Gonadotropins (LH + FSH)
■ Delayed puberty, delayed secondary characteristics
c. TSH
■ Children: growth retardation
■ Adults: fatigue, cold intolerance, constipation, weight gain, dry skin
d. Adrenocorticotropic hormone
e. Prolactin (RARE)
f. Antidiuretic hormone (ADH) — associated with BRAIN TUMORS
Hypothyroidism
● Congenital hypothyroidism (more common in infants
than acquired hypothyroidism)
○ PATHO: absent or undeveloped thyroid — not
enough thyroid hormones :(
○ RF: premature infants
○ Complications: intellectual impairment (loss of
IQ points)
○ TX: levothyroxine 4 life w/ breast
milk/formula/water
● Acquired hypothyroidism = AUTOIMMUNE
thyroiditis = Hashimoto
○ Hashimoto thyroiditis most common cause;
may have normal thyroid function but
elevated/positive thyroid antibodies
○ PATHO: thyroid gland produces inadequate amount of thyroid hormone as it is being destroyed by
antibodies
○ DX: recheck in 6 mo + check TSH + monitor S/S
■ If TSH elevated after 6 mo, DX w/ hypothyroidism
■ High TSH, Low T4 (primary hypothyroidism)
○ S/S: congenital hypothyroidism, good and quiet, distended abdomen, large fontanel, large tongue, delayed
stool after birth (constipation), poor feeding, sleepy, lethargic, hoarse cry, prolonged jaundice,
hypoactivity, goiter (inflamed gland)
○ Complications: if left untreated, can cause intellectual impairment (loss of IQ points)
○ TX: lifelong thyroid hormone replacement, Levothyroxine (synthroid), no soy/fiber/iron/fortified
formula w/ medication
■ Teach parents to administer at same time each day
Gland Functions
● Hypothalamus: brain
○ Body temp regulation, sleep, appetite
○ Dopamine, GH-Releasing hormone, Corticotropin
releasing hormone, gonadotropin releasing hormone,
thyrotropin releasing hormone
● Adrenal: top of kidneys
○ Regulate sodium and electrolyte levels
○ Steroid hormones: aldosterone and cortisol
■ Aldosterone: regulates BP, retention of Na and
secretion of K
■ Cortisol: released in response to stress,
increases blood glucose, breaks down
fat/protein/carbs, electrolyte regulation
○ Responsible for androgens (sex hormones) that cause
development of pubic hair, oily skin, oily hair, body
odor
● Thyroid: neck
○ Metabolism
○ TSH which stimulates release of thyroxine
● Parathyroid: behind thyroid
○ Control calcium and phosphorus metabolism
● ***Pituitary: master gland, brain
○ Growth and development
○ Stimulates or inhibits release of hormones
○ If pituitary doesn’t work → hormone problems
○ Anterior: TP FLAG (TSH, Prolactin, FSH, LSH, ACTH, GH)
○ Posterior: (ADH/Vasopressin, Oxytocin) — DI lacks ADH
Hormone Target Organ Effects/Function
Follicle Stimulating Hormone (FSH) Female: Ovaries Stimulates production of estrogen (F) and
GONADOTROPIN Male: Testes testosterone (M).
Luteinizing Hormone (LH) Female: Ovaries Stimulates production of estrogen (F) and
GONADOTROPIN Male: Testes testosterone (M).
Adrenocorticotropic Hormone (ACTH) Adrenal Cortex Stimulates release of cortisol
Thyroid Stimulating Hormone (TSH) Thyroid Gland Stimulates release of thyroxine
, Prolactin Mammary Glands Stimulates the production of breast milk
Endorphins Act on opioid receptors Make you happy!
(made primarily in CNS)
Growth Hormone (GH) Liver Stimulates the production of Insulin-like
Growth Factor (IGF-1)
Major Six Hormones of Endocrine System
● ACTH (Adrenocorticotropic hormone
● TSH (Thyroid Stimulating Hormone)
○ Responsible for growth and development → kids can have developmental delays (loss of IQ)
○ Hypothyroidism → mental retardation
● FSH (Follicle Stimulating Hormone) and LH (Luteinizing hormone)
○ Gonadotropins = reproduction aka stimulate follicular growth and ovulation
● GH (Growth hormone)
Pathophysiology Overview
● Negative feedback loop
○ Hypothalamus stimulates pituitary → pituitary secretes TSH → TSH stimulates thyroid to secrete T3 and
T4 → when enough T3 and T4 released, feedback mechanism alerts hypothalamus + pituitary to halt
release of TSH
● Primary hypothyroidism
○ pituitary works, thyroid doesn’t → pituitary makes lots of TSH but thyroid can’t produce T3/T4
■ HIGH TSH - LOW T4
● Secondary hypothyroidism
○ Pituitary doesn’t work, thyroid works → LOW TSH-LOW T4
● Thyroid function tests: TSH, Free T4, thyroid antibodies
● HPA Axis – Hypothalamus, Pituitary, Adrenal Axis
○ Hypothalamus releases corticotropin releasing hormonestimulates
pituitary to release adrenocorticotopic hormonestimulates adrenal
cortex to release cortisol.
Terminology
● Primary and secondary disorder
○ Primary – Gland is not working!
■ For example: primary hypothyroidism is when the thyroid is malfunctioning so T3 and T4 are
low but the pituitary gland is producing alot of TSH to stimulate the thyroid (like compensating)
○ Secondary – Gland is fine but it is not stimulating anything!
■ For example: secondary hypothyroidism is when pituitary isn't making TSH so the thyroid isn’t
being stimulated to make T3 and T4.
● First and Second Messenger
○ First Messenger – Extracellular
○ Second Messenger – Intracellular
, Panhypopituitarism
● PATHO: does not make ANY pituitary hormones
● **Children w/ panhypo should wear medical identification bracelets
● Order of pituitary hormone failure:
a. Growth Hormone
■ Growth failure: crossing growth percentile after 18mo-2yrs
■ Normal: does not cross percentile
b. Gonadotropins (LH + FSH)
■ Delayed puberty, delayed secondary characteristics
c. TSH
■ Children: growth retardation
■ Adults: fatigue, cold intolerance, constipation, weight gain, dry skin
d. Adrenocorticotropic hormone
e. Prolactin (RARE)
f. Antidiuretic hormone (ADH) — associated with BRAIN TUMORS
Hypothyroidism
● Congenital hypothyroidism (more common in infants
than acquired hypothyroidism)
○ PATHO: absent or undeveloped thyroid — not
enough thyroid hormones :(
○ RF: premature infants
○ Complications: intellectual impairment (loss of
IQ points)
○ TX: levothyroxine 4 life w/ breast
milk/formula/water
● Acquired hypothyroidism = AUTOIMMUNE
thyroiditis = Hashimoto
○ Hashimoto thyroiditis most common cause;
may have normal thyroid function but
elevated/positive thyroid antibodies
○ PATHO: thyroid gland produces inadequate amount of thyroid hormone as it is being destroyed by
antibodies
○ DX: recheck in 6 mo + check TSH + monitor S/S
■ If TSH elevated after 6 mo, DX w/ hypothyroidism
■ High TSH, Low T4 (primary hypothyroidism)
○ S/S: congenital hypothyroidism, good and quiet, distended abdomen, large fontanel, large tongue, delayed
stool after birth (constipation), poor feeding, sleepy, lethargic, hoarse cry, prolonged jaundice,
hypoactivity, goiter (inflamed gland)
○ Complications: if left untreated, can cause intellectual impairment (loss of IQ points)
○ TX: lifelong thyroid hormone replacement, Levothyroxine (synthroid), no soy/fiber/iron/fortified
formula w/ medication
■ Teach parents to administer at same time each day
