PATHO Endocrine System, DM, GI
Exam Question and Answers Latest
Updates 2026 Graded A+
Posterior Lobe Pituitary Disorders
Hyperpopituitarism
- Syndrome of inappropriate antidiuretic hormone; SIADH
Hypopopituitarism
- Diabetes insipidus, DI
Clinical Manifestations of Hyperpituitarism
- enlargement and bony changes in hands, feet, face, and spine
- deepened voice due to increased size of larynx and respiratory tract
- cardiomegaly, atherosclerosis
- obstructive sleep apnea
- disorders of fat and carbohydrate metabolism
- excessive sweating, heat intolerance
- frequent headaches and visual impairment
- muscle weakness/ fatigue
Clinical Manifestations of Hypopituitarism
CLASSIC PRESENTATION:
- normal intelligence
- short stature
- obesity
- immature facial features
- delayed/abnormal puberty
CONGENITAL:
- smaller length at birth, followed by slow growth
SIADH (syndrome of inappropriate antidiuretic hormone)
vasopressin (ADH) is secreted even when plasma osmolarity is low or
normal
- feedback mechanisms do not function properly
- water is retained, resulting in hyponatremia (decreased sodium level) -
-> volume is diluted
- may occur with disorders of the central nervous system, such as head
injury, brain injury or tumor, and infection
,Causes of SIADH
- malignancy
- pulmonary disorders: tuberculosis, asthma, cystic fibrosis, respiratory
failure
- head injury/ stroke/ brain infections
- surgery
- drugs: narcotics, anesthetics, antidepressants, antipsychotics, chemo,
NSAIDS
Hypopituitarism (DI)
- water metabolism problem caused by ADH deficiency --> polyuria
- related to dehydration, tends to drink 2-20 L of fluid daily
- increase in frequency of urination and excessive thirst (polydipsia)
- dehydration and hypertonic saline tests used for diagnosis of the disorder
- urine diluted with a low specific gravity (<1.005)
- increased SG means urine is more concentrated
- may occur secondary to head trauma, brain tumor, or surgical ablation or
irrigation of the pituitary gland
Neurogenic or Central Causes of DI
- lesions in the hypothalamus, infundibular stem, or posterior pituitary
- inflammation, autoimmune, vascular disease, heredity, head trauma
Nephrogenic Causes of DI
- adequate ADH, but decreased response to ADH at the kidneys
- congenital
- drugs: lithium toxicity, certain types of diuretics, antibiotics, anesthetics
- kidney problems: pyelonephritis, polycystic kidney disease
- electrolyte issues: hypokalemia and chronic hypercalcemia
- pregnancy
When ADH is LOW, we pee MORE and the urine that comes out is...
more diluted
Hematocrit
the ratio of the volume of red blood cells to the total volume of blood
fluid overload: DECREASED Ht
fluid deficit: INCREASED Ht
DI and SIADH patiemts present with...
excessive thirst
DI vs. SIADH
DI:
, - high urinary output
- low levels of ADH
- hypernatremia
- dehydrated
- lose too much fluid (fluid replacement, vasopressin)
SIADH:
- low urinary output
- high levels of ADH
- hyponatremia
- over hydrated
- retain too much fluid (fluid restriction, diuretic)
Thyroid Gland
- thyroid hormones: T3 and T4 also produce calcitonin
- iodine is contained in the thyroid hormone
- TSH from the anterior pituitary controls the release of the thyroid
hormone
- TRH from the hypothalamus controls the release of TSH
- thyroid hormone controls cellular metabolic activity
- T3 is more potent and rapid-acting than T4
- increase the metabolic rate, protein and bone turnover, and
responsiveness to catecholamines, necessary for fetal and infant
growth and development
- calcitonin is secreted in response to high plasma calcium levels and
increases calcium deposition in bone (lowers blood calcium levels)
Calcitonin
- maintains a strong bone matrix
- prevents calcium from leaving the bones
- inhibits calcium reabsorption from bone
- increases calcium storage in bone
- increases renal excretion of calcium
- calcitonin calcifies the bone!
T3
triiodothyronine
T4
thyroxine
Thyroid Hormones
- TSH
Exam Question and Answers Latest
Updates 2026 Graded A+
Posterior Lobe Pituitary Disorders
Hyperpopituitarism
- Syndrome of inappropriate antidiuretic hormone; SIADH
Hypopopituitarism
- Diabetes insipidus, DI
Clinical Manifestations of Hyperpituitarism
- enlargement and bony changes in hands, feet, face, and spine
- deepened voice due to increased size of larynx and respiratory tract
- cardiomegaly, atherosclerosis
- obstructive sleep apnea
- disorders of fat and carbohydrate metabolism
- excessive sweating, heat intolerance
- frequent headaches and visual impairment
- muscle weakness/ fatigue
Clinical Manifestations of Hypopituitarism
CLASSIC PRESENTATION:
- normal intelligence
- short stature
- obesity
- immature facial features
- delayed/abnormal puberty
CONGENITAL:
- smaller length at birth, followed by slow growth
SIADH (syndrome of inappropriate antidiuretic hormone)
vasopressin (ADH) is secreted even when plasma osmolarity is low or
normal
- feedback mechanisms do not function properly
- water is retained, resulting in hyponatremia (decreased sodium level) -
-> volume is diluted
- may occur with disorders of the central nervous system, such as head
injury, brain injury or tumor, and infection
,Causes of SIADH
- malignancy
- pulmonary disorders: tuberculosis, asthma, cystic fibrosis, respiratory
failure
- head injury/ stroke/ brain infections
- surgery
- drugs: narcotics, anesthetics, antidepressants, antipsychotics, chemo,
NSAIDS
Hypopituitarism (DI)
- water metabolism problem caused by ADH deficiency --> polyuria
- related to dehydration, tends to drink 2-20 L of fluid daily
- increase in frequency of urination and excessive thirst (polydipsia)
- dehydration and hypertonic saline tests used for diagnosis of the disorder
- urine diluted with a low specific gravity (<1.005)
- increased SG means urine is more concentrated
- may occur secondary to head trauma, brain tumor, or surgical ablation or
irrigation of the pituitary gland
Neurogenic or Central Causes of DI
- lesions in the hypothalamus, infundibular stem, or posterior pituitary
- inflammation, autoimmune, vascular disease, heredity, head trauma
Nephrogenic Causes of DI
- adequate ADH, but decreased response to ADH at the kidneys
- congenital
- drugs: lithium toxicity, certain types of diuretics, antibiotics, anesthetics
- kidney problems: pyelonephritis, polycystic kidney disease
- electrolyte issues: hypokalemia and chronic hypercalcemia
- pregnancy
When ADH is LOW, we pee MORE and the urine that comes out is...
more diluted
Hematocrit
the ratio of the volume of red blood cells to the total volume of blood
fluid overload: DECREASED Ht
fluid deficit: INCREASED Ht
DI and SIADH patiemts present with...
excessive thirst
DI vs. SIADH
DI:
, - high urinary output
- low levels of ADH
- hypernatremia
- dehydrated
- lose too much fluid (fluid replacement, vasopressin)
SIADH:
- low urinary output
- high levels of ADH
- hyponatremia
- over hydrated
- retain too much fluid (fluid restriction, diuretic)
Thyroid Gland
- thyroid hormones: T3 and T4 also produce calcitonin
- iodine is contained in the thyroid hormone
- TSH from the anterior pituitary controls the release of the thyroid
hormone
- TRH from the hypothalamus controls the release of TSH
- thyroid hormone controls cellular metabolic activity
- T3 is more potent and rapid-acting than T4
- increase the metabolic rate, protein and bone turnover, and
responsiveness to catecholamines, necessary for fetal and infant
growth and development
- calcitonin is secreted in response to high plasma calcium levels and
increases calcium deposition in bone (lowers blood calcium levels)
Calcitonin
- maintains a strong bone matrix
- prevents calcium from leaving the bones
- inhibits calcium reabsorption from bone
- increases calcium storage in bone
- increases renal excretion of calcium
- calcitonin calcifies the bone!
T3
triiodothyronine
T4
thyroxine
Thyroid Hormones
- TSH
