Endocrine Pathology Flashcards
(98 cards)
Organs of the Endocrine System
Pituitary gland • Thyroid gland • Parathyroid gland • Adrenal gland • Pancreas
Hypothalamus
— coordinating center
- Temperature regulation
- Food intake
- Thirst and water intake
- Sleep and awake patterns
- Emotional behavior
- Memory
Hypothalamic-pituitary axis
Involves the Thyroid gland, Adrenal glands, and Gonads
CRH (hypothalamus) –> ACTH –> cortisol (cortisol negatively feedbacks on both CRH and ACTH)
- Influences growth
- Milk production
- Water balance
General Terms in Endocrine disorders
Hypo-secretion — Hormone deficiency
Hyper-secretion — Hormone excess
Tumors — benign or malignant
Major Pituitary Gland Disorders
Acromegaly,
Diabetes insipidus,
Hypopituitarism,
Pituitary tumor
Major Anterior Pituitary Hormones
ACTH (adrenal cortex) salt and water balance, BP, blood sugar levels, muscle
strength, mood, immune system, heart, lungs, blood vessels, nervous system
o TSH = thyroid metabolism
o GH =strong bones, lean muscle, protein production
o MSH = smooth firm skin (MSH)
o FSH, LH (gonadotropins) = testes and ovaries for sex characteristics and libido
o Prolactin = breast milk production
Major Posterior Pituitary Hormones
ADH (kidney) =water retention, blood pressure
Oxytocin = muscle contraction (breast)
*note that the posterior pituitary does not PRODUCE hormones but stores hormones made in the hypothalamus
List of Pituitary Hormones
TSH — Thyroid stimulating hormone (thyrotropin)
- PRL — prolactin
- ACTH — adrenocorticotropic hormone (corticotropin)
- GH — growth hormone (somatropin)
- FSH — follicle stimulating hormone
- LH — luteinizing hormone
- MSH — melanocyte stimulating hormone
Stimulatory releasing factors (hypothalamus)
- TRH — thyrotropin releasing hormone
- CRH — corticotropin releasing hormone
- GHRH —growth hormone releasing hormone
- GnRH — gonadotropin releasing hormone
Inhibitory hypothalamic influence
- PIF — prolactin inhibiting factor
- GIH — growth inhibiting factor (somatostatin)
Hyperpituitarism — tumors
- Excess
- Adenoma, hyperplasia, carcinoma of the anterior pituitary
Hypopituitarism — small injury
- Deficit
- Destructive processes, ischemic injury, surgery, radiation, inflammatory reactions and
nonfunctional adenomas
Types of Pituitary Tumors
Adenomas (most common)
Proclatinomas
Non-functional Pituitary Adenomas
tend to be larger than those that secrete hormone
- Start out slow growing and don’t have any symptoms
- But eventually become very large
- Compress everything around it
- Thus symptoms in the beginning may not be associated with a tumor!
Compresses the optic nerve –> tunnel vision, headaches, etc
Tunnel vision = bilateral (always) compression of the optic nerve, so no peripheral vision
Secreting Pituitary Adenomas
Can effect the following cells and cause these syndromes
Lactoproh > Prolactin > Galactorrhea, Amenorrhea, Infertility
Somatotroph > GH and Prolactin > Gigantism and Acromegaly
Corticotroph > ACTH > Cushing syndrome and Nelson syndrome
Thyrotroph > TSH > Hyperthyroidism
Gonadotroph > FSH, LH > Hypogonadism and Hypopituitarism
most common alterations in pituitary adenomas
G-protein mutations
- G-proteins play a critical role in signal transduction
- G-protein hyperactivity
Gigantism
Hyperpituitaryism
Adenoma appears in children BEFORE the epiphyses have closed
Increase in body size with disproportionally long arms and legs
Acromegaly
Excessive secretion of growth hormone AFTER BONESN ALREADY FORMED (adulthood)
- Excessive growth of hands, legs, soft tissues
- Protruding jaws
- Enlargement of organs
Compression from an adenoma will create different problemsin different parts of the body - Certain body parts can’t expand anymore!!
Common signs and symptoms:
- Headaches, vision changes, hypertension, heart enlargement (from greater demand),
pulmonary problems, glucose intolerance (T2D associated with it), pain in joints,
difficulty with mobility
- Main characteristics are in the extremities
- Chief complaint at dentist = “my profile is changing and my teeth are shifting/getting
more spaces”
o Teeth get more spacing because the jaw is growing
Effects of Excess Growth Hormone in the body
Gonadal dysfunction
Diabetes mellitus
Muscle weakness
Hypertension
Arthritis
Congestive heart failure
Increased risk of GI cancer
GH regulates IGF, which is primarily secreted in the liver
- This will affect different parts of the body depending
on when the problem occurred
- Specifically, it affects bone metabolism and growth
Corticotroph adenomas
Secrete ACTH
Main characteristics:
- Cushing syndrome
- Hyperpigmentation
Cushing syndrome
Excessive production of ACTH — Cushing disease
The various causes of Cushing’s syndrome:
- 1. A pituitary tumor makes ACTH, which stimulates production of cortisol by the adrenal
gland. High cortisol levels inhibit CRH secretion and ACTH secretion from normal
pituitary cells
- 2. Ectopic ACTH secretion —a non-pituitary tumor makes ACTH, which stimulates
production of cortisol by the adrenal gland. High cortisol levels inhibit CRH secretion and
ACTH secretion from normal pituitary cells
- 3. Primary adrenal disease —adrenal glands independently make too much cortisol.
High cortisol levels inhibit CRH secretion and ACTH secretion from normal pituitary cells
Key
Most common is anterior lobe pituitary adenoma
Macroadenomas and microadenomas
Functioning – associated with endocrine signs and symptoms
Non-functioning — mass effects, visual disturbances
- Slow growing and can get very big
- First symptoms will be visual disturbances and headaches
Hypopituitarism
Low secretion of hormones Diseases of the hypothalamus or of the pituitary - Destructive disorders - Tumors/mass lesions - Traumatic brain injury - Surgery or radiation - Apoplexy - Ischemic disorders and Sheehan syndrome - Cyst - Hypothalamic lesions - Inflammatory disorders and infections
Sheehan syndrome
due to ischemic necrosis
- During pregnancy gland size increases
- If obstetrical hemorrhage occurs, relative hypoxia compromises gland
- Can also occur in DIC, sickle cell, meningitis, inflammatory disorders, and sarcoidosis
o Sickle cells can obstruct blood vessels
Anterior Pituitary Hypofunction
Clinical manifestations GH deficiency — growth failure LH and FSH —amenorrhea and infertility PRL — failure of postpartum lactation TSH and ACTH — hypothyroidism and hypoadrenalism
Diabetes Insipidus
Insufficient production of Anti-diuretic hormone
- Excessive thirst and excretion of large amounts of urine
- Thirst, blurred vision, dehydration, extreme urination, fever, diarrhea, and vomiting
Etiology — Central diabetes insipidus
- Pituitary surgery, Craniopharyngioma, Post-traumatic head injury, Congenital malformations, Genetic mutations, Autoimmune disorders, Medications (phenytoin),Cerebrovascular accident (CVA, stroke)
Etiology – Nephrogenic diabetes insipidus
- Medications (long term lithium, cisplatin, propoxyphen)
- Chronic diseases — sickle cell anemia, renal sarcoidosis, poorly controlled diabetes
mellitus
Thyroid Gland
Abnormalities in the anterior pituitary or the thyroid gland itself can result in abnormal thyroid hormone production
Thyrotropin releasing hormone (from hypothalamus) >> thyroid stimulating hormone (from anterior pituitary) >> thyroid hormone (from thyroid gland, has direct effect on gland)
3 hormones —T4, T3, Calcitonin Needed for: - Growth and maturation of tissues - Cell respiration - Energy expenditure