Endocrine Flashcards
What is glactorrhea? What is its cause?
Milk secretion in men or non lactating females. Most common cause a Prolactin secreting tumor- Prolactinoma
What is another name for the anterior pituitary gland?
Adenohypophysis
what is another name for the posterior pituitary gland
Neurohypophysis
Name the respective originating tissues for Adenohypophysis and Neurohypophysis
Epithelial tissue and nervous tissue
what are the six trophic hormones secreted by the Adenohypophysis.
TSH, ACTH, FSH, LH, GH, Prolactin
what are the hormones released by the hypothalamus ?
4 that stimulate are:
1. Corticotropin-releasing hormone (CRH) by acts on corticotroph in Adenohypophysis
2. Gonadotropin- releasing hormone (GnRh) acts on Gonadotroph in Adenohypophysis
3. Thyrotropin-releasing hormone (TRH) acts on throptrophs
4. Growth hormone-releasing hormone (GHRH) acts on somatotroph
2 inhibitory hormones :
Prolactin-inhibiting hormone (PIH, dopamine) acts on lactotrophs
Somatostatin inhibits somatotrophs
What does prolactin do and where is it secreted?
It promotes milk production in the mammary glands and is secreted by the anterior pituitary gland.
Are carcinomas of the pituitary rare?
YES !!! Caricinomas of pituitary are rare !!!
Begnin Tumors or Adenomas of the pituitary are they common?
Yes, Adenomas of the pituitary are common.
How are Adenomas of the pituitary dangerous ?
When the grow the exert mechanical pressure on the surronding brain structures.
What is the most common symptom of the pituitary Adenoma?
Excessive secretion of their hormones
What is the most common Adenoma and what are the symptoms
Prolactinomas -> excessive prolactin leads irregular menstral cycles or completely stoped, amenorrhea, low libido, low infertilty. Men may experience impotence and loss of libido. These are the symptoms with functional prolactinomas.
What is the name of the small bony structure that craddles the pituitary gland?
Sella Turcica
Are prolactinomas the only thing that can cause galactorrhea, if not what are the examples
Anything that would interrupt the production of PIH like High doses of Estrogen Therapy and some drugs.
What is the second most common Adenoma?
Non-functional adenomas, or Null cell Adenomas.
Symptoms are due to growing mass pushing against
surrounding structures rather than excessive hormone production.
Name the two types of organs that the pituitary acts on
Organs that have endocrine activiteis, adrenal, thyroid, ovary and testis and nonendocrine organs, like breast , uterus, kidney, bone, and muscle.
When there is too much GH in children…
It causes Giganticism
When there is too much Gh in Adults
It causes Acromegaly
What are the S/S of Acromegaly
Extra large hands, feet, face, skull, jaw, liver, heart, thyroid, adrenal gland, and other viscera. Expansion of the skin and soft tissue.
Associated with ACromegaly Secondary Type II diabetes, hypertension, muscle weakness, heart failure, arthritis, and osteoporosis.
What are least common Adenoma of the pituitary glans
Tumors of gonadotrophs and thyrotrophs
What are causes of Hypopituitarism
Masses (tumors or Cysts) i. pituitary ii. Suprasellar (mostly hypothalamus iii. metastatic Ishemic infarction (Sheehan Syndrome) Inflammation or infection (usually chronic) Brain Trauma Surgical ablation of a tumor Radiologica ablaction of a tumor
What hormones do the posterior pituitary gland secrete
The neurohypophysis secretes ADH and oxytocin
what is another name for hyposecretion of ADH
Diabetes Insipidus
what is another name for Hypersecretion of ADH
SIADH, Syndrome of inappropiate Anti-Dieuretic Hormone
What is the unique characteristic of Oxytocin Abnormalities?
They are unknown.
What does deficiency of ADH cause ? Why?
Polyuria and Polydypsia. Because ADH concentrates Urine so w/o enough ADH, there will be more HOH in Urine need to urinate which results in dehydration, need to drink polydypsia.
What would be the blood sodium and blood osmality in the case of Diabetes Insipidius. Why?
Both would be would be high because of the frequent urination which indicates that not enough HOH is being reabsorbed during the kidney filtration process.
What are the two different pathogenosis of Dibates insipidus?
A. Central: insufficient ADH secretion
B. Nephrogenic: defective ADH receptors in the kideneys.
How does ADH reabsorb HOH?
By the insertion of aquaporins in the collecting ducts. they bind to receptors in teh plasma membrane that buds off from the golgi complex. Similar to the the eay insulin works by the insertion of glut..
How is the urine in the abscence of ADH?
Very dilute. WHY? It cannont be concentrated in absence of ADH.
Which type of ADH deficiency can be treated by Exogenus ADH and WHY
Central Diabetes insipidus.
What happens in SIADH
With too much ADH secretion, the body is unable to regulate HOH balance. There will be too much HOH. W/O ADH the body retains or reaborbs HOH and Urine becomes super concentrated. Blood sodium and blood osmality dropp, causing cerebral edema, neurological disturbances , coma and death. WHY
What are the exacerbations of SIADH
Blood Na and blood osmolality drop dangerously low. causing cerebral edema, cytotoxic edema, leading neurological distrubances, coma and death. Water in blood not URINE !!!!
In most cases of SIADH where is the tumor that secretes the excessive amounts of ADH.
In an non pitiuitary tumor (one in the lungs)
What are the S/S of Cushing Syndrome
facial hair, acne, a moon face, stretch marks, and truncal obesity, high blood pressure, appeared depressed and irritable, urinating frequently and always thirsty , legs very thin and bruised marks.
enlargment of heart, glycosuria, and secondary diabetes due to reduced sensitivity of cells to insulin, suppressed immunity
Habitus is a strong indicator.
What is the Most common cause of elevated blood cortisol?
Exogenous administration of corticsteroids.
How is Primary Cushing Syndrome produced?
EXcessive amounts of corticol by tumors or hyperplasia of the adrenal cortex that act autonomously w/out influcence by ACTH.
Name the three causes for Primary Cushing Syndrome
- Benign tumors of the Adrenal Cortex
- Carinomas of the Adrenal Cortex
- Primary Adrenocortical Hyperplasia.
What would the lab report look like for Primary Cushing Syndrome?
It would be High levels or Cortisol, Aldosterone and low levels of ACTH.
