endocrine Flashcards
Endocrine System basic functions
Maintain metabolic equilibrium (homeostasis)
* Secrete chemical messengers (hormones)
* Regulate activity of various organs
how is the endocrine system regulated
feedback loops
- Process of feedback inhibition
- Increased activity of target tissue, typically down-regulates activity of gland secreting stimulating hormone**
- Endocrine diseases
a. hormone production?
b. diseases associated with development of?
a. diseases of under/over-production of hormones
b. diseases associated with development of mass lesions
Classification of Endocrine Diseases
- Too Little
- Too Much
- Other: Tumors
functional tumors
tumors of endocrine glands, whether benign or malignant, may secrete the hormone native to the gland. Such
tumors are said to be “functional” tumors. It may be the mass effect
of the tumor or the metabolic effect of the excessive hormone that
calls attention to the tumor.
Pituitary gland
where located?
connection?
role?
components?
how dx are divided?
- Base of brain-sella turcica
- Connected to hypothalamus
a. stalk composed of axons
b. venous plexus - Central role in regulation of other endocrine glands
- Two components
a. anterior lobe (adenohypophysis)
b. posterior lobe (neurohypophysis) - Diseases divided according to lobe mainly affected
ant and post additonalt names
ant: adenohypophysis
post: neurohypophysis
what do the produce?
cells of the adenohypophysis
Somatotrophs: Produces growth hormone
* Lactotrophs: Produces prolactin
* Corticotrophs: Produces adrenocorticotrophic hormone
* Thyrotrophs: Produces thyroid simulating hormone
* Gonadotrophs: Produces follicle stimulating hormone and luteinizing
hormone
hormones of the neurohypophysis
ADH and oxytocin
dx of the ant pituitary
a. Decreased/increased secretion of trophic hormones
b. Hypopituitarism/hyperpituitarism
Hypopituitarism causes
a. Destructive lesions/processes –ischemia, radiation, inflammation, neoplasms
local effects of the cause?
Hyperpituitarism cause
Hyperpituitarism
a. Functional adenoma within anterior lobe
b. Local mass effects –enlargement of sella turcica, visual field abnormalities, increased intracranial pressure
Hypopituitarism can result from?
- Pituitary Adenomas
- Radiation Treatment
- Neurosurgery
- Sheehan Syndrome/ Ischemic necrosis of pituitary gland
growth? fertility? sex? lactation? thyroid? adrenal?
Clinical Manifestation:
Hypopituitarism
- Pituitary Dwarfism
- Amenorrhea & Infertility
- Libido & Impotence
- Postpartum lactation failure
- Hypothyroidism
- Hypoadrenalism
Hyperpituitarism can result from?
- Pituitary Adenomas
- Pituitary Hyperplasia
- Pituitary Carcinomas
- Hypothalamic disorders
Possible clinical Manifestations of Hyperpituitarism
- Gigantism
- Acromegaly
- Cushing disease
usual cause? affects? when?
gigantism
- Primary tumor causing Excess growth hormone (GH)- Adenoma of anterior pituitary
- 2nd most common form
- Affects all “growing tissues”
- Gigantism- before growth
plate closure
head? fatique? bones/joints? bp? heart?
gigantism signs
*Generalized overgrowth= 3 standard deviations
*Headaches
*Chronic fatigue
*Arthritis, osteoporosis
* Muscle weakness
*Hypertension
*Congestive heart failure
when is it diagnosed? vision? enlarged?
acromegaly
- Late diagnosis, excess GH after plate closure
- Poor vision; photophobia
- Enlarged skull, hands, feet, ribs
- Soft tissue, viscera
- Enlarged maxilla, mandible, nasal and frontal bones, maxillary sinus
- Intraoral signs of acromegaly
- Diastemas
- Malocclusion
- Macroglossia
- Enlarged lips
- Sleep apnea
- open bite
classic acromegaly
Posterior Pituitary dx
- Diabetes Insipidus (Central)
- Secretions of Inappropriately High
Levels of ADH (SIADH)
- Diabetes Insipidus (Central) signs
- Polyuria
- Dilute urine
- Polydipsia