Endocrine and Hepatobiliary Flashcards
_____ system
• Maintain metabolic equilibrium (homeostasis)
• Secrete chemical messengers (hormones)
• Regulate activity of various organs
• Process of feedback inhibition
• Increased activity of target tissue, typically down-
regulates activity of gland secreting stimulating
hormone
•diseases
a. diseases of under/over-production of hormones
b. diseases associated with development of mass
lesions
Endocrine System
• 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
Pituitary gland
• Produces growth hormone
• Somatotrophs
• Produces prolactin
• Lactotrophs
• Produces adrenocorticotrophic hormone
• Corticotrophs
• Produces thyroid simulating hormone
• Thyrotrophs
• Produces follicle stimulating hormone and luteinizing
hormone
• Gonadotrophs
- Pituitary Adenomas
- Radiation Treatment
- Neurosurgery
- Sheehan Syndrome
- Ischemic necrosis of pituitary gland
- Pituitary Dwarfism
- Amenorrhea & Infertility
- Libido & Impotence
- Postpartum lactation failure
- Hypothyroidism
- Hypoadrenalism
Hypopituitarism
- Pituitary Adenomas
- Pituitary Hyperplasia
- Pituitary Carcinomas
- Hypothalamic disorders
- Gigantism
- Acromegaly
- Cushing disease
Hyperpituitarism
• Primary tumor • Excess growth hormone (GH) • Adenoma of anterior pituitary • 2nd most common • Affects all “growing tissues” • Gigantism- before growth plate closure
Hyperpituitarism
•Generalized overgrowth• 3 standard deviations •Headaches •Chronic fatigue •Arthritis, osteoporosis • Muscle weakness •Hypertension •Congestive heart
Gigantism
• Late diagnosis • Poor vision; photophobia • Enlarged skull, hands, feet, ribs • Soft tissue, viscera • Enlarged maxilla, mandible, nasal and frontal bones, maxillary sinus • Intraoral: • Diastemas • Malocclusion • Macroglossia • Enlarged lips • Sleep apnea
Acromegaly
\_\_\_\_\_\_\_ pituitary issues: • Diabetes Insipidus (Central) • Polyuria • Dilute urine • Polydipsia • Secretions of Inappropriately High Levels of ADH (SIADH) • Hyponatremia • Cerebral edema • Neurologic dysfuction • Total Body Water • Blood volume normal • No peripheral edema
Posterior pituitary
____ controls TSH secretion
TRH
_____ controls T3 and T4 production
TSH
What 3 things are responsible for thyroid function? (glands)
Hypothalamus
Pituitary
Thyroid
What 3 things are responsible for thyroid function? (glands)
Hypothatlamus
Pituitary
Thryoid
\_\_\_\_\_ hypothyroidism • Intrinsic abnormality in the thyroid • Surgery • Radiotherapy • Autoimmune
Primary
_____ hypothyroidism
• Pituitary failure
Secondary
- Adult
- Generalized fatigue
- Apathy
- Mental sluggishness
- Listless
- Cold intolerance
- Overweight
Myxedema
• Childhood • Impaired skeletal development • Severe mental retardation • Short stature • Course facial features • Delayed tooth eruption
Cretinism
Symptoms of ______:
- Cold intolerance
- Fatigue, lethargy
- Weight gain
- Constipation
- Bradycardia
Hypothyroidism
• Autoimmune • Painless enlargement • Symmetric & diffuse • Risk of B-cell non- Hodgkins Lymphomas
Hashimoto thyroiditis
Clinical signs and symptoms Goiter (small) Exophtalmus (frequent) Heat intolerance Weight loss Malabsorption and diarrhea Tachycardia Irritability and anxiety Most common causes Autoimmune - Graves’ disease and Hashimoto’s thyroiditis Laboratory T4 and Free T4 elevated T3 and Free T3 elevated TSH and TRH suppressed
Hyperthyroidism
Symptoms of _____:
- Weight loss
- Nervousness
- Rapid pulse
- Goiter
- Muscle wasting
Hyperthyroidism
- Tachycardia
- Increased appetite
- Weight loss
- Exophthalmos
- Intolerance to heat
Graves disease
• Diagnosis • TSH • Primary-low • Secondary- normal to high • T4 (T3) increased • Treatment • Ablation • Significance • Thyroid storm • Caused by infection, stress, trauma • Elevated body temp. • Tachycardia • 20-40% mortality
Graves disease
• Thyroid enlargement • Impaired synthesis of thyroid hormone • Iodine deficiency • Endemic • Hyperplasia of follicles • Pituitary stimulation • Maintenance of minimal function (euthyroid) • Diffuse early on, then nodular • Diet deficient in iodine • Decreased output of T3 & T4 by thyroid • Pituitary responds by secreting TSH • Thyroid hyperplasia
Goiter
Derived from developing pharyngeal pouches
Lie in close proximity to upper and lower poles of each thyroid
lobe
May be found on path of descent of pharyngeal pouches –
carotid sheath, thymus, anterior mediastinum
Secrete Parathormone (PTH) which, with calcitonin regulates
calcium homeostasis –controlled by the level of free (ionized)
calcium
Parathyroid gland
_____: Activates osteoclasts activity
Increases Ca renal tubular resorption
Increases conversion of Vit. D into the active
dihydroxy form in the kidneys
Increases urinary excretion of phosphates
Increases Ca absorption by the GI tract.
PTH: