Pathophys EXAM 2

Pituitary gland

resides inside the sella turcica of the sphenoid bone. Connects to the hypothalamus via the infundibulum

Pituitary neuroendocrine tumor

causes headaches:

• presses on surrounding tissue and optic chiasm causing visual disturbances and headaches.

Bitemporal Hemianopsia

loss of visual field because of resulting damage of a tumor pressing on optic chiasm

surgical removal of a bitemporal hemianopsia is done one of two ways

can be done transsphenoidal or transcranial

ADH hormone

conserves water in body

ADH synthesized

supraoptic and paraventricular nuclei of hypothalamus

ADH Stored

in posterior pituitary; stored and released

Receptors for ADH

on principal cells in collecting ducts of kidneys

Diabetes Insipidus

body cannot preserve water because of no ADH; results in high amounts of dilute urine produced, dehydration, and increased thirst

DI- Neurogenic

not enough ADH released or produced

DI- Nephrogenic

kidneys don’t respond to ADH

Polyuria

excessive amount of urine

Polydipsia

excessive thirst

Extracellular Sodium Concentration

135-145 mEq/L

SIADH

high amounts of ADH; kidneys hold lots of water

• can be caused by cancer, brain injury, CNS infection, surgery, or medications

Hyponatremia

excess water dilutes na in the blood; treatment is a fluid restriction

Pituitary Giantasm

GH-oma that overproduces growth hormone

Acromegaly

GH-oma that overproduces growth hormone when the epiphiseal plates have already closed

• enlarged jaw, forehead, and tongue. Increased bone density. Enlarged hands and feet. Increased insulin resistance. and increase sebaceous and sweat gland activity.

Pituitary Dwarfism

Growth hormone deficiency that results as short stature.

Hormone Addition: stimulates bone growth, tissue growth, increased height, helps growth to occur at a normal rate.

Thyroid Horome pathway

Hypothalamus secretes TRH (thyrotropin-releasing hormone)

Anterior Pituitary secretes TSH ( Thyroid stimulating hormone)

Thyroid Gland secreted T3/T4 (follicular cells)

which thyroid hormone is most biologically active

T3

Thyroid hormone activity

increases metabolic rate, O2 consumption, and heat production

Negative Feedback when increasing TH

hypothalamus less TRH, anterior pituitary less TSH, and thyroid gland less TH

Negative Feedback when decresing TH

Hypothalamus more TRH, Anterior pituitary more TSH, and Thyroid gland more TH

Thyroid ATROPHY

reduced stimulation or autoimmune destruction of tissue

Thyroid HYPERTROPHY

prolonged TSH stimulation or graves disease, or iodine deficiency

GOITER causes

graves disease, iodine deficiency, hashimotos, and prolonged TSH stimulation

Primary Hyperthyroidism

overreactive thyroid suppresses the TSH release

Secondary Hyperthyroidism

overreactive thyroid is due to the pituitary gland overstimulating TSH release

Graves Disease

autoimmune disease that over stimulates TSH release

• symptoms: weight loss, decreased appetite, rapid heartbeat, sweating, goiter, and eye bulge.

Treatment: antithyroid medications, radioactive iodine, and thyroidectomy.

Hypothyroidism

not enough TH produced

• symptoms; fatigue, weight gain, cold intolerance, decreased heart rate and difficulty concentrating

Treatment; Levothyroxine- synthetic T4

Congenital hypothyroidism

TH deficiency present at birth; underdeveloped/absent thyroid gland.

INSULIN

-made by beta cells

-increases glucose transport into cells, decreases blood glucose, and enhances protein synthesis

Diabetes mellitus

symptoms; polyuria, polydipsia, and polyphagia; excessive hunger

Type I Diabetes mellitus

insulin dependent, juvenile onset, b-cells that make insulin in pancreas are destroyed- no insulin made

• causes: HLA-DR3/ HLA-DR4

Type II diabetes mellitus

non-insulin dependent, adult onset, b-cells still make insulin. Insulin receptors are just desensitized.

• causes: obesity

Acute affects of no insulin

increased blood glucose, dehydration, and fat breakdown.

Hypoglycemia adremic response

anxiety, sweating, tremor, tachycardia, and weakness

Hypoglycemia neurological response

disorientation, convulsation, unconsciousness, and shock.

Hormones that increase blood sugar

growth hormone, epinephrine, cortisol, and glucagon.