Endocrine System Part 3 Flashcards
Primary adrenal insufficiency (Addison’s disease)
Loss of adrenal cortical function
- Hyponatremia
- Hyperkalemia
- Low blood pressure
Adrenal Insufficiency
Cortisol - chronically lower than normal
Symptoms:
* Weakness
* Lethargy
* Loss of appetite
* Low blood pressure
* Cortisol permissive of epinephrine
* Low blood sugar
* Especially after fasting
* Loss of the normal metabolic actions of cortisol
Aldosterone normally:
- Promotes sodium (Na⁺) reabsorption
- Promotes potassium (K⁺) excretion
- Helps retain water (indirectly through sodium
retention) - Maintains blood pressure and blood volume
Cushing’s Syndrome
Excess cortisol in the blood, even when nonstressed
- Primary defect
E.g., a cortisol-secreting tumor of the adrenal - Secondary defect
Usually due to an ACTH-secreting tumor of the pituitary gland
In Cushing’s disease
Uncontrolled catabolism of bone, muscle, skin, and other organs
- Osteoporosis
- Muscles weakness
- Blood sugar increases to levels observed in diabetes mellitus
- Immunosuppression
- Redistribution of fat (buffalo hump and moon face)
- Hypertension (high blood pressure)
- Treatment of Cushing’s Syndrome depends on the cause.
- Surgical removal of the pituitary tumor
- Adrenalectomy
Major hormones
Growth hormone and “Insulin-like” growth factors
* Thyroid hormones
* Insulin
* Sex hormones (testosterone, estrogen)
* Cortisol (anti-growth effects)
Which two organs are mainly responsible for metabolizing or excreting hormones?
Kidneys and liver
Hormone secretion from the adrenal medulla is directly controlled by ______.
neural stimulation
Increased insulin secretion causes ______.
lowered blood glucose concentration
Peptide and catecholamine hormones exert their effects on target cells by ______.
influencing the generation of intracellular second-messenger molecules
The type of hyposecretion where the endocrine gland is not damaged but is receiving too little stimulation by its tropic hormone is called
_________ hyposecretion.
secondary
Anterior pituitary hormones that stimulate target glands to secrete their hormones are called
_________ hormones. They might also stimulate the growth of the target glands, an effect specifically referred to as a(n) ________ effect.
tropic
trophic
Hormones released by the anterior pituitary gland
Thyroid-stimulating hormone
Adrenocorticotropic hormone
Follicle-stimulating hormone
Luteinizing hormone
Prolactin
Hypophysiotropic hormones are neurosecretions released by the hypothalamus that influence the secretion of hormones from the anterior pituitary gland. Which of these are hypophysiotropic hormones?
Dopamine
Gonadotropin-releasing hormone
Somatostatin
Corticotropin-releasing hormone
Hormones (other than cortisol) that are released during stress include
vasopressin, ADH, or antidiuretic hormone and aldosterone
