BLOCK III - UNIT 1. Endocrine System Flashcards
What system is composed of various glands located throughout the body?
The endocrine system
The endocrine system has 5 general functions, what are they?
• Differentiate reproductive and central nervous systems in fetuses
• Stimulate growth and development during childhood and adolescence
• Coordinate male and female reproductive systems
• Maintain an optimal internal environment
• Initiate corrective and adaptive responses during emergencies
which system does a stimulus elicits the release of a substance; once the substance reaches a certain level, it sends a signal that stops further release of the substance?
Negative Feedback Loop/ system
What are the 3 mechanisms by which the endocrine glands are stimulated to synthesize and release hormones?
• Humoral stimuli
• Hormonal stimuli
• Neural stimuli
Hormones operate within what systems to maintain optimal internal environment?
negative or positive feedback systems
Hormones may be classified by what?
their structure, gland of origin, effects, or chemical composition.
What sits at the base of the brain and regulates hormones secretion from the anterior pituitary?
Hypothalamus
How is the Hypothalamus Connected to the anterior pituitary?
through the hypophyseal portal blood vessels
How is the Hypothalamus Connected to the pituitary gland?
by the infundibulum (pituitary stalk)
How is the Hypothalamus Connected to the posterior pituitary?
through a nerve tract
Which gland synthesizes and secretes hormones into the blood which then travel to target organs/glands to regulate physiological processes?
Anterior pituitary gland
What Secretes adrenocorticotropic hormone (ACTH )? And what organ does this hormone target?
Anterior pituitary gland, target organ is the adrenal cortex
What Secretes thyroid stimulating hormone (TSH)? And what organ does this hormone target?
Anterior pituitary gland, target organ is the thyroid gland
Which gland stores and releases antidiuretic hormone (ADH) and oxytocin?
Posterior pituitary gland
Which gland releases Antidiuretic Hormone (ADH)? And what organ does this hormone target?
Posterior pituitary gland, target organ kidneys
Light sensitive nerve cells in the retina detect light, the nerves then send signals through nerve fibers to the spinal cord up to which gland to release melatonin hormone?
pineal gland
What gland is located in the center of the brain?
Pineal gland
Which gland releases Melatonin hormone? And what does this hormone do?
-Pineal gland
-Melatonin is responsible for inducing sleep, regulating circadian rhythms, growth hormone releasing hormone, immune function, and ageing.
The thyroid is regulated through what?
A negative feedback loop
Thyrotropin is released from the hypothalamus into the hypothalamic-pituitary portal system and circulates to the anterior pituitary, where it stimulates the release of what hormone?
thyroid-stimulating hormone (TSH).
what releases the T3 and T4 into the blood so it can go to the targeted tissues?
thyroid-stimulating hormone (TSH)
What paired gland located behind the upper and lower poles of the thyroid gland?
parathyroid
Which gland produces a hormone that Regulates serum ionized calcium levels, Acts on the kidney to increase calcium reabsorption, and Decreases phosphate reabsorption?
parathyroid
What’s located behind the stomach and houses the Islets of Langerhans?
The pancreas
What is the hormonal organs that regulate the carbohydrate metabolism in the body?
the Islets of Langerhans
What is an antagonist to insulin that acts to increase blood glucose during fasting, exercise, and hypoglycemia?
glucagon
Alpha cells come from where and do what for the body?
Comes from the pancreas and secretes glucagon
Beta cells come form where and what do they secrete?
The pancreas, they secrete insulin and amylin
What promotes glucose uptake and use, glycogenesis, glycogenolysis, glycolysis, gluconeogenesis?
Insulin
What facilitates the intracellular transport of potassium (K+), phosphate, and magnesium?
Insulin
What glands are located close to upper pole of each kidney?
Adrenal glands
The cortex have 3 layers, what is the most outer layer?
Zona glomerulosa
What produces aldosterone which conserves sodium?
Zona glomerulosa (outer layer of adrenal glands cortex)
But so does Zona reticularis (inner) but in the notes the NA is specific for the glomerulosa
The cortex have 3 layers, what is the middle layer?
Zona fasciculata (middle layer of adrenal glands cortex)
What layer of the adrenal cortex secretes cortisol, cortisone, and corticosterone?
Zona fasciculata (middle layer of adrenal glands cortex)
What steroid hormones is released under stressful conditions and have metabolic, neurologic, anti- inflammatory, immunosuppressive, and growth-suppressing effects?
Glucocorticoids
The cortex have 3 layers, what is the inner layer?
Zona reticularis (inner layer of adrenal glands cortex)
What layer of the adrenal gland secretes aldosterone, androgen, estrogen and glucocorticoids?
Zona reticularis (inner layer of adrenal glands cortex)
What is stimulated by the anterior pituitary hormone; ACTH produces glucocorticoids released in response to stress?
Adrenal cortex
What stores and secretes the catecholamine’s epinephrine and norepinephrine to produce a quick response, “fight or flight.”?
Adrenal medulla
What is A complication related to the deficiency of insulin and the increase in catecholamine, cortisol, and glucagon?
Diabetic Ketoacidosis (DKA)
In the absence of insulin, the release of free fatty acids from adipocytes increases the production of what to do what?
ketone bodies to increase pH.
Which state is a result of insulin deficiency with the absence of ketosis?
Hyperglycemic Hyperosmolar State (HHS)
How long does it take DKA to develop?
1-2 days
What is likely to develop with Patients that are typically older or very young type 2 diabetics with other comorbidities?
HHS
Both HHS and DKA have what in common?
• Decreased glucose utilization; a lot of glucose in the bloodstream
• Increased gluconeogenesis; increased production of glucagon
• An increase in glycogenolysis; increased destruction of glucose molecules
The big differences between DKA and HHS are what?
• The presence of ketones in DKA
• DKA patient’s breath has a fruity odor due to the ketones
• Dehydration in HHS is more severe than in DKA
The big differences between DKA and HHS are what?
• The presence of ketones in DKA
• DKA patient’s breath has a fruity odor due to the ketones
• Dehydration in HHS is more severe than in DKA
A patient presents with the follow Sx, what is the Dx?
DKA
Patient presents with the following Sx, what is the Dx?
DKA
Patient presents with the following Sx, what is the Dx?
HHS
Why is monitoring for hypokalemia important for DKA/ HHS Tx?
Potassium moves into the cell with insulin
What is it called when the pituitary gland does not produce enough antidiuretic hormone?
Diabetes Insipidus
What happens when the pituitary gland does not produce enough antidiuretic hormone?
Insufficient antidiuretic hormone activity causes excretion of large volumes of dilute urine
You have a patient who is complaining of Polyuria, Nocturia (frequent urination at night), Thirst that is unresolved after oral replacement, Polydipsia ( about 8-12 L per day). What is the Dx?
Diabetes Insipidus
What is it called when too much ADH is secreted from the pituitary gland causing increased plasma volume/water retention?
Syndrome of Inappropriate Antidiuretic Hormone (SIADH)
Will Nephrogenic DI respond to DDAVP?
No, only Neurogenic DI will
SIADH can lead to what?
Hyponatremia (Serum sodium less than 135).
What can aid the renal tubules to develop resistance to ADH?
Demeclocycline (tetracycline)- an antibiotic, is used to treat SIADH in the absence of infection because it aids the renal tubules to develop resistance to ADH, may be used to treat resistant or chronic SIADH.
What is it called when there’s a Sudden release of T3 and T4 exceeds metabolic needs?
Thyroid storm/ Thyrotoxic Crisis
like giving the body jet fuel
What is it called when a patient is in An extreme hypothyroid state that can lead to a diminished consciousness?
Myxedema Coma
The TSH levels are increased with a decreased T3 and T4.
Why does Hypothermia happen in Myxedema Coma?
Hypothermia occurs because the decreased level thyroid hormone slows the body’s normal heat production
Why does Hyponatremia happen in Myxedema Coma?
hyponatremia occurs because there is decreased free water excretion
*Increased ADH from hypothyroidism induces a decrease in cardiac output because of less volume.
Adrenal Cortex disorders are characterized as
What?
hypocortisolism, which is a decreased serum cortisol level (adrenal steroids).
What is a life-threatening state caused by insufficient levels of cortisol?
Adrenal Crisis or Addisonian Crisis.
What can happen with Acute withdrawal of corticoids?
Adrenal Crisis or Addisonian Crisis.
results in crisis because the patient will have a sudden serum decrease of corticoids, causing a shock in the system
What is the Dx?
Adrenal Crisis or Addisonian Crisis.
What happens in primary adrenal cortex disorder ?
Adrenals are unable to secrete the adrenal hormones. Caused by adrenal gland insufficiency from an auto immune disorder
What happens in secondary adrenal cortex disorder ?
The pituitary is diminished or unable to secrete adrenocorticotropic hormone (ACTH) but has normal functioning adrenal glands and hypothalamus
What happens in tertiary adrenal cortex disorder ?
The hypothalamus is diminished or unable to secrete corticotrophin releasing hormone (CRH) but has normal functioning adrenal gland and pituitary glands
Low levels of cortisol can cause?
Complete vascular collapse and shock
