Endocrine System Flashcards
What are 5 functions of the endocrine system?
- Differentiation of the reproductive and central nervous system fetus
- Stimulation of sequential growth and development
- Coordination of the male and female reproductive
- Maintenance of an optimal internal environment
- Initiation of corrective and adaptive responses
The endocrine system is a system of ___
Glands
What is the endocrine system stimulated by?
-Central Nervous System
-Physiologic state
____ are produced, secreted, and sent to the site of action
Hormones
____ are highly specific to each hormone
Receptors
____ refers to the “fit” of the receptor and the ligand
Specificity
Receptors and ligands are similar to a ___ and ___ mechanism
Lock and key
_____ is the strength of the attraction between the ligand and the receptor
Affinity
___ ____ is the production of more receptors when more hormone is needed
Up-regulation
With down-regulation, less _____ are expressed so there is less protein and less action
Receptors
____ is when the presence of one hormone permits or impacts the effectiveness of another hormone (ex: high thyroid hormone makes more receptors for epinephrine)
Permissiveness
Hormones are made in one place and released into the ____ where they can travel to a distant cell where they have their action
Bloodstream
There are ___ soluble and ____ soluble hormones
Water and lipid
Hormone release is controlled via ___ ___
Feedback loops
With a ___ feedback loop, hormone release is inhibited by some other action or substance
Negative
One example of a negative feedback loop is ____, in which high levels shut off additional production
Cortisol
With a ____ feedback loop, something stimulates the release of more hormone
Positive
One example of a positive feedback loop is ____ release during breastfeeding; the pituitary releases it and stimulates milk production and so as long as the baby keeps suckling, it will continue to be released
Oxytocin
Mechanism of the physiological axis:
The hypothalamus stimulates the pituitary gland which stimulates either the thyroid, adrenal, or gonad gland
The ____ links the brain to the endocrine system and the rest of the body
Hypothalamus
The hypothalamus is important for ___ ___ ___ function and also provides feedback and produces hormones
Autonomic nervous system
____ will stimulate the anterior pituitary gland
Neurohormones
The formal endocrine glands include…
-Pituitary (anterior and posterior)
-Thyroid
-Adrenals
-Gonads
-Endocrine pancreas
Hormones released by the anterior pituitary (adenohypophysis) include…
-ACTH
-TSH
-FSH
-LH
-Prolactin
-Growth hormone
-Melanocyte-stimulating hormone
-Lipotropin
-Endorphins
Hormones released by the posterior pituitary (neurohypophysis) gland:
-Oxytocin
-Arginine
-Vasopressin
Hormones released by the thyroid gland:
-Thyroxine (T4)
-Triiodothyronine (T3)
Mechanism of the hypothalamus-pituitary-thyroid (HPA) axis:
-The hypothalamus secretes TRH
-TRH stimulates TSH production and release
-TSH stimulates T3 and T4
Thyroxine (T4) makes up ___% of circulating hormone and will be converted to T3
90
Triiodothyronine (T3) is ___ ___
Biologically active
___% of triiodothyronine (T3) is released from the endocrine gland, and the remaining is converted from T4 in the periphery
15%
What are 4 functions of the thyroid hormone?
- Increases cellular metabolism
- Increases blood pressure maintenance
- Some growth functions (skeletal)
- Temperature maintenance (primarily increases)
Adrenal glands are located above the ___ on either side
Kidneys
Adrenal glands get stimulus from the ____
Pituitary
The adrenal glands are a very ____ structure
Vascular
The adrenal gland is broken up into different ____ that make different hormones
Zones
The ____ is the outer layer of the adrenal gland
Cortex
The cortex of the adrenal gland contains the ___ ____, which is the outermost layer
Zona glomerulosa
The zona glomerulosa produces mineralocorticoides like ____
Aldosterone
The cortex also contains the ___ ____ (one layer in from the glomerulosa)
Zona fasiculata
The zona fasiculata produces things like ____, which helps with low blood pressure and also regulates the autonomic nervous system
Cortisol
The ___ ___ is the next innermost layer
Zona reticularis
The zona reticularis produces ___ ___
Androgenous steroids (sex hormones)
____ are produced in the medulla
Catecholamines
The ___ axis functions in the production of cortisol
HPA
Gonads are very important for ___ ___
Reproductive function
In the HPA axis, the hypothalamus is ____, the pituitary is ____ and the thyroid, adrenal, and gonal are ____
Tertiary, secondary, primary
Syndrome of ____ ___ ____ causes increased secretion of the hormone which leads to excess water retention which leads to hyponatremia and hypervolemia
Inappropriate antidiuretic hormone
Syndrome of inappropriate antidiuretic hormone is caused by ____ ____ dysfunction
Posterior pituitary
Syndrome of inappropriate antidiuretic hormone can be caused by…
-Tumors
-Head trauma
-Medications
____ ___ is caused by decreased posterior pituitary function
Diabetes Insipidus
What are the two types of diabetes insipidus?
-Neurological DI
-Nephrogenic DI
Neurological diabetes insipidus can be seen in people with high ____ consumption
Alcohol
Nephrogenic diabetes insipidus can be caused by poor binding of receptors and this can be seen with ___ ___
Renal transplant
With diabetes insipidus, people don’t have enough ___ ___ ____ which leads to too much water being excreted, highly concentrated blood, and hypernatremia
Antidiuretic hormone
What hormones are produced by the anterior pituitary gland?
-ACTH
-TSH
-FSH
-LH
-Prolactin
-Growth hormone
-
With ____, there is too much production of thyroid hormones which ramps up the metabolic rate and oxygen consumption
Hyperthyroidism
What are some possible causes of hyperthyroidism?
-Graves disease (autoimmune disorder)
-Adenoma (benign tumor of the gland)
-Thyroiditis (inflammation of the thyroid gland)
-Overtreatment of hypothyroidism
-Sudden discontinuation of antithyroid meds
-Iodine overload
What are some manifestations of hyperthyroidism?
-Tachycardia
-High sweat output
-Increased growth and development
-Anxiety
-Heat intolerance
-Diarrhea
-Bulging eyes
-Goiter
-Dyspnea
-Weight loss
A hyperthyroid crisis, also known as a ___ ___, can be caused by pre-existing hypersecretion, stress, or increased catecholamine receptors
Thyroid storm
A thyroid storm causes sudden onset of ____ symptoms
Hyperthyroid
With ____, there is not enough production of thyroid hormone
Hypothyroidism
What are some possible causes of hypothyroidism?
-Surgical removal of the gland
-Tertiary disorders of the hypothalamus
-Secondary disorders of the pituitary
-Primary disorders of the thyroid gland
-Hashimoto’s
-Pituitary radiation or removal
Manifestations of hypothyroidism include…
-Bradycardia
-Lethargy
-Decreased level of consciousness
-Coma
-Hypothermia
-Hypoventilation
-Decreased GI motility
-Constipation
-Weight gain
____ ____ is a primary disorder of the thyroid gland
Myxedema coma
Myxedema coma can be caused by ____ with pre-existing hypothyroidism (low-level hypothyroidism, commonly undiagnosed)
Stress
What are manifestations of myxedema coma?
-Extreme hypothyroid state
-Lowered metabolic rate (severe)
-Altered mental status
-Hypothermia
-Hypoglycemia
-Hypotension
-Hyponatremia
-Bradycardia
-Hypoventilation
Interstitial accumulation of _____ may cause myxedema
Mucopolysaccharide
____ ____ ____ is an adaptive response
Sick euthyroid syndrome
With sick euthyroid syndrome, rather than ___ being converted to ___, it is converted to ___
T4 to T3; rT3
rT3 is identical to T3 except flipped in conformation which makes it ___ ___
Biologically inactive
In hospitalized patients, we often see low ___ but high ___ because there is less metabolic driving hormone which explains why we rent and heal while we are sick
T3; rT3
With sick euthyroid syndrome, we see ____ levels of thyroid stimulating hormone
Normal
What can stimulate sick euthyroid syndrome?
-Fasting
-Sepsis
-Trauma
-Burns
-Cardiopulmonary bypass
-Malignancy
-Heart failure
-Myocardial infarction
-Hypothermia
-Chronic renal failure
-Cirrhosis
-Diabetic ketoacidosis
What are two adrenal hormones produced by the pituitary?
-Cortisol
-Aldosterone
Adrenal insufficiency is also known as ___ ___
Addison’s Disease
Addison’s Disease causes sudden and severe drop in ___ ___
Hormone levels (aldosterone and cortisol)
Many times, Addison’s Disease goes ____ until it is far gone and severe
Undetected
Possible causes of Addison’s Disease (adrenal insufficiency) include…
-Decompensation in patients with chronic adrenal insufficiency
-Destruction of the adrenal glands
-Discontinuation of corticosteroid therapy
-Kidney injury
-Genetic disorders
-Pituitary disorders
-Pituitary of Hypothalamus damage
-Infection
What are some clinical presentations of Addison’s Disease?
-Hypoglycemia
-Hypotension
-Hyponatremia
-Hyperkalemia
-Hyperpigmentation
____ causes elevated cortisol levels in the body
Hypercortisolism
What are two possible causes of hypercortisolism?
-Exogenous glucocorticoid ingestion
-Tumors
Cushing’s Disease is ____ _____ hypercortisolism
Adrenocorticotropic hormone (ACTH) dependent
Cushing’s Disease can be caused by…
-Pituitary-driven rise in adrenocorticotropic Hormone
-Ectopic adrenocorticotropic hormone release
-Exogenous adrenocorticotropic hormone administration
With Cushing’s Disease, increased adrenocorticotropic hormone stimulates increased ____ production
Cortisol
___ ___ is adrenocorticotropic hormone-independent hypercortisolism
Cushing’s Syndrome
With Cushing’s Syndrome, the ___ ___ increases cortisol output
Adrenal gland
With Cushing’s Syndrome, adrenocorticotropic hormone level is often ____
Decreased
What are some manifestations of hypercortisolism?
-Sodium and water retention
-Buffalo hump and back pain
-Osteoporosis
-Cardiac hypertrophy
-Hypertension
-Diabetes
-Polydipsia
-Catabolism
-Moon face/tomato face
-Muscle wasting
-Fat accumulation
-Pendulous abdomen and breasts
-Thin arms and legs
-Thin skin
-Easily bruising
___ hyperaldosteronism is due to a problem of the adrenal glands themselves (usually due to a noncancerous tumor of the adrenal gland)
Primary
____ hyperaldosteronism is due to a problem somewhere else in the body that causes the adrenal glands to release too much aldosterone
Secondary
Hyperaldosteronism causes alterations in ___ and ____ balance
Fluid and electrolyte
Secondary hyperaldosteronism occurs due to excessive activation of the ___-___-___ system due to a tumor, renal artery stenosis, or edematous disorders like heart failure, pregnancy, cor pulmonale, or cirrhosis with ascites
Renin-angiotensin-aldosteronism
What are some manifestations of hyperaldosteronism?
-Hypertension
-Edema
-Hypernatremia
-Hypokalemia
____ is a unique disorder of the adrenal gland
Pheochromocytoma
Pheochromocytoma causes an excess of _____ production
Catecholamine
Pheochromocytoma is caused by ____
Tumors
Manifestations of pheochromocytoma:
-Hypertension
-Headache
-Diaphoresis
-Palpitations
-Tachycardia
-Anxiety and emotional lability
-Weight loss
Diabetes is heavily influenced by the ____
Pancreas
The pancreas produces enzymes for ____ as well as pancreatic enzymes
Digestion
____ is released from the pancreas in response to increased protein and glucose in the blood, usually due to the absorption of food
Insulin
4 steps of endocrine glucose management:
- Glucose binds to a GLUT1 transporter protein that has its binding site open to the outside of the cell (T1 conformation)
- Glucose binding causes the GLUT1 transporter to shirt to its T2 conformation with the binding site open to the inside of the cell
- Glucose is released to the interior of the cell, initiating a second conformational change in GLUT1
- Loss of bound glucose causes GLUT1 to return to its original T1 conformation, ready for a further transport cycle
4 steps of endocrine release of insulin:
- When the insulin receptor binds insulin, the activated receptor phosphorylates the IRS-1 protein; IRS-1 can lead to recruitment of GRB2, activating the Ras pathway
- IRS-1 activates PI 3-kinase, which catalyzes the addition of a phosphate group to the membrane lipid PIP2, thereby converting it to PIP3; PTEN can convert PIP3 back to PIP2.
- PIP3 binds a protein kinase called Akt, which is activated by other protein kinases
- Akt catalyzes phosphorylation of key proteins, leading to an increase in glycogen synthase activity and recruitment of the glucose transporter, GLUT4, to the membrane
Insulin upregulates…
-Glucose uptake in muscles and adipose tissue
-Glycolysis
-Glycogen synthesis
-Protein synthesis
-Uptake of ions (especially potassium and phosphate)
Insulin downregulates…
-Gluconeogenesis
-Glycogenolysis
-Lipolysis
-Ketogenesis
-Proteolysis
_____ has the opposite effect of insulin and is released with low blood glucose
Glucagon
____ is a hormone that regulates a variety of bodily functions by hindering the release of other hormones, the activity of the GI tract, and the rapid reproduction of cells
Somatostatin
___ ___ is a metabolic disorder when there is either not enough insulin or inadequate response to insulin (or both)
Diabetes mellitus
____ intolerance is a common condition associated with diabetes mellitus
Glucose
With type 1 diabetes, the body does not produce insulin due to ___ ___ ___
Beta cell destruction
Only about ___-__% of diabetics are type 1
5-10
Individuals with type 1 diabetes are prone to ____
Ketoacidosis
What are some symptoms of type 1 diabetes?
-Ketoacidosis
-Elevated blood and urine glucose
-Polyuria
-Polydipsia
-Vision changes
-Irritability
-Weight loss
With thype 2 diabetes, there is a defect in ___ ___ and its’ use in the body
Insulin secretion
___% of diabetics are type 2
90
Type 2 diabetes is no longer an ___ onset disorder
Adult
Type 2 diabetes is ____ diabetes
Secondary
Type 2 diabetes is associated with…
-Poor diet
-Low activity
-Insulin resistance
-Defect in insulin selection so the body doesn’t produce enough or the body can’t respond to it
Symptoms of type 2 diabetes:
-Elevated blood and urine glucose
-Polyuria
-Polydipsia
-Vision changes
-Irritability
-Weight loss
With ___ ___, women who are not diabetic develop diabetes during pregnancy (secondary diabetes)
Gestational diabetes
Gestational diabetes has features of ___ ___ diabetes
Type 2
Gestational diabetes occurs in about ___% of pregnancies
10
___-___% of women who develop gestational diabetes go on to develop type 2 diabetes after birth
5-10
Symptoms of gestational diabetes:
-Elevated blood and urine glucose
-Polyuria
-Polydipsia
-Vision changes
-Irritability
-Weight loss
Diabetic ketoacidosis is much more common in type ___ diabetes
1
Diabetic ketoacidosis is caused by an absolute lack of ___
Insulin
Precipitating factors of diabetic ketoacidosis:
-Infection
-New onset diabetes
Physical or emotional ___ can increase risk of diabetic ketoacidosis
Stress
Pathophysiology of diabetic ketoacidosis:
-Increased cortisol
-Lack of insulin
-Increased gluconeogenesis
-Increased fatty acid metabolism
Symptoms of diabetic ketoacidosis:
-Frequent urination
-Dehydration
-Increased lipolysis
-Sweet-smelling breath
-Altered consciousness
-Coma
Hyperosmolar nonketotic state is more common in type ___ diabetes
2
Hyperosmolar nonketotic state is brought on by ___ ___
Physiologic stress
Hyperosmolar nonketotic state has a much ____ onset than diabetic ketoacidosis
Slower
With hyperosmolar nonketotic state, there is reduced ____ uptake at the cellular level, causing higher blood glucose levels
Glucose
The hyperosmolar nonketotic state causes dumping of ___ and ___ into the blood which causes a hyperglycemia state and dehydrated cells
Water and electrolytes
With hyperosmolar nonketotic state, blood glucose levels are around 1200 which is much ____ that with diabetic ketoacidosis
Higher
Symptoms of hyperosmolar nonketotic state:
-Dry mouth
-hyperglycemia
-Extreme thirst
-Warm skin without sweat
-Fever
-Confusion
-Vision loss
-Hallucinations
____ may occur in diabetics as a response to treatment or not eating (can also happen in people without diabetes)
Hypoglycemia
Symptoms of hypoglycemia:
-Cellular energy failure
-Adrenal gland goes into overdrive and secretes catecholamines
-Increased gluconeogenesis
-Anxiety
-Tachycardia
-Nausea
-Confusion
-Weakness
-Seizures
The ____ ____ states that early morning hyperglycemia occurs due to a rebound effect from late-night hypoglycemia
Somogyi Phenomenon
What are some manifestations of the Somogyi phenomenon?
-Nightmares
-Morning headache
-Inconsistent glucose levels (morning glucose level may show the initial hypoglycemia or the rebound hyperglycemia)
