55 Questions
the target of aldosterone is the ____ cells in the DCT & collecting duct and the ____ cells in the collecting duct
principle, intercalated
Order the steps of aldosterone changing gene transcription
Lipid solubility → diffusion = Step 1 Binds to cytoplasmic mineralocorticoid receptor = Step 2 Aldosterone-receptor complex → nucleus → DNA → mRNA→ protein = Step 3 --> transepithelial Na+ transport = Step 4
non-genomic effects of aldosterone are faster and involve activation of ____ system (e.g. incr H+ secretion and bicarbonate retention on the intercalated cells of the collecting duct)
second messenger
____ has the opposite effect of aldosterone
ANP
Excess aldosterone leads to metabolic ____.
alkalosis
Both hyperkalemia and angiotensin II lead to ____ secretion.
aldosterone
In the distal collecting duct of the kidney, Aldosterone _______ the reabsorption of Na+, _____ the excretion of K+ , and ______ the secretion of H+, leading to an increase in blood pressure.
↑,↑,↑
With genetic deficiency of 11β-HSD2 activity, ____ may have substantial mineralocorticoid effect
cortisol
Consumption large amounts of licorice and glycyrrhetinic acid can block the activity of ______ leading to a decrease in the conversion of cortisol to cortisone.
11β-hydroxysteroid dehydrogenase type 2
Cortisol mobilizes amino acids from the ____ tissues --> diminishes the tissue stores of protein and at the same time it incr the liver enzymes required for the hepatic effects
non-hepatic
cortisol stimulates to ____ occur 6-10x faster in order to increase BG
gluconeogenesis
Cortisol effects metabolism by:
all of the above
increased glucocorticoid secretion occurs when increased ACTH stimulated the zona fasciculata during ____ situations
stressful
What is the result of the increased capillary permeability in the inflamed area?
Leakage of large quantities of almost pure plasma out of the capillaries
What occurs over time in the inflamed area that often helps in the healing process?
Ingrowth of fibrous tissue
What effect does cortisol have on the migration of white blood cells into the inflamed area?
It decreases the migration of white blood cells
How does cortisol affect the formation of prostaglandins and leukotrienes?
It decreases the formation of prostaglandins and leukotrienes
What is the effect of cortisol on fever during inflammation?
It decreases fever by decreasing release of interleukin-1
How does cortisol contribute to the subside of inflammation?
By decreasing tissue reactions that promote inflammation
What are the two basic anti-inflammatory effects of cortisol?
Blocking the early stages of the inflammation process and increasing the rapidity of healing
What is the effect of cortisol on the migration of white blood cells into the inflamed area?
Cortisol inhibits the migration of white blood cells
How does cortisol contribute to the resolution of inflammation?
By reducing the secretion of prostaglandins and leukotrienes
How does cortisol affect the immune response in infectious diseases?
It decreases blood eosinophils and lymphocytes
What is the impact of excess cortisol secretion on red blood cell production?
It leads to polycythemia
How does cortisol contribute to the prevention of shock or death in anaphylaxis?
By blocking the inflammatory response
What characterizes the diurnal rhythm of CRH, ACTH, and cortisol secretion?
High in the early morning and low in the late evening
At which time of day are CRH, ACTH, and cortisol secretion high according to the diurnal rhythm?
Early morning
Cortisol effects inflammation by:
all of the above
Cortisol effects inflammation by binding to the glucocorticoid receptor and stimulation transrepression of anti-inflammatory proteins
True
Adrenal androgens are converted to____ in the testes
testosterone
____ can be caused by autoimmune antibodies that react with several steroidoogenic enzymes (most often 21-hydroxylase), tuberculosis, cancer, fungal infections, adrenal hemorrhage
Addison's Disease
____ adrenal insufficiency is also referred to as Addison's disease
Primary
Secondary adrenal insufficiency is typically caused by the pituitary gland failing to produce sufficient ____
ACTH
Addison's disease leads to hyperpigmentation due to upregulation fo the ____ gene, leading to increased ___ production
POMC, MSH
____ syndrome describes the signs and symptoms associated with prolonged exposure to inappropriately high levels of the hormone cortisol
Cushing's
Primary aldosteronism is also known as ____ syndrome
Conn's
Patients with Cushing’s Syndrome present with all of the following, except:
Impaired fuel mobilization due to primary adrenal insufficiencies
The adrenal medulla composes ~____% of the adrenal mass
10
Most catecholamines circulate in the blood bound to ____ (low affinity)
albumin
the hypothalamus releases ____, which stimulates the anterior pituitary to release ACTH
Corticotropin-releasing factor (CRF)
How much of cortisol is bound by corticosteroid binding globulin (CBG, transcortin) and albumin?
90-95%
How much of aldosterone is bound by corticosteroid binding globulin (CBG, transcortin) and albumin?
60%
Match the following values for aldosterone and cortisol
aldosterone: normal blood concentration (µg/dL) = 0.006 aldosterone: normal secretory rate (mg/day) = 0.15 cortisol: normal blood concentration (µg/dL) = 12 cortisol: normal secretory rate (mg/day) = 15
Aldosterone stimulates the ___ in locations such as the sweat glands, salivary glands, and intestinal epithelial cells to conserve salt when needed
Na+/K+ ATPase
Effects on protein production from aldosterone are not immediate, taking up to ____ min for protein synthesis
45-60
____ can be caused by autoimmune antibodies that react with several steroidoogenic enzymes (most often 21-hydroxylase), tuberculosis, cancer, fungal infections, adrenal hemorrhage
Addison's disease
Net excess of aldosterone in the serum leads to ___ [Na+] and ____ [K+] in the ECF
increased, decreased
when there is no aldosterone, large amounts of [Na+] are lost in the urine leading to ____ in ECF volume
decrease
Cortisol is ____ as potent as aldosterone when acting as a mineralocorticoid but plasma conc. of cortisol is ____
1/3000, 2000x higher
Which of the following stimulates to occur 6-10x faster in order to increase BG?
cortisol
Catecholamines are amino acid derived hormones synthesized from ____
tyrosine
One cause of Conn's syndrome (primary aldosteronism) can be caused by small tumor of the ____ that secretes large amounts aldosterone
zona glomerulosa
One cause of Conn's syndrome (primary aldosteronism) is hyperplastic adrenal cortices secrete aldosterone rather than ____
cortisol
Chromaffin cells are the principle cell type within the adrenal medulla, which are “modified” postganglionic neurons richly innervated by ____ from the thoracolumbar spinal cord
cholinergic preganglionic neurons
Pheochromocytoma is a tumor of ____ cells
chromaffin
Study Notes
Aldosterone
- The target of aldosterone is the principal cells in the distal convoluted tubule (DCT) and collecting duct and the intercalated cells in the collecting duct.
- Aldosterone changes gene transcription through the following steps:
- Binding to mineralocorticoid receptor
- Formation of a complex with heat shock proteins
- Translocation to the nucleus
- Binding to specific DNA sequences
- Activation of gene transcription
- Non-genomic effects of aldosterone are faster and involve activation of the protein kinase C system.
- Cortisol has the opposite effect of aldosterone.
Cortisol
- Cortisol mobilizes amino acids from muscle tissues, diminishing tissue stores of protein and increasing liver enzymes required for hepatic effects.
- Cortisol stimulates gluconeogenesis to occur 6-10 times faster to increase blood glucose.
- Cortisol effects metabolism by increasing glucose release from stored glycogen and increasing gluconeogenesis.
- Increased glucocorticoid secretion occurs when increased ACTH stimulates the zona fasciculata during stress situations.
Inflammation and Immunity
- Cortisol increases capillary permeability in the inflamed area, leading to an influx of white blood cells and resulting in inflammation.
- Over time, cortisol helps in the healing process by reducing inflammation.
- Cortisol inhibits the migration of white blood cells into the inflamed area, reducing inflammation.
- Cortisol inhibits the formation of prostaglandins and leukotrienes, reducing inflammation.
- Cortisol reduces fever during inflammation.
- Cortisol contributes to the subsidence of inflammation.
- The two basic anti-inflammatory effects of cortisol are:
- Reducing the formation of prostaglandins and leukotrienes
- Inhibiting the migration of white blood cells into the inflamed area
- Cortisol contributes to the resolution of inflammation by reducing inflammation.
- Cortisol affects the immune response in infectious diseases by reducing inflammation.
- Excess cortisol secretion impairs red blood cell production.
Diurnal Rhythm and CRH
- The diurnal rhythm of CRH, ACTH, and cortisol secretion is characterized by high levels in the morning and low levels at night.
- CRH, ACTH, and cortisol secretion are high in the morning.
Adrenal Glands
- Adrenal androgens are converted to testosterone in the testes.
- Addison's disease is caused by autoimmune antibodies that react with several steroidogenic enzymes, tuberculosis, cancer, fungal infections, or adrenal hemorrhage.
- Secondary adrenal insufficiency is typically caused by the pituitary gland failing to produce sufficient ACTH.
- Addison's disease leads to hyperpigmentation due to upregulation of the melanocortin 1 receptor gene, leading to increased melanin production.
- Cushing's syndrome describes the signs and symptoms associated with prolonged exposure to inappropriately high levels of cortisol.
- Primary aldosteronism is also known as Conn's syndrome.
- The adrenal medulla composes approximately 10% of the adrenal mass.
- Most catecholamines circulate in the blood bound to albumin.
Aldosterone and Cortisol Binding
- 95% of cortisol is bound by corticosteroid binding globulin (CBG, transcortin) and albumin.
- 30% of aldosterone is bound by corticosteroid binding globulin (CBG, transcortin) and albumin.
Aldosterone Effects
- Aldosterone stimulates the ENaC channel in locations such as the sweat glands, salivary glands, and intestinal epithelial cells to conserve salt when needed.
- Effects on protein production from aldosterone are not immediate, taking up to 30 minutes for protein synthesis.
- Net excess of aldosterone in the serum leads to high [Na+] and low [K+] in the ECF.
- When there is no aldosterone, large amounts of [Na+] are lost in the urine, leading to decreased ECF volume.
- Cortisol is 1/100th as potent as aldosterone when acting as a mineralocorticoid, but plasma concentrations of cortisol are higher.
A Gonzalez Block 3 Week 4
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
