Adrenal Gland

The adrenal gland is located on the kidneys. This is because the adrenal glands are small, triangular-shaped organs that sit on top of each kidney. They are responsible for producing hormones that regulate various bodily functions, including metabolism, stress response, and blood pressure.

The arrangement of the zona reticularis is described as netlike. This suggests that the cells in this region are arranged in a network or mesh-like pattern. This arrangement may be important for the function of the zona reticularis, which is responsible for producing and secreting hormones such as androgens. The netlike arrangement may allow for efficient communication and interaction between the cells, ensuring the proper functioning of this endocrine gland.

GFR : Glomerulosa, Fasciculata, Reticularis

Aldosterone is the most potent mineralocorticoid because it is primarily responsible for regulating the balance of water and electrolytes in the body. It acts on the kidneys to increase the reabsorption of sodium and the excretion of potassium, leading to increased blood volume and blood pressure. This hormone also plays a role in maintaining the balance of other ions, such as chloride and hydrogen ions. Deoxycorticosterone is also a mineralocorticoid, but it is less potent than aldosterone. Testosterone, cortisol, and adrenaline are not mineralocorticoids and do not have the same effects on electrolyte balance.

The given clinical features such as hirsutism, acne, buffalo hump, moon facies, and abdominal purple striae are all associated with cortisol hypersecretion, also known as Cushing's syndrome. This condition occurs when there is an excessive production of cortisol, either due to an overactive adrenal gland or long-term use of corticosteroid medications. It can lead to a variety of symptoms including weight gain, high blood pressure, muscle weakness, and mood swings. Therefore, based on the presented symptoms, the most likely diagnosis is cortisol hypersecretion.

According to the graph, the effect of the cold pressor test on blood pressure and heart rate is an increase. This means that when the hand is immersed in cold water for 3 minutes, both blood pressure and heart rate will go up.

This is a Iatrogenic Cushing's Syndrome

Dexamethasone is the treatment for Pituitary Cushing's Syndrome. Dexamethasone is a glucocorticoid, which is a type of medication that mimics the effects of cortisol, a hormone produced by the adrenal glands. In Pituitary Cushing's Syndrome, there is an overproduction of adrenocorticotropic hormone (ACTH) by the pituitary gland, leading to excessive cortisol production. Dexamethasone works by suppressing the production of ACTH, thereby reducing cortisol levels and alleviating the symptoms of Cushing's Syndrome.

The correct answer is acidic because the loss of K+ ions will result in an increase in H+ ions in the blood, leading to a decrease in pH and making the blood more acidic.

Receptors:

Nocireceptor: pain
Thermo: temperature
Mechano: physical
Baro: blood pressure
Chemo: glucose, acid, O2
In Special senses: sight, smell

Cushing's syndrome is a condition characterized by an excessive production of cortisol, a hormone produced by the adrenal glands. High cortisol levels can lead to a variety of symptoms such as weight gain, high blood pressure, and muscle weakness. It is caused by various factors such as long-term use of corticosteroid medications or tumors in the adrenal glands or pituitary gland. Therefore, the correct answer is "High cortisol" as it accurately reflects the hormonal imbalance associated with Cushing's syndrome.

Same as ADH. It will increase no. of Na+ channels on the apical membrane. The reabsorption of Na will cause a decreased osmolality in the tubules. hence water will be reabsorbed as well via osmotic pull.

The arrangement of the cells in the zona fasciculata is in the form of linear cords. This means that the cells are aligned in a linear pattern, forming cords or strands. This arrangement allows for efficient secretion and production of hormones, as the cells are closely packed together and organized in a specific pattern. The linear cords arrangement is characteristic of the zona fasciculata, which is one of the three distinct layers of the adrenal cortex.

Both secrete glucocorticoids & androgens

Probably because glucocorticoid will stimulate the hypothalamus. In this case, adrenal cushing's is specifically due to an adrenal cortical lesion.

Inhibit ADH release

Binds to cortisol receptors ---> inhibit ADH release ---> increase in free water loss ---> polyuria.

Why?

Dexamethasone acts on Pituitary alone.

Cushing's Syndrome is a condition characterized by excessive levels of cortisol in the body. It can be caused by various factors, including an ectopic lesion. In this case, the hormone that will be in high levels is ACTH (adrenocorticotropic hormone). ACTH is produced by the pituitary gland and stimulates the production and release of cortisol from the adrenal glands. When there is an ectopic lesion causing Cushing's Syndrome, it leads to excessive production of ACTH, which in turn increases cortisol levels in the body.

The arrangement of the cells in the zona glomerulosa is in a whorl pattern. This means that the cells are arranged in a circular or spiral shape, with each layer of cells overlapping the previous one. This arrangement allows for efficient secretion of aldosterone, which is the primary hormone produced in the zona glomerulosa. The whorl pattern ensures that the cells are closely packed together, maximizing their contact with blood vessels and facilitating the release of aldosterone into the bloodstream.

Post-menopausal women experience a decline in estrogen production due to the regression of the ovaries. However, other hormones, such as androgens, can act as important precursors for estrogen synthesis in these women. Androgens can be converted into estrogens through a process called aromatization, which occurs in various tissues including adipose tissue, liver, and the brain. Therefore, androgens play a crucial role in compensating for the lack of estrogen production in post-menopausal women.

# Adenomas – slow growing , pure hypercortisolism (only cortisol)
# Carcinomas – larger, more cortisol precursors & adrenal androgens
# Micronodular hyperplasia – rare, common in young adults, autosomal dominant, asso. with pituitary & testicular lesions.

In Cytoplasm, Cholesterol + Acetate = Cheolesteryl esters stored in storage vacuoles.

Cholesteryl esters ---b/d---> Fatty acid + Cholesterol

1st step : Cholesterol enter mitochondrion –--enzyme desmolase/ SCC---> convert to Pregnenolone (RATE LIMITING STEP)

2nd step : Pregnenolone enters cytoplasm ---enzyme dehydrogenase, isomerase ---> Progesterone ----> Enter Endoplasmic reticulum

3rd step : Progesterone --- enzyme hydroxylase ---> 17 a- hydroxyprogesterone

4th step : 17a-hydroxyprogesterone --- enzyme hydroxylase ---> 11-Deoxycortisol

5th step : 11-Deoxycortisol enters mitochondrion --- enzyme hydroxylase ---> Cortisol ----> Enter cytoplasm

Action potential go to..

-> hypothalamus (neuroendocrine response)
-> somatic sensory cortex (perception/stress)
-> motor cortex (voluntary action response)
-> limbic cortex (emotions)

In ACTH-dependent Cushing's disease, the most prominent ectopic lesion is small cell carcinoma of the lungs. This type of cancer is known to produce ACTH, which stimulates the adrenal glands to produce excessive cortisol. This leads to the symptoms of Cushing's disease, such as weight gain, high blood pressure, and muscle weakness. Therefore, small cell carcinoma of the lungs is the most likely cause of ACTH-dependent Cushing's disease.

Hyperaldosteronism is a condition characterized by excessive production of aldosterone hormone by the adrenal glands. It is more commonly seen in adult females compared to other demographics. This could be due to various factors such as hormonal changes, pregnancy, or certain underlying medical conditions that affect the adrenal glands. However, hyperaldosteronism can also occur in other demographics, but the frequency is higher in adult females.

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Physiological stressors are factors that cause stress on the body's physical systems. Pregnancy can be considered a physiological stressor because it involves significant changes in hormone levels, physical discomfort, and increased demands on the body. These changes can put stress on various physiological systems, such as the cardiovascular and endocrine systems. Acidosis, trauma, and anger can also be considered physiological stressors as they can have direct physical effects on the body. Peer pressure, on the other hand, is more of a psychological stressor as it primarily affects one's emotional well-being rather than directly impacting the body's physiological systems.

Retention of Na+ due to antidiuretic effect of aldosterone?

Will also cause Hypokalemia which will present as muscle weakness and cardiac arrhythmia

Noradrenalin & Adrenaline

equally potent in increasing alertness (adrenaline evokes more anxiety & fear)
Known familiar stress –> more Noradrenaline
Unknown stress – > more Adrenaline

Develop beard
Masculine pattern of body hair distribution
Clitoris grows to resemble small penis
Also linked to Polycystic Ovarian Syndrome (another post)

Alarm state/Compensation phase:

When the stressor is noticed, there will be onset of shock and decreased resistance.
During this time, both sympatho-adrenal & hypothalamo-pituitary-adrenocortical axis are activated.
Resistance phase:

Resistance to the stressor increased as animal adapted & coped with it
Lasts for as long as the animal can support this heightened resistance.
Exhaustion/Decompensation phase:

Resistance has exhausted

E & NE are catecholamines

If there is hypersecretion of ACTH from the pituitary, it will lead to an excessive production of cortisol by the adrenal cortex. This can result in bilateral cortical hyperplasia, which is the enlargement of both adrenal cortices. This occurs as a compensatory response to the increased stimulation from ACTH.

Always remember, when there is increase in cortisol, there will be increase in aldosterone but decrease in ADH.

Glucocorticoids (Cortisol)

Stimulate protein catabolism –> liver uptake of amino acids –> conversion to glucose (gluconeogenesis)
**Anti-insulin action on muscle (own local supply) & adipose tissue (inhibit uptake of glucose)
Increase glucose supply to brain
TG breakdown –> glycerol + FA (fuel for muscle activity)
Increase plasma AA, glucose, glycerol & FA
Permissive effects (gives permission) for:
-Catecholamines (vasoconstriction, bronchodilation, lipolysis)
-Glucagon (gluconeogenesis)
Antiallergic effect
Increase RBC count
Increase neutrophil count
Due to the permissive actions for catecholamines & glucagon, secretion of ACTH & glucocorticoids (cortisol) are essential for survival when stress is severe.

Prolonged stress can have various effects on health, including cardiovascular disease. This is because stress can contribute to high blood pressure, inflammation, and the development of plaque in the arteries, all of which can increase the risk of cardiovascular problems. Additionally, prolonged stress can lead to the release of glucocorticoids in large amounts, which can suppress the immune system. This can make individuals more susceptible to infections and illnesses. Furthermore, excessive glucocorticoid production can also increase protein catabolism, leading to muscle loss.

* High plasma renin levels – reninoma (not involved in the renin-angiotensin-aldosterone axis)
* High water retention (oedema)
* Renal ischemia (?)

No specific plasma carrier protein, forms weak association with albumin.
Due to lack of specific plasma carrier protein, aldosterone is rapidly cleared from plasma by liver (form tetrahydroaldosterone 3-gluocronide) which will be excreted in the urine.

Instead, long term stressors will suppress immune system. Effects are more serious on the elderly & those that are already ill.

HIV +ve patients will experience rapid decline in T-helper cells if only provided with low social support.

Action potential go to..

-> hypothalamus (neuroendocrine response)
-> somatic sensory cortex (perception/stress)
-> motor cortex (voluntary action response)
-> limbic cortex (emotions)

Androsterotenedione and DHEA are precursors to the sex hormones. Androsterotenedione is converted into testosterone and estrogen, while DHEA can be converted into both testosterone and estrogen as well. These precursors play a crucial role in the synthesis of sex hormones and are essential for the proper functioning of the reproductive system.

Hypernatremia, hypokalemia, and alkalosis are signs and symptoms of aldosteronism, which is the hypersecretion of aldosterone. Hypernatremia refers to an elevated level of sodium in the blood, which can occur due to aldosterone causing increased reabsorption of sodium in the kidneys. Hypokalemia is a condition characterized by low levels of potassium in the blood, which can also result from aldosterone's effect on the kidneys, leading to increased excretion of potassium. Alkalosis refers to an elevated pH level in the blood, which can be caused by aldosterone promoting the excretion of hydrogen ions in the kidneys. These symptoms collectively indicate the presence of aldosteronism.

# Associated with low plasma renin levels (positive feedback? due to increased blood volume from the action of aldosterone, initiating the renin-angiotensin-aldosterone system)
# Low K+ level (in exchange of Na+ by Na/K pump) –> muscle weakness

Adrenal Cushing's is not indfluenced by hormonal stimulation of ACTH/CRH. If ACTH level is high, it is known as Pituitary Cushing's Syndrome.

The adrenal cortex is responsible for the biosynthesis of steroid hormones. These hormones are derived from cholesterol, which is a type of lipid. Therefore, it makes sense that the adrenal cortex contains cells with large amounts of lipids, as they are necessary for the production of steroid hormones. Additionally, the smooth endoplasmic reticulum (SER) is involved in the synthesis of lipids, including cholesterol. Therefore, the presence of SER in the adrenal cortex further supports the production of steroid hormones.

The adrenal cortex mainly secretes corticosteroids of the C19 and C21 types. These include hormones such as cortisol, cortisone, and corticosterone, which are involved in regulating metabolism, immune response, and stress response. These hormones play important roles in maintaining homeostasis in the body and are essential for various physiological processes.

Orthostasis is a physical stressor because it refers to the body's response to changes in posture, particularly when standing up from a sitting or lying position. This change in position can cause a temporary drop in blood pressure, leading to symptoms such as dizziness, lightheadedness, and even fainting. These physical changes and the body's response to them can be considered physical stressors as they put strain on the cardiovascular system.

Aldosterone is needed to conserve Na & eliminate K.

Stress will cause release of corticotropin releasing hormone (CRH) from hypothalamus ----> Adrenocorticotropin (ACTH) from anterior pituitary ----> act on adrenal gland ----> produce aldosterone.

Aldosterone release will cause increase in blood volume & BP, ensuring adequate delivery of O2/CO2 and nutrients during stressful period.

IgA will decrease.

Epstein-Barr virus will increase. (DAMAGING!)

Overactivity of pituitary alone is not enough to cause Cushing's, as it is not specific and constant in duration and volume.