Short Term Stress vs Long Term Stress

Summary

The transcript explains the physiological differences between short-term (acute) and long-term (chronic) stress. It details how short-term stress activates the adrenal medulla, leading to the release of catecholamines like epinephrine, triggering a sympathetic response (e.g., increased heart rate, blood pressure). Long-term stress involves the adrenal cortex, releasing hormones like cortisol and aldosterone. Cortisol increases blood sugar, suppresses the immune system, and promotes bone degeneration, while aldosterone regulates sodium and potassium levels, impacting fluid retention and blood pressure. The focus is on the distinct hormonal pathways activated by different types of stress.

Takeaways

• 🧬 Stress can be categorized into short-term (acute) and long-term (chronic) stress, which have different physiological impacts on the body.
• 🔍 Short-term stress primarily involves the adrenal medulla, which secretes catecholamines like epinephrine, norepinephrine, and acetylcholine to trigger a sympathetic response.
• 💓 The sympathetic response to short-term stress includes increased heart rate, blood pressure, bronchodilation, vasoconstriction in the digestive system, and dilation in the skeletal system.
• 👁️‍🗨️ Long-term stress affects the adrenal cortex, leading to the release of hormones like cortisol, which is a glucocorticoid with anti-inflammatory and immunosuppressant effects.
• 🩸 Cortisol increases blood sugar to provide energy for the brain during stress, but chronically can lead to bone degeneration due to its impact on connective tissue.
• 🌡️ Mineral corticoids, such as aldosterone, are also released during long-term stress, regulating sodium and potassium levels, which can affect blood volume and blood pressure.
• 🚫 Chronic stress can increase susceptibility to secondary infections like colds or flu due to cortisol's immunosuppressant properties.
• 🧠 The brain is considered the most important organ during stress responses, as it requires glucose for metabolism and is protected by the body's stress response mechanisms.
• 💧 Changes in osmolarity due to aldosterone can lead to fluid retention, increasing blood volume and potentially causing high blood pressure.
• 🔄 The distinction between short-term and long-term stress lies in the types of hormones secreted and their effects on the body's physiological systems.

Q & A

What are the two types of stress responses discussed in the script?

The script discusses short-term stress, also known as acute stress, and long-term stress, also referred to as chronic stress.

How does stress affect the body's physiology?

Stress affects the body's physiology by altering hormone concentrations, which in turn activate various physiological pathways.

What is the role of the adrenal glands in stress responses?

The adrenal glands secrete endocrine hormones in response to stress. They have two main regions: the medulla, which secretes catecholamines during short-term stress, and the cortex, which secretes steroids during long-term stress.

What are catecholamines and which hormones are included in this category?

Catecholamines are amino acid-derived hormones that include epinephrine, norepinephrine, and acetylcholine. They are secreted by the adrenal medulla during short-term stress.

What physiological changes occur during a short-term stress response?

During short-term stress, there is an increase in heart rate, blood pressure, bronchodilation, vasoconstriction in the digestive system with blood flow redirection to the skeletal muscles, and pupil dilation.

What triggers the secretion of catecholamines during short-term stress?

The secretion of catecholamines is triggered by sympathetic activity generated from preganglionic sympathetic neurons coming from the central nervous system.

How does long-term stress differ from short-term stress in terms of the hormones involved?

Long-term stress involves the adrenal cortex, which secretes glucocorticoids and mineral corticoids, unlike short-term stress which involves catecholamines from the adrenal medulla.

What is the primary function of cortisol, a glucocorticoid hormone released during long-term stress?

Cortisol, a glucocorticoid, has anti-inflammatory and immunosuppressant effects, increases blood sugar, and can lead to bone degeneration when released in high amounts over time.

What is aldosterone and what does it do in the body?

Aldosterone is a mineral corticoid that regulates mineral balance by increasing sodium reabsorption and potassium secretion, which can affect blood volume, blood pressure, and fluid balance.

What are the potential health implications of chronically high levels of cortisol?

Chronically high levels of cortisol can lead to increased susceptibility to infections, elevated blood sugar, and bone degeneration due to its anti-inflammatory, immunosuppressant, and glucocorticoid properties.

How does the body's response to stress aim to protect the brain during a stress response?

The body's stress response aims to protect the brain by increasing blood sugar levels through the action of glucocorticoids like cortisol, as glucose is a primary metabolite needed by the brain.