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What is the 鈥渇ight or flight鈥� response, and what is its effect on the excretory system? a. Aldosterone is the 鈥渇ight or flight鈥� that is released by the adrenal medulla under extreme stress. This hormone constricts the smooth muscles of the blood vessels. It constricts the afferent arterioles, causing the flow of blood into the nephrons to stop. b. Epinephrine and norepinephrine are the 鈥渇ight or flight鈥� hormones that are released by the adrenal medulla and the nervous system, respectively, under extreme stress. These hormones constrict the smooth muscles of the blood vessels. They constrict the afferent arterioles, causing the flow of blood into the nephrons to stop. c. ADH is the 鈥渇ight or flight鈥� hormone that is released by the adrenal medulla under extreme stress. This hormone constricts the smooth muscles of the blood vessels. It constricts the efferent arterioles, causing the flow of blood into the nephrons to stop. d. Epinephrine and norepinephrine are the 鈥渇ight or flight鈥� hormones that are released by the adrenal medulla and the nervous system, respectively, under extreme stress. These hormones constrict the smooth muscles of the blood vessels. They constrict the efferent arterioles, causing the flow of blood into the nephrons to stop.

Step by step solution

01

Identify the accurate 'fight or flight' hormones

Analyze the options and identify that epinephrine and norepinephrine are the correct 'fight or flight' hormones. These are released by the adrenal medulla and the nervous system, respectively, under extreme stress.

02

Determine the correct action of these hormones

Review the options to find which one correctly describes the action of these hormones. Notice that epinephrine and norepinephrine constrict the smooth muscles of blood vessels.

03

Understand the impact on the excretory system

Consider the effect on the kidneys鈥� arterioles. The afferent arterioles (leading into the nephrons) being constricted would reduce the flow of blood into the nephrons.

04

Review the options based on these criteria

Option b correctly describes that epinephrine and norepinephrine are the 'fight or flight' hormones and that they cause constriction of the afferent arterioles, affecting the blood flow into the nephrons.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

epinephrine

Epinephrine, also known as adrenaline, is a hormone and neurotransmitter that plays a crucial role in the body's 'fight or flight' response. This hormone is produced by the adrenal medulla, the inner part of the adrenal glands located on top of the kidneys. When you encounter a stressful situation, the body releases epinephrine to prepare you for action. It increases heart rate, dilates air passages, and mobilizes energy stores, which can help you either fight the threat or flee from it.
In addition to these effects, epinephrine also narrows blood vessels, leading to higher blood pressure.
This constriction involves the smooth muscles of the blood vessels and impacts blood flow to various organs, including the kidneys.

norepinephrine

Norepinephrine, often called noradrenaline, is another vital hormone and neurotransmitter in the 'fight or flight' response. It is closely related to epinephrine and serves many similar functions. However, norepinephrine is primarily produced by the nervous system's nerve endings, whereas epinephrine is produced by the adrenal medulla.
This hormone also works to enhance your alertness and readiness when faced with stress. It increases heart rate and blood flow to muscles, enabling quick movements and responses.
Norepinephrine also causes vasoconstriction, or the narrowing of blood vessels, particularly affecting the smooth muscles. This can lead to increased blood pressure and reduced blood flow to some organs, impacting their function during high-stress situations.

adrenal medulla

The adrenal medulla is the central part of the adrenal glands, which are situated on top of each kidney. It plays a vital role in the body's response to stress through the production and release of the 'fight or flight' hormones 鈥� epinephrine and norepinephrine.
When your body perceives a threat or experiences stress, the adrenal medulla quickly releases these hormones into the bloodstream. This swift response activates various physiological changes to prepare for immediate physical activity.
Understanding the role of the adrenal medulla in stress response helps explain why our bodies react so dramatically during stressful events, gearing up for potential danger or escape.

excretory system

The excretory system is essential for removing waste products and toxins from the body, maintaining homeostasis. This system includes the kidneys, ureters, bladder, and urethra.
In stressful situations, where epinephrine and norepinephrine are released, the function of the excretory system can be altered. One significant effect is the constriction of the afferent arterioles鈥攕mall arteries that lead blood into the nephrons within the kidneys.
This constriction reduces blood flow into the kidneys, decreasing their ability to filter waste from the blood. While this might seem counterintuitive, it allows the body to prioritize more immediate responses to danger, such as increased muscle action and alertness.

afferent arterioles

Afferent arterioles are tiny blood vessels that carry blood to the nephrons in the kidneys. Nephrons are the filtering units of the kidneys, responsible for filtering out waste and excess substances from the blood.
During the 'fight or flight' response, the release of epinephrine and norepinephrine causes these arterioles to constrict. This constriction significantly reduces the blood flow into the nephrons, affecting the kidneys' filtration functions.
By understanding the role of afferent arterioles in the excretory system and their response to stress hormones, we can appreciate how our bodies prioritize vital functions when facing stress.