Chapter 17 - Section 17.3 - Study Guide - Assess Your Learning Outcomes - Page 669: 6

The adrenal medulla is the innermost part of the adrenal glands and is responsible for producing two main hormones: epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones are part of the body's immediate stress response, often referred to as the "fight or flight" response. They play crucial roles in preparing the body to deal with stressful situations or emergencies. Here are the hormones and functions of the adrenal medulla: 1. **Epinephrine (Adrenaline):** - **Function:** Epinephrine is a powerful hormone and neurotransmitter that rapidly prepares the body for intense physical activity and heightened awareness in response to stress. It triggers a cascade of physiological changes to help the body respond effectively to challenges. - **Effects:** - **Increased Heart Rate:** Epinephrine stimulates the heart to beat faster, increasing cardiac output and blood flow to vital organs and muscles. - **Dilated Airways:** Airways in the lungs expand, allowing for more oxygen to enter and support increased oxygen consumption during physical exertion. - **Dilated Pupils:** Pupils dilate to improve visual acuity and awareness of the surroundings. - **Increased Blood Glucose:** Epinephrine prompts the liver to release glucose into the bloodstream, providing an immediate energy source for muscles. - **Redirected Blood Flow:** Blood flow is redirected away from non-essential functions, like digestion, and toward the muscles and brain. - **Enhanced Alertness and Focus:** Epinephrine enhances mental alertness and sharpens focus, helping the body respond to potential threats. - **Suppression of Non-Essential Functions:** Processes such as digestion and immune responses are temporarily suppressed to prioritize immediate survival responses. 2. **Norepinephrine (Noradrenaline):** - **Function:** Norepinephrine works in conjunction with epinephrine to prepare the body for stress responses, but its effects are slightly different. It contributes to the "fight or flight" response by increasing alertness and readiness. - **Effects:** - **Increased Heart Rate:** Similar to epinephrine, norepinephrine increases heart rate and cardiac output. - **Blood Vessel Constriction:** Norepinephrine causes blood vessels in non-essential areas (such as skin and digestive organs) to constrict, redirecting blood to vital organs and muscles. - **Enhanced Awareness:** Norepinephrine enhances vigilance, attention, and overall mental focus. In summary, the hormones produced by the adrenal medulla, epinephrine, and norepinephrine, play essential roles in the body's "fight or flight" response to stress. They work together to increase heart rate, direct blood flow, enhance oxygen intake, raise blood glucose levels, sharpen focus, and prepare the body for quick and intense physical actions. These responses are designed to help individuals effectively deal with challenging or dangerous situations by providing an immediate surge of energy and heightened alertness.

The adrenal medulla is the innermost part of the adrenal glands and is responsible for producing two main hormones: epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones are part of the body's immediate stress response, often referred to as the "fight or flight" response. They play crucial roles in preparing the body to deal with stressful situations or emergencies. Here are the hormones and functions of the adrenal medulla: 1. **Epinephrine (Adrenaline):** - **Function:** Epinephrine is a powerful hormone and neurotransmitter that rapidly prepares the body for intense physical activity and heightened awareness in response to stress. It triggers a cascade of physiological changes to help the body respond effectively to challenges. - **Effects:** - **Increased Heart Rate:** Epinephrine stimulates the heart to beat faster, increasing cardiac output and blood flow to vital organs and muscles. - **Dilated Airways:** Airways in the lungs expand, allowing for more oxygen to enter and support increased oxygen consumption during physical exertion. - **Dilated Pupils:** Pupils dilate to improve visual acuity and awareness of the surroundings. - **Increased Blood Glucose:** Epinephrine prompts the liver to release glucose into the bloodstream, providing an immediate energy source for muscles. - **Redirected Blood Flow:** Blood flow is redirected away from non-essential functions, like digestion, and toward the muscles and brain. - **Enhanced Alertness and Focus:** Epinephrine enhances mental alertness and sharpens focus, helping the body respond to potential threats. - **Suppression of Non-Essential Functions:** Processes such as digestion and immune responses are temporarily suppressed to prioritize immediate survival responses. 2. **Norepinephrine (Noradrenaline):** - **Function:** Norepinephrine works in conjunction with epinephrine to prepare the body for stress responses, but its effects are slightly different. It contributes to the "fight or flight" response by increasing alertness and readiness. - **Effects:** - **Increased Heart Rate:** Similar to epinephrine, norepinephrine increases heart rate and cardiac output. - **Blood Vessel Constriction:** Norepinephrine causes blood vessels in non-essential areas (such as skin and digestive organs) to constrict, redirecting blood to vital organs and muscles. - **Enhanced Awareness:** Norepinephrine enhances vigilance, attention, and overall mental focus. In summary, the hormones produced by the adrenal medulla, epinephrine, and norepinephrine, play essential roles in the body's "fight or flight" response to stress. They work together to increase heart rate, direct blood flow, enhance oxygen intake, raise blood glucose levels, sharpen focus, and prepare the body for quick and intense physical actions. These responses are designed to help individuals effectively deal with challenging or dangerous situations by providing an immediate surge of energy and heightened alertness.