Case Study: Drink and Flush
“Wow, this line for the restroom is long!” Olivia says to Tricia, anxiously bobbing from side to side to ease the pressure in her bladder. Tricia nods and says, “It’s always like this at parties. It’s the alcohol.”
Olivia and Tricia are 21-year-old college students at a party. They and many other people have been drinking alcoholic beverages over the course of the evening. As the night has gotten later, the line for the restroom has gotten longer and longer. You may have noticed this phenomenon if you have been to places where large numbers of people are drinking alcohol, like at the ballpark below.
Olivia says, “I wonder why alcohol makes you have to pee?” Tricia says she learned about this in her Human Biology class. She tells Olivia that alcohol inhibits a hormone that helps you retain water. So instead of your body retaining water, you urinate more out. This could lead to dehydration, so she suggests that after their trip to the restroom, they start drinking water instead of alcohol.
For people who drink occasionally or moderately, this effect of alcohol on the excretory system — the system that removes wastes such as urine — is usually temporary. However, in people who drink excessively, alcohol can have serious, long-term effects on the excretory system. For example, heavy drinking on a regular basis can cause liver and kidney disease.
As you will learn in this chapter, the liver and kidneys are important organs of the excretory system, and impairment of the functioning of these organs can cause serious health consequences. At the end of the chapter, you will learn which hormone Tricia was referring to, and some of the ways alcohol can affect the excretory system, both after the occasional drink and in cases of excessive alcohol use and abuse.
Chapter Overview: Excretory System
In this chapter, you will learn about the excretory system, which rids the body of toxic waste products and helps maintain homeostasis. Specifically, you will learn about:
- The organs of the excretory system, which include the skin, liver, large intestine, lungs, and kidneys, which eliminate waste and excess water from the body.
- How wastes are eliminated through sweat, feces, urine, and exhaled gases; and how toxic substances in the blood are broken down by the liver.
- The urinary system, which includes the kidneys, ureters, bladder, and urethra.
- The main function of the urinary system, which is to filter the blood and eliminate wastes, mineral ions, and excess water from the body in the form of urine.
- How the kidneys filter the blood, retain needed substances, produce urine, and help maintain homeostasis, such as proper ion and water balance.
- How urine is stored, transported, and released from the body.
- Disorders of the urinary system, including bladder infections, kidney stones, polycystic kidney disease, urinary incontinence, and kidney damage due to factors such as uncontrolled diabetes and high blood pressure.
As you read the chapter, think about the following questions:
1. Which hormone do you think Tricia was referring to? Remember that this hormone causes the urinary system to retain water and excrete less water out in the urine.
2. How and where does this hormone work?
3. Long-term, excessive use of alcohol can affect the liver and kidneys. How do these two organs of excretion interact and work together?