The Urinary System

Max’s Maximum: A Case Study on the Urinary System”

1. What does the color of Max’s urine tell Tracey about how concentrated or dilute it is? How does Max’s urine color/concentration compare to the urine specific gravity at the same time?

Don't use plagiarized sources. Get Your Custom Essay on
The Urinary System
From $10/Page
Order Essay

Max’s pale urine tells Tracey that his urine is diluted. The yellow urine is more concentrated, and the dark yellow urine is super concentrated. Specific gravity is the ratio of the density of a substance compared to the density of an equal volume of distilled water. Urine, with its various solutes, has a greater specific gravity than water which is (1.001-1.035), and depending on the concentration of the solute it can vary. The more concentrated the urine, the darker the color will be and specific gravity will be higher.

2. Based on the urine color and specific gravity, what might Tracey conclude about the hydration status of Max’s body at the three different times?

When Max’s urine is pale with a low specific gravity, his body is likely to be well hydrated; the kidneys are reabsorbing less water, allowing it to be eliminated in urine. When his urine is dark yellow with a higher specific gravity, his kidneys are concentrating urine and reabsorbing more water in an attempt to maintain body fluid homeostasis (defend plasma osmolality). Dehydration will trigger this response. The yellow urine signals euhydration; the corresponding high-normal specific gravity is likely due to the small amount of glucose in the urine.

3. Antidiuretic hormone (ADH) regulates the formation of concentrated or dilute urine. In which time period is Max’s body secreting its highest amount of ADH? Explain your answer.

ADH is going to be highest when the body is most dehydrated. In Max’s case, this is right after his 2-hour run. During his run, Max loses water via sweat and exhalation, and doesn’t effectively replace it. The osmolality of his blood increases, signaling the posterior pituitary to release ADH. ADH targets the principle cells in the collecting ducts of the kidney tubules, causing them to increase reabsorption of water from the filtrate. This negative feedback mechanism attempts to conserve water in order to decrease blood osmolality and restore body fluid homeostasis.

4. Tracey knows that proteinuria (protein in the urine) after intense exercise is physiological (normal). However, protein is typically not present in urine. Why is that?

The glomerulus is a passive filter that acts as a barrier to larger molecules, such as most plasma proteins. Also, because most proteins carry a net negative charge, they are repelled by the membrane, thereby hindering their passage. However, some smaller proteins can and do pass through the filtration membrane. Most of them are reabsorbed in the proximal convoluted tubule by endocytosis and then broken down into amino acids to be returned to the blood in the peritubular capillaries. The mechanism of exercise-induced proteinuria is unclear, but it is typically a transient occurrence. Any kidney disease can render the glomerulus dysfunctional, leading to a more sustained proteinuria. In fact, Max’s hypertension, if left unchecked, could damage the filtration membrane of the glomerulus. The proteinuria will increase the specific gravity of his urine (along with his relative dehydration).

5. Tracey had been slightly concerned about the trace glucose that was found in Max’s urine six hours after his exercise until she discovered that he had eaten an entire large pizza an hour before the urinalysis. Explain why glucose might show up in Max’s urine after a particularly heavy meal.

Glucose passes easily through the glomerular filtration membrane, and normally 100% of it is reabsorbed in the proximal convoluted tubule (PCT). The reabsorption of glucose is accomplished by secondary active transport and requires a transport protein in the membrane to facilitate the movement of glucose across the membrane. Typically, there are more than enough of these transport proteins, but they do have an upper limit beyond which no more glucose can be transported. This is called the transport maximum (Tm) for glucose. Generally, the Tm for glucose is not reached until blood levels of glucose exceed 180 mg/dL, which is known as the renal threshold. The most common cause of hyperglycemia (high blood glucose) is diabetes mellitus. So, if the renal threshold is exceeded for glucose in the PCT, it will “spill” into the filtrate and be eliminated in urine. Without further testing, it’s unknown whether Max has a lower-than-normal renal threshold for glucose, or has exceeded the normal renal threshold of 180 mg/dL with his heavy meal.

6. Lactic acid accumulation can be a consequence of intense exercise. Tracey notes that Max’s kidneys are working to defend his body against acidosis. How can she tell? Describe this mechanism.

Max’s pH is more acidic right after his run. This is evidence of a higher hydrogen concentration in urine. When pH drops, the tubule cells secrete hydrogen into the filtrate, allowing it to be lost in urine. They also reabsorb bicarbonate (a base) to help buffer the body fluids. The result is a restoration of normal pH.

7. Based on Max’s urinalysis data, should he drink more water prior to exercise to ensure that he doesn’t dehydrate during intense activity? Explain your answer.

Max’s urine is already extremely dilute before exercise, indicating he is probably well hydrated. If he were to drink more, then he would simply end up with a full bladder during his run (the kidneys would eliminate the excess water). Better advice would be to drink more strategically during his run. For instance, when he is doing his training runs, Max could take a drink every 15 minutes (more if he is sweating heavily) and practice different drinking regimens when he trains until he finds one that keeps him hydrated but does not require him to stop to urinate during his run.

8. Max’s regular exercise regimen has reduced his high blood pressure, allowing him to achieve normal blood pressure on a single antihypertensive medication. The medication he takes is called an angiotensin converting enzyme inhibitor, or ACE inhibitor, which blocks the activation of angiotensin II. Describe at least two mechanisms by which angiotensin II targets the kidneys to increase extracellular fluid volume and, therefore, increase blood pressure.

Angiotensin II directly signals the renal tubules to reabsorb sodium. Where sodium goes, water follows by osmosis, causing blood volume and pressure to increase.

Angiotensin II signals the release of ADH from the posterior pituitary. ADH acts on the principle cells of the collecting ducts to cause reabsorption of water from the filtrate into the blood. Blood volume and pressure are increased.

Angiotensin II is a potent vasoconstrictor, which leads to a decline in peritubular capillary hydrostatic pressure and more fluid reabsorption. Blood volume and pressure are increased.

Angiotensin II prompts the release of aldosterone from the adrenal medulla. Aldosterone stimulates renal tubules to reabsorb sodium (with water following) and this leads to an increase in blood volume and pressure.

Angiotensin II stimulates the glomerular mesangial cells to contract and reduce glomerular filtration rates. Less filtrate is produced, less fluid is lost in urine, and blood volume and pressure are increased.

Angiotensin II triggers thirst by acting at the hypothalamus. This increases blood volume and blood pressure.To continue with the answer check on mycoursewriter.com/

MyCourseWriter
Order NOW For A 35% Discount!
Pages (550 words)
Approximate price: -

Why Choose Us

Quality Homework Writing

Do you need to ace your test? We have qualified writers to assist you in writing 100% quality homework writing. Mycoursewriter offers students unique and personalized custom papers that help them in getting good grades. Our academic experts will assist you with your dissertation papers, thesis writing, research papers, term papers, and case study homework help. Our writers are experienced and have perfected the art of crafting the best essay writing papers regardless of your academic level. Order now and get our superb homework writing services.

Expert Academic Writers

A student needs professional assistance outside class time. Before hiring our writers, they undergo thorough tests and strict educational backgrounds. After passing a test, our writers undergo training to ensure they deliver expert professional papers to our customers. We ensure they meet the timely delivery of papers and follow our customers' provided instructions. Every writer is an ENL writer and is from the USA, Canada, UK, or Australia. Our experts approach papers effectively depending on their area of specialization.

Affordable Price Guarantees

Is the deal too good to be true? Mycoursewriter is the most affordable assignment help website on the market. We consider students' daily needs for academic help. Our paper costs are reasonably priced to approximately 90% of students around the globe. Our main aim is to ensure students achieve academic excellence, and we believe inconsiderable prices should not hinder students from getting quality homework writing help. In case of any dissatisfaction, we offer unlimited revisions and rewrites without extra charges.

Timely delivery of papers

Tight deadline? Is your paper due in the next few hours? Worry no more. Our writers are here for your rescue. Many college students find it hard to balance their social and academic life and get caught up with academic deadlines. Drafting your paper at the last minute does not allow you to conduct extensive research and craft the correct answers. We have expert writers ready to work on your assignment writing. Urgent writing services are the ultimate solutions you need. We guarantee you timely delivery of papers at your convenience and specified time delivery of the customer.

100% Original Tasks

The ultimate deal-breaker in achieving good grades is submitting imitative papers. Plagiarism is a breach of examination standards and has serious consequences. Students need to deliver papers written in their understanding by paraphrasing their research findings and relevant citations. Our expert's primary consideration is providing free plagiarized papers that meet the lecturers' requirements. Our editors will proofread your paper before delivery ad ensure your papers will not be substandard. We guarantee extreme originality, and in case of any customer concerns, we offer a plagiarism report.

All Round the clock Customer Support

Our website is user-friendly and super useful! Mycoursewriter is the most trusted online writing website always available to provide you with assignment writing services that you need. Our primary concern is meeting customer need specifications by our friendly customer support team that Is available all the time. Our website usability is self-learnable but in case of any problem, feel free to contact us directly through our website email: support@mycourserwiter.com. We have diligently satisfied thousands of students, and you can witness this on our sites' review page.

Try it now!

Calculate the price of your order

We'll send you the first draft for approval by at
Total price:
$0.00

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Advantages of Using Our Assignment writing Services

Mycoursewriter welcomes you for superb essay writing services. We are a legit site offering help with your most challenging homework writing assignments at affordable prices. Your essay paper will be assigned to a professional writer who will craft the paper from scratch according to your provided instructions.

Essays

Essay Writing and Proofreading Services

Essay writing is a common assignment writing for most college students. It takes a lot of time to craft a complete perfect essay. Mycourserwiter offers the best essay writing and proofreading services for most college students. Your paper is assigned to an expert writer who does thorough research on fresh ideas and personalizes your essay paper according to your assignment writing guidelines. Our essays are entirely exceptional and undergo a strict procedure that includes papers free from plagiarism and thorough proofreading.

Admissions

Admission and Business Papers

Writing an admission paper is not every student's desire, and this should not hinder any student from earning an admission. Writing a perfect personal statement to earn a position in a dream school or job can be stressful. Personal statements should display a high level of confidence and uniqueness. Admission essays require you to have a vast knowledge of the current happenings in the world and knowhow of the business world. We have qualified writers with skills who will write your admission paper through comprehensive research. All you have to do is provide us with little details about yourself, instructions and our writers will craft a perfect paper for you.

Editing

Editing and Proofreading

Mycoursewriter offers you assignment writing services free from grammatical and formatting mistakes. An error-free paper is significant in scoring the desired maximum grades. We have a team of editors who will go through your paper after our expert writers have delivered their fully crafted papers. Our writers will cover all the aspects of your paper instructions, such as fonts, spacing, and educational formats. Our team of editors will check through your paper to make sure it meets the formatting style provided in the paper instructions. Under no circumstances will a poorly formatted paper will be forwarded to you as our team of editors will ensure careful proofreading.

Coursework

Technical Papers

Assignment writing is part of a learning process, and one may not have the knowledge to answer all questions correctly. This should not be a stress to you as we have qualified essay writing experts to help you. Our qualified writers are holders of PhDs, Degrees, and Masters in different areas of study and can handle any papers regardless of the complexity. Multiple assignments may be challenging to finish on time. Our skilled professional writers are here to assist you in crafting all the correct answers for your assignment. Stop stressing about your homework writing and place an order with us, and our expert writers will provide you with the best assignment help.