PLTW HBS - Urinary System / Excretory System (4.1.1 -> 4.1.5)

Note for me: 4.1.1, 4.1.2, & 4.1.3 are done. need to add nephron and kidney diagrams

What are the kidneys’ shape? What do they do?

Bean shaped. They filter blood, regulate fluid volumes, and produce urine

What are the ureters’ shape? What do they do? How do they make sure there isn’t any backflow?

Long tubes. Transports urine from the kidney to the bladder. Each ureteric orifice into the bladder controls mucosal flaps to prevent backflow of urine from the bladder back into the ureter

What is the bladder’s shape? What does it do? How does it act when it is empty? When it is full?

Roughly pyramid-shaped. Stores urine. When empty, it rests entirely inside the pelvic space. As the bladder fills with urine, it's superior surface domes upward, protruding into the abdominal cavity

What is the urethra’s shape? What does it do? How long is it?

Small tube. It carries urine from the bladder outside of the body. In females, the urethra is about 1-2 inches long. In males, the urethra passes through the penis and is about 8 inches long

What is the primary role of the urinary system?

Remove waste products and chemicals from the blood

What are three other roles of the urinary system?

1. Maintains fluid and electrolyte balance

2. Regulates blood pressure by maintaining sodium and water balance and releasing hormones that influence vessel constrictum

3. Produces erythropoietin, a hormone that stimulates production of red blood cells

Diagram of the kidney

What is the primary function of the renal pelvis?

Primary collector for urine

What is the primary function of the renal medulla?

Regulates urine concentration

What is the primary function of the renal cortex?

Filters blood and produces urine

What is the primary function of the medullary pyramid?

Concentrate urine and transport it to the calyces

What is the primary function of the renal capsule?

Protects delicate kidney tissue

What is the primary function of the calyx?

Collects urine from renal pyramids and transports ot renal pelvis

What is the primary function of the ureters?

Transports urine from renal pelvis to bladder

What is the primary function of the renal artery?

Carries oxygenated blood from abdominal aorta to each kidney

What is the primary function of the renal vein?

Carries filtered deoxygenated blood away from kidneys to heart via the inferior vena cava

How does urine move from the kidney out of the body? Use bladder, kidney, urethra, and ureters

Kidney → Ureters → Bladder → Urethra

Which main kidney regions / layers are the glomerulus and the Bowman’s capsule located?

Renal cortex (outer region of kidney)

Which main kidney regions / layers are the collecting ducts and the loop of Henle located?

Renal medulla

What is the primary function of the nephron?

Filters blood to produce urine

How does water help to regulate body temperature? How else does it help the body?

It moistens tissues in the eyes, mouth, and nose, and lubricates joints. It dissolves minerals and nutrients, making them accessible to the body. It flushes out waste products and helps deliver nutrients and oxygen to cells.

How does the urinary system help to maintain homeostasis?

The urinary system filters blood and removes excess water and waste products. The body works to maintain homeostasis by matching the amount of water leaving the body through urine, sweat, feces, and evaporations from the lungs to the amount of water that is ingested.

What are electrolytes?

Electrolytes are minerals that when they dissolve in blood, it takes on a negative or a positive charge.

Which 7 electrolytes are needed for life & why?

Sodium, potassium, magnesium, calcium, chloride, bicarbonate, and phosphate. Needed for survival because they maintain the voltage necessary for nerve impulses to travel and to generate a charge across the cell membrane

What is the nephron? What does it do?

Functional unit of the kidney. Each kidney has over 1 million nephrons. The nephron forms urine through filtration, reabsorption, and secretion

Describe filtration

In glomerulus and Bowman’s capsule. Only small molecules can move through to renal tubule. RBCs, proteins, platelets, and wastes are filtered out. “The first pass through filtration”

Describe reabsorption

Renal tubule. Some components pass back to blood (water, NaCl, other electrolytes). “Good substances” are put back in blood

Describe secretion

Small toxic waste substances are removed from the blood and added to the urine, which passes into the collecting duct, which eventually empties into ureter. “Take out the remaining bad stuff”

Each nephron receives a stream of blood delivered by the _____, and returned back by the _____

Renal artery, renal vein

What is the composition of urine when it is finished being made?

Water and metabolic waste

Does glucose move from the filtrate to the blood or from the blood to the filtrate in the nephron?

filtrate to the blood

Does water move from the filtrate to the blood or from the blood to the filtrate during reabsorption in the nephron?

filtrate to the blood

Study this picture of the nephron

Why do we need to look at blood flow through the kidneys?

Blood flow is needed to filter blood and maintain fluid balance and electrolytes

How do the circulatory system and kidneys interact to create urine?

Circulatory pumps blood to kidneys which is where nephrons filter out wastes, salts, and excess water

Where is Antidiuretic Hormone (ADH) secreted, its target structure, what does it control, and what does diuretic medication do to someone’s body?

Secreted: Hypothalamus. Target structure: Kidney tubules. Control: body water balance, blood pressure, urine concentration, and homeostasis. Effects of medications: Causes kidneys to remove excess salt and water from the body through increased urine output

What are algorithms?

Set of step-by-step instructions for solving a problem or performing a calculation

What is a decision tree?

A type of algorithm that you may have unknowingly used to answer a question

What variables do clinical algorithms have to take into account while being used to try to diagnose someone?

Patient symptoms, medical history, demographics, and test results

Common symptoms of heart attacks in women?

Anxiety, chest pain, nausea, upper back and shoulder pain

Common symptoms of heart attacks in men?

Cold sweats, chest pain, pain in arms, neck, and jaw, lightheadedness

What is the glomerular filtration rate (GFR)?

The amount of fluid and dissolved substances both kidneys can filter per minute

What is kidney disease often referred to, and why?

Chronic kidney disease (CKD) because of the damage to your kidneys happens slowly over a long period of time

What can an accurate GFR result help us with?

Managing kidney disease and catching early-stage CKD

What determines whether an individual is put on the kidney transplant or not?

How much function their kidneys have; too low = transplant list

Define creatinine

A byproduct of a chemical compound called creatine

Define creatine

An amino acid that helps to maintain a continuous supply of energy to your muscles. As muscle use creatine, it exits your body as a waste product in urine

Define Cystatin C

A protein that slows down the breakdown of other proteins so that they can stay in the body longer. This protein plays a role in growth hormone production, bone metabolism, and potentially acts to prevent brain damage

mGFR vs. eGFR

Measured GFR vs. estimated GFR

What is the usual eGFR number in adults?

>90 mL/min

What eGFR is considered to have kidney function at 100%?

120 mL/min

What eGFR indicates that someone has severe loss of kidney function and has to start dialysis?

15 - 29 mL/min

What eGFR indicates kidney failure and qualifies individuals to be evaluated for a kidney transplant & placed on the kidney transplant list?

≤ 15 mL/min

Does eGFR decline with age, even in people without kidney disease?

Yes

Why does eGFR values decline with age?

Natural psychological aging as loss of functional neurons, reduced blood flow, and structural change of kidneys becoming smaller

Risk factors for CKD?

Diabetes, high blood pressure, heart disease, obesity, family history, and age over 60

Symptoms of later-stage CKD?

Extreme fatigue, swelling (legs / ankles), little to no urine production, persistent itching, nausea, vomiting, shortness of breath

What are the two tests doctors use to monitor kidney health? What does each test measure?

Urine test, measures ucar, if there is albumin in your urine then it indicates that your kidneys are damaged. Blood test (along with urine albumin to creatine ratio) to measure EGFR to determine how well the kidneys clean your blood

What is a data scientist?

A professional who organizes large quantities of data in different ways to help them seek meaningful insights from the data

Are algorithms race based?

Yes

How are race based algorithms often inaccurate?

They were often developed using small, homogeneous data sets, and when it is applied to a diverse population, it can lead to delayed care and unequal treatments of individuals from marginalized communities

Is the Body Mass Index (BMI) accurate? Why or why not?

No, it doesn’t distinguish between harmful fat, beneficial muscle, or healthy bone, nor does it indicate the distribution of fat on an individual

What is a kidney transplant chain?

A donor provides a kidney to someone in need of one, with someone else ready to receive a donation on their behalf, but is incompatible with them or a poor match