C7 - How do we rid of toxic wastes?

Question 1

What are the main organs of the urinary system?

Answer 1

Kidneys, ureters, bladder, urethra

Question 2

Which organs produce urine and which transport urine?

Answer 2

Kidneys produce urine; ureters transport urine

Question 3

What is a nephron and what are its parts?

Answer 3

The functional unit of the kidney; parts include renal corpuscle, proximal convoluted tubule, loop of Henle, distal convoluted tubule

Question 4

What are the three processes necessary for urine formation?

Answer 4

Filtration, tubular reabsorption, tubular secretion

Question 5

What components make up the filtration membrane?

Answer 5

Fenestrae of capillaries, basement membrane, filtration slits

Question 6

How does the renal corpuscle contribute to urine formation?

Answer 6

It filters blood to form filtrate, which enters the proximal convoluted tubule

Question 7

What role does the proximal convoluted tubule play in urine formation?

Answer 7

Site of tubular reabsorption of water, ions, and nutrients

Question 8

What substances are typically reabsorbed from urine during its production?

Answer 8

Water, glucose, electrolytes

Question 9

What substances are secreted into the urine during its production?

Answer 9

Urea, creatinine, excess ions

Question 10

What is the function of the loop of Henle?

Answer 10

Concentrates urine by reabsorbing water and sodium

Question 11

What is facilitated diffusion?

Answer 11

Movement of substances across cell membranes via protein channels

Question 12

What is the role of active transport in the nephron?

Answer 12

Moves substances against their concentration gradient

Question 13

What is the difference between cortical and juxtamedullary nephrons?

Answer 13

Cortical nephrons are located higher in the cortex; juxtamedullary nephrons have longer loops extending deep into the medulla

Question 14

How many nephrons are there in each kidney?

Answer 14

Approximately 1.3 million

Question 15

What is the average length of a nephron?

Answer 15

50 – 55 mm

Question 16

What percentage of the Australian population shows signs of chronic kidney disease (CKD)?

Answer 16

10%

Question 17

What are two main causes of CKD?

Answer 17

Diabetes, high blood pressure (hypertension)

Question 18

What is the main health problem associated with CKD?

Answer 18

Cardiovascular disease

Question 19

What are three risk factors for kidney disease?

Answer 19

• Diabetes
• Hypertension
• Obesity (BMI > 30)

Question 20

What components in urine can indicate kidney problems?

Answer 20

Protein, blood

Question 21

What hormone promotes water retention in the body?

Answer 21

Anti-diuretic hormone

Question 22

What is the name of the muscle found in the wall of the bladder?

Answer 22

Detrusor

Question 23

What is the reflex that controls urination?

Answer 23

Micturition

Question 24

The kidneys are said to be _______.

Answer 24

retroperitoneal

Question 25

What is the primary function of the renal fascia?

Answer 25

Anchors the kidney and attaches it to surrounding tissue

Question 26

What are the layers covering the kidneys?

Answer 26

* Renal capsule * Adipose tissue * Renal fascia

Question 27

What is the role of the collecting duct?

Answer 27

Collects urine from multiple nephrons

Question 28

What does the term 'filtrate' refer to?

Answer 28

Fluid that has passed through the filtration membrane

Question 29

What is the significance of blood pressure in the glomerulus?

Answer 29

Affects the rate of fluid filtration into the nephron

Question 30

What happens to urine output when a person is dehydrated?

Answer 30

Produces small volumes of concentrated urine

Question 31

What is the primary waste product excreted in urine?

Answer 31

Urea

Question 32

What does tubular secretion do?

Answer 32

Removes additional wastes from blood into urine

Question 33

What is the nephron higher in the cortex called?

Answer 33

Cortical nephron

Question 34

What is the nephron that is lower in the cortex with a long Loop of Henle called?

Answer 34

Juxtamedullary nephron

Question 35

What is the main role of the proximal convoluted tubule?

Answer 35

Main area for reabsorption of water (80%), 100% reabsorption of amino acids and sugars

Question 36

What does the distal convoluted tubule control?

Answer 36

Secretion of wastes, toxins, excess ions and alters concentration of urine by varying water reabsorption

Question 37

What is the role of the Loop of Henle?

Answer 37

Reabsorbs ions and water

Question 38

What is the segment following the distal convoluted tubule?

Answer 38

Collecting duct

Question 39

What happens to urine volume if you drink a bottle of water (600ml) in an hour?

Answer 39

Urine volume will increase

Question 40

What do coffee and alcohol act as?

Answer 40

Diuretics

Question 41

What is the effect of diuretics on urine production?

Answer 41

They increase urine production by affecting water reabsorption

Question 42

What happens to urine volume if a person is stranded at sea for 24 hours without fresh water?

Answer 42

Decreased urine output due to dehydration

Question 43

What abdominopelvic region is the right kidney located in?

Answer 43

Right lumbar

Question 44

What organ lies superior to the left kidney?

Answer 44

Stomach and pancreas

Question 45

What body cavity does the bladder lie within when it is empty?

Answer 45

Pelvic

Question 46

What is the typical volume of urine the bladder can hold at capacity?

Answer 46

Up to 1 L

Question 47

What tube transports urine from the kidney to the bladder?

Answer 47

Ureter

Question 48

How do the ureters enter the bladder?

Answer 48

Posteriorly

Question 49

What is the risk of backflow of urine?

Answer 49

Can lead to urinary tract infections

Question 50

What is the role of the muscular layer in the bladder wall?

Answer 50

Contracts to help expel urine

Question 51

What is the epithelium lining the bladder called?

Answer 51

Transitional epithelium

Question 52

What is the name of the tube that transports urine from the bladder to outside the body?

Answer 52

Urethra

Question 53

What is the length of the female urethra?

Answer 53

3 - 5 cm

Question 54

What is the length of the male urethra?

Answer 54

18 - 20 cm

Question 55

What are the three general processes that occur within the nephron leading to urine formation?

Answer 55

* Filtration * Tubular reabsorption * Tubular secretion

Question 56

Where does filtration occur in the nephron?

Answer 56

In the renal corpuscle

Question 57

What is the solution called that enters the Bowman’s capsule?

Answer 57

Filtrate

Question 58

What is tubular reabsorption?

Answer 58

Return of water and solutes to the blood following filtration

Question 59

What solutes are reabsorbed from the nephron to the blood?

Answer 59

* Amino acids * Glucose * Fructose * Ions (e.g. Na+, Cl-, K+, Ca2+)

Question 60

What is tubular secretion?

Answer 60

Substances are secreted into the filtrate from the blood

Question 61

What type of transport does the sodium-potassium exchange pump use?

Answer 61

Active transport

Question 62

Which ions are moved by the Na+/K+ pump?

Answer 62

* Na+ is pumped out of the cell * K+ is pumped into the cell

Question 63

What is co-transport (symport)?

Answer 63

Glucose moves from the filtrate into the nephron cells by 'piggybacking' with Na+

Question 64

What is facilitated diffusion?

Answer 64

Movement of molecules across the cell membrane via specific carrier proteins

Question 65

Is facilitated diffusion an active or passive process?

Answer 65

Passive process

Question 66

What effect does adding urea into a solution have?

Answer 66

Increases osmolarity on that side of the membrane

Question 67

What is the solution with the higher concentrations of solutes called?

Answer 67

Hypertonic

Question 68

What is the solution with lower concentration of solutes called?

Answer 68

Hypotonic

Question 69

What is the purpose of haemodialysis?

Answer 69

To substitute the excretory functions of the kidney

Question 70

How does dialysis fluid facilitate the removal of wastes?

Answer 70

Wastes and other molecules move across the semi-permeable membrane by simple diffusion

Question 71

What process removes extra fluid in the blood during dialysis?

Answer 71

Ultrafiltration

Question 72

What is the main function of the dialysis machine?

Answer 72

To remove solutes and water from the blood into the dialysis fluid

Question 73

In which direction does blood move in the dialysis process?

Answer 73

In one direction, while the dialysis fluid flows in the opposite direction

Question 74

What process allows molecules to move across the dialysis membrane?

Answer 74

Simple diffusion

Question 75

What is the normal range of sodium (Na+) concentration in blood?

Answer 75

135 - 147 mMol/L

Question 76

What is the concentration of sodium (Na+) in the dialysis fluid?

Answer 76

150 mMol/L

Question 77

Where does sodium (Na+) move during dialysis?

Answer 77

Into dialysis fluid

Question 78

What is the normal range of potassium (K+) concentration in blood?

Answer 78

3.5 - 5.0 mMol/L

Question 79

Where does potassium (K+) move during dialysis?

Answer 79

Into dialysis fluid

Question 80

What is the concentration of chloride (Cl-) in the dialysis fluid?

Answer 80

90 mMol/L

Question 81

Where does chloride (Cl-) move during dialysis?

Answer 81

Into blood, small change

Question 82

What is the concentration of creatinine in the dialysis fluid?

Answer 82

0 mg/dL

Question 83

Where does creatinine move during dialysis?

Answer 83

Into dialysis fluid

Question 84

What is the concentration of uric acid in the dialysis fluid?

Answer 84

0 mg/dL

Question 85

Where does uric acid move during dialysis?

Answer 85

Into dialysis fluid

Question 86

What components of blood do not move across the dialysis membrane?

Answer 86

Cells in the blood (red and white blood cells), platelets, and plasma proteins

Question 87

What are the main waste removal systems in the body?

Answer 87

* Urinary system * Digestive system * Sweating

Question 88

What is a significant disadvantage of dialysis compared to a healthy kidney?

Answer 88

Waste products build up over time

Question 89

How long does each dialysis session typically take?

Answer 89

4-6 hours

Question 90

How many times per week does a patient typically undergo dialysis?

Answer 90

3 times per week

Question 91

What lifestyle changes might a dialysis patient like Fred need to make?

Answer 91

* Modified diet * Avoid alcohol * Possible help with housework

Question 92

True or False: Dialysis is a perfect substitute for kidney function.

Answer 92

False

Question 93

What resources can help students improve their understanding of the subject matter?

Answer 93

* iLectures * Textbooks * Workshop questions * UniPASS study sessions

Question 94

Fill in the blank: The kidneys filter blood and reabsorb water and other molecules through the _______.

Answer 94

[nephrons]

Question 95

What should students do if they have unclear concepts after the workshop?

Answer 95

Ask questions in the workshops and speak to their tutor