Renal System 🚽

Front 1

What are the functions of the urinary system?

Back 1

- removes most of the physiological waste from the body

- produces urine

Front 2

What is the goal of urine production?

Back 2

- maintaining homeostasis

Front 3

How does urine production maintain homeostasis?

Back 3

- by regulating the volume and composition of blood

Front 4

What are the functions of the urinary system?

Back 4

- regulate blood pressure and blood volume

- regulating plasma concentrations of ions such as sodium, calcium potassium and chloride

- helping to stabilise Ph

- conserving valuable nutrients

Front 5

How does the urinary system regulate blood pressure and blood volume?

Back 5

- adjusting the volume of water in the urine

- releasing erythropoietin

- releasing renin

Front 6

What hormones are produced in the urinary system?

Back 6

- erythropoietin

- calcitrol

- detoxify superoxides, free radicals and drugs

- renin

Front 7

What does erythropoietin do?

Back 7

- stimulates red blood cell production

Front 8

What does calcitriol do?

Back 8

- is used to treat and prevent low levels of calcium and bone disease in patients whose kidneys or parathyroid glands

Front 9

What does renin do?

Back 9

- Blood pressure regulation is the main function of renin

Front 10

What are the components of the urinary system?

Back 10

- kidneys

- ureter

- urinary bladder

- urethra

Front 11

What is the basic function of the kidneys?

Back 11

- to produce urine

Front 12

What is the basic function of the ureter?

Back 12

-to transport urine toward the urinary bladder

Front 13

What is the basic function of the urinary bladder?

Back 13

- temporarily stores urine prior to elimination

Front 14

What is the basic function of the urethra?

Back 14

- conducts urine to exterior

Front 15

What makes kidneys ‘retroperitoneal’?

Back 15

- the left kidney is superior (bigger) than the right

Front 16

What is the kidney surrounded by?

Back 16

- fibrous capsule

Front 17

Where to the renal artery and the renal nerve enter?

Back 17

- hilum

Front 18

Where do the renal vein and ureter exit?

Back 18

- hilum

Front 19

What is urine produced by?

Back 19

- urine is produced by nephrons

- per kidney, there is about 1 million nephrons

Front 20

Where does urine collect from the calyces?

Back 20

- the renal pelvis

Front 21

After the renal pelvis, where does urine go?

Back 21

- the ureter

Front 22

What is a short definition of a nephron?

Back 22

- the nephron is the functional unit of the kidney where all the functions of the system takes place

Front 23

What are the two types of nephrons?

Back 23

- cortical nephrons

- 85% of all nephrons

- located in the cortex

- juxtamedullary nephrons

- closer to the renal medulla

- loops of Henley extend deep into renal pyramids

Front 24

What are nephrons made up of?

Back 24

- each nephron is made up of a renal corpusle consisting of the glomerular capsule and a capillary network known as glomerulus.

- it also has a renal tubule which begins at the glomerulus. It is a long tubular structure that may be 50mm in length

Front 25

What are the functions of nephrons?

Back 25

- production of filtrate

- reabsorption of organic nutrients

- reabsorption of water and ions

- secretion of waste products into tubular fluid

Front 26

Explain filteration

Back 26

Filtration

- The filtration process is much like the making of espresso or cappuccino. In a cappuccino machine, water is forced under pressure through a fine sieve containing ground coffee; the filtrate is the brewed coffee. The arrangement of the glomerular capillaries in series with the peritubular capillaries is important to maintain a constant pressure in the glomerular capillaries, and thus a constant rate of filtration, despite momentary fluctuations in blood pressure. Once the filtrate has entered the Bowman's capsule, it flows through the lumen of the nephron into the proximal tubule.

Front 27

What is the glomerulus involved in?

Back 27

- it is involved in filtration of the blood

- it keeps the large particles (blood cells, large proteins etc) out of the filtrate ➡️ the filtrate becomes urine in the collecting tubule

Front 28

What are the renal tubules involved in?

Back 28

- involved in reabsorption ( putting the needed substances back into the blood)

- and secretion (moving wastes from the blood to the filter are to be excreted in urine

Front 29

What are the filtration pressures in glomerular filtration?

Back 29

- Occurs as fluids move across the glomerulus

- Blood pressure at the glomerulus forces water and solutes out of the blood steam and into the capsular space

- Filtration pressure in the glomerulus is higher than capillary blood pressure because of differences in diameter of afferent and efferent arterioles

Front 30

Where does blood pressure force the fluid and dissolved substances?

Back 30

- blood pressure forces fluid and dissolved substances across the endothelial wall of glomerular capillaries into the capsular space

Front 31

Where does blood pressure force the fluid and dissolved substances?

Back 31

- blood pressure forces fluid and dissolved substances across the endothelial wall of glomerular capillaries into the capsular space

Front 32

What does the glomerular filtration rate (GFR) depend on?

Back 32

- blood pressure

Front 33

What can affect filtration?

Back 33

- any change in blood pressure

Front 34

What triggers the release of renin?

Back 34

- a decline in filtration pressure (blood pressure)

Front 35

What triggers the release of renin?

Back 35

- a decline in filtration pressure (blood pressure)

Front 36

Where is renin released from?

Back 36

- the juxtaglomerular apparatus

Front 37

What can renin increase?

Back 37

- renin can lead to increased blood volume and blood pressure

Front 38

What happens to glomerular filtration rate (GFR) after the release of renin?

Back 38

- it return to normal

Front 39

What does renin restore after its release?

Back 39

- homeostasis

Front 40

How many litres of filtrate is produced at the glomeruli each day?

Back 40

- roughly 180 litres of filtrate

Front 41

What is reabsorption?

Back 41

- the removal of water and solutes from the filtrate

Front 42

How does reabsorption take place?

Back 42

- diffusion

- or carrier proteins

Front 43

How does the reabsorption of water take place?

Back 43

- osmosis

Front 44

Where do the reabsorbed substances go?

Back 44

- back into the blood

Front 45

(Secretion), What does the blood contain which enters the peritubular capillaries?

Back 45

- some undesirable substances what didn’t cross the filtration membrane at the glomerulus.

Front 46

What happens if the concentration of undesirable substances entering the peritubular capillaries is too high?

Back 46

- the tubular cells will absorb them from the peritubular fluid and secrete them into the tubular fluid. Some examples of the substances secreted are K+, H+, creatinine and ammonia

Front 47

What is secretion?

Back 47

- the process of removing waste materials such as nitrogenous waste though the excretory system

Front 48

What happens in the kidneys at the proximal convoluted tubule?

Back 48

- reabsorbs critical substances from the filtrate, eg nutrients, ions and proteins

- releases them into surrounding interstitial fluid

- enter peritubular capillaries and return to blood stream

Front 49

What does the loop of henle do? (Reabsorption and secretion)

Back 49

- reclaims water and ions from filtrate

- ascending limb pumps out sodium and chloride ions

- descending limb absorbs water

- interstitial osmotic pressure pulls water from tubular fluid

- urea concentration rises and fluid is lost

Front 50

What does the distal convoluted tubule do? (Reabsorption and secretion)

Back 50

- if performs the final adjustment

-secrets or reabsorbs ions

- reabsorbs sodium in exchange for secreted potassium and hydrogen ions

- aldosterone increases sodium reabsorption and potassium loss

Front 51

How is urine controlled by antidiuretic hormone (ADH)?

Back 51

- it regulates water loss

-DCT (distal convoluted tubule), collecting tubule, collecting duct made permeable to water by ADH

- water then exits to interstitial fluid and remains in the body

- urine becomes concentrated (low in water, high in solute)

- the higher the ADH level, the more concentrated the urine

Front 52

Where is aldosterone released from?

Back 52

- the adrenal glands at the top of the kidneys

Front 53

What does aldosterone do?

Back 53

- it leads to the conservation of sodium (and sometimes water) and the excretion of potassium

- raises blood pressure by increasing blood volume

Front 54

What is renin?

Back 54

- an enzyme secreted by juxtaglomerular cells in the kidneys in response to low blood pressure or volume

Front 55

What can the release of renin lead to?

Back 55

- a cascade of reactions that results in production of angiotensin ll, a vasoconstrictor

Front 56

What does angiotensin ll stimulate?

Back 56

- aldosterone production from the adrenal glands

Front 57

What increases after renin production?

Back 57

- blood pressure

Front 58

When does filtrate modification and urine production end?

Back 58

- when fluid enters the renal pelvis

Front 59

What organs are responsible for the transport, storage and elimination of urine?

Back 59

- ureters

- urinary bladder

- urethra

Front 60

What are the pair of ‘muscular tubes’ called and what do they do?

Back 60

- the muscular tubes are called the ureters and they are in a pair

- they conduct urine from the kidneys to the urinary bladder

Front 61

Describe the urinary bladder.

Back 61

- a hollow, muscular organ that stores urine prior to micturition

Front 62

What does the distal convoluted tubule (DCT) do?

Back 62

- transport activities

- actively secretes substances into urine

- actively reabsorbs sodium from urine

Front 63

Describe the middle layer of the bladder wall.

Back 63

- The middle layer of the bladder wall is made up of inner and outer layers of longitudenal smooth muscle with a circular layer in between. The three layers of smooth muscle form the powerful detrusor muscle of the bladder which contacts on urination to expel urine from the bladder.

Front 64

What does the bladder do?

Back 64

- holds urine

Front 65

What is the bladder made up of?

Back 65

- smooth muscle

Front 66

What triggers the urge for a person to urinate?

Back 66

- stretch receptors in the wall of the bladder

- this occurs after 200 ml of urine is collected

Front 67

What is the maximum capacity of the bladder

Back 67

- around 800-1000ml

Front 68

When does micturition occur?

Back 68

- (urination) when it is convenient to go

Front 69

What is the composition of urine?

Back 69

- mostly water

- urea, creatinine and uric acid formed by the breakdown of proteins and nucleus acids

- trace amounts of amino acids and various ions

Front 70

What does the juxtaglomerular apparatus do?

Back 70

- releases renin, erythropoietin

- located at the start of DCT

Front 71

Tubular reabsorption/secretion - what does the PCT (proximal convoluted tubule) do?

Back 71

- it reabsorbs 60-70% of filtrate

- nutrients

- sodium and ofher ions

- water

Front 72

Where does the filtrate absorbed by the PCT then go?

Back 72

- it is released into the venous drainage for return back to the blood stream

Front 73

Where else does the PCT secrete substances?

Back 73

- into tubular fluid

Front 74

What is the function of the glomerulus?

Back 74

- production of filtrate

Front 75

What is the function of the PCT

Back 75

- reabsorption of nutrients

Front 76

What is the function of the DCT, collecting duct?

Back 76

- reabsorption of water and ions

Front 77

What can affect the concentration of urine?

Back 77

- ADH (antidiuretic hormone - released from pituitary gland) enhances the reabsorption of water in the collecting ducts

- Triggered when blood pressure and volume are low

- Makes urine very concentrated

- Urine is dilute when ADH is not present