Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Renal Physiology > Urinary physiology > Flashcards

Urinary physiology Flashcards

0
Q

renal cortex function

A

protects kidney, holds everything together, made out of connective tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
1
Q

structure of urinary system

A

urine forming organs ( kidneys)
-structures that carry urine from kidneys to the outside for elimination from the body ( ureters, urinary bladder, urethra)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

order of renal blood supply

A

renal artery- segmental artery- interlobar artery- arcuate artery- interlobular artery - afferent arteriole- glomerulus- efferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

each nephron has its own

A

afferent arteriole, capillary tuft, and efferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

vasa recta

A

they are efferent arterioles from the peritubular capillaries that wraps around nephron structure.
- the loop structure enables them to pick up interstitial fluid without removing excess solute

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

function of kidney

A

regulate blood ionic composition, maintain blood osmolarity, regulate blood volume, blood pressure, acid and base balance, excretion of waste products, endocrine functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

structure of kidneys

A

bean-shaped, concave side inward

  • located in posterior part of abdomen on each side of the spine, top of kidney at 12th thoracic vertebrae
  • right kidney sits below liver
  • left kidney sits below diaphragm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

urinary bladder

A
  • stores urine temperature

- a hollow, distensible, smooth-muscle walled sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Urethra

A
  • urine is emptied from bladder to outside through this due to bladder contraction
  • female is short and straight
  • male is longer and curving course, serves as a passageway for semen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nephron

A

is the functional unit of kidney, about 1 million nephron per kidney

  • has 2 components: vascular and tubular
  • regulate water and solute ( especially electrolytes) by filtering blood under pressure and then reabsorbing necessary fluid and molecules back into blood while secreting other unneeded molecules.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

vascular component

A

glomerulus: ball like tuft of capillaries through which part of the water and solutes is filtered from blood passing through

afferent arteriole: where blood is carried to glomerulus

efferent arteriole: where blood is exiting

peritubular capillaries: supply renal tissue, exchange with fluid in tubular lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

tubular component

A

bowman’s capsule: collects the glomerular filtrate

proximal tubule: uncontrolled reabsorption and secretion of selected substances

loop of henle: establishes an osmotic gradient in renal medulla that is important in the kidney’s ability to produce urine

distal tubule and collecting duct: variable, controlled reabsorption of Na and water, secretion of potassium and hydrogen ions occur here, fluid leaving collecting duct is urine, which enters renal pelvis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

combined vascular/tubular component

A

Juxtaglomerular apparatus: produces substances involved in the control of kidney function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Glomerular filtration

A

where a portion of the blood plasma is filtered into kidney
-passes through 3 layers (fluid): walls of capillaries, basement membrane, inner layer of Bowmann’s capsule (podocytes): narrow slits in between capsular filtration slites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

GFR rate

A

determined by filtration pressure in glomeruli and permeable surface of glomerular membrane

  • pressure varies from different end of glomerulus to efferent end ( pressure from capsule and afferent arteriole)
  • normal GFR is 125 for male and 115 for female
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Forces in GFR

A

net filtration pressure: total pressure that promotes filtration

glomerular capillary blood pressure: hydrostatic pressure by fluid and colloidal ( protein and albumin)

plasma colloid osmotic pressure: plasma protein distribution and back pressure in bowman’s capsule ( constant in normal condition, change in abnormal condition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

2 major control mechanisms

A

autoregulation: prevents changes in GFR, include myogenic mechanism aka muscle generated tissues AND tubuloglomerular feedback

extrinsic sympathetic control ( long term regulation of arterial blood pressure): by SNS input to afferent arterioles and baroreceptor reflex

17
Q

role of mesangial cells

A

located around glomerular capillaries, regulate SA available for filtration (contraction decrease SA, relaxation increase SA)
-lower SA, increase filtration pressure

18
Q

Tubuloglomerular feedback aka negative feedback

A
  • each nephron can regulate its own GFR
  • Juxtaglmerular apparatus controls this process, include glomerulus, macular densa, specialized juxtaglomerular cells: produce and release Renin
19
Q

Macula densa cells

A

sample the NaCl content in the distal tubule, signal the juxtaglomerular apparatus to make appropriate adjustments in GFR

20
Q

Hormonal regulation of GFR

A
  1. Atrial natriuretic peptide ( ANP)- INCREASE GFR
    - stretching of the atria that occurs with an increase in blood volume cause hormonal release
    - inhibits sodium reabsorption
    - promotes diuretic effects
  2. Angiotensin II: DECREASE GFR
    - potent vasoconstrictor that narrows both afferent and efferent arterioles
21
Q

Tubular reabsorption

A

involves the transfer of substances from the tubular lumen back into the peritubular capillaries

  • involves transepithelial transport ( cross 5 barriers)
  • cross luminal membrane, pass through cytosol, cross basolateral membrane, diffuse through interstitial fluid, penetrate capillary wall to enter blood plasma
22
Q

Reabsorption of glucose

A
  • glucose filter freely across glomerular membrane
  • reabsorbed in proximal tubule by sodium dependent cotransporter
  • if cotransporter has too much glucose, it can lead to glycosuria and reach renal threshold where the glucose begins spilling in the urine
23
Q

renal threshold (tubular max)

A

maximum ability of the kidney to absorb

  • active reabsorption required carrier
  • carrier is substance specific, so nothing beyond is absorbed except for sodium
  • 275 mgm of glucose per min
24
Q

tubular secretion

A

transfer of selective substances from peritubular capillaries into tubular lumen

  • mainly H+ and K+ ions, organic anions and cations
  • Hydrogen is secreted in proximal, distal, and collecting tubules
  • Potassium is secreted in distal and collecting duct
  • Organic ions is secreted in proximal tubules
25
Q

H+ and K+ secretion effects

A

when body is too acidic, more hydrogen ions are secreted, so potassium is retained in body fluids.
-Na and H are secreted in exchange for Na reabsorption

26
Q

excretion

A
  • end product that includes excess ions, water, molecules, toxins, foreign molecules
  • include nitrogenous waste, ammonium, excess urea
  • urine output is 1 to 1.5L a day
27
Q

Medullary countercurrent mechanism

A
  • happens in juxtamedullary nephrons
  • contributes to vertical osmotic gradient
  • Descending limb: thin epithelium and permeable to water only, NO sodium reabsorption
  • Ascending limb: thick epithelium and IMpereable, actively transports NaCl out of tubular lumen into interstitial fluid
28
Q

benefits of countercurrent mechanism

A
  • effective water reabsorption

- final adjustment depends on condition of body fluid

29
Q

Role of Vasopressin

A
  • distal and collecting tubules are impermeable to water in absence of ADH
  • has no influence on loop of henle and proximal tubule
30
Q

role of aldosterone

A
  • acts on distal and collecting tubule
  • through activation of RAAS
  • Na reabsorption
31
Q

renal endocrine function

A

kidney normally secrete erythropoietin, a growth factor for RBC and active vitamin D, a cofactor for calcium reabsorption
-in chronic renal failure, anemia and osteodystrophy are consequences

32
Q

Erythropoietin

A
  • peptide growth factor that stimulates RBC development in bone marrow
  • increased release with hypoxia and decrease circulating red cell mass
33
Q

Vitamin D

A
  • Kidney performs second hydroxylation of vitamin D to form 1,25 hydroxycholecalciferol, an active form of vitamin D needed for calcium reabsorption
  • facilitate calcium reabsorption in kidney tubules
34
Q

Renal plasma clearance

A

volume of plasma cleared of a particular substance per minute

  • clearance rate is U times V/P
  • U is urine concentration
  • V is urine flow rate/min
  • P is plasma concentration of substance
35
Q

creatine and insulin clearance

A

creatine- end product of muscle metabolism, filtered, not reabsorbed, slightly secreted

insulin- syn. carb, more accurate measurement of GFR

36
Q

Dialysis

A

separation of large solutes from smaller ones through use of selectively permeable membrane

  • hemodialysis: filter blood through artificial kidney machine
  • peritoneal dialysis: catheter or peritoneum
37
Q

net filtration pressure formula

A

glomerular capillary blood pressure - opposition blood pressure = NFP

  • favour filtration
  • about 20% of plasma entered is filtered at NFP
38
Q

transepithelial transport

A

passive is no energy
active is glucose, amino acid, sodium, phosphate
-active can be Na-K ATPase pump: where most is reabsorbed in the proximal tubule

39
Q

Countercurrent mechanism extra info

A
  • descending loop is permeable to water and equilibrates with the rising interstitial solute concentration
  • so when filtrate reaches ascending loop, it is more concentrated, allowing ascending loop to further increase the osmolarity of the interstitial fluid

Renal Physiology (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions