Exam 4: Respiratory & Renal Flashcards

Question

Explain gas partial pressures of inspired air vs alveolar air

Answer 1

Gas dissolved in liquid exerts a pressure In liquid equilibrated with a gas mixture, partial pressures are equal in the 2 phases The amount of each gas dissolved in liquid is determined by - temp in fluid - partial pressure of the gas - solubility of the gas

Answer 2

Flattened biconcave discs with a large surface area to promote diffusion of gases Each RBC contains hemoglobin that contains iron The iron group of the heme helps to transport O2 from the lungs to the tissues

Answer 3

**S-Shape** - binding cooperatively **Upper plateau** - O2 loading in lungs **Steep slope** - unloading in tissues As PO2 increases, % of hemoglobin saturated with bound oxygen increases until all of the binding sites are occupied at 100% saturation Systemic venous blood is typically 75% saturated with oxygen

Answer 4

↑pH and ↓H+ - left shift (more affinity) ↓pH and ↑H+ - right shift (less affinity)

Answer 5

↓PCO2 - left shift (more affinity) ↑PCO2 - right shift (less affinity)

Answer 6

↓Temperature - left shift (more affinity) ↑Temperature - right shift (less affinity)

Answer 7

↓ 2,3-DPG - left shift (more affinity) ↑ 2,3-DPG - right shift (less affinity)

Answer 8

HCO3- **(70%)**: Carbonic anhydrase Dissolved CO2 **(10%)** Carbaminohemoglobin **(20%)**

Answer 9

Low concentration of carbon dioxide in the alveolar air sets up the gradient that moves it from the pulmonary blood into the alveolar air At active cells, the production of carbon dioxide during fuel catabolism sets up the gradient to move it from the cells into the systemic blood

Answer 10

Pathological conditions that **reduce alveolar ventilation and gas exchange** PO2 normal in alveoli and blood

Answer 11

**Destructive disease** ↓ alveoli ↓ surface area (↓ gas exchange; ↓ diffusion) ↓ elastic recoil of lung ↑ Lung compliance (very stretchy) PO2 is normal/low in alveoli and PO2 low in the blood

Answer 12

**Restrictive Disease** Thicker alveoli - ↑ distance for diffusion (slows gas exchange) Loss of lung compliance Ex: Black Lung (inhalation of particulate matter) PO2 is normal/low in the alveoli and PO2 is low in the blood

Answer 13

Hypersensitivity of the smooth muscle tone **Obstructive disease** ↑ Airway resistance, ↓ Ventilation Bronchioles constricted, PO2 low in alveoli, and PO2 low in blood

Answer 14

Emphysema (**destructive**) and chronic bronchitis (**obstructive**) Treatment: - Quit smoking, avoid lung irritants - **Medicines** - bronchodilators, steroids, flu shots, oxygen therapy - Surgery-bullectomy, lung volume reduction surgery (removing dead parts), lung transplant

Answer 15

Tidal volume - volume of gas inspired or expired in an unforced respiratory cycle Inspiratory reserve volume - maximum volume of gas that can be inspired during forced breathing Expiratory reserve volume - maximum volume of gas that can be expired during forced breathing Residual volume - volume of gas remaining in lungs after a maximum expiration Total lung capacity - total amount of gas in lungs after maximum inspiration Vital capacity - maximum amount of gas that can be expired after max inspiration Inspiratory capacity - max amount of gas that can be inspired after normal tidal expiration Functional residual capacity - gas remaining in lungs after a normal tidal expression

Answer 16

During forced exhalation, uneven transmural pressures within the lungs can cause some airways to collapse Air becomes trapped in these collapsed airways to reduce the forced vital capacity (FVC) High volume of gas trapping will cause forced vital capacity (FVC) to be smaller

Answer 17

FEV -> forced expiratory volume in 1 sec FVC -> forced vital capacity Ratio is calculated in order to diagnose obstructive and restrictive lung disease Changes with disease: - **Restrictive Disease**: i.e. black lung; ratio is similar to normal ratio but **less** volume - **Obstructive disease**: i.e. asthma; can **reduce** ratio by **increasing resistance** of air flow - **Severe Obstructive Disease**: COPD; can **increase resistance** and **decrease FVC** due to gas trapping

Answer 18

Excess interstitial fluid ↑ diffusion distance I.e. congestive heart failure PO2 in alveoli is normal, PO2 in blood is low ↑ Blood hydrostatic pressure

Answer 19

An infection of one or both lungs, in which alveoli fill with pus and other liquid

Answer 20

Disease caused by the coronavirus, can cause lasting lung damage (fibrosis) Can cause: - Lung complications (pneumonia) and in severe cases ARDS (acute respiratory) -> Type II alveoli cells - Fluid enters alveolus disrupting normal gas exchange - Alveoli can collapse due to fluid and loss of surfactant Treat with: - vaccines, antivirals, ventilator, steroids (↓ inflammation), ECMO, proning (on stomach/side)

Answer 21

Measures percentage of hemoglobin in the blood Device sends 2 different wavelengths of light (red and infrared) through the finger and measuring the light with a photodetector as it exits **Hemoglobin absorbs light differently depending on its saturation with O2** Normally ranges 95-100, lower indicates hypoxemia or low blood oxygen

Answer 22

Receptor reflexes that affect automatic breathing Sensory fibers in vagus 3 receptor types: **Unmyelinated C fibers** - respond to bradykinin, histamine (injury) - produces rapid/shallow breathing (pain) **Rapidly-adapting receptors** - located in airway mucosa - respond to inhaled irritants - stimulate cough **Pulmonary stretch receptors (Hering breuer reflex** - Sense lung volume - expansion reduces inspiration effort (preventing over inflation of lungs) - Important for normal breathing pattern in infants

Answer 23

Rf = frequency (breaths/min) Vt = tidal volume (ml) **Minute ventilation** = Rf x Vt -> Vd = atomic dead space (air in conducting zone) -> Lungs are **bidirectional**, which means air can get trapped in the conducting zone **Alveolar ventilation** = Rf x (Vt - Vd) - Vd usually around 150ml - strongly affects gas exchange - slow, deep breathing vs. panting (cause change in alveolar ventilation without change in minute ventilation)

Answer 24

**Loss** of "automatic" respiratory pathway Must be **conscious (awake)** to voluntarily control breathing rare, but shows that there are 2 separate pathways -> **voluntary and involuntary** Normal "automatic" breathing is generated in medulla -> respiratory rhythm generator (multiple groups of neurons signaling)

Answer 25

No respirator "pacemaker cells" Neuron groups interact to generate basic inspiratory pattern Neurons project to spinal motor neurons that innervate respiratory muscles

Answer 26

At the PNS (always sensing PCO2 and pH) which is the aortic and carotid bodies CNS is at the medulla oblongata

Answer 27

**Cerebral cortex** - conscious control ("hold your breath") - separate spinal pathway **Subcortical Regions** - automatic coordination - motor tasks ("stop breathing when you thread a needle") - emotion ("stop breathing during last second shot of a game") **Pons** - fine-tunes medullary output - integrates vagus nerve input

Answer 28

Monitor changes in arterial blood PCO2, PO2, pH (mainly only PCO2 and pH on a breath by breath basis) Peripheral (carotid bodies and aortic bodies and will detect PO2 if it drops dramatically) Aortic bodies stimulated by: - rise in **arterial PCO2** - rise in arterial H+, fall in pH - fall in arterial PO2 (**sensitive to this signal i.e. large drop) - rapid response (sec) Arterial PCO2 is primary variable regulated by automatic breathing

Answer 29

Detect changes in **arterial PCO2-** via pH H+ does not cross blood-brain barrier CO2 diffuses in, forms H2CO3 (carbonic acid) Neurons detect drop in CSF pH Slow response (min)

Answer 30

Controlled by negative feedback loop

Answer 31

**Work** -> effort used to move a mass W = Force x Distance **Exercise** -> work at a faster rate Work rate = work/time Proportional to volume of CO2 produces (Vco2) and volume of O2 consumed (Vo2) per unit time Direct indication of metabolic needs Proportional to heart rate and minute ventilation (Ve)

Answer 32

Ventilation and heart rate **increase** with exercise

Answer 33

Tidal volume and stroke volume increase with exercise intensity but flatten out Work of expanding increases (resistance and stretch) -> law of diminishing returns -> start to spend more O2 to get O2

Answer 34

Exercise shortens transit time in pulmonary capillary but does not change PO2 pulmonary venous blood

Answer 35

Because ventilation is increasing to keep PO2 and PCO2 stable At some point ventiliation can increase all the way to hyperventiliation, where PO2 has no change and PCO2 starts to drop

Answer 36

1. Regulates water and electrolyte (Na+, K+, Cl-, Ca++, Mg++, PO4--) balance 2. Excrete endogenous (urea) and exogenous (drug metabolites) waste products 3. Regulate arterial blood pressure and RBC synthesis - renin angiotensin aldosterone signaling (affect total peripheral resistance) - erythropoietin (stimulates RBC production) 4. Regulates plasma pH (H+ and HCO3-) HCO3- = bicarbonate

Answer 37

Maintain overall fluid/electrolyte homeostasis Note done solely by the kidneys but they are vital (other systems involved) If kidneys are non-functioning, need dialysis every 2-3 days

Answer 38

60% H2O 40% Intracellular H2O 20% extracellular H2O Total body water (TBW) = 60% of body weight TBW = ICF (intracellular) + ECF (extracellular) ECF = plasma (1/4) + interstitial fluid (3/4)

Answer 39

2 kidneys Renal artery + vein Ureter - smooth muscle Bladder - smooth muscle, storage sac, normally sterile Urethra - smooth muscle (4cm female; 20cm male) - site of potential UTI - Internal urethral sphincter - smooth muscle - innervated by automatic nerves (parasympathetic) - external urethral sphincter (skeletal muscle - voluntary)

Answer 40

Outer cortex: Contains many capillaries Medulla: Pyramid contains minor calyces which unite to form a major calyx Major calyces form renal pelvis, renal pelvis collects urine -> Transport urine to ureters

Answer 41

20-25% of cardiac output goes to the kidneys Allows kidneys to constantly process extracellular fluid Essential to allow enough oxygen to sustain function

Answer 42

Renal artery -> interlobar artery -> arcuate artery -> interlobular artery -> portal arterial system -> interlobular vein -> arcuate vein -> interlobar vein -> renal vein

Answer 43

Reflex control center in spinal cord regulates internal and external urethral sphincters Filling of bladder activates **stretch** receptors that **send impulses** to the **micturition center** - activates **parasympathetic system** causing **contraction** of **detrusor** muscle and **inhibition of sympathetic** causes **relaxation** of **internal urethral sphincter** **↑ stretch, ↑ parasymp activity, ↑ detrusor muscle contracts** **↓ skeletal muscle neuron input, opens external sphincter** Urination occurs when descending motor tracts from micturition center **inhibit somatic motor neurons to relax external urethral sphincter**

Answer 44

Function unit of the kidney Interface between **blood and urine** **Transport processes** include **diffusion** and **carrier-mediated transport** Needed for diffusion - ↑ surface area, ↑ [ ] gradient, ↓ thickness About 1 million nephrons per adult kidney Each nephron is one epithelial cell thick Proximal tube -> loop of henle -> distal tube -> collecting tube

Answer 45

Excretion -> lost from body Filtered -> moved from one compartment to another by selective diffusion (permeability) Secreted -> transported out of blood into nephron Reabsorbed -> transported out of nephron Amount excreted = amount filtered + amount secreted - amount reabsorbed

Answer 46

**Glomerular filtration**: plasma filtered from glomerular capillaries into Bowman's space **Tubular reabsorption**: movement of substances from lumen into the peritubular capillary **Tubular secretion**: movement of substances from the peritubular capillary into the lumen

Answer 47

Afferent arteriole - delivers blood into the glomeruli Glomeruli (glomerular capillaries) - capillary network that produces filtrate that enters urinary tubules/nephrons Efferent arteriole - delivers blood from glomeruli to peritubular capillaries Peritubular capillaries (vasa recta) - important for secretion and absorption

Answer 48

Portal system - 2 capillary beds in series Afferent arteriole -> glomerular capillary -> efferent arteriole -> peritubular capillary Allows blood to be altered and go immediately to next capillary bed Glomerular capillaries - relatively high pressure Peritubular capillaries - low pressure

Answer 49

glomerular capsule -> proximal convoluted tubule (PCT) -> descending and ascending limbs of loops of henle (LH) -> distal convoluted tubule (DCT) -> collecting duct (CD)

Answer 50

**Filtration** Endothelial cells -> anchoring protein (basement membrane) -> epithelial cell lining (podocyte) - filtration slits between these create a barrier of what can get into the nephron Filtered: - water, amino acids, glucose, electrolytes, <5000 daltons (molecular mass) Not filtered: - cells, proteins, fats, complex carbs, negatively charged molecules (can't get through basement membrane), >5000 daltons **Ultrafiltrate**: - fluid that enters glomerular capsule Glomerular filtration: - producing ultrafiltrate under **hydrostatic pressure** of blood Glomerular filtration **rate** (GFR): - volume of filtrate produced by both kidneys each minute - avg = 125ml/min

Answer 51

Stimulates vasoconstriction of afferent arterioles - preserve blood volume to muscles and heart - prevents rise in GFR with increased Cardiac Output (CO)

Answer 52

Ability of kidney to maintain a constant GFR despite systemic changes – Achieved through effects of locally produced chemicals on the afferent arterioles Maintaining GFR: - When MAP drops to 70 mm Hg, afferent arteriole dilates - When MAP increases, vasoconstrict afferent arterioles

Answer 53

**REABSORPTION** - ↑ surface area & 2/3 of filtrate is absorbed - reabsorbs salt and H2O - returns back into peritubular capillaries - keep the sugar save the glucose About 180 L/day of ultrafiltrate produced but only 1-2L of urine excreted per day (**only need 500ml/day urine needed to excrete metabolic wastes**) Made of Cuboidal epithelial cells and lots of microvilli

Answer 54

Transcellular: - through cell membrane - carriers (may be active, carrier-mediated) - pores (passive) Paracellular - around cell (strictly passive diffusion & requires gradient)

Answer 55

Filtered glucose and amino acids (small and filtered) are reabsorbed in PCT by **secondary active transport** with membrane carriers Carrier mediated transport displays: - saturation - transported molecules concentration needed saturate carriers and achieve maximum transport rate Renal transport threshold: - minimum plasma [substance] that results in excretion of that substance in the urine - renal plasma threshold for glucose = 180-200mg/dl

Answer 56

PCT total [solute] = 300 mOsm/L - same as plasma (ISOTONIC) Reabsorption of H2O by osmosis - cannot occur without active transport of Na+ Na+/K+ ATPase pump extrudes Na+ Electrical gradient causes Cl- movement towards higher [Na+] H2O follows by osmosis

Answer 57

65% Na+, Cl-, H2O reabsorbed across the PCT into the vascular system 90% K+ reabsorbed Reabsorption occurs constantly regardless of hydration state - **not subject to hormonal regulation** Energy expenditure is **6%** of calories consumed at rest

Answer 58

Cortical nephron (80% in human kidney) - originates in outer 2/3 of cortex - osmolarity of 300 mOsm/l - involved in solute reabsorption Juxtamedullary nephron (20% in human kidney) - originates in inner 1/3 cortex - important in the ability to produce a concentrated urine - has longer loop of henle

Answer 59

Deeper regions of medulla reach 1400 mOsm/L **Impermeable** to passive diffusion of **NaCl** **Permeable** to **H2O** Hypertonic interstitial fluid causes H2O movement out of the descending limb via osmosis, and H2O enters capillaries Fluid volume decreases in tubule, causing higher [Na+] in the ascending limb

Answer 60

**NaCl** is actively extruded from the ascending limb into surrounding interstitial fluid - **NaCl is reabsorbed** **Na+** diffuses into tubular cell with **secondary active transport of K+ and Cl-** Occurs at a ration of Na+ : K+ : 2 Cl- **Impermeable** to **H2O**

Answer 61

It can generate an osmotic pressure of the medullary interstitial tissue fluid that can be 4x that of plasma (hyperosmotic) This is due to **descending being permeable to water and impermeable to NaCl** which counters the **ascending limb, which is impermeable to water and reabsorbed NaCl**

Answer 62

Transports H2O from interstitial fluid **Recycles NaCl and urea** **NaCl** and **urea diffuse** into **descending limb** and **diffuse** back into **medullary tissue fluid** At each level of the medulla **[solute]** is **higher in ascending limb** than in the **interstitial fluid** AND **higher in interstitial fluid** than in **descending** **Walls of the capillaries are permeable to H2O, NaCl, and urea** Water always moves in vesa recta (due to **colloid osmotic pressure in vasa recta > interstitial fluid**)

Answer 63

300 -> 1400 -> 100 -> 300 -> 1400

Answer 64

Has epithelial cells and **few** microvilli **Secretion and reabsorption** Terminates in **cortical collecting duct** Creates a **hypotonic** filtrate, which permits hypotonic urine excretion (water loss)

Answer 65

TGF = tubuloglomerular feedback which is responsible for Na+ reabsorption Granular cells within afferent arteriole secrete renin - initiates the renin-angiotensin-aldosterone system - negative feedback Macula densa - region where ascending limb is in contact with afferent arteriole -inhibits renin secretion when [Na+] in blood ↑

Answer 66

Reabsorption of NaCl controlled by aldosterone (secreted by adrenal cortex) Aldosterone secretion stimulated by angiotensin II (RAAS) Reabsorption of the final [Na+] in cortical collecting duct (about 15% of which is filtered) is controlled by aldosterone When RAAS is activated, all Na+ in DCT is reabsorbed Aldosterone ↑ Na+ retention (absorption) in exchange for K+ secretion

Answer 67

↑ [Na+] in blood - ↑ filtered load - more Na+ in tubule - inhibits renin - less renin released RAAS is inhibited - less conversion of angiotensin -> AI by renin - less conversion of AI -> Angiotensin II by ACE in lung - less angiotensin II leads to ↓ aldosterone signaling, ↓ Na+ reabsorption, ↓ water reabsorption (more urine produced) Until [Na+] in blood returns to set point levels

Answer 68

Aldosterone stimulates Na+ reabsorption in DCT cortical CD and creates electrical gradient for K+ secretion **During acidosis, H+ is secreted at the expense of K+**

Answer 69

90% filtered K+ reabsorbed in early part of the nephron (PCT) Secretion of K+ occurs in cortical CD Amount of K+ secreted depends on - amount of Na+ delivered to the region - amount of aldosterone secreted As Na+ is reabsorbed, lumen of tubule becomes negatively charged, which drives secretion of K+ into tubule Transport carriers for Na+ are separate from transporters for K+ Final [K+] concentration controlled in CD by aldosterone - when aldosterone is absent, no K+ is excreted in urine **ONLY means by which K+ is secreted**

Answer 70

**Impermeable to high [NaCl]** that surrounds it - walls of CD are **permeable to H2O** H2O is drawn out of CD by osmosis - rate of osmotic movement is determined by # of **aquaporins (water pores)** in the cell membrane Permeable to H2O - **depends on presence of ADH** - when ADH binds to its membrane receptors on CD, acts via cAMP, stimulating fusion of vesicles with plasma membrane and incorporates water channels into plasma membrane **Reabsorption of H2O**

Answer 71

ADH stimulates insertion of pre-existing aquaporin channels into the luminal membrane, ↑ cyclic AMP -> ↑ translocation of channel-containing vesicles to luminal membrane -> ↑ fusion and insertion (exocytosis) -> ↑ water permeability Process is reversible ↓ ADH -> vesicle retrieval (endocytosis) -> ↓ water permeability

Answer 72

Regulated by: hypothalamic osmoreceptors: ∆ POSM → ∆ ADH → ∆ H2O reabsorption

Answer 73

ISO-osmotic urine (300 mOsm) - lose water and salt proportionally (no changes is plasma osmolarity) - **occurs when you balance water and salt intake with water and salt loss** HYPER-osmotic urine ( >300 mOsm) - lose more salt than water (retaining more H2O than salt and ↓ plasma osmolarity) HYPO-osmotic urine ( <300 mOsm) - lose more H2O than salt (retain more salt than water and ↑ plasma osmolarity)

Answer 74

Ability to remove molecules from plasma and excrete those molecules in urine If GFR is completely cleared, substance is filtered but not reabsorbed (but water is!) - substance filtered but also secreted and excreted Volume of plasma from which a substance is completely removed in 1min by excretion in the urine Renal plasma clearance with be > 125 ml/min

Answer 75

If a substance is not reabsorbed **or** secreted - amount excreted = amount filtered **Inulin** is an exogenous substance not reabsorbed or secreted Quantity inulin excrete (mg/min) = V x Ui - V = rate of urine formation (ml/min) - Ui = inulin/substance concentration in urine (mg/ml)

Answer 76

Rate at which inulin is filtered by the glomeruli Quantity filtered = GFR x Pi - Pi = [inulin/substance] in plasma Amount filtered = amount excreted GFR x Pi = V x Ui (usually 125ml/min)

Answer 77

Clinically we measure creatinine concentration to see how filtration is going in the kidneys

Answer 78

Secretion of substance from peritubular capillaries into interstitial fluid then transported into lumen of tubule and into urine Allows kidneys to rapidly eliminate certain substances including potential toxins

Answer 79

Not all blood delivered to glomeruli is filtered in glomerular capsules - most glomerular blood passes to different efferent arterioles - 20% renal plasma flow filtered and substances are returned back to blood Substances in unfiltered blood can be secreted and cleared into tubules by active transport (PAH) - PAH can be used to measure renal plasma flow PAH = Aminohippuric acid or para-aminohippuric acid

Answer 80

filtration and secretion clear the molecules dissolved in plasma - PAH clearance measures renal plasma flow - averages 625 ml/min To convert to total renal blood flow, the amount of blood occupied by Red Blood Cells (erythrocytes) must be PAH taken into account

Answer 81

45% blood is RBCs (hematocrit) 55% plasma Total renal blood flow = PAH clearance/0.55 Rough estimate = 625ml/min / 0.55 = **1.1-1.2 L/min**

Answer 82

**Filtered, reabsorbed and excreted** Urea contributes to total osmolarity of interstitial fluid Ascending limb LH and medullary CD are permeable to urea - medullary CD has urea transporters Urea diffuses out medullary CD and into ascending limb LH

Answer 83

Urea is filtered into glomerular capsule and **reabsorbed** into blood Urea clearance is 75ml/min (whereas inulin is 125 ml/min) - 40-60% of filtered urea is always reabsorbed Passive process occurs via facilitated diffusion of ureas **> 125 filtered and secreted < 125 filtered and reabsorbed**

Answer 84

Kidneys help regulate blood pH by excreting H+ and reabsorbing HCO3- Most of H+ secretion occurs across the walls of the DCT in exchange for Na+ - antiport mechanism moves Na+ and H+ in opposite directions Normally urine is slightly acidic because the kidneys reabsorb almost all HCO3- and excrete H+ - returns blood pH back to normal range

Answer 85

Apical membranes of tubule cells are impermeable to HCO3- – Reabsorption is indirect When urine is acidic, HCO3- combines with H+ to form H2CO3, which is **catalyzed by Carbonic anhydrase (ca)** located in the apical cell membrane of PCT – As [CO2] increases in the filtrate, CO2 diffuses into tubule cell and forms H2CO3 – H2CO3 dissociates to HCO3- and H+ HCO3- generated within tubule cell diffuses into peritubular capillary

Answer 86

In states of acidosis the kidney must excrete more H+ This occurs in the distal tubule … the secreted H+ combines with two lumen buffers … phosphate and NH3

Answer 87

Nephron cannot produce a urine pH < 4.5 In order to excrete more H+, the acid must be buffered H+ secreted into the urine tubule and combines with HPO4-2 or NH3

Answer 88

Respiratory acidosis - hypoventilation - ↑ CO2 -> ↑ H+ Respiratory alkalosis - hyperventilation - to treat, we would give a medication causing metabolic acidosis Metabolic acidosis - Loss of HCO3- Metabolic alkalosis - Loss of H+ Initial disturbance and compensation - resp. acidosis leads to compensating metabolic alkalosis

Answer 89

They ↑ urine volume excreted - ↑ the proportion of glomerular filtrate that is excreted as urine Loop diuretics - inhibit NaCl transport out of the ascending limb LH Thiazide diuretics - inhibit NaCl reabsorption in the 1st segment of DCT Osmotic diuretics - ↑ osmotic pressure of filtrate (mannitol) Carbonic anhydrase inhibitors - inhibits reabsorption of HCO3- in PT Potassium sparing - inhibits actions of aldosterone or Na+ reabsorption/K+ secretion in the DT/CD

Answer 90

1. Water and electrolyte imbalance - change body fluid volume, osmolarity, electrolyte imbalance including hyperkalemia (high extracellular K+) 2. Uremic toxicity (azotemia ↑ plasma creatinine and blood urea nitrogen levels) 3. Changes in blood pressure, edema (plasma protein imbalance) and anemia (decreased erythropoietin synthesis) - due to fluid imbalance - erythropoietin stimulates RBC production 4. Metabolic acidosis (pH < 7.4) - not secreting ions like needed

Answer 91

10% of U.S. adults have some form of kidney disease **Acute renal failure** (reversible) - Pre-ARF ↓ renal blood flow and GFR - Intro- ARF tubular necrosis (ischemic, toxin) - Post-renal ARF urinary tract obstruction **Chronic renal failure** - Glomerulonephritis, hypertension, diabetes **End-stage renal disease** - GFR < 10% - renal transplant (limited supply, rejection) - dialysis (uses diffusion across artificial membrane (hemo-) or capillaries (peritoneal))

Answer 92

Blood flows through the upper compartment (recirculate) Dialysis fluid flows in the counter direction through the lower compartment (frequent renewed) 1. Renal failure -> ↑ plasma creatinine, hyperkalemia (↑[K+] ), ↑ water 2. low concentration in the dialysis fluid, allows net diffusion from blood into dialysate 3. Excess water is removed by hydrostatic pressure (high in blood, low in dialysate) 4. 3-5 hr treatment period, repeated every 2-3 days