final lecture exam a&P 2

cells of the tubule...what is outer surface called and what kind of transport keeps sodium concentration low in cytoplasm? what membrane is exposed to lumen

Basal membrane = outer surface of cell exposed to IF Active transport keeps Na+ concentration low in the cytoplasm (Na+/K+ pump) Osmosis Facilitated Diffusion of: Symported : Apical membrane = exposed to lumen Steep concentration gradient of Na+ between lumen and cell cytoplasm oAllows for symport of : Osmosis...secondary active transport use proteins within plasma membrane to physically move ions aka cotransport, symport and anitport sliiiide 67

glomerular filtration rate is based on

Based on: total surface area available for filtration (number of functioning glomeruli) permeability of filtration membrane oNormally, total surface area available and permeability of filtration membrane do not change; can be changed by disease net filtration pressure ovaries with systemic blood pressure oKidney adjusts resistance to blood flow to maintain normal, adequate filtration rate by regulating diameter of afferent (and efferent) arterioles

NFP: Opposing Forces

Capsular hydrostatic pressure (CHP) physical pressure of fluids in : pushes fluid : normally approx. : (Glomerular) blood colloid osmotic pressure (BCOP) osmotic pressure created by : draws fluid : normally :...CHP pressure is pressure between visceral(podocytes) and parietal(capsule), this space has 10 mmHG...other pressure is (glomerular) blood colloid osmotic pressure ( BCOP) GFR- the only one that can change on this slide is net filtration pressure- we always want to maintain 10 mmHg and 125 mL ...bcop created by concentration of blood proteins 30 mmHg moves fluid from bowmans capsule into the blood by osmosis SLIDE 51....capsular hydrostatic pressure (CHP) - The hydrostatic force which is the mechanical pressure exerted on the plasma filtrate by the the elastic recoil of the glomerular capsule, which tends to push water and dissolved solutes from the plasma filtrate back into the capillaries of the glomerulus; this is the main force slowing the rate of filtrate production within the renal corpuscle itself...blood colloid osmotic pressure (BCOP) - The osmotic force (water concentration gradient) which is the result of differences in water concentration between plasma and plasma filtrate, which tends to pull water from the plasma filtrate and back into the plasma in the glomerular capillaries; it results from the failure of most proteins to leave the plasma and move to the plasma filtrate, therefore, as water leaves, the proteins exert an increasing osmotic "pull" on the water in the plasma filtrate.... http://apbrwww5.apsu.edu/thompsonj/Anatomy%20&%20Physiology/2020/2020%20Exam%20Reviews/Exam%204/CH25%20Physiology%20of%20Glomerular%20Filtration.htm

macula densa, what is histology, what does it secrete and what does this do?

macula densa- special cells that monitor solute concentration(consistency of that filtrate eg too much water or not enough water), send info to afferent and efferent arterioles to change- secrete vasoconstrictor, if too much solute we are not filtering enough, ...Macula densa cells are columnar epithelium thickening of the distal tubule. The macula densa senses any increase in the sodium chloride concentration in the distal tubule of the kidney and secretes a locally active (paracrine) vasopressor which acts on the adjacent afferent arteriole to decrease glomerular filtration rate (GFR), as part of the tubuloglomerular feedback loop. Specifically, excessive filtration at the glomerulus or inadequate sodium uptake in the proximal tubule / thick ascending loop of Henle brings fluid to the distal convoluted tubule that has an abnormally high concentration of sodium.

aldosterone, where is it made, what secretes ACTH? and what cells does ACTH target and to do what, what is obligatory water reabsorption and what affect does it have on blood pleasure and volume

made mainly by zona glomerulosa of adrenal cortex Secreted in response to : : : ; ACTH is secreted by adenohypophysis...targets cells of DCT and collecting ducts to increase Na+ reabsorption and K+ secretion It increases : water follows Na+ by osmosis (obligatory reabsorption) in PCT, which is nearby, but not DCT which is impermeable to water unless stimulated by ADH Obligatory water reabsorption by PCT increases blood volume increases blood pressure........NOTES Slide 111 aldosterone goes to DCT(dis convo) and collecting ducts binding to receptors there and it increases Na reabsorption and secretion, secretion into filtrate other out(sodium potassium pumps being build being triggered here by aldosterone)...obligatory water reab sorption is drawing more water out because increased amount of sodium ions, obligatory is because increasing osmotic gradient and still all aldosterone action, slide 112 is sodium potassium pumps

NFP: Forces Supporting Filtration

move fluid out of blood into filtrate Glomerular capillary (hydrostatic) pressure (GCP) main force supporting filtration blood pressure within : normally approx. : oefferent arteriole is smaller diameter than afferent arteriole oLarge inlet, small outlet creates backup pressure....Net filtration pressure- combo of hydrostatic pressure in capillaries and glumeruls space as well plus there is osmotic pressure...glamerulat capillary is hydrostatic pressures and it is 50mmHg. And this is forcing fluids through spaces from above...efferent arteriole is smaller diameter than afferent arteriole making huge impact on maintaining pressure(50 mmhg)

visceral layer of bowmans capsule are what kind of cells

podocytes

sodium potassium pump is a form of what kind of transport

primary transoport- Requires direct use of ATP Sodium-potassium pump moves Na+ into interstitial fluid (IF); decreases intracellular Na+ creates Na+ and K+ gradients increases osmolarity of IF

kidney covering

renal fascia dense irregular CT that anchors kidney to posterior abdominal wall adipose capsule fatty tissue surrounding and cushioning kidney outside of renal capsule Fibrous (renal) capsule connective tissue covering

what does sympahtetic stimulation result in pertaining to afferent arterioles and what hormone does this, does this cause more or less blood to enter glomerulus, increase or decrease filtration, decrease or increase volume loss to maintain bp, occur during exercise or acute circualtory shock?

sympathetic stimulation results in vasoconstriction of afferent arterioles due to norepinephrine This will override normal GFR less blood enters glomerulus lowers GHP (lowers NFP) decreases filtration decreases volume loss to maintain blood pressure Occurs with exercise or acute circulatory shock...Slide 61 very important that it lowers GHP (lowers NFP) decreases filtration..exercising you don't urinate often and if you do it is concentrated, lots is going into sweating

Collecting Ducts are what type of epithelium and they converge where

Simple Cuboidal epithelium, few microvilli Converge at medullary pyramid

proximal convoluted tube (pct), histology? what is peritubular fluid

Simple cuboidal epithelium with microvilli Basement membrane underneath Designed for primary absorption and secretion....Peritubular fluids- fig 26.5 white space is IF called this between tubes and blood vessels of kidneys

micturition , explain what is happening, make sure to include what tells brain and how that works think tina in the car

It's a : Distension of bladder activates stretch receptors in the muscle when ~ 200 ml of urine has accumulated Stimulates a visceral reflex arc Sensory impulses to sacral spinal cord segments Result in parasympathetic impulses BACK to smooth muscle of bladder and internal urethral sphincter oresults in contraction of bladder and relaxation of internal urethral sphincter oNo urine will exit unless we consciously control the External Urethral Sphincter. Sensory input to brain allows conscious recognition of need to urinate and conscious control of external urethral sphincter which is : Reflexive contractions of bladder cease after ~ 1 minute if urine is not voided Cycle begins again after an additional ~ 200-300 ml of urine have accumulated

what do juxtaglomerular cells do and what type of cells are they...what do they secret?

Juxtaglomerular (JG) cells modified smooth muscle on the walls of the: respond to decreased blood pressure (BP) by : Also secrete :...the pink cells are juxtaglomerular cells that have a similar effect, by secreting rennin, also secrete erythropoietin

juxtaglomerular apparatus, where located?

Juxtaglomerular apparatus- (consists of juxtaglomerular cells and the macula densa) helps control how much is going to be filtered, too much or too little in the convoluted tubes can be bad...The juxtaglomerular apparatus is a microscopic structure in the kidney, which regulates the function of each nephron. The juxtaglomerular apparatus is named for its proximity to the glomerulus: it is found between the vascular pole of the renal corpuscle and the returning Distal Convoluted Tubule of the same nephron. This location is critical to its function in regulating renal blood flow and glomerular filtration rate. The three cellular components of the apparatus are the macula densa of the distal convoluted tubule, smooth muscle cells of the afferent arteriole and juxtaglomerular cells.

structures of urinary system, what is urination called? what is space where these structures are called?

Kidneys retroperitoneal perform functions of urinary system Ureters transport urine to urinary bladder Urinary Bladder stores urine before micturition Urethra transports urine to outside

histology of urethra

Lining varies from transitional to pseudostratified columnar to stratified squamous epithelium Internal sphincter of smooth muscle External sphincter of skeletal muscle

macula dense does what

Macula densa Specialized cells of the : respond to changes in solute concentration of filtrate in lumen of tubule secrete local vasoconstrictor to :...In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the distal tubule at the point of return of the nephron to the vascular pole of its parent glomerulus, (glomerular vascular pole). The cells of the macula densa are sensitive to the concentration of sodium chloride in the distal convoluted tubule. A decrease in sodium chloride concentration initiates a signal from the macula densa that has two effects: (1) it decreases resistance to blood flow in the afferent arterioles, which increases glomerular hydrostatic pressure and helps return glomerulus filtration rate (GFR) toward normal, and (2) it increases renin release from the juxtaglomerular cells of the afferent and efferent arterioles, which are the major storage sites for renin.[1] The release of renin is an essential component of the renin-angiotensin-aldosterone system (RAAS), which regulates blood pressure and volume.

glomerar capsule histology, also capsular space is?

1. Glomerular (Bowman's) capsule of nephron Parietal layer osimple squamous epithelium - forms outer wall and is continuous with : Visceral layer- in contact with glomerulus omodified simple squamous epithelium :that wrap around capillaries •filtration slits - slits within podocytes which permit filtrate to enter capsular space Capsular space ospace between visceral and parietal layers ospace into which plasma is filtered

proximal convoluted tubule, howm uch filtrate is reabsorbed, what surface has sodium potassium pump and what does this create on other side, what is symported, facilitated diffusion?

60-70% of the total filtrate reabsorbed Steep gradient of Na+ across apical surface created because of Na+/K+ pump on basal surface. oglucose, AA, K+, Cl- Symported with Na+ across apical surface , and either symported or use of facilited diffusion across basal surface. Water- via osmosis through :. Other molecules may move between cells. Filtrate concentration is :...Proximal convoluted tubule made of simple cuboidal epithelium, in proximal 60-70% of 125 ml gets reabsorbed, sodium potassium pump on basal important and important for a gradient so symportes work otherwise sodium would pass along and we do not absorb amino acids without symports, in addition aquaporins are water channels not active transport or protein carriers, filtrate concentration of 300 mOsm/kg is the ratio or concentration of solute to solvent..if value is increased more solutes per water(which is solvent) 0 would be a balance

afferent and efferent arterioles, which one has a larger diameter? is the diameter differences between the two important...why?

Afferent Arteriole Brings blood to glomerulus Arises from : Has larger diameter than efferent arteriole Efferent Arteriole Drains glomerulus Becomes :...The efferent arteriole carries blood away from the glomerulus. Because it has a smaller diameter than the afferent arteriole, it creates some resistance to blood flow, producing the back-up of blood in the glomerulus which creates higher pressure in the glomerular cavity.

Loop of Henle, histology, if there is different portions of this loop what are they called and dont forget the histology...what parts are more permeable to water and what parts more permeable to ions?

Also called Nephron Loop Descending limb- permeable to : Simple cuboidal epithelium to Simple squamous epithelium The simple squamous portion is called the Thin segment Ascending limb permeable to : Simple squamous epithelium to Simple cuboidal epithelium Thin segment to Thick Segment Important to concentrated urine Most are entirely medullary... Thin descending limb of loop of Henle The thin descending limb has low permeability to ions and urea, while being highly permeable to water. The loop has a sharp bend in the renal medulla going from descending to ascending thin limb. Thin ascending limb of loop of Henle The thin ascending limb is not permeable to water, but it is permeable to ions. Thick ascending limb of loop of Henle Sodium (Na+), potassium (K+) and chloride (Cl-) ions are reabsorbed from the urine by secondary active transport by the Na-K-2Cl symporter (NKCC2). The electrical and concentration gradient drives more reabsorption of Na+, as well as other cations such as magnesium (Mg2+) and importantly calcium (Ca2+). Cortical thick ascending limb—The cortical thick ascending limb drains urine into the distal convoluted tubule.[1] ......In the kidney, the loop of Henle (or Henle's loop or ansa nephroni) is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after its discoverer F. G. J. Henle, the loop of Henle's main function is to create a concentration gradient in the medulla of the kidney.[1] By means of a countercurrent multiplier system, which utilizes electrolyte pumps, the loop of Henle creates an area of high urine concentration deep in the medulla, near the collecting duct. Water present in the filtrate in the collecting duct flows through aquaporin channels out of the collecting duct, moving passively down its concentration gradient. This process reabsorbs water and creates a concentrated urine for excretion.[1]

Glomerular Filtration Rate

Approx. 1-1.2 l of blood passes through kidney per minute : of this, about 125 ml is filtered(~180 L per day!) and creates Filtrate. This is the Glomerular Filtration Rate Approx. 99% of filtrate is reabsorbed Filtrate is processed in nephron to become urine that leaves through collecting ducts

regulating urine concentration, what hormone concentrates urine? water reabsorption increases when water permeability of ____ increases and when solute concentration increases

Concentrating urine is a response to dehydration or increased ADH +/or aldosterone secretion Urine is concentrated by reabsorption of water Water reabsorption increases when water permeability of CDs increases and when solute concentration increases This is hormonally controlled...Slide 109- we can also affect convoluted tubule to reabsorb more solutes and water than normal BY affecting not just transport proteins here but also aquaporins by building more of both of them which is hormone driven, know what hormone does what. Aldosterone is released from adrenal gland SLIDE 110, ACTH is released during exercise,

types of nephrons, locations?

Cortical nephrons (~ 85% of all nephrons) Shallow loop Juxtamedullary nephrons renal corpuscle located near medulla loops of Henle' extend far into medulla...Two general classes of nephrons are cortical nephrons and juxtamedullary nephrons, both of which are classified according to the length of their associated Loop of Henle and location of their renal corpuscle. All nephrons have their renal corpuscles in the cortex. Cortical nephrons have their Loop of Henle in the renal medulla near its junction with the renal cortex, while the Loop of Henle of juxtamedullary nephrons is located deep in the renal medulla; they are called juxtamedullary because their renal corpuscle is located near the medulla (but still in the cortex). The nomenclature for cortical nephrons varies, with some sources distinguishing between superficial cortical nephrons and midcortical nephrons, depending on where their corpuscle is located within the cortex.[3] The majority of nephrons are cortical. Cortical nephrons have a shorter loop of Henle compared to juxtamedullary nephrons. The longer loop of Henle in juxtamedullary nephrons create a hyperosmolar gradient that allows for the creation of concentrated urine.[4]

examples of secondary active transport

Cotransport of substance using same protein that carries Na+ from lumen into cells of tubule wall Movement of ions(mostly Na+), coupled by movement of another molecule (glucose, AA, etc). oSymport - If it's same direction as Na+ oAntiport - if it's opposite direction of Na+ Substances cotransported: simple sugars (glucose, galactose, fructose), amino acids, some ions

Countercurrent Multiplier: Descending limb

Descending limb (thin segment) is relatively impermeable to solutes, but freely permeable to water Water flows out of descending limb into IF It is drawn there because of high IF osmotic pressure oHigh Osmotic pressure due to solutes leaving Ascending Limb (that's coming next). Tip of loop Filtrate is very concentrated due to continual loss of water It then moves into the Vasa Recta.

distal convoluted tubule design for two processes _____ and ______, composed of _____, secretes____, reabsorbs _____, principal cells respond to hormones _____ and _____, intercalated cells respond to ____

Designed for absorption & secretion simple cuboidal epithelium Secretion of acids, drugs and ions Reabsorption of Na+, Cl- and water principal cells respond to hormones ,epinephrine and renin intercalated cells - respond to pH

fenstrated capillaries are whay and what cell type are they on and where? what does blood enter in and where does it go?

Fensttrated capillaryies have large holes so things go in and out, slits on these podocytes, and it gets collected and contained in glomerulan capsule or bowmans capsule, this has an exit out and enter tube system, all goes in afferent arteriole and most leaves efferent arteriole but as written above some does go through tube system

nephron consists of four things...

Functional unit of the kidney Consist of: 1.Renal Corpuscle 2.Proximal convoluted tubules (PCT) 3.Nephron loop 4.Distal convoluted tubules (DCT)

glomerular filtration, what is force that drive filtration?

Glomerular Filtration Force that drives filtration is blood pressure (hydrostatic pressure) Filtrate resembles blood normally lacks :(only small molecules, RBC too big so blood in urine is bad) ions and other solutes are in proportion to concentration in blood....Glomerular filtration main drive is hydrostatic pressure (osmatic pressure is driven by solutes)..RBC WBC and platelets are formed elements , ions and nutrients make way to become filtrate

three main processes of urine formation

Glomerular Filtration initial movement of fluid from blood into the capsular space of Bowman's capsule of nephron, caused by : Tubular Reabsorption moves water and solutes from tubule back to blood Tubular Secretion moves solutes from blood into tubule for removal from body

ascending limb, histology? permeable to what? transport of what sort goes on on what parts? and what ions?

Has a thin, simple squamous section Not permeable to water, permeable to solutes Concentration of filtrate gets to 1200 mOsm/kg It increases in descending limb and decreases in ascending limb...Has a thick section, simple cuboidal section NOT permeable to water OR solutes. However... Through apical surface... oK+ and Cl- are transported into via symport with Na+ o Due Na+/K+ pump on basal surface Through basal surface... oK+ and Cl- then into IF via Facilitated transport oBut K+ will also be pumped back into cell due to active transport (Na+ is actively transported into IF) Movement of ions into IF will affect osmolarity for Counter Current Multiplier....Ascending limb- thick and thin here as well, no water leaves on this end, what is driving solutes out? No channels involved, it is symports (which are driven my gradients) Fig 26.14a, what number means a balance? 0. Are there more solutes or solvents in these areas???, we start out at 300 because there is not equal meaning more solutes than water, soon it becomes like boiling tea more water is leaving and it goes up to 600 cuz less water...at bottom 1200 but when up it is 100 cuz solutes move out because higher concentration than outside, osmosis is the water chasing those solutes(I think recheck osmosis vs diffusion)

renal corpuscle is

In the kidney, a renal corpuscle is the initial blood-filtering component of a nephron. It consists of two structures: a glomerulus and a Bowman's capsule. The glomerulus is a small tuft of capillaries containing two cell types. Endothelial cells, which have large fenestrae, are not covered by diaphragms. Mesangial cells are modified smooth muscle cells that lie between the capillaries and the glomerulus. They regulate blood flow by their contractile activity and secrete extracellular matrix, prostaglandins, and cytokines. Mesangial cells also have phagocytic activity, removing proteins and other molecules trapped in the glomerular basement membrane or filtration barrier. The Bowman's capsule has an outer parietal layer composed of simple squamous epithelium. The visceral layer, composed of modified simple squamous epithelium, is lined by podocytes. Podocytes have foot processes, pedicels, that wrap around glomerular capillaries. These pedicels interdigitate with pedicels of adjacent podocytes forming filtration slits. FROOOOM NOTES---Renal corpuscle is site of filtration- parietal layer surrounds the capillary and is part of tube system.....visceral layer is modified simple squamous epithelium(more like a hand with fingures and spaces called podocytes and found outside capillaries, spaces between them is called filtration slits...capsular space is space between two layers(recall podocytes actually wrap around capillaries)...capillary is called glumerulus and it is fenestrated(endothelial cells mean simplse squamolus epithelium) also have a basement membrane whether or not depicted

Countercurrent Mechanism

Increasing osmolarity of IF occurs at the Ascending loop Osmotic pressure wants to draw water out of loop BUT Ascending limb is impermeable to water - water cannot leave!! Descending limb is close by and subject to osmotic pressure of IF, because it's permeable to water. Loss of water from filtrate increases concentration of solutes remaining in filtrate in descending limb Urea is more concentrated (as are other remaining solutes) because the amount of urea has not changed while the amount of water has decreased Water and excess Na+, Cl- are removed from IF around descending limb by vasa recta solute concentration in IF stays highSLIDE 98 figure on it know this

Mechanisms of urine formation-every min __ liter of blood, but only ____of that _____gets filtered out, that what is in the tube system is called filtrate and of this 99% gets reabsorbed back into blood...we filter a lot of blood, we are getting rid of____ liters a day, so if don't drink enough H2O dehydration symptom fatigue Secretion is from PF -> tubes, filtration is ____% secretion __% both into the tube

Mechanisms of urine formation-every min 1 liter of blood, but only 125mL of that 1000 gets filtered out, that what is in the tube system is called filtrate and of this 99% gets reabsorbed back into blood...we filter a lot of blood, we are getting rid of 1.5-2 Liters a day, so if don't drink enough H2O dehydration symptom fatigue Secretion is from PF -> tubes, filtration is 95% secretion 5% both into the tube

calyx and renal pelvis, how many renal papillae(what is this)

Minor calyces Small cone shaped spaces at tip of papillae, received urine from renal papillae (8-20 total) Major calyces (singular = calyx) Larger cones, receive fluid from minor calyces Renal pelvis : 2-3 Major Calyces form this funnel shaped collecting chamber...Two or three minor calyces converge to form a major calyx. The major calyx, in the kidney, surrounds the apex of the renal pyramids. Urine formed in the kidney passes through a renal papilla at the apex into a minor calyx then into major calyx before passing through the renal pelvis into the ureter. Peristalsis of the smooth muscle originating in pace-maker cells originating in the walls of the calyces propels urine through the renal pelvis and ureters to the bladder.the renal papilla is the location where the medullary pyramids empty urine into the minor calyx.

what get reabsorbed, and what regulates some of these? is antidiuretic hormone or aldosterone direct

Most organic nutrients (e.g., glucose, amino acids, vitamins) Most ions Na+ and K+ highly regulated (by aldosterone) H+ regulated to maintain pH balance minerals (e.g., Ca2+) regulated by hormones (PTH) Water reabsorption is highly regulated antidiuretic hormone (direct) & Aldosterone (indirect)...78- what gets reabsorbed anything not in excess we need, ions being na and cl and H, minerals glucose amino acids, water...any ion or water in excess of normal will not be reabsorbed, if not enough water in body we retain it but if we don't need it so its excess

histology of urinary bladder

Mucosa transitional epithelium designed to withstand stretching Muscularis smooth muscle Called Detrusor muscle contracts to expel urine

ureters histology

Mucosa - transitional epithelium (allows stretching) Muscularis - smooth muscle (propels urine by peristalsis) Adventitia - fibrous connective tissue (anchors ureters)

myogenic mechnanism

Myogenic mechanism (stretch response) smooth muscle of afferent arteriole will : Increased systemic BP osmooth muscles are stretched oreflexive constriction of afferent arterioles decreases flow and pressure in glomerulus. oMAINTAINS NORMAL filtration pressure ominimizes increase in pressure due to increased systemic BP to prevent damage to glomerulus.. Decrease in systemic BP stretches afferent arteriole : resulting in dilation of afferent arterioles allows more blood to pass through glomerulus thus increasing filtration pressure MAINTAINS NORMAL filtration pressure even when BP decreases in order to maintain removal of wastes if diameter remained the same with decreased BP:...How do we maintain 10ml- myogenic mechanism is one way(change diameter of afferent arteriole) this is a reflex meaning does not go through nervous system, constrict this causes volume to go down(dilate would cause it to go up), (sliiiiiide 58)....the 50 can be changed the most by bleeding or exercising, if 120/80 goes up to 140 so does 50 and so does the net because 50 goes up and the other two stay the same Myogenic decrease= if internal bleeding pressure goes down so not enough stretch or pressure so 10 mmHg goes down by dilating AND NOT ABOUT CREATING PRESSURE HERE BUT ABOUT CREATING BF INTO GLOMERULAR WHICH CREATES PRESSURES,

Composition of Urine, normally and abnormally

Normal constituents include: substances that are only partially reabsorbed (e.g., NaCl, water) substances that are secreted (e.g., organic acids, organic bases, K+, H+) Abnormal constituents include: blood cells (white or red) organic nutrients (e.g., simple sugars, amino acids -- normally completely reabsorbed) Hemoglobin, bile pigments Normally clear and sterile If it's yellow, its due to urobilin( pigments produced from bacteria in Large Intestine

tubular processing, where does it occur and what does filtrate ultimately become?

Occurs in the proximal convoluted tubule, loop of Henle, distal convoluted tubule and collecting ducts. Tubular reabsorption : Tubular secretion :...Filtrate ultimately becomes urine, but we produce more filtrate than urine..we already have filtration down so now we talking reabsorption and secretion of the tubular sorts slide 644444

nephron loop, descending limb histology? permeability to what? of the 30-40% of total filtrate the loop reabsorbs how much percent water and how much percent more ions? does secretion move in or out?

Of the 30-40% of total filtrates, the loop: Reabsorbs 50% more water and 66.6% more ions Descending limb Goes from simple cuboidal (Thick) to Simple squamous epithelium (Thin) The THIN SEGMENT oVery permeable to water •Water leaves tubule into IF •Solutes left in tubule become concentrated oLess permeable to most solutes...Nephron loop slide 83- it is divided into ascending and descending but also divided into thick(simple cuboidal) and thin segment(simple squamous), at thin segment almost only water leaves, less permeable to most solutes and the permeability for it to go into the tube because of SECRETION WHICH MOVES IN NOT OUT

Filtration Membrane, what are parts, what are openings between endothelial cells called. name some histology

Parts: capillary endothelium with fenestrations basement membrane visceral layer of glomerular capsule (podocytes) Selectively permeable depends on size and electrical properties... Filtration membrane- openings between endothelial cells are fenstrates, there is basement membrane in middle other side podocytes which also have filtration slits, on endothelial side is blood(inside glomerulus) SLIDE 48 IS A GOOD PIC...There are three layers that make up the filtration membrane: two epithelia and the basement membrane that lies between them. ...The first step in renal processing involves the filtration of plasma in the glomerulus. Glomerular filtration is a process of bulk flow: water and low molecular weight substances move from the lumen of the capillary, across the filtration membrane, and into Bowman's space. What is filtered? Any low-molecular weight substance that is freely dissolved in plasma is filtered. This includes various polar organic molecules such as glucose or amino acids, ions, peptides, drugs, and waste products of organic metabolism such as creatinine and urea. Because filtration involves bulk flow, the concentration of a substance in Bowman's space will be the same as its concentration in the plasma. What is not filtered? Cells, of course, are too large to be filtered. Importantly, proteins are not filtered, but are retained in the plasma. Also, small molecular weight substances that are bound to proteins will not be filtered. It is the structure of the filtration membrane that prevents proteins from being filtered.

peritubular fluid aka, where does it come from and where does it go afterwards

Peritubular fluids- fig 26.5 white space is IF called this between tubes and blood vessels of kidneys...Also known as : Found outside all of the renal structures. Fluids, ions, etc that are reabsorbed come from tubes, go to PF, then into blood.,,In the renal system, peritubular capillaries are tiny blood vessels that travel alongside nephrons allowing reabsorption and secretion between blood and the inner lumen of the nephron. Ions and minerals that need to be saved in the body are reabsorbed into the peritubular capillaries through active transport, secondary active transport, or transcytosis. The ions that need to be excreted as waste are secreted from the capillaries into the nephron to be sent towards the bladder and out of the body. The majority of exchange through the peritubular capillaries occurs because of chemical gradients, osmosis and Na+ pumps.

ADH, produced where? secreted from where and when? response to what? acts on what areas and does what here?

Produced in hypothalamus Secreted from neurohypophysis when hypothalamic cells detect increase in blood osmotic pressure Response to dehydration Acts on DCT and collecting ducts to increase water permeability, thus allowing increased reabsorption of water = facultative water reabsorption It causes an increase in :....NOTES ADH- facultative water reasborption is facilitating water leaving by building channels, if you did not pee all day and you finally pee it means u didn't consume enough water and body retained as much as it could and produced very little urea with mostly potassium waste products....adh released by posterior pituitary but produced by hypothalamus

Net Filtration Pressure (NFP)

Provides force for movement of fluid into capsular space NFP difference between pressures forcing fluid into glomerular space and pressures resisting filtration Uses forces similar to those involved in movement of fluid between blood and interstitial fluid at other capillaries

distal convoluted tubules***stuff from wiki unanswered questions try slide 92/93

Reabsorption primarily controlled by : Filtrate volume is now only 15-20% Undesirable substances (e.g., urea) are more concentrated reabsorption of H+, Na+, Cl- (controlled by : ) Ca+- controlled by : water (influenced by : )...Distal convoluted tubule more reabsorption happens here because hormones control, we can increase the rate of reabsorption...WIKI- Sodium and potassium levels are controlled by secreting K+ and absorbing Na+. Sodium absorption by the distal tubule is mediated by the hormone aldosterone. Aldosterone increases sodium reabsorption...It also participates in calcium regulation by reabsorbing Ca2+ in response to parathyroid hormone. [1] PTH

urinary system functions(four things all with the word regulates) if you can go into more detail for 3 of the four

Regulates composition and volume of blood: Regulates water content Maintains ionic concentrations Maintains pH balance Removes metabolic wastes (especially urea) Regulates blood pressure renin-angiotensin pathway Regulates erythrocyte formation by secreting erythropoietin Helps with Vit D. regulation....The renin-angiotensin system (RAS) or the renin-angiotensin-aldosterone system (RAAS) is a hormone system that regulates blood pressure and water (fluid) balance. When blood volume is low, juxtaglomerular cells in the kidneys secrete renin directly into circulation. Plasma renin then carries out the conversion of angiotensinogen released by the liver to angiotensin I.[2] Angiotensin I is subsequently converted to angiotensin II by the enzyme angiotensin converting enzyme found in the lungs. Angiotensin II is a potent vaso-active peptide that causes blood vessels to constrict, resulting in increased blood pressure. Angiotensin II also stimulates the secretion of the hormone aldosterone from the adrenal cortex. Aldosterone causes the tubules of the kidneys to increase the reabsorption of sodium and water into the blood. This increases the volume of fluid in the body, which also increases blood pressure. If the renin-angiotensin-aldosterone system is too active, blood pressure will be too high. There are many drugs that interrupt different steps in this system to lower blood pressure. These drugs are one of the main ways to control high blood pressure (hypertension), heart failure, kidney failure, and harmful effects of diabetes.[3][4]

starting with renal artery go through all 14stops

Renal Artery segmental artery interlobar artery arcuate artery interlobular artery afferent arteriole glomerulus efferent arteriole peritubular capillaries and vasa recta interlobular vein arcuate vein interlobar vein Renal vein

know kidney anatomy

Renal cortex Outer region of kidney renal columns : Renal medulla Cone shaped medullary (renal) pyramids formed from collecting tubules papilla : Renal sinus

renin-angiotensin pathway, renin hydrolyses ______, where is angiotensin 1 converted into angiotensin 2 and what does angiotensin 2 trigger?

Renin released by : Renin hydrolyses angiotensinogen(plasma protein produced by liver) to angiotensin I angiotensin I is then converted to angiotensin II (occurs in the lungs) by : Angiotension II triggers directly raises BP by systemic vasoconstriction greater constriction of efferent than afferent arterioles at nephron, increasing pressure and filtration rates Direct reabsorption of Na+ and H2O in PCT stimulates release of aldosterone from adrenal cortex stimulates release ADH - which increases water reabsorption at DCT Increases thirst

formation of dilute urine, what results in dilute urine, reabsorption of what in the DCT and CDs dilutes urine. are any hormones released?

Response to excess fluid intake or decreased secretion of ADH or aldosterone Normally, collecting ducts (CDs) are not very permeable to water, therefore, lots of water leaves with filtrate, resulting in a dilute urine Reabsorption of solutes but not water from DCT and CDs further dilutes urine ADH and Aldosterone aren't released

counter current mechanism:ascending limb

The ascending limb is impermeable to water but Na+, Cl-, K+ are actively reabsorbed from filtrate. Na+, Cl- enters IF, making it very concentrated K+ is moved back into the ascending limb because of Na+/K+ pumps filtrate remaining in nephron becomes less concentrated (more fluids than solute)...Slide 96- let us talk about see saw aka countercurrent mechanism, the fact that there is water only leaving occurs because of high solutes on ascending and they are ahigh cuz of other side just like see saw in the end it means urea becomes more concentrated, total volume has been decreased and that's the counter current, we would never extract so many solutes if weren't for this mechanism

tubular secretion at PCT, movement of solutes from blood into ____, what solutes secreted here, how is hydrogen transported(symport, cotransport, antiport) what is actively transported her also

Secretion Movement of solutes from blood (via IF) INTO filtrate Solutes secreted include:(check slide 92/93) H+ is antiported Neurotransmitters, bile, uric acid area, drugs actively transported...In proximal its mostly hydrogen being antiported with sodium with hydrogen going in SLIDE 92, both potassium and hydrogen exchanging with sodium fot distal...WIKI The proximal tubule regulates the pH of the filtrate by exchanging hydrogen ions in the interstitium for bicarbonate ions in the filtrate; it is also responsible for secreting organic acids, such as creatinine and other bases, into the filtrate. Fluid in the filtrate entering the proximal convoluted tubule is reabsorbed into the peritubular capillaries. This is driven by sodium transport from the lumen into the blood by the Na+/K+ ATPase in the basolateral membrane of the epithelial cells. Sodium reabsorption is primarily driven by this antiporter. This is the most important transport mechanism in the PCT.

Hormone Regulation of GFR Renin-Angiotensin Pathway, secreted by what and when? cells of ___ detect reduced osmotic concentration, sympathetic or parasympathetic stimulation of JG cells, how is angiotensin activated? how is this different from aldosterone and ADH effects?

Slower method of control in response to lower systemic blood pressure Renin (enzyme) secreted by juxtaglomerular cells when: oReduced stretch of afferent arteriole due to drop in systemic BP, total blood volume or renal blockage omacula densa cells detect reduced osmotic concentration (via Na+) - Low H20, High Solute oSympathetic stimulation of JG cells...NOTES Adh and aldosterone work shorter term, affecting reabsorption rates, what is setting this up is low water and pressure...rennin angiotension pathway SLIDE 116- ion concentration and water concentration affecting Blood pressure overall..if our BP is low, in addition to constricting of vessels we talked about earlier as this is not enough sooo, rennin gets released and what rennin does, angiotensin always floating around is activated by rennin, SLIDE 117 it turns into angiotensin 1 then angiotensin 2 and angiotensin 2- raises BP by systemic vasoconstriction NOT JUST LOCAL, only needed when significant low blood pressure, in addition to this a greater local constriction is triggered affecting efferent more than afferent...also the rest of these bullets are circled on SLIDE 118 basically everything we have talked about so far is being amped up, has a lot to do with dehydration aka low water

tubular secretion at DCT and collecting ducts, solutes secreted include, what is actively transported and what is it in exchange for? antiport of what?, what plays a role in buffering?

Solutes secreted include: Active Transport of K+, in exchange for Na+ at Apical Surface Antiport of K+ and H+ at basal membrane oH+ plays a huge role in buffering...In proximal its mostly hydrogen being antiported with sodium with hydrogen going in SLIDE 92, both potassium and hydrogen exchanging with sodium fot distal

what substances are not reabsorbed and why?

Substances that are not reabsorbed or reabsorbed only in small amounts Because they lack carriers, limited lipid solubility, large some substances are partially reabsorbed then later secreted into the DCT Nitrogenous wastes urea: 50% to 60% of urea is reabsorbed because it is small Creatinine - large, not lipid soluble uric acid is reabsorbed by PCT, but most is secreted again later

GFR is maintained by which two things

The kidneys maintain a constant GFR even though systemic blood pressure can vary greatly. Rate is maintained by: Myogenic Mechanism Tubuloglomerular Feedback

reabsorption pathways what are they, talk a little about how material goes from cell to cell

Transcellular materials move through tubule cells transport of some substances requires presence of membrane channels or carriers Na+/K+ Paracellular materials go between cells held together by tight junctions...Primary Active Transport Uses ATP - Na+/K+ pump Secondary Active Transport Movement of ions(mostly Na+), coupled by movement of another molecule (glucose, AA, etc). oSymport - If it's same direction as Na+ oAntiport - if it's opposite direction of Na+ Facilitated Diffusion - K+, Glucose, AA - Basal Membrane Osmosis...65- what makes up these tubes? One of two tissues, simple cuboidal or simple squamous , there are gap junction, aquaporins are channels, everything else needs to be physically transported, primarily active transport(sodium potassium pump using atp), secondary active transport use proteins within plasma membrane to physically move ions aka cotransport, symport and anitport sliiiide 67

tubulogomular feedback

Tubuloglomular Feedback If flow rate past macula densa increases, macula densa release paracrine signals to juxtaglomular cells of afferent arteriole which will constrict. If flow were to be too fast, then there'd be too little reabsorption If flow were too slow, then there'd be reabsorption of waste products...Slide 60 macula densa talk, if myogenic does not work enough the convoluted stretches causes afferent arteriole send message to constrict(possibly constrict further) limiting amount of flow in maintaining 10 mmHg, tubular glomerular feedback, two diff locations of sensation where we detect this pressure being high

urea cycling, what part of loop of henle can urea diffuse into? what affect on osmolarity does this have

Urea is able to diffuse into the Descending limb of the Loop of Henly but no into(or out of) the Ascending Limb. This also helps keep osmolarity high in the loop...Slide 105- ions move osmosis osmosis move ions it is the countercurrent mechanism

urine content regulation urine concentration varies from _______ mOsm/kg, how about in the cortex compared to the medulla, what mechanism achieves this?

Urine Concentrations vary from 65-1300 mOsm/kg(milli-osmole per kilogram) That's in the tube Extracellular fluid (IF) maintains 300 mOsm/kg in cortex but will achieve 1200 mOsm/kg in the Medulla This is achieved by the Countercurrent Multiplier

passive transport

Uses energy of concentration gradient set up by active reabsorption of Na+ Facilitated diffusion requires membrane proteins K+, Glucose, AA Simple diffusion through lipid bilayer fat-soluble substances, urea some ions (e.g., K+, Cl-, HCO3-) move through channels

vasa recta check slide 98 and 104, sometimes figures are only way to undertand

Vasa recta acts as countercurrent exchange Vasa recta (VR) parallel Nephron loop of juxtamedullary nephrons and descends into inner medulla Vasa recta is freely permeable to both water and Na+, Cl- preserves osmotic gradient of IF Vasa recta removes excess water and solute from IF...Wiki form a series of straight capillaries (recta is from the Latin for "straight") in the medulla. They lie parallel to the loop of Henle. These vessels branch off the efferent arterioles of juxtamedullary nephrons (those nephrons closest to the medulla), enter the medulla, and surround the loop of Henle.

collecting ducts, what is reabsorbed from collecting ducts, is osmolarity high or low outside of collecting ductsso what kinda transport channels

Water is reabsorbed from CD, causing urine to be concentrated. Osmolarity outside of CD is high causing reabsorption...Collecting duct has aquaporins built in, by time we get there we have 1 percent of that 125 ml left

mechanisms of concentration, water movement in pct and nephron moves in accordance to ____, what is this? what will make up urea?

Water movement in PCT and Nephron loop is not controlled Called Obligatory water reabsorption, water follows Na+ by osmosis Water left in DCT and collecting ducts is what will make up the urea (19%) of the filtrate volume This water volume can be controlled Called Facultative water reabsorption

osmosis, based on movement of what? what is it controlled by(hormone)?

based on movement of solute (active Na+ movement) Water molecules move through Aquaporins obligatory water reabsorption follows osmotic gradient facultative water reabsorption controlled by ADH