kidney Flashcards
sensory nerve and motor nerve detects the
degree of stretching of the gallbladder
Fibers of the kidneys
sensory nerve fiber
motor nerve fiber
skeletal motor fiber
skeletal motor fiber
transmitted through the pudendal nerve to the external bladder spinchter
Transcellular transport
passing through the cell basally and laterally to the apex of the cell
difference between plasma and ICF
plasma and ICF are the same except that plasma has protein and Red blood cells and white blood cells, but both have equal amount of ions
Isotonic solute
the concentration of the solute outside the cell is equal to the concentration of the solute inside the cell
Transcellular fluids
potion of the total body water contained within epithelial lined space, part of the extra cellular fluid ex of this fluid are cerebrospinal fluid, ocular fluid, and bladder urine. this fluid contains Na ion, cl ions and bicarbonate
carrier mediated transport
primary and secondary transport active transport ( eg Na K pump)
active transport
requires energy to move ions gradient across the cell against its gradient
Paracellular Transport
the movement of solute between the cell and epithilum
aldosterone has a role in
Na absortion
Glucose is transported in the cell by
active transport against concentration graduate, once in the cell it leaves via facilitated diffusion.
Fructose and amino acids are transported
similarly to glucose
kidney s involved in the production of red blood cells via
erythropoietin, hormone like substance triggers erythropoisis in the stem cells of the bone marrow
Tubulo-glomerular feedback
feedback mechanism to perform the function of auto regulation linked to the change in Nacl at the macula densa
controls the renal arteriolar resistance - ensure a constant delivery of the nacl to distal tubules and helps prevent spurious fluctuation of renal excretion
two component of tubulo-glomerular feedback
afferent arteriol feed back mechanism and efferent arterial feedback mechanism
Sacral Cord
the cord that connect the pelvic nerve to the spinal cord, this is the nerve supply of the bladder
parasympathetic effect on the kidney
stimulate the peristaltic contraction in the ureter while sympathetic inhibit
vitamin D and the kidneys
the kidney is involved with the activation of vitamin D to its active form
pudendal nerve
the skeleton motor fiber are transmitted through this nerve, it carries both sensory and motor fibers, and it innervates external genitalia
Podocytes
epithelial cell surrounding the filtration barrier of visceral layer, these are cells in the Bowman’s capsule in the kidney that wrap around the capillaries of the glomerulus. involved in filtrate by hold back protein and other important molecules also involved in regulation of GFR
the glomerular capillaries give rise to
peritubular capilaries, in this system there is an afferent arteriol and efferent arteriol
Bowman’s Capusule
this accepts the filtrate from the glomerular capillary reabsorption into the renal tubular capillaries, secretion from the peritubular capillaries to the Bowman’s capillaries, then excreted
Renal corpuscle
filtration, reabsorbtion, secretion, and excretion take place here . the structures here is the glomerulus capillaries and Bowman’s capsule
urine formation begins
when large amount of fluid that is protein free is filtered from the glomerular capillaries into bowman’s corpuscle
Excretion is
filtration - reabsorption + secretions
Uretorenal reflex
when a ureter is blocked reflex constriction occurs this is associated with intense pain, causing a sympathetic reflex back to the kidney to constrict the renal arterioles there by decreasing urine out put from kidneys
tubular reabsorbtion
the substance like glucose, amino acid, electrolyte is freely filtered at the glomerular capillaries and are all is reabsorbed back into the blood due to been highly able to be reabsorbed
Autoregulation
the relativity between renal blood flow and GF, to maintain the delivery of oxygen and nutrient at a normal level and to remove the waste product of metabolism despite change in the arterial pressure
Sympathetic nervous system affects GFR
afferent and efferent arterioles are richly innerverted by sympathetic NS, it can constrict the renal arterioles and decrease renal blood flow and GFR
Hormones and autacoids affects
GFR (glomerular filtration rate)
hormnes like norepinerphrine , epinerpherine , endothelin constrict
renal blood vessel and decrease GFR
autacoids are
vasoactive substance endothelin( vaso constrictor)that are released in the kidneys and act locally these constrict blood flow in the renal blood vessels and decrease GFR
Physiological control of GFR
glomerular hydrostatic pressure and the glomerular capillary control osmotic pressure , these variable are influenced by sympathetic nervous system, hormones and autocoids
tubular secretion
opposite direction to absorbtion, secondary active transport ( atp N / k pump at the basal part of the cell) peritubular capillaries ( secretion of hydrogen ions from the blood across the tubular walls, there is a counter porter at the apex of the cell ( na in and H out)
transport maximum Tm
substance that are actually transported have a limit of rate at which they can be transported, this is Tm, this is due to saturation of the transport system
absorption of H20 is via
simple diffusion
Fluid gain and loss
intake and output has to be equal , intake fluid is associated with water obtained from drinking and food, cellular respiration also provide water
glucose , amino acid, water is transported
by facilitated diffusion passive diffusion at the basal end of the cell into the ecf then bulk flow
kidney act as a
waste eliminated organ eliminating urea (nitrogenous waste) ,hormone metabolism , drug and toxic material
production of uric acid
is due to metabolism of nucleic acid, high uric acid is produce if once diet is high in protein.
too much uric acid leads to the formation of
Gout
Ultrafiltration
take part in the formation of urine via bulk flow, this is mediated by hydrostatic and colloid osmotic force, there is a net reabsorptive force that moves the fluid and solute from the interstitial into the blood
functional part of the kidney
kidney tubules and kidney nephrons
micturition
the process by which the urinary bladder empties when it gets filled. First step the bladder fills progressively until the tension rises above a threshold level. this elicts the second step which invoves the micturtion reflex
Mictrition Refelx
is a nervous relfex that empties the bladder or causes the desire to urinate
detrusor muscle
smooth muscle of the bladder the contraction of this muscle is a major step in the emptying of the bladder , conduct action potential that cause contraction of the bladder
tubular secretion
substance is free filtered at the golmerular capillary blood into renal tubles
the kidneys maintain tonicity by
maintaining isotonic instead of having an hypertonic or hypotonic effect, hypotonic leads to crenation and hypotonic will lead to cell wall lysis
juxtameduallary nephrons
this is the glomeruli that lie deep in the renal cortex near the meduall into the renal papillae sometimes, has long loop of henle has a role in urine concentration, where most of nephrons is located, the vascular structure of here is the vasa recta
counter current flow
water is carried by the peritubular capillaries opposite the floww of the fluid in the nephrons , hypertonic , is the concentration of the movement of fluid from vasa recta into the DCT
Tubluar reasborption
the susbstance is freely filtered at the glomerulus and all is reabsorbed into the blood , it is passive transport
Vasa recta
it is a capillary that continues into the loop of henle( efferent ateriol), the tensity is the same as the loop of henle, it associates with the juxtamedullary receptors, runs parallel to henle’s loop , provides nutrients , the tensity is same as the autocoids
GRF
glomerular filtration rate(net filtration present + glomerular capillaries filtration coefficient)
the kidney is surrounded by
connective tissue
calyx is
where urine is deposited
the vascular structure of the kidneys
renal artery and renal vein and 20% of cardiac output will flow through the kidney
net filtration pressure
the sum of hydrostatic and colloid osmotic force across the glomerular membrane
transport of small peptide involves
cytopempsis the transport of substance in the cell and through the cytoplasm in a vesicles without using the cells energy
solute drag
water pulls the solute as it moves through the cell the concentration of the solute goes up
insensible water loss
water losses that can not precisely regulated and we are not consciously aware of it eg are evaporation from the respirator tract and and diffusion through the skin, sweating is not part of this
types of water loss
insensible water loss, sweating , feces, kidneys
function of the kidneys
excretion of metabolic wastes and foreign chemical
regulation of water and electrolyte balance
regulates blood pressure
erythropoesis .
three fluid compartment
extracellular: plasma and interstitial fluid
intracellular
Transcellular fluid
two type of nephrons
cortical and juxtamedullary nephrons
cortical nephrons
these are nephrons that have glomeruli located in the outer cortex , they have short loops of henle that penetrate short distance of the medulla, their vascular structure are network of peritubular capillaries
vasa recta
the vascular structure of the juxtamedullary nephrons which are long efferent arterioles extend from the glomeruli down into outer medulla and then divide into specialized peritubular capillaries lying next to the long loop of henle and also has it tonicity… this is important for concentrated urine
glomerular capillaries are encased in the
Bowman’s capsule
the fluid filtered form the glomerular capillaries flows into
the Bowman’s capsule then into the proximal tubule to the loop of Henle that dips into the medulla
loop of henle
there are two loops the ascending and descending loop of henle where the ascending loop of henle has a thick and thin loop
conservation of water
water is conserve by producing an hypertonic urine and absorbing water from filtrate involving counter current flow.
how is water conserved
the loop of henle goes down into the medulla, there are physiological change in the tubules it becomes thinner at the base and thicker as it ascends, ascending loop pumps ( na+ cl-urea) out to maintain tonicity the cell are impermeable to water and solute and the DCT, in the cortex DCT is 100 and vasa recta is 325 , this induces water to move passively through the cortes by the help of ADH ( recruit aqua porin 1 and 2) descending loop is permeable to water and solute
obigatory urine
urine that must be produce or excreted regardless of water intake. the solute of this urine solute diuretic
what plays a role in the concentration of urine
juxtamedullary nephrons, vasa recta , and ADH
role of ADH
increase the permeability of the DCT, collecting tubule , collecting duct through the recruitment of aqua porin 2 to the apical side of the cells, aquaporin 3 and 4 are at the basal side of the cell taking water out
diabetes insipidus
hypotonic urine is produced
nephorngenic diabetes insipidus
there is no receptor for ADH to bind to
kidney regulates blood presure
it regulate blood volume by renal pressure system, renin is produced by the Jg apparatus, angiotensinogen is converted to angiotensin1 in blood and ACE converts it to 2 this will increase blood pressure
function of uricase
converting or urea to uric acid
hypoxia can also trigger
erythropoietin
the kidneys ability to make concentrated urine depends on
a hypotonic environment
proximal tubule are
permeable to water
AV3V
controls the osmolarity, ADH secretion, thirst sodium appetite and blood presure.
