chapter 24 urinary Flashcards
Excretion – the removal of waste products.
Elimination – discharge of these products to the environment.
Homeostatic regulation of blood volume and solute concentration of blood. - hormonal impact on kidney
function of urinary system
Regulating blood pressure by regulating volume and releasing EPO (blood cell formation) and renin (angiotensin aldosterone)
Regulating ion concentration especially Na+, K+, Cl-, Ca
Stabilizing pH by eliminating excess H+
Conserving valuable nutrients* due to the filtering of things from blood but the valuable items are reabsorbed, like glucose, fatty acids, vitamins
Detoxification
other function of kidneys
The corpuscle, PCT, and DCT are located in the cortex.
The loop and collecting ducts are in the medulla.
Collecting ducts merge and drain through the renal papilla in the minor calyx.
nephron location and blood supply
Each one consists of a renal corpuscle and a renal tubule.
Blood from the afferent arteriole enters the glomerulus (capillaries).
Blood leaves the glomerulus through efferent arteriole.
Filtration of the blood occurs here at the renal corpuscle.
nephron
From the corpuscle filtrate will enter the renal tubule which has three functions.
Reabsorption of useful substances.
Reabsorption of water.
Secretion of waste products.
nephron 2
renal artery --> segmental arteries --> interlobar arteries --> arcuate arteries --> cortical radiate arteries --> afferent arterioles --> glomerulus --> efferent arteriole --> peritubular capillaries --> venules --> cortical radiate veins --> arcuate veins --> interlobar veins --> renal vein
blood supply process
Blood hydrostatic pressure forces water and solutes across the capillary wall.
filtration - basic process of urine formation
Removal of water and useful solutes from the filtrate back to the body. This occurs by diffusion, osmosis, carrier mediated transport etc…
reabsorption - basic process of urine formation
Transport of solutes and wastes into the renal tube by diffusion, osmosis, carrier mediated transport etc…
secretion - basic process of urine formation
High pressure creates filtrate that collects in capsular space and slowly moves through the tube
The descending loop is permeable to water – water exits tube by osmosis if there is highly concentrated blood flowing through the vessel
The ascending loop is permeable to ions
renal corpuscle
During filtration the blood pressure forces out water, solutes, and other small particles.
Useful substances such as glucose, amino acids, fatty acids, vitamins, etc.. are also filtered.
Cells and large plasma proteins are not filtered
renal corpuscle 2
The PCT reabsorbs nutrients, ions, water, and protein.
The descending loop is permeable to water. The ascending loop is permeable to ions but not water.
The DCT varies in function depending on the presence of hormones such as ADH, Aldosterone, Calcitonin
PCT, loop, DCT
is the result of BHP(35) – BCOP(25) = 10 mm Hg.
Remember that everything is filtered except large proteins, and cells.
Nephrons create about 48 gallons of filtrate per day. About 99% is reabsorbed.
The rate of filtration must be constant or death may result.
Blood volume cannot be controlled.
pH cannot be controlled.
Wastes accumulate.
glomerular filtration
is an endocrine structure that secretes EPO and Renin.
juxtaglomerular complex
job is to make RBC and stimulus to release this is low oxygen levels
we make new RBC in bone marrow
EPO
