CH19 KIDNEYS

The urinary system uses the principle of ______ to maintain homeostasis

Mass balance

Filtration occurs in the ____ capillary bed

First

Reabsorption occurs in the _____ capillary bed

Second

Renal blood flow goes from the _______ to the _______, to ________ to _________.

Afferent arteriole ->glomerulus. Efferent arteriole -> pertibular capillaries

The ______ capillaries dip into the medulla

Vasa rects

Fluid filters from the glomerulus into ______

Bowmans capsule

The movement of fluid from plasma into bowmans capsule

Filtration

Movement of filtered materials from tubule to blood

Reabsorption

Movement of selected molecules from blood to tubule

Secretion

Average urine volume is _____

1.5L/day

1/5 of renal plasma flow filters into the

Tubule lumen

The percentage of total plasma volume that filters

Filtration fraction

Bowmans capsule epithelium has specialized cells called ______ that wrap around the glomerular capillaries and create _______

Podocytes, filtration slits

Support the glomerular capillaries

Mesangial cells

Filtration allows most components of plasma to enter the tubule but excludes _____ and

Blood cells and almost all plasma proteins

The amount of fluid that filters into Bowmans capsule per unit time

Glomerular filtration rate

______ in glomerular capillaries can be altered by changing resistance in the afferent and efferent arterioles

Hydrostatic pressure

Autoregulation of glomerular filtration is accomplished by a _______ of vascular smooth muscle in response to pressure changes and by ______

Myogenic response, tubuloglomerular feedback

Reflex control of GFR is mediated through systemic signals, such as hromones and through the ______

Autonomic nervous system

Most reabsorption takes place in the _______.

Proximal tubule

The actiive transport of _____ and other solutes creates concentration gradients for passive reabsorption of urea and other solutes

NA+

Most reabsorption involves

transepithelial transport

The plasma concentration at which a substance first appears in the urine

Renal threshold

_________ reabsorb fluid along their entire length.

Peritubular capillaries

______ enhances ______ by removing solutes from the peritubular capillaries.

Secretion enhances excretion

Molecules that compete for renal carriers _____ the secretion of a molecule

Slow

The excretion rate of a solute depends on its:

-Filtered load

-Whether it is reabsorbed or secreted as it passes through the nephorn

Describes how many milimeters of plasma passing through the kidneys have been totally cleared of a solute in a given period of time

Clearance

______ Clearance is equal to GFR

Inulin

In clinical settings, _______ is used to measure GFR.

Creatinine

______ can be used to determine how the nephron handles a solute filtered into it

Clearance

The external sphincter of the bladder is skeletal muscle that is tonically contracted except during ____

Urination

______ is a simple spinal reflex subject to conscious and unconscious control

Micturition

______ Cause contration of the smooth muscle in the bladder wall

Parasympathetic neurons

_______ leading to the external sphincter are simultaneously inhibited

Somatic Motor Neurons

A metabolite of hemoglobin called _____ gives urine its yellow color

Urobilinogen

Supply blood TO the kidneys

Renal arteries

Supply blood AWAY to the inferior vena cava

Rena veins

Almost ____ % of nephrons are found in the cortex

80

Metabolic disease characterized by high blood concentration of uric acid

Gout

The combination of glomerulus and bowmans capsule =

Renal capsule

Filtration takes place in the

Renal corpuscle

First filtration barrier

capillary endothelium

Second filtration barrier

basement membrane

Third fltraton barrier

Epithelium of bowmans capsule

GFR is influenced by:

net filtration pressure and filtration coefficient

Filtration pressure is determined by

renal blood flow and blood pressure

GFR ic controlled primarily by:

Regulation of blood flow through the renal arterioles.