The Urinary System

KidneysBlood Supply

Flows through kidney starting from

Aorta

Renal artery

Segmental artery

Interlobar artery

Arcuate artery

Cortical radiate artery

Afferent arterioles

Glomerulus

Efferentarterioles

Peritubular capillaries

& vasa recta

Cortical radiate vein

Arcuate vein

Interlobar vein

Renal vein

Inferior vena cava

Filter blood, excrete hydrophilic wastes, maintain water balance & pH, help produce RBCs, vitamin

D , & control BP

Functions

Nephrons

Contains >1 millionThe kidneys structural &

functional units

Are

Consist of

Renal Corpuscle

Renal Tubule

Cortex & Medulla

Located in

GlomerulusBowman’s

capsule

Surrounds

Capillary bed

Is a

Afferent arterioles

Efferent arterioles

Fed & drained by

Carry blood to

glomerulus

Carry blood away from glomerulus

Capsular space

Collects filtrate

contains

Proximal convoluted

tubule

Loop of Henle

Collecting ducts

Narrows into

Distal convoluted

tubule

Carries urine to Carries urine to Carries urine to

Renal cortex

Located in

Renal cortex

Receives filtrate from many

nephronsCortex

Ascending limb

Descending limb

Located in

Renal Cortex

Located in Renal Cortex & medulla

Located in

Renal pelvis

Brings toThin

segmentThick

segment

Consists ofConsists of

Located inFiltration membrane

Form urine

Function

Filtrate

Produces

Peritubular

capillariesVasa recta

In cortical nephron supply

In Juxtamedullary nephron supply

Juxtaglomerular apparatus

Regulates rate of filtration &

systematic BP

Granular cells

contains

Extraglomerular cells

Macula densa

Mechanoreceptors

Act as

chemoreceptors

Act as

Sends signals btw

Sense BP in afferent arteriole

Respond to NaCl content

changes in filtrate

Urine Formation

2. Selective Tubular

Reabsorption

Specialized contact point btw afferent arteriole & distal tubule

Passive process

Fluids are moved from the blood to the Glomerular

capsule

Glomerular hydrostatic pressure

Due to

andNet filtration

pressure

Filtrate formation

Responsible for

1. Glomerular Filtration

Return of essential solutes & water from nephron back to blood

Transepithelial process

Proximal tubules

Filtrate enters

3. Tubular Secretion

Movement of substances from

blood into tubules to enter filtrate

Reverse of reabsorption

urinevia

Important for excretion of Drugs, metabolites, excess

K+, reabsorbed substancesBlood

pH

& regulation of

Diabetes Insipidus

Differs fromDiabetes mellitus

Results from

Excessive thirst and urination as a result of inadequate output of ADH or lack of normal response by kidney to ADH

IsInsulin deficiency or resistance leading to high levels of glucose in the blood. More common & urination output is not as large/ frequent & diluted as DI.

Symptoms are

• Increase urine output- urine is pale colourless, diluted with mostly water

• Frequent urination• Nocturia• Bedwetting• Dehydration

4 ty

pes

Central

Gestational

Nephrogenic

Dipsogenic

Damage to pituitary gland

Damage to thirst

mechanism in hypothalamus

Caused by

Caused by

Occurs

During pregnancy. enzyme produced

by placenta destroys ADH in

mother

Kidney’s inability to respond to

ADH.

Caused byResults from

Inheritable genetic defects, drugs, kidney

disorders

Indomethacin (Indocin)

Hydrochlorothiazide

Nonsteroidal anti-inflammatory drug that relieves pain, fever &

inflammation, by reducing production of

prostaglandins.

Diuretic used for treating

accumulation of fluid &

hypertension. Blocks salt &

fluid reabsorption in kidneys &

causes increased urine output.

Mode of action

Mode of action

Side effects

Nausea, vomiting, diarrhea, heartburn, rash, stomach

discomfort

Side effects

Hypotension, weakness, impotence,

jaundice, rash, nausea.

Anaphylaxis,

Cortical nephron

Juxtamedullary nephron

Efferent arteriole supplies

Peritubular capillaries

Short loop of henle & glomerulus

has

And its

long loop of henle &

glomerulus

Efferent arteriole

supplies vasa recta

has

And its

Cortex-medulla junction

locatedFurther from

Near to

Ignore this slide