The Anatomical Aspects

of the Renal System

Dr. Mahmud Abuauba MBChB, DCH, MD, PhD

Consultant Pediatrician & pediatric Nephrologist

Assistant Professor of Pediatrician

Zawia Kidney Center

28th

Apr. 2018

برعاية

الزاوية-ركز علاج أمراض الكلىم

BODY ORGANIZATION

THE RENAL SYSTEM

OR

URINARY SYSTEM

Nephrologists usually say

the RENAL SYSTEM

and

Urologists usually say

the URINARY SYSTEM

THE URINARY SYSTEM

Paired kidneys (2)

Paired ureters (2)

Unpaired urinary bladder (1)

Unpaired urethra (1)

SIX ORGANS

THE URINARY SYSTEM

FUNCTIONS

Mainly to maintain internal body homeostasis through filtration, reabsorption & secretion to form urine

Regulation of body fluid osmolarity

Maintain acid-base balance

Excretion of metabolic waste products (BUN, Cr, UA)

Excretion of toxic substances

Arterial blood pressure regulation

Endocrine function (epo, VitD, Renin)

THE KIDNEY I

Normally, There are two kidneys

1 in 500-1000, has a single kidney

(unilateral renal agenesis)

1/10,000 has no kidneys Potter’s

(bilateral renal agenesis) syndrome

THE KIDNEY II

It is a bean-shaped organ

Reddish to brown in color

Size of a fist

Lies high up on the posterior

abdominal wall

It is a retroperitoneal organ

THE KIDNEY III

On anterior abdominal wall, the

hilum of each kidney lies on the

transpyloric plane about 3 finger

breath from the midline

On the back, the kidneys extend

from T12 to L3 spines, slightly above

the umbilicus

The hilli lie opposite L1 vertebra

T12

L3

The renal angle overlies the lower part of the

kidney, tenderness in this area may indicate

perinephric abscess, infection or hemorrhage

THE KIDNEY III

Two borders

Hilum at medial border

Two poles

Two surfaces

Lies obliquely

THE HILUM

It is vertical slit-like depression

Located on medial concave border

Contains the vascular bundle:

⚫Renal vein, exits (V.A.U.A)

⚫Renal artery, enters

⚫Renal nerves, enter

⚫Renal lymphatics, exit

⚫Renal pelvis, exits

Transpyloric plane

RENAL SINUS

Hilum leads into renal sinus

It is a central cavity within the

kidney

Contains

⚫Renal pelvis

⚫Renal vessels

⚫Renal nerves & lymphatics

⚫Perirenal fat

Surrounded by renal capsule

THE KIDNEY IV

Lies obliquely

⚫Upper pole ~ 2.5 cm

⚫Hilum ~ 5.0 cm

⚫Lower pole ~ 7.5 cm

Lower pole 2.5 cm from iliac rest

Lower in standing position ~2.5cm

Move with respiration ~ 2 cm

Rt is lower than the Lt ~ 1.25 cm

THE KIDNEY V

The left kidney is:

Higher

Larger

Longer

Thinner

Narrower

Nearer to the midline

Than the right kidney

CAN BE PALPABLE

Right kidney

Tall

Thin

Female

Standing

Full inspiration

SUPRARENAL GLANDS

Adrenals, yellow in color

Two (Rt & Lt)

Upper pole of the kidney

Right is pyrimdal in shape

Left is crescent in shape

MEASUREMENTS

Length

In adult

⚫11-12 cm in length

⚫5-6 cm in width

⚫2-3 cm in thickness

In FT newborn 5 cm (4.5 to 6 cm)

with age

MEASUREMENTS

Weight

In adults:

⚫Female 135 g ( 115-155 g)

⚫Male 150 g (125-175 g)

⚫1/240 of body weight

⚫In FT newborn 24 g

⚫1/80 of body weight

with age

2175 g

RENAL COVERING

Renal fibrous capsule

Perirenal or perinephric fat

Renal fascia

Pararenal fat

RENAL CAPSULE

Surface of the kidney is smooth

It is lobulated in fetus

Covered by thin glisting, tight,

rough capsule

Easily removable normally

Adherent in diseased kidney

Covers the surfaces, renal sinus &

vascular bundle

PERINEPHIC FAT

It is perirenal

A mass of adipose CT

Surrounding the renal capsule

Maintain position of the kidneys

Prevent trauma

RENAL FASCIA

Surrounding perinephric fat

It is fibro-aleolar CT

Encloses kidney & adrenal gland

Has two layers

l Anterior

l Posterior

Behind it, paranephric or pararenalbody (fat)

POSITION

The kidneys held in position by:

Perirenal fat

Renal fascia

Pararenal fat

Surrounding neighbour structures

Vascular bundle

RENAL PELVIS

It is the funnel-shaped expanded

upper end of ureter

Formed by 2-3 major calyces

Each major calyx formed by 2-3

minor calyces

Each minor calyx is indented by 1-3

renal papillae, apex of renal pyramid

& acts as a pacemaker

Average capicty < 5 ml

Abdominal

Examination

Methods

Inspection

Palpation:

❖Superficial

❖Deep

❖Bimanual or ballottement

Percussion

Auscultation

Abdomen

Two imaginary

lines separate

abdominal region

into four quadrants

•Palpation for kidneys:

•Should use bimanual palpation, lie patient flat

with abd muscles relaxed, place your left hand

posteriorly in right renal angle & your right hand

over the anterior abdominal wall 5 cm away from

the midline, upper quadrant

•Push both hands towards each other as the patient

breaths out then feel for lower pole moving down as

patient breaths in, if palpable, push kidney

backwards & forwards between both hands

(ballotting), this confirms that it is the kidney

•Palpate for full distended urinary bladder in

suprapubic area

THE URETERS 1

Two ureters (Rt & Lt)

A muscular tube, 25-30 cm lenght

As a continuation of renal pelvis

Ends in posteior wall, base of UB

Has an oblique course, lies on

anterior surface of psoas major

Has three layers, mucosa,

muscularis & adventitia

THE URINARY SYSTEM

THE URETERS 2

The most common sites of ureteral

constrictions that are susceptible to blockage

by renal calculi:

❖Ureteropelvic junction

❖When ureter crosses the pelvic inlet

❖Ureterovesical junction

THE URINARY BLADDER I

A muscular sac-like organ

Temporary store urine at low

pressure

Is an abdominal organ in infancy

Shape, size & position vary

Has a base, neck, body, apex, sup

surface & two inferiolaterally surface

THE URINARY BLADDER II

Internal surface is folded, except

trigone is smooth

❖Trigone is smooth triangular area at

the base of UB

❖Its base is superior & bounded by

two opening of ureters

❖Apex points inferiorly & joins urethra

Has three layers, mucosa,

muscularis & advetitia

Ureterovesical junction

Both ureters enter UB posteriorly at

UVJ through an oblique course for 2

cm then through submucosal tunnel

to open at lateral angle of the trigone

Acts as a valve-like mechanism to

prevent VUR

Histologically I

the mucosa of calyces, renal pelvis,

ureter & UB consists of transitional

epithelium & lamina propria of CT

Underneath is smooth muscle

sheath then adventitia

Muscle fibers of UB run in any

direction but at bladder neck

arranged into 3 layers

Histologically II

Internal longitudinal layer becomes

circular around prostatic urethra in

♂ & to external meatus in ♀ & forms

true involuntary urethral sphincter

Middle layers ends in bladder neck

Outer longitudinal continues to end

of prostate in♂ & external meatus ♀

THE URETHRA

It is a tube for excretion of urineIn female 4-5 cm

In male 15-20 cm

Prostatic, membranous, penile

Has two sphincters:

⚫ Internal urethral sphincter (involuntary)

⚫ External urethral sphincter (voluntary)

around membranous part

⚫In ♀external voluntary sphincter

surrounds mid urethra

Parasympathetic from

vagus nerve of unknown

role, but may cause nausea

& vomiting with renal colic

Sympathetic innervations cause:

•Vasoconstriction of renal

vessels

•Stimulation of renin secretion

•Stimulation of Na & Cl

reabsorption from renal tubules

LYMPHATIC SUPPLY

Has rich lymphatic supply

Follow the blood vessels & join at

hilum to form large lymphatic trunks

Drain into para-aortic lymph nodes

Arranged into superficial & deep

RENAL BLOOD SUPPLY

Both kidneys receive approx. 21%

(20–25%) of cardiac output, at rest

High blood supply ~ 4 ml/g/min of

kidney tissue; why?

High O2 consumption

RENAL ARTERY

Each kidney receives a single

main renal artery (Rt &Lt)

From abd. aorta at Rt angle, at L2

Lt RA is shorter

In about 30%, accessory RA or

abberent RA, lower pole

BRANCHES

Each main RA upon or just arrivalto hilum divides into twodivisions; anterior & posterior

Supplying five vascular segments

Primary branches are segmentalarteries (5)

Pos. division supplies only pos.segment

No anastomoses be segmental As

HeartAbdominl aorta

Renal artery (Lt&Rt) IVC

Segmental arteries Renal veins

Lobar arteries Interlobar veins

Interlobar arteries Arcuate veins

Arcuate arteries Interlobular veins

Interlobular arteries Peritubular capillaries

AGA Glomerulus EGA

THANKS FOR

ATTENTION