The primary job of the urinary system is to filter blood, producing urine as a waste product in the process. The renal pelvis, bladder, urethra, ureters, and kidneys are the organs that make up the urinary system. The nutrients in meals are transformed by the body into energy.The kidneys secrete urine, which is a liquid waste product. The fluid known as urine is translucent and clear, typically with an amber tint. An average person excretes five to eight cups, or forty to sixty ounces, of pee in a 24-hour period. Urine is mostly composed of salt, urea, and uric acid in a watery solution.The kidneys, ureters, bladder, and urethra make up the human urine system, sometimes referred to as the urinary tract or renal system. The elimination of waste from the body, blood volume and pressure regulation, electrolyte and metabolite level control, and blood pH regulation are all functions of the urinary system. The body's drainage system for eventually eliminating urine is the urinary tract.[1] Via the renal arteries, which exit the kidneys through the renal vein, the kidneys receive a substantial blood supply. Nephrons are the functional units that make up each kidney. Wastes (in the form of urine) leave the kidney through the ureters, tubes composed of smooth muscle fibres that direct urine into the bladder, where it is collected and processed further.The organs that generate urine and carry it to the excretory site are referred to as the urinary system. The kidneys are situated in the space between the parietal peritoneum and the dorsal body wall on both the left and right sides of the human urinary system.The kidney's functional unit, the nephrons, is where urine is first formed. After that, urine travels via the nephrons and the collecting ducts, a network of convergent tubules. The minor and major calyces that eventually connect to the renal pelvis are formed by the union of these collecting ducts. Urine then proceeds from the renal pelvis into the ureter, where it is transported to the bladder. Males and females have different urinary system anatomy, specifically in relation to the urine bladder. The prostatic, membranous, bulbar, and penile urethras in men are formed by the urethra's progression from the internal urethral aperture in the bladder's trigone via the external urethral orifice. The urine leaves the body through the external meatus of the urethra. The female urethra, which starts at the neck of the bladder and ends in the vaginal vestibule, is substantially shorter.Bowman's capsule filters blood entering the tubules from the circulatory system in the first segment of the nephron. Filtration across a semipermeable membrane is facilitated by gradients of osmotic and hydrostatic pressure. Water, ions, and tiny molecules that easily flow through the filtering membrane make up the filtrate. However, the filtration barrier blocks the passage of bigger molecules like proteins and blood cells. The glomerular filtration rate, or GFR, is the volume

1. Ms.N.S.Kamble

2.  Excretion is the process by which unwanted substances & metabolic waste are
eliminated from the body.
 Although there are various systems in our body that are involved in the
excretion process, but urinary system has major excretory system of human
body.
 It is also known as Renal System.

3.  Parts of Urinary System
1.A pair of Kidneys
2.Ureters
3.Urinary Bladder
4.Urethera

4.  It is present in a pair in our body
 Kidneys are two bean shaped organ
located at each side of vertebral
column.(T-12 - L-3)
 It is reddish brown in colour
 It is about 10-12 cm long & 5-7 cm
wide
 Weight is about 120-170 gm
 Layers of Kidney-
1.Outer cortex
2.Inner medulla
3.Renal Pelvis

5.  Nephrons are the major functional
unit of kidney.
 Nephron is mainly consist of two
parts
 Renal Corpuscle
 Renal Tubule
Renal Corpuscle
It is present in the cortex of kidney.
The major function of renal corpuscle
is filtration of blood.
It can be further subdivided into two
portions
Glomerulus: Bunch of capillaries.
Bowmans capsule:Upper end of renal
tubule

6. Renal Tubule
It is a tube like structure and the continuation
of Bowman's capsule.
Proximal & Renal tubule mainly consist of 3
parts
1)Proximal Convoluted Tubule : Present in
Cortex
2)Loop Of Henle: Present in Medulla
3)Distal Convoluted Tubule : Present in Cortex
Loop of Henle can be further subdivided into 2
parts :
(i) Descending Limb
(ii) Ascending Limb

7. Types of Nephrons
Nephrons are of basically two
types:
Cortical Nephrons: 85%, short
Loop of Henle
Juxta - Medullary Nephrons:
15%, Long Loop of Henle

8.  Urine formation is a Blood Cleansing function.
 Normally about 1300 ml of blood enters into the kidney.
 kidney excreted the unwanted substances from the blood as Urine Normal
Urine Output is 1-1.5 Liter/ day.
Formation of Urine:
It mainly involves 3 steps:
Glomerular Filtration
Tubular Reabsorption
Tubular Secretion

9.  Glomerular Filtration:
 It is a process by which blood is filtered while
passing through glomerular Capillaries by
filtration membrane.
 It is first step of Urine formation
 When blood passes through glomerular
Capillaries the plasma is filtered in bowman's
Capsule
 All the substance of plasma filtered in
glomerular filtration except plasma protein. &
filtered fluid is known as Glomerular filtrate.

10.  Glomerular filteration Rate
 Glomerular filteration rate (GFR) is defined as total quantity of filterate formed in all the
nephrons of both the kidney in the given unit of time.
 Normal GFR is
125 ml/minute or 180 L/day
 Factors Affecting GFR
 Renal blood flow
 Glomerular capillary Pressure
 Colloidal Osmotic Pressure
 Hydrostatic Pressure of bowman's capsule

11.  Tubular Reabsorption
 As we clearly saw that about 180 L filterate
formed per day but only 1.5 litre urine is
excreted out from our body that means
about gar. part of filterate again reabsorbed
in blood.
 It is the process by which water & other
necessary substances are reabsorbed from
Renal Tubule to Blood.
 The reabsorbed substances moves into the
interstitial fluid of renal medulla & after that
they moved into cep tubular capillaries.
 Tubular reabsorption is a selective
reabsorption as the tubular cells reabsorbs
only those substances that are necessary for
our body.

12. Proximal Covulated Tubule Loop of henle Distal convulated tubule
Glucose,Amino
acid,Sodium,Potassium,
Bicarbonate,calcium,Chlorides,
Phosphate,Urea,Uric
acids,Water
Sodium,chloride,water Sodium,Calcium,Bicarbonate,
Water
Essential substances get reabsorbed excreted out from body while unwanted
substances are excret out.

13.  TUBULAR SECRETION
 It is process in which substance are transported from blood to renal tubules.
 The unwanted substances that are not get filtered from blood to Bowman's Capsule in first step
are directly transported to renal tubules later in this process.
Substance secreted in different segment of renal tubule
Proximal Convulated Tubule :Potassium, Ammonia, H+ ions.
Loop of Henle:Urea
Distal Convulated Tubule:Potassium,H+ ions
Collecting ducts:Potassium

14.  It helps in the excretion of waste products
 It maintains water- electrolyte balance.
 It maintains acid- base balance.
 It also helps in the process of erythropoiesis by secreting erythropoeitin & also in
thrombopoeisis by secreting thrombopoeitin.
 It secretes renin, prostaglandin harmones.
 It also helps in regulation of blood pressure.
 It also regulates blood- calcium level.

15.  They are paired tube like
structures.
 They carry urine from kidney to
urinary bladder.
 The wall of ureter is made up of 3
layers.
 Inner Mucous Layer
 Outer Fibrous Layer
 Middle Mascular Layer

16. The length of the ureters varies but typically ranges
from about 25 to 30 centimeters (10 to 12 inches)
long. They have a diameter of around 3 to 4
millimeters.
 Inner Mucous Layer-The innermost layer of the
ureter is the mucosa, which is lined with transitional
epithelium. This epithelium can stretch to
accommodate the passage of urine.
 Middle Mascular Layer-The middle layer is the
muscularis, which is composed of smooth muscle
fibers.
 Outer Fibrous Layer-The outermost layer is the
adventitia, which is made of connective tissue.

17.  It is an inverted pear shaped structure that
ads as a collector for Urine.
 It lies in the pelvic cavity.
 The lower part of bladder is known as base
while upper part is called Fundus.
 It has three opening two for ureter & one for
urethra.
 It has 4 layers.
 Outer Serous Layer
 Muscular Layer
 Sub-Mucous Layer
 Mucus layer

18.  It is a canal through which urine passes from bladder to outside.
 It is different in males & females.

19.  Buffer system
 Respiratory system
 Renal System
 Acid base balance is a part of homeostasis process that deals with maintainance of PH
 Most of the reactions in our body occurs at a specific pH & change in this PH can lead to major
disturbances.
 The normal pH value of blood is approx 7.42 & survival range of pH in blood is between 6.8-8.0,
now if the PH limit Crosses this value then it may lead to death, so it becomes very important to
maintain pH balance of our body.
 Now, there are various mechanism in our body to regulate this acid-base balance but the renal
mechanism is the most effective & final process of acid base balance in which kidneys play major
role.

20.  It mainly works by 2 mechanism.
 Excretion OF H+ ions
 Reabsorption of bicarbonate ions

21. STEPS
 This step mainly occurs proximal
tubule.
 CO₂ combines with H2O to form
H2CO3
 Now H2CO3 dissociates into HCO3-
H+
 H+ is secreted in Lumen in exchange
to Na+
 Now this H+ is excreted out from
body through Urine.

23.  RAS stands for Renin Angiotensin
System.
 Renin Angiotensin system is a
physiological harmone system
involved in the regulation of
arterial blood pressure & plasma
sodium concentration
 Renin is a hormone secreted by
Juxtaglomerular Apparatus.
 Angiotensinogen is a plasma
protein released by liver
Angiotensinogen
Angiotensin-I
Angiotensin-II
Vasoconstriction
Blood pressure
Increased
Renin
Angiotensin
Converting
Enzyme
Liver
Increased
Sympathetic
activity
Blood pressure
increased
Release
aldosterone from
adrenal cortex
Increased Na+ &
H2O reabsorption,
Blood volume
increased

24.  Mictirution is a process by which the urinary bladder empties when it becomes
filled.
 This involves two main steps:
① first the bladder fills progressively until the tension in its walls rises above a
threshold level.
② Now in the second step as bladder is filling continuously.
 A nervous reflex generates known as Mictirutional Reflex that empties the
bladder or at least cause a desire of Urination

25. Stimulation of stretch
receptor
Signal sends to brain
via sensory nerves
Command received by
bladder via motor
neuron
Contraction of bladder
muscles & relaxment of
urethra
Emptying of bladder
Filling of urinary
bladder

26.  There can be various disorders related to Urinary System:
 Polycystic kidney Disease
 Urinary Tract Infection
 Nephrotic Syndrome
 Urinary Incontinence
 Kidney Stones

27.  Enlargement of kidneys because
of presence of many cyst within
them.
 Polycystic kidney disease is an
inherited disorder in which
Clusters of cyst develops over the
kidney that cause enlargement of
kidney & loss function over time

28.  Urinary Tract infections (UTI) are generally
caused by harmful microorganism in Urinary
Tract
 UTI are generally more common in females.
 The usually occur in bladder or Urethra, but more
serious Infections involve the kidney
 Bladder Infection leads to pain with urination,
blood in the Urine & Increased urge to urinate.
 A kidney infection may cause back pain, nausea,
vomiting and fever Bacteria that lives in vaginal
or anal area may enter the urethra & travel to
bladder & can cause an infection.
 It can be of two types:
 Upper UTI

29.  It is a type of renal failure occur due
to increased glomerular permeability
 Nephrotic syndrome is a kidney
disorder that causes your body to pass
to much protein in your urine.
 It generally occurs due to damage in
blood vessels of kidney.

30.  It is a common & embarassing problem in which bladder Control get lost.
 If this the urge of urination gets so strong that you can't control without discharge

31.  kidney stones are hard deposits of mineral e salt that
forms inside your kidney.
 They can be painful when passing through the
urinary Tract but usually don't cause permanent
damage.
 It can be occur due to :
 Drinking too little water
 Obesity
 Weight loss surgery
 Eating food with too much salt or sugar