EXCRETORY SYSTEM

BY: HARSH RAMAN ANUJA SHARMA

Objectives Of The Class

At the end of the presentation, all of you should able to:

Enlist the organs of excretory system.

Explain about function of liver.

Describe the functions of large intestine and skin.

Illustrate functions of kidneys.

Describe renal blood supply of kidney.

Objectives Of The Class contd…

Illustrate functions of kidneys?

Enlist parts of nephron?

Explain about urinary bladder?

Explain about urethra?

Explain about polyurea, anurea, and hematurea

INTRODUCTION OF EXCRETORY SYSTEM

The human excretory system functions to remove waste from the human body.

EXCRETORY SYSTEM

Excretory system consist of following :

Liver

Lungs

Large intestine

Skin

Urinary system

LIVER

It is a largest gland of the body.

Remove toxins from the blood.

The liver also produces bile.

LUNGS

Filter out carbon dioxide, from the blood.

Large Intestine

Collects waste from throughout the body.

Extracts any remaining usable water and then removes solid waste.

SKIN

Excretes sweat through sweat glands throughout the body.

Helps to keep the body cool when it is warm.

Urinary System

Urinary system

It consists of following structures:

Kidneys

Ureters

Urinary bladder

Urethra

KIDNEY

KIDNEYS Contd

KIDNEY- location

Lies in the abdominal cavity below diaphragm.

On each side of the vertebral column.

Extend from the level of 12th thoracic vertebra to the 3rd lumbar vertebra.

The right kidney is usually slightly lower than the left.

About 11cm long, 6cm wide, 3cm thick and weight 125-170 gm.

Organs associated with the kidney

Organs Associated With Kidney

RIGHT KIDNEY

Superiorly- the right adrenal gland.

Anteriorly - the right lobe of the liver.

Posteriorly - the diaphragm and muscles of the posterior abdominal wall.

Organs Associated With Kidney contd…

LEFT KIDNEY

Superiorly- the left adrenal gland.

Anteriorly - the spleen.

Posteriorly - the diaphragm and muscles of the posterior abdominal wall.

Organs associated with the kidney

LEFT KIDNEY

Superiorly- the left adrenal gland.

Anteriorly- the spleen, stomach, jejunum and splenic flexure of the colon.

Posteriorly - the diaphragm and muscles of the posterior abdominal wall.

GROSS STRUCTURE OF THE KIDNEY

Fibrous capsule- surrounding the kidney.

Cortex- a reddish brown layer of tissue.

Medulla- Innermost layer, consisting of pale conical shaped striations is called renal pyramids.

Gross Structure Of Kidney

Hilum- Is the concave medial border of the kidney where the renal blood and lymph vessels, the ureter and nerves enter.

It has a number of distal branches called calyces. Calyces are of two types.

Major calyx

Minor calyx

MICROSCOPIC STRUCTURE OF KIDNEY

The kidney is composed of about 1 million functional units called Nephrons and a smaller number of collecting tubes.

FUNCTIONS OF KIDNEY

Formation of urine.

Simple filtration.

Selective reabsorption

Secretion

Water balance and urine output

Electrolyte balance

BLOOD SUPPLY OF KIDNEY

Need constant supply in order to control the composition of body fluids.

Renal artery a branch from aorta enters the kidney at hilum.

supplies blood rich in nitrogenous waste, oxygen and nutrients.

Renal vein: carries deoxygenated blood to the inferior vena cava and then to the heart.

Blood Flow

Nerve supply to kidney

The greater, lesser and least stlanchnic nerve provide nerve supply to kidneys.

NEPHRON

NEPHRON

Is the basic structural and functional unit of the kidney.

Its chief function is-

To regulate the concentration of water and soluble substances

Reabsorbing what is needed and excreting the rest as urine

NEPHRON

Eliminates wastes from the body

regulates blood volume and blood pressure

control levels of electrolytes and metabolites

regulates blood pH.

NEPHRON contd.

Each nephron consists of the following parts:

Glomerulus

Bowman’s capsule

Proximal tubule

loop of Henle

Distal tubule

Collecting duct.

PARTS OF NEPHRON

Bowman’s capsule: is the initial dilated part of nephron.

Glomerulus: is formed of a tuft of capillaries into the bowman’s capsule.

Proximal convoluted tubule: PCT lumen is continuous with that of Bowman’s capsule.

PARTS OF NEPHRON contd..

Loop of henle: it consists of a descending limb

which continues into the thin segment from

which arises the thick ascending limb.

Distal convoluted Tubule: Thick ascending limb is

continued with the distal convoluted tubule.

Collecting tubules: DCT join to form collecting

tubules.

Composition of urine

About 96% of the urine is water.

2% is salts, mainly sodium chloride.

Urea make up 2%.

About 1.5L urine is produced daily.

FORMATION OF URINE

FORMATION OF URINE

The first step in urine formation is filteration of blood in kidneys.

Nephron filter blood by regulating concentration of water and soluble substances like sodium salts.

Reabsorbing what is needed and excreting what is waste.

Urine formation continue…

Filtrate includes water, small molecules and ions that can easily pass through filtration membrane.

Large molecules such as proteins and blood cells cannot pass through the membrane.

Amount of filtrate produced every minute is called glomerular filtration rate. Or GFR.

Normal GFR = 125ml/ minute=170-180L/day

Ureters

The ureter is the tube that carries urine from the kidney to the urinary bladder. In humans there are two ureters, one attached to each kidney.

Ureters continue………

Upper half located - in the abdomen

lower half - located in the pelvic area.

12 inches long.

thick walls composed of a fibrous, a muscular, and a mucosa coat, which are able to contract.

Urinary Bladder

The urinary bladder is a muscular sac in the pelvis, just above and behind the pubic bone. When empty, the bladder is about the size and shape of a pear.

Urinary bladder continue…

Urine is made in the kidneys

Travels down two tubes called ureters

Then to the bladder.

The bladder stores urine, allowing urination to be infrequent and voluntary.

Lined by layers of muscle tissue that stretch to accommodate urine.

The normal capacity of the bladder is 400 to 600 ml.

Urethra

In both genders, the urethra works as a tube connecting the urinary bladder to the genitals.

Urethra continue…….

The bladder collects and stores urine until when it is ready to be discharged through the urethra.

While the function remains the same for both genders, slight differences exist due to differences between male and female genitals.

URETHRA

Anuria: absence of urine .

Oliguria: absence of urine output.

Polyuria: excess urine output.

Bacteriuria: bacteria in urine.

Diuresis: increased urine excretion.

Dysuria: painful or difficult urination.

Medical Terms Related To Excretory System

Medical terms related to excretory system contd…

Nephrectomy: removal of kidney.

Incontinance: inability to control urination.

Cystectomy: surgical removal of uriary

bladder.

Cystitis: inflammation of urinary bladder.

Medical Terms Related To Excretory System:

Glomerulonephritis

Horse shoe kidney:

Urinary Tract Infection

A urinary tract infection (UTI) (also known as acute cystitis or bladder infection) is an infection that affects part of the urinary tract.

Renal Failure

Renal failure (also kidney failure or renal insufficiency) is a medical condition in which the kidneys fail to adequately filter waste products from the blood.

Nurse’s Role

Nurse’s Role

Monitor intake and output characteristics of

the urine as it provides information about

renal functions and presence of

complications.

Determine the patient’s voiding pattern.

Encourage increased fluid intake as increased

hydration will flush the bacteria

Nurse’s Role

Review the full bladder complaints as urinary

retention may occur causing tissue distension.

Observation of changes in mental status,

behaviour and level of consciousness as

accumulation of residual uremic and

electrolyte imbalnce can be toxic to central

nervous system.

Nurse’s Role

Provide information on sources of infection and

prevent the spread, explain the administeration

of antibiotics, it will help to reduce anxiety.

Provide opportunity for patient to express

feelings and concern about the treatment plan

CONCLUSION

The excretory system is passive biological system that removes

excess

unnecessary

from an organism, so as to help maintain homeostasis within the organism and prevent damage to the body. It is responsible for the elimination of waste product of metabolism as well as other liquid and gaseous waste.

To sum up

The kidneys regulate the amount of water, salts

and other substances in the blood.

The kidneys are fist-sized, bean shaped

structures that remove nitrogenous wastes

(urine) and excess salts from the blood.

The ureters are tubes that carry urine from the

pelvis of the kidneys to the urinary bladder.

The urinary bladder temporarily stores urine until it is released from the body.

The urethra is the tube that carries urine from the urinary bladder to the outside of the body.

The outer end of the urethra is controlled by a circular muscle called a sphincter

RECAPTUALIZATION

Enlist the organs of excretory system?

Enlist the structures of urinary system?

explain the organs associated with kidneys?

Illustrate functions of kidneys?

Enlist parts of nephron?

Explain about urinary bladder?

Explain about urethra?