3.2 : The Urinary System in Human The Urinary System

•  Renal arteries bring blood to kidneys

•  Renal veins carry blood away from kidneys

•  Kidneys filter the blood & remove waste products that dissolve in water as urine

•  Ureter flows urine to urinary bladder as storage

•  Urine is released via urethra (short tube)

•  Opening of urethra is controlled by sphincter muscles

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human The Kidneys

•  Human has 2 bean-shaped kidneys

•  Situated each side of the backbone & held in place by fatty tissues

•  Reddish brown & is protected by capsule (tough transparent membrane)

•  Each kidney has a renal artery & renal vein

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human The Kidneys

•  Ureter (long tube) leads out from each kidney – connected to bladder

•  Enlarged part of ureter inside the kidney is pelvis

•  Two regions on kidney: –  Cortex (outer

dark red region) –  Medulla (inner

pale-red region) Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human The Kidneys

•  Cortex has numerous tiny red spots consisting of blood capillaries called glomeruli

•  Medulla consists of 12–16 conical shaped tissues called the pyramids

•  Pyramids consist of fine tubules where urine is formed.

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Functions of Kidneys

Formation of urine •  Filter excess water,

mineral salts & nitrogenous waste products e.g. urea, uric acid & ammonia

•  Unwanted substances form urine which excreted through the urinary system

Reabsorption of useful substances •  Reabsorb glucose &

amino acids into the blood stream

•  This helps the body to maintain the substances dissolve in blood plasma

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Functions of Kidneys

Regulation of water in the blood •  Maintain the volume

of water in the blood (maintaining water balance)

•  If loses too much water, dehydration happens

•  If too much water, blood becomes more dilute than normal

Regulation of glucose in the blood •  Regulate the amount

of glucose in the blood

•  Diabetic people may have a very high glucose level in blood after meal –  Kidneys do not

reabsorb the glucose but let it pass out from the body in urine

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Looking After Our Kidneys

Our kidneys can be damaged by : •  Hypertension (high

blood pressure •  Diabetes mellitus

(high level of glucose in blood)

•  Excessive use of alcohol

•  Long term use of medicines (aspirin, antibiotics, panadol)

•  Old age Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Looking After Our Kidneys

Kidney damage or diseases can be detected through signs such as: •  Uncontrollable high

blood pressure •  Blood in the urine •  Albumen in the urine •  Reduced volume of

urine •  Fatigue, tiredness &

poor appetite Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Looking After Our Kidneys

To ensure good kidneys, we should : •  Test for urine for

albumen (dipsticks may be used)

•  Test for urine for glucose (dipsticks may be used)

•  Carry out kidney scan (see doctor)

•  Go on low-salt & low-sugar diet

•  Exercise regularly •  Live a relaxed life &

control stress Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Living with Kidney Failure

•  Kidney damage leads to kidney failure – causes harmful substances to accumulate & poison the body

•  A person can still lead a normal life if one of the kidneys do not function

•  If both kidneys fail (85% – 90% of kidney failure), dialysis for 3 times a week is a must

•  Dialysis enables them to continue with daily life

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Living with Kidney Failure

In dialysis, a machine is used to filter the patients blood : •  Blood from artery in one

arm is passed through a tubing in the dialysis machine

•  Dialysis fluid surrounds the tubing

•  Small particles (waste products) diffuse into the fluid

•  Large particles (blood cells, glucose & amino acids) cannot diffuse through

•  Filtered blood is returned to a vein in the patients’ arm Prepared  by  Ms  Sue  Soh  Ya  Lee  

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Looking After Our Kidneys

3.2 : The Urinary System in Human

radial vein

Prepared  by  Ms  Sue  Soh  Ya  Lee  

Prepared  by  Ms  Sue  Soh  Ya  Lee  

3.2 : The Urinary System in Human Looking After Our Kidneys

3.2 : The Urinary System in Human Living with Kidney Failure

•  A patient with kidney failure may have a kidney transplant – an operation in which damaged kidney is replaced with a healthy kidney from a donor

•  Transplanted kidney must be compatible with the patients’ or else, it will be rejected by the patients’ body

Prepared  by  Ms  Sue  Soh  Ya  Lee