3.2 Urinary System

8/2/2019 3.2 Urinary System

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Kidney VS Ipad









Excretion



Lesson outcomes:

Students are able to:-

Identify the locations of kidneys and other parts of the urinary system,

Identify the structures of the kidney, Describe the functions of the kidney,



3.2 The Urinary System in Man

1. The human urinary system consists of several parts.2. The kidneys are located at the back of the abdominal cavity .

The other parts of the urinary system are :

Kidneys

Ureters

Urinary bladder

Urethra

Renal artery

Renal vein




1. The human urinary system consists of several parts.2. The kidneys are located at the back of the abdominal cavity .

The other parts of the urinary system are :

Kidneys Filter the blood and remove excess water, urea and mineral salts from the blood to

form urineUreters Channel urine from the kidneys to the

urinary bladder

Urinary bladder

Stores urine

Urethra Channels urine from the urinary bladderout of the body

Renal artery Transport oxygenated blood to the kidneys

Renal vein Transport deoxygenated blood away fromthe kidneys




Side view of urinary system in males and females.




3. Excess amino acids (protein) are converted to urea in the liver.

4. The urea is sent to the urinary system. The flow of the urea into theurinary system starts from the kidney, to the ureter, then to thebladder, and lastly to the urethra. From the urethra it is removed as

urine through the penis or vagina.



Structure of the Kidney 1. The kidneys are dark red in colour and is bean-shaped.

2. Each kidney is roughly about the size of a fist.

3. Thick layer of fat cover and protect each kidney.

4. The outer, transparent coat of the kidney is called the

capsule. The capsule is a tough membrane.



Structure of the Kidney

5. When the kidney is cut longitudinally,

the kidney can be seen to consist of two parts.

6. These are the outer, darker,protective part known as the cortex,

and the inner lighter layer called themedulla.

7. The cortex makes up about one-thirdof the kidney .

8. The medulla forms several pyramids which open into a sac-like cavity called the pelvis.

9. From the pelvis, a long, narrow tube,the ureter, leads to the bladder.

cortex

medula



Functions of the Kidney 1. The functions of the kidney are :

a) To filter blood

b) To remove urea, excess mineral salts and water to form urine.

c) To regulate the water and chemical balance in the body.

d) To reabsorb water into the circulatory system.

If the body system has too much water, less water will be reabsorbed,

the urine will be diluted.

When the body system lacks if water, more water will be reabsorbed,urine will be concentrated.

e) To control the chemical composition of the blood (ph value)



The Importance of MaintainingHealthy Kidneys

1. The kidney is a relatively strong organ. However, weneed to protect our kidneys from damage.

2. (a) Food may contain toxic substances such asmercury , lead, arsenic and insecticides. Thesesubstances can damage the kidney .

(b) Food that is too salty and sweet is also bad for thekidneys.

3. To have healthy kidneys, we should drink plenty of water

and consume less salt and sugar.



Why diabetic patients are likely todevelop kidney disease ?



Diabetes and Kidney Failure?

1. When our bodies digest the protein we eat, the processcreates waste products.

2. In the kidneys, millions of tiny blood vessels (capillaries) with even tinier holes in them act as filters.

3. As blood f lows through the blood vessels, smallmolecules such as waste products squeeze throughthe holes.



Diabetes and Kidney Failure?

4. These waste products become part of the urine.

5. Useful substances, such as protein and red blood cells,

are too big to pass through the holes in the filter andstay in the blood.

6. Diabetes can damage this system.

7. High levels of blood sugar make the kidneys filtertoo much blood.



Diabetes and Kidney Failure? 8. All this extra work is hard on the filters. After many years, they start to leak and useful protein is lost

in the urine. Having small amounts of protein inthe urine is called microalbuminuria.

9. In time, the stress of overwork causes the kidneys tolose their filtering ability .

10. Waste products then start to build up in theblood.

11. Finally, the kidneys fail.

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3.2 Urinary System