Urinary & Excretory Systems Flashcards
What does the structure of the excretory system consist of?
- 2 kidneys
- 2 ureters
- the urinary bladder
- urethra
Where are the kidneys located?
-the kidneys lie against the back wall of the abdomen behind the liver and the stomach
What are the kidneys covered by?
-peritoneum and embedded fat
Where is the bladder located?
- lies in front of the pelvis
- and the ureters curve round the lower part of the abdomen to meet it
How many kidneys are there and where do they lie?
The two kidneys lie just above the waste on either side of the spine
(On the back wall of the abdomen behind the liver and stomach)
What is the size of a kidney compared to?
-the size of an average adult kidney is about the size of a mans fist
What is the kidneys function? for the urinary system.
-to produce urine and to maintain the fluid balance in the body
What circulates through the kidneys?
Blood
What do the Kidneys retain? And what do they filter?
-retain useful substances and filter out waste substances (which are then excreted as urine)
How will the kidneys respond if water is depleted in the bloodstream?
-the kidneys will reabsorb water to maintain balance
How will kidneys respond if there is excess water in the blood stream?
-kidneys will excrete water to maintain balance
Besides producing urine, the kidneys play an important role in regulating blood pressure because:
-they control blood volume ….which has a direct effect on blood pressure
Kidneys maintain the balance of_______ and _______ in the body:
- sodium and potassium
- acid and alkaline (pH balance)
Why are sodium and potassium important?
It is important for the kidneys to balance these minerals because they are important for healthy function of muscle and bone
From the kidneys, Urine moves down through the_________.
Ureters
What are the ureters?
Tubes that transport urine to the urinary bladder
What does the urinary bladder do?
Expands to HOLD the urine
What prevents urine from backing up into the kidneys from the bladder?
There are valves which close to prevent the urine from backing up into the kidney when the bladder is full
What signals a person to relieve their bladder?
When the bladder is filled to capacity, there is a feeling of urgency (which signals the person to relieve their bladder)
How much urine can the bladder hold?
-200ml to 400 ml of urine
The urine passes through the______ to the external opening.
Urethra
Muscles that are under voluntary control which we can over-ride the reflex to urinate by conscious effort:
External sphincter
When is control over external sphincters achieved in life?
Infants require training to gain control over the sphincter muscles and usually achieve this around two years old
What is a UTI?
- Urinary tract infection
- one of the most common problems
Why are UTIS more common in women than men?
Because the urinary tract is shorter and close to the vagina and rectum, offering little protection against entry of micro-organisms into the bladder
What are women advised to do after using the toilet?
-always wipe from front to back to avoid transmitting bacteria into the urethra
What are women who are susceptible to UTI infection advised to do?
- white cotton underwear
- white toilet paper
- drink lots of water
What is the danger of using a hot tub?
UTI infections can sometimes be transmitted by use of hot tubs
What is Cystitis:
An inflammation of the urinary bladder
How is Cystitis caused?
-may be caused by bacterial infection, chemicals, or mechanical injury
What are the symptoms of Cystitis?
Burning on urination or painful urination
What is an obstructive disorder of the kidneys?
-Often causes infection by stones which form in the kidneys (kidney stones)
What are kidney “stones”?
-crystalline structures made up of materials that the kidneys usually excrete in the urine
What are most stones made up of?
Calcium
What happens if kidney stones move down into the urethra or ureter?
-causes severe cramping and pain
Small stones usually pass through the system on their own, what needs to be done if they are not?
-stones may have to be removed using either shock wave therapy or surgery
What is the excretory system responsible for?
-responsible for purifying the body by eliminating waster matter
Why is it important for the excretory system to eliminate waster matter?
-The metabolism of the body cells forms various toxic substances that, if retained, could poison the body
Name the organs that play an important function in the excretory system?
- alimentary canal
- lungs
- skin
- kidneys
What is the alimentary canal function of the excretory system?
-removes the residues of the food through the anus by defecation
What is eliminated with the residues of food by the alimentary canal?
- heat, water and salts
- special waste materials such as the bile pigments
Describe the lungs role in the excretory system:
- lungs remove carbon dioxide.
- considerable quantities of heat and water may be lost incidentally of the inspired air is dry or cold
Describe the role of skin for the excretory system:
-skin removes excess heat not lost through breathing
Loss of heat in the body is aided by:
Excretory system
-the evaporation of sweat
What does sweating also remove?
-some nitrogenous waste, salts and water
(And excess heat not lost through breathing)
What are the kidneys role in the excretory system?
- Kidneys removes nitrogenous waste and excess salts not removed by sweating
- and excess water not lost through sweating or breathing
Why are the kidneys, with their ducts, called the excretory system?
-because kidneys balance the system and remove metabolic waste materials which are not lost in other ways
