The Urinary System Flashcards
List the 2 functions of the urinary system:
- Produce urine
2. Eliminate it from the body
What organs make up the urinary system?
2 kidneys 2 ureters 1 bladder 1 urethra Also male and female genitalin
What anchors the kidneys to surrounding structures and helps maintain normal position?
Connective tissue
What supplies blood to the kidneys?
Renal artery
What is the definition of nephrons?
Nephrons is where the kidneys work is actually done
What are the 3 main parts of nephrons?
- Glomerulus
- Tubule
- Bowman’s capsule
Where does filtration take place?
In the glomerulus
What processes the blood before returning it to the general circulation?
The kidneys
Functions of the kidneys:
- To produce and secrete urine
- stability of the body’s internal environment depends on it - Fluid and electrolyte balance
- varying the amounts of water and electrolytes leaving the blood in urine - Acid-base balance (proper pH)
- acids are constantly being produced by cell metabolism
Urea:
nitrogenous wastes from protein metabolism
What happens in kidney failure?
Certain things are not held to their normal concentrations leading to possible death
- sodium
- potassium
- chloride
- nitrogenous wastes (urea) from protein metabolism
How do kidneys form urine?
By means of 3 processes:
- Filtration
- Reabsorption
- Secretion
Filtration:
Water, electrolytes, and nutrients move from the blood, in the glomerulus, to bowman’s capsule and eventually move into the kidney tubules
Reabsorption:
A major portion of water and electrolytes (not all) and normally all nutrients move from the tubules back into the blood.
Two hormones that regulate urine volume:
AHD Aldosterone (adrenal)
Secretion:
Other substances move from the blood and into the distal tubules
What regulates the volume of urine produced?
Changes in the amount reabsorbed from the distal and collecting tubules
What happens after urine is secreted?
It drops out of the collecting tubules into the ureters and eventually down to the bladder
What does ureters contain?
Muscle tissue
Function of ureters:
- Collects urine as it forms in drains into the bladder
- waves of involuntary muscle contraction force urine down to ureters and into the bladder
What forms the wall of the bladder?
Smooth muscle fibres
Bladder structure:
- Bladder capable of considerable distension.
- Three openings in the floor of the bladder. Two form ureter and one into urethra
Functions of the bladder:
- Reservoir for urine before it leaves the body
2. Aided by urethra, expels urine from the body
Urethra male versus female:
Female: 1-1/2 inches
Male: approx. 8 inches
Functions of the urethra:
- passageway from the bladder to the outside of the body
- male urethra is terminal portion of reproductive tract (passageway for semen)
- female it serves only urinary tract
The male urethra has two passageways, what are they for?
Semen and urine
Urine is water/waste produced in the kidneys and released from what?
The bladder
True or false
Urine is approximately 95% water.
True
Urine (95% water) dissolves in several kinds of substances, what are they?
- Nitrogenous waste from protein metabolism such as urea
- Electrolytes – mainly sodium, potassium, chloride etc.
- Toxins – during disease, bacterial poisons leave the body in urine
- Pigments – Yellow form bile pigments
- Hormones – to determine, urine is checked for a certain hormone
- Various abnormal constituents – Glucose and blood most common
What does the integumentary system (skin) excrete?
Water
Electrolytes
Small amounts of nitrogenous waste
What does the respiratory system (lungs) excrete?
Carbon dioxide
Water
What does the digestive system (large intestine) excrete?
Wastes from digestion
Some metabolic wastes
Salts of calcium and other heavy metals
Functions of the urinary tract, is the most important mechanism for maintaining a…?
Constant internal environment for the body, essential for life
True or false
The left kidney is usually slightly larger than the right kidney.
True
