Excretory System Flashcards
Excretory system
Main function is to regulate the volume and composition of fluids by removing wastes and returning needed substances back to the body for reuse
Metabolic wastes
Can include excess water and ions ( like Na+ Cl- H+ and K+)
Carbon dioxide
Nitrogenous compounds ( main ones and the most we need to get rid of) ex: ammonia urea uric acid
Excretion
The process by which metabolic wastes are separated from blood and removed from the body is called excretion
(Other body systems also help do this job too like respiratory getting rid of C02 but most metabolic wastes are excreted by the excretory (urinary) system)
Deamination
We often consume more
Protein than needed so our body must convert it to other types of molecules, but in order to convert amino acids, we need to do deamination.
Process of removing the amine group ( which is the nitrogen and hydrogen) from amino acids
This process occurs in the kidney and in the liver but mainly liver
Urea
A byproduct of deamination is ammonia, which is a toxic water soluble gas. To make this toxic substance safer, ammonia combines with carbon dioxide to produce urea, which is a less deadly water soluble waste product.
Mainly in bio 20, we focus this process mainly in the liver, so ammonia is turned into urea, mainly in the liver then the urea will be passed down to the kidney
Simple pathway of excretion
Simple pathway always starts with WASTE IN THE BLOOD to the
KIDNEY then to the URETER, then to the BLADDER, then to the URETHA.
Waste in the blood,
kidney
ureter
bladder
urethra
Kidneys
Are bean shaped one on each side of the spinal cord near the lower back
To regulate chemical composition of blood by
Removing metabolic wastes from the blood
Returning water and nutrients back to the blood
Forming urine for excretion of wastes
Kidney flow of liquids
Unfiltered blood enters the kidney through the renal artery
The filtered blood exits through the renal vein
The third vessel, the ureter leaves, each kidney carrying waste in the form of urine
Important thing to the word renal is just a way to say kidney like how pulmonary is a way to say lungs
Kidney parts
The kidney has three regions
Renal cortex the outer most region site of filtration of wastes from blood.
Renal medulla the middle region regulate salt/water balance of blood
Renal pelvis hollow final like chamber, collects urine, and direct it to the ureter.
Bladder
The urethra thief, each kidney intake urine to be stored in the bladder A hollow elastic and muscular organ that stores urine prior to excretion the bladder can stretch to hold about 600 ML of liquid and once full urine is expelled via the urethra
UTI
Infections of the bladder/urethra can be caused by viruses and bacteria entering the urinary tract, causing inflammation, burning pain, and frequent urination
This condition is much more common than females because the urethra is much shorter and in much closer proximity to anal opening this condition is usually treated with antibiotics
Mucturition
Urine leaves the bladder because of the micturition reflex.
Stretching of the urinary bladder, triggers, nerve impulses, causing the urge to urinate
When these contractions become strong enough, the internal urethral sphincter is forced open and you’re an enters the urethra
The external urethral printer is under conscious or voluntary control (most of the time)
Kidney stones
When not enough water is available urea and uric acid and other substance can crystallize out of solution. Normally, the tiny solid particles are not noticed as they are excreted in small amounts and are coated with a special protein to keep them from growing into larger particles. Kidney stones are developed in the Renal pelvis. These stones can block the ureter most usually pass naturally, but are very painful. They can also be broken down by ultrasonic waves or if larger they need to be surgically removed.
