what does the excretory system do?

Answer 1

Excretory organs:
a). collect fluids from somewhere in the body.
b). modifies the fluids by reabsorbing substances the body needs.
c). provides a way to expel the excretory product from the body.

These organs expend metabolic energy to carry out these functions. The human kidney makes up .05% of the bodies weight and uses 7.2% of the oxygen it consumes.

Every vertebrate has a pair of kidneys.
Their functional units are called nephrons. The kidney contains more than a million nephrons, which collect fluid from filtered blood.
The renal arteries and renal veins carry blood to and from the kidney.
The collected waste material leaves the kidney via the ureter and is stored in the urinary bladder; it is then expelled from the body through the urethra.
The kidney filters 1600 liters of blood per day, producing 1 liter of urine.

Function of the Nephrons: Let's follow the process of urine formation in a nephron.

The nephron's cup shaped Bowmans Capsule surrounds a knot of blood capillaries called the glomerulus. Much of the bloods fluid filters into the glomerulus due to pressure from the circulatory system. Left behind are large proteins and whole cells, which are too large to fit through. This filtrate is then passed through the nephron tubule, which has 4 main parts ( proximal convoluted tubule, loop of Henle, distal convoluted tubule, and the collecting duct).
In the proximal convoluted tubule, a considerable amount of resorbtion occurs. Small proteins, glucose, and ions are returned to the blood by active transport. Negatively charged ions follow passively, followed by the osmosis of water. About 75% of the filtrate is returned in this section of the nephron.
The loop of Henle, lie in the medulla of the kidney, the other parts of the nephron lie outside of the medulla in the cortex. Salt is actively transported out of the filtrate, and since this area impermeable to water, water cannot follow the ions out here.
The distal convoluted tubule, urine is then passed through here to the collecting duct where it is concentrated due to its permeability to water. It leaves the collecting duct into the pelvis of the kidney, which leads to the ureter and the bladder where it is stored.

Regulation of Kidney function:
Urine composition and the rate of urine formation are largely regulated by hormones vasopressin, aldosterone, and angiotensin, and the enzyme rennin.

Vasopressin (ADH) is produced by the posterior pituitary gland and increases the bodies ability to resorbtion of water. it increase the permeability of the collecting ducts.
Diabetes insipidus is caused due to a lack of this hormone. It is characterized by thirst, and the production of large amounts of dilute urine.

Angiotensis and Aldosterone are hormones that regulate the amount of sodium that is resorbed from the filtrate in the nephrons. Aldosterone is produced by the adrenal gland. it promotes the resorbtion of sodium by the distal tube. Its action is directed by the bloods salt content. The kidney secretes an enzyme rennin, which changes a plasma protein angiotensinogen into angiotensin, which helps to increase the production of aldosterone and the blood pressure of the kidney.

Answer 2

The excretory system is like the liver and the kidneys. They both wash ou toxins from the blood. After the blood has been cleaned, the waste products from the blood are then transported to the urinary bladder. Where they are removed from the body.

Answer 3

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RE:
what does the excretory system do?

Answer 4

The excretory system is the system of an organism's body that performs the function of excretion, the bodily process of discharging wastes.

Kidneys for excreting urine.
Intestine for excreting faeces.
Lungs for excreting carbon dioxide.
Sweat glands for excreting sweat.

Answer 5

Collect water and filter body fluids.
Remove and concentrate waste products from body fluids and return other substances to body fluids as necessary for homeostasis.
Eliminate excretory products from the body.

Answer 6

the excretory system gets rid of stuff that the body doesn't need.
This would include undigestable food ("crap") and urea ("pee")

Urea is actually cellular waste- poisons that the body's cells produce when they breathe and metabolize things. In humans and other mammals, urine is produced. In birds, uric acid is produced and in fish ammonia is produced.

the feces portion is stuff that was not digestable. It is waste, but is simply bulky stuff that the body didn't adsorb

Answer 7

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Answer 8

the system's role is to remove all the waste products from your body

Answer 9

They excrete waste substance from your body. They are essential as the waste contains toxic.

Answer 10

That would be "poop"...or "pee", whichever you have to do worse.

Surprisingly enough, it also includes sweating and breathing.