The Excretory System & Waste Management Now “urine” for it!

The Excretory System & The Excretory System & Waste ManagementWaste Management

Now “urine” for it!Now “urine” for it!

Excretion - The act or process of Excretion - The act or process of discharging metabolic waste matter discharging metabolic waste matter from the blood, tissues, or organs.from the blood, tissues, or organs.

#1 vs. #2

Metabolic WastesMetabolic Wastes

All the metabolic wastes are excreted in a All the metabolic wastes are excreted in a form of water solutes through the form of water solutes through the excretory organs, with the exception of excretory organs, with the exception of CO2, which is excreted together with the CO2, which is excreted together with the water vapor throughout the lungs. water vapor throughout the lungs.

The elimination of these compounds The elimination of these compounds enables the chemical homeostasis of the enables the chemical homeostasis of the organism.organism.

Homeostasis: process of maintaining a Homeostasis: process of maintaining a stable internal environment.stable internal environment.

LungsLungs

Waste: COWaste: CO22 + H + H22OO Carbon Dioxide is toxicCarbon Dioxide is toxic Too much water thins blood and Too much water thins blood and

bloats cells to the point of rupturebloats cells to the point of rupture Also major organ for alcohol release Also major organ for alcohol release

LiverLiver

UreaUrea proteinsproteinsamino acids amino acids NHNH22 removed removed forms forms

ammonia, liver converts to urea ammonia, liver converts to urea Breaks down amino acids -> Ammonia is a Breaks down amino acids -> Ammonia is a

waste productwaste product Ammonia (NHAmmonia (NH33), which is highly toxic, is ), which is highly toxic, is

quickly converted to ureaquickly converted to urea

Is the liver an excretory organ?Is the liver an excretory organ?

SkinSkin Sweat: Urea, Water, Mineral SaltsSweat: Urea, Water, Mineral Salts 2 functions of sweat: release toxins 2 functions of sweat: release toxins

and cool bodyand cool body 2 types of sweat glands: eccrine 2 types of sweat glands: eccrine

glands and apocrine glandsglands and apocrine glands Eccrine glands are the primary gland Eccrine glands are the primary gland

for perspirationfor perspiration Does sweat have an odor?Does sweat have an odor?

KidneyKidney

Filters blood plasma, eliminates Filters blood plasma, eliminates waste, returns useful chemicals to waste, returns useful chemicals to bloodblood

Forms Urine: Urea, Water, Mineral Forms Urine: Urea, Water, Mineral SaltsSalts

Does urine have an odor?Does urine have an odor?

Urine vs. SweatUrine vs. Sweat

WASTE PRODUCTSWASTE PRODUCTS ORIGIN OF WASTEORIGIN OF WASTE EXCRETORY ORGANEXCRETORY ORGAN

1. Ammonia (NH1. Ammonia (NH33)) - breaks down of - breaks down of amino acids in liveramino acids in liver

kidneyskidneys

2. Urea2. Urea - Converts NH- Converts NH33 to to urea in liver urea in liver

kidneys, skinkidneys, skin

3. CO3. CO22 Cell respiration – Cell respiration – break down of break down of glucose in cellsglucose in cells

lungs, intestines, skinlungs, intestines, skin

4. H4. H22OO Cell respiration – Cell respiration – break down of break down of glucose in cellsglucose in cells

kidneys, lungs, skinkidneys, lungs, skin

5. Mineral salts5. Mineral salts - From food & water- From food & water kidneys, skinkidneys, skin

Urinary SystemUrinary System

The urinary system is The urinary system is composed of 2 kidneys, 2 composed of 2 kidneys, 2 ureters, 1 urinary bladder ureters, 1 urinary bladder and a urethra.and a urethra.

These are the structures that These are the structures that are directly involved in the are directly involved in the production and excretion of production and excretion of urine. Each kidney is like a urine. Each kidney is like a big filter that cleans the big filter that cleans the blood. blood.

The ureters are tubes that The ureters are tubes that carry urine from the kidneys carry urine from the kidneys to the urinary bladder. to the urinary bladder.

The bladder stores the urine The bladder stores the urine temporarily. temporarily.

The urethra is the tube The urethra is the tube through which the urine through which the urine leaves the body when you leaves the body when you urinate.urinate.

A pair of renal arteries branch off the A pair of renal arteries branch off the aorta, which carries blood full of aorta, which carries blood full of wastes, into the kidneys.wastes, into the kidneys.

The kidneys form urine by filtering The kidneys form urine by filtering wastes & excess water from the wastes & excess water from the blood.blood.

The cleaned blood is returned to the The cleaned blood is returned to the circulatory system by the renal veins. circulatory system by the renal veins.

The urine is stored in the renal pelvis The urine is stored in the renal pelvis of the kidney before it trickles out of the kidney before it trickles out each kidney through the ureters into each kidney through the ureters into the bladder. The elastic walls of the the bladder. The elastic walls of the bladder stretch as it gradually fills. A bladder stretch as it gradually fills. A sphincter keeps the bladder closed.sphincter keeps the bladder closed.

When you urinate, the sphincter When you urinate, the sphincter relaxes & the urine flows into the relaxes & the urine flows into the urethra, which leads to outside the urethra, which leads to outside the body.body.

Urine is about 96% water & 4% Urine is about 96% water & 4% wastes. wastes.

Bile pigments from the liver give Bile pigments from the liver give colour to both urine & feces. The colour to both urine & feces. The yellow colour of your urine depends on yellow colour of your urine depends on how dilute the pigment is. If you drink how dilute the pigment is. If you drink a lot of liquids, your urine will be pale a lot of liquids, your urine will be pale yellow. If you sweat a lot or drink very yellow. If you sweat a lot or drink very little, you will not urinate as often and little, you will not urinate as often and your urine will be dark yellow (like first your urine will be dark yellow (like first thing in the morning).thing in the morning).