Excretory SystemExcretory System

SwensonSwenson

ExcretionExcretion – – Removal of nitrogenous Removal of nitrogenous wastewaste..

What is Nitrogenous waste?What is Nitrogenous waste? Waste from the breakdown of Proteins, Waste from the breakdown of Proteins,

and other cellular functions.and other cellular functions. Builds up in blood after being released Builds up in blood after being released

from cells.from cells. Is poisonous if it builds up in the body.Is poisonous if it builds up in the body.

3 Types:3 Types: Ammonia (NH3) – highly toxic – may be Ammonia (NH3) – highly toxic – may be

excreted by Fish.excreted by Fish. Urea [(NH2)CO] - Urea [(NH2)CO] - Less toxic form Less toxic form

excreted by many land animalsexcreted by many land animals Uric acid [C5H4N4O3] – Uric acid [C5H4N4O3] – less toxic form less toxic form

excreted by many birds and insectsexcreted by many birds and insects

Why remove wasteWhy remove waste? ?

1. poisons tissues 1. poisons tissues

2. If left in blood poison 2. If left in blood poison organs.organs.

3. Gout – uric acid crystals 3. Gout – uric acid crystals that settle in joints, from that settle in joints, from protein-rich diets (liver)protein-rich diets (liver)

How wastes are removed?How wastes are removed?

Aquatic organismsAquatic organisms – live in H2O and – live in H2O and excrete ammonia, diluted with water excrete ammonia, diluted with water to decrease toxicity.to decrease toxicity. Fish – have kidneys to do this.Fish – have kidneys to do this.

Terrestrial organismsTerrestrial organisms – land – land organisms convert ammonia to urea organisms convert ammonia to urea or uric acid.or uric acid.

    Earthworms – Earthworms – excrete ammonia through skin into wet excrete ammonia through skin into wet soil and urea from kidneys.soil and urea from kidneys.

    Insects, Reptiles, Birds – Insects, Reptiles, Birds – excrete uric acid as insoluble crystals excrete uric acid as insoluble crystals that will not dissolve in water.that will not dissolve in water.

Human/Mammals – Human/Mammals – have kidneys that excrete urea, have kidneys that excrete urea, HH22O, and salts in urine.O, and salts in urine.

StructureStructure

Kidneys Job is Kidneys Job is FiltrationFiltration

Located – Located – Embedded in fat Embedded in fat along either side of along either side of the spine.the spine.

NephronNephron Make urine = urea Make urine = urea

+ excess salts + + excess salts + H2O H2O

LiverLiver Ammonia + CO2 to form less toxic Ammonia + CO2 to form less toxic

urea, sent to kidneyurea, sent to kidney

Renal Artery - Renal Artery - Carries blood to Carries blood to kidney to be filtered. (Filtered every kidney to be filtered. (Filtered every 30 min.30 min.

Nephron -Tube in kidney that Nephron -Tube in kidney that filtersfilters

Glomerulus - Glomerulus - Ball of capillaries in Ball of capillaries in kidneykidney

Bowman’s Capsule - Bowman’s Capsule - Extracts water, Extracts water, salt, wastes from Glomerulus, takes salt, wastes from Glomerulus, takes too much H2O & salts from the blood.too much H2O & salts from the blood.

Tubule - Tubule - Tube in kidney that Tube in kidney that returnsreturns 99% of H2O & salts back to blood.99% of H2O & salts back to blood.

ADH – hormone that triggers body to ADH – hormone that triggers body to absorb water, rather than excrete it.absorb water, rather than excrete it.

Renal vein - Renal vein - Carries filtered blood to Carries filtered blood to body. body.

Ureters - Ureters - Carries urine to bladder Carries urine to bladder (2)(2)

Urinary Bladder - Urinary Bladder - Stores urine.Stores urine. Urethra - Urethra - Tube through which urine Tube through which urine

leaves bladder.leaves bladder.

ProblemsProblems:: Alcohol – diuretic - elevates the rate Alcohol – diuretic - elevates the rate

of bodily urine excretion of bodily urine excretion Caffeine – diureticCaffeine – diuretic Nephritis – inflammation of nephron - Nephritis – inflammation of nephron -

excessive removal of protein from excessive removal of protein from the blood and its excretion in urinethe blood and its excretion in urine

Kidney failure – need dialysis to filter Kidney failure – need dialysis to filter blood.blood.

Homeostasis – balance of salt & H2OHomeostasis – balance of salt & H2O

Diabetes insipidus – extreme thirst Diabetes insipidus – extreme thirst due to passage of large quantities due to passage of large quantities of dilute urine.of dilute urine.

Diabetes Mellitus – sugar in urine Diabetes Mellitus – sugar in urine due to lack of insulin.due to lack of insulin.

Plants excrete? Plants excrete? No wastesNo wastes

Review for testReview for test

In the Lung

At the Body Tissues

External Respiration

Internal Respiration

Step Inspiration (in) Expiration Step Inspiration (in) Expiration (out)(out)

11 Rib Muscles Contract Relax Rib Muscles Contract Relax

22 Diaphragm Contracts RelaxDiaphragm Contracts Relax

33 Lowers Pressure Lung Tissue Lowers Pressure Lung Tissue

ShrinksShrinks

44 Creating a Vacuum Forcing Air OutCreating a Vacuum Forcing Air Out

Average Breaths per minute = 18Average Breaths per minute = 18

StructureStructure