Excretion - __________________________________ Wastes – animals - ___________________________ plants – __________________________ Nitrogenous wastes (from protein metabolism) Uric Acid - _______________________ Urea - ______________ Ammonia – ___________ removal of wastes of metabolism/life processes some are toxic and must be excreted can store toxic & recycle nontoxic Nontoxic, not soluble in water Moderately toxic Highly toxic

Processes that produce wastes

Excretory means/systems of organisms

1. Protists:  Diagram

 Passive transport – Water and their nitrogenous waste ___________, diffuse through the cell membrane. Ammonia is very soluble in water, so it is easily excreted.  Active transport – for those organisms that live in fresh water, they have a __________ _______to pump out water that comes in the cell. In photosynthetic protests (________) they can use their wastes from respiration (__________ and __________) for ____________ contractile vacuole alga CO2H2Ophotosynthesis ammonia

2. Hydra

 All cells are in contact with the water environment. Wastes leave the cells by the process of _________. Their main nitrogenous waste is _________. diffusion ammonia

3. Earthworm

 Carbon dioxide leaves the earthworm by diffusion through its ________, ________ skin.  Water, mineral salts, ammonia, and its main nitrogenous waste _________. Are filtered through specialized execratory organs called _________ (singular, ___________)  They are found in most body segments. Wastes are filtered and excreted through pores in the skin. The waste excreted is called __________. thinmoist urea naphridianephridium Urine

4. Grasshopper

 A grasshopper has an open circulatory system. Carbon dioxide diffuses into the body fluids from the cells, into the ________ ______ and out the __________. Water, mineral salts, and uric acid accumulate in special excretory organs called __________ _______. The blood bathes these so the wastes simply diffuse out of the blood and into the tubules. Uric acid is essentially harmless because it is insoluble in water. The uric acid leaves, along with the feces, through the anus. tracheal tubes spiracles Malpighion tubules

5. Human  The ____________ are the organs of excretion of nitrogenous waste in the human. They really serve two functions for us: 1.Filtration - __________________________________ 2.Regulation of substances in the body - __________ _______________________________ kidneys Remove urea from the blood water Salts, sugar ect.

 The functional unit of the kidney is the ___________. Each kidney contains about 1 million nephrons. **Renal** nephron

 Structure of the Nephron:

 Functions:  a. Filtration – as blood flows through the capillaries of the _________, water, salts urea, amino acids and glucose diffuse out of the blood into the __________ capsule. This Stage Is Filtration. nephron Bowman’s

b. Reabsorption – as the materials in the __________capsule flow through the tubule, some of the water, salts urea, amino acids and glucose diffuse are reabsorbed by active transport into capillaries surrounding the tubule. Bowman’s

c. Urine – The fluid that reaches the the end of the tubule consists of mostly water, urea and salt is called ________. Urine

Malfunctions  Kidney Diseases:  Kidneys unable to excrete nitrogenous wastes  High protein diets can cause problems – exceed capacity of nephrons to dispose of protein.  Gout –  form of arthritis – accumulation of uric acid in the joints.

Other Excretory Organs The lungs are also considered excretory in nature because they get rid of the body of _______ _________ and _________ from the process of _______________ Carbon DioxideWater Respiration

The liver also has an excretory function. It detoxifies the body. Deamination – removal of an amino group _______ from amino acids. It makes _____ and then sends it to the kidneys to be excreted. (NH2) Urea

**cirrhosis** - _________________________________ ______ The liver becomes overgrown w/ excess tissue

The Skin  Still, the skin is excretory because it rids the body of a little urea, but mostly it rids the body of ________ HOW? ___________________________ Heat Evaporation of sweat + Cooling