Human excretory system pdf


 

HUMAN EXCRETORY SYSTEM. In humans, waste materials from the cells diffuse into the blood. As the blood circulates through the body, four different organs. PDF | The excretory system eliminate nonsolid waste from the body. EXCRETORY PRODUCTS AND. THEIR ELIMINATION. CHAPTER Human. Excretory. System. Urine Formation. Function of the. Tubules.

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Human Excretory System Pdf

Read Pages (stop at the section titled. "The Artificial Kidney"). *Complete Questions #1&2 on page *Create a flowchart type diagram outlining the. Although the urinary system has a major role in excretion, other organs contribute to the excretory function. Four Organs of the Excretory System. The lungs in. process. Humans excrete uric acid as an end product of the metabolism of purine . excretory systems to control water and electrolytes contents in the body. 4.

The human excretory system functions to remove waste from the human body. This system consists of specialized structures and capillary networks that assist in the excretory process. The human excretory system includes the kidneys and their functional unit, the nephron. The excretory activity of the kidneys is modulated by specialized hormones that regulate the amount of absorption within the nephron. The human kidneys are the major organs of bodily excretion see Figure They are bean-shaped organs located on either side of the backbone at about the level of the stomach and liver. Blood enters the kidneys through renal arteries and leaves through renal veins. Tubes called ureters carry waste products from the kidneys to the urinary bladder for storage or for release.

Such animals are known as osmoconformers , as there is little water transport between the inside of the animal and the isotonic outside environment. Marine vertebrates, however, have internal concentrations of salt that are about one-third of the surrounding seawater. They are said to be osmoregulators. Osmoregulators face two problems: Fish deal with this by passing water out of their tissues through their gills by osmosis and salt through their gills by active transport.

Cartilaginous fish have a greater salt concentration than seawater, causing water to move into the shark by osmosis; this water is used for excretion.

Freshwater fish must prevent water gain and salt loss. They do not drink water, and have their skin covered by a thin mucus.

Water enters and leaves through the gills and the fish excretory system produces large amounts of dilute urine. Terrestrial animals use a variety of methods to reduce water loss: Water loss can be considerable: Many invertebrates such as flatworms use a nephridium as their excretory organ.

At the end of each blind tubule of the nephridium is a ciliated flame cell. As fluid passes down the tubule, solutes are reabsorbed and returned to the body fluids. Excretory system of a flatworm.

Image from Purves et al.

Excretory system of an earthworm. Body fluids are drawn into the Malphigian tubules by osmosis due to large concentrations of potassium inside the tubule. Body fluids pass back into the body, nitrogenous wastes empty into the insect's gut.

Water is reabsorbed and waste is expelled from the insect. Excretory system of an ant. Images from Purves et al. ALL vertebrates have paired kidneys.

Excretion is not the primary function of kidneys. Kidneys regulate body fluid levels as a primary duty, and remove wastes as a secondary one. The urinary system is made-up of the kidneys, ureters, bladder, and urethra. The nephron, an evolutionary modification of the nephridium, is the kidney's functional unit. All Rights Reserved 5. All Rights Reserved 6. All Rights Reserved 7. Parts of the KidneyKidneys filter about liters of blood daily in the average adult.

Excretory System | Kidney | Urine Formation

All Rights Reserved 9. Two partsa. Renal Corpuscle1. Bowman Capsule2. Fenestrae - pore in endothelial walls of glomerulus.

Human Excretory System

Podocytes - specialized cells. Filteration slitsb.

Renal Tubule - Series of single layer tubules1. Proximal Convoluted tubule2. Loop of Henle3. Distal Convoluted tubuleNephronKidneys are made up of nephrons. Blood enters the nephron, whereimpurities are filtered out and emptied into the collecting duct.

Thepurified blood leaves the nephron through the renal vein. All Rights Reserved All Rights ReservedNephron Each kidney contains more than 1 million nephrons.

How is blood filtered? UretersPeristalsis, a rhythmiccontraction of the ureter smoothmuscle which helps to move theurine into the bladder. Multicellular organisms, and animals in particular, must have a specialized organ system to concentrate and remove wastes from the interstitial fluid into the blood capillaries and eventually deposit that material at a collection point for removal entirely from the body.

Excretory systems regulate the chemical composition of body fluids by removing metabolic wastes and retaining the proper amounts of water, salts, and nutrients. Components of this system in vertebrates include the kidneys, liver, lungs, and skin.

Not all animals use the same routes or excrete their wastes the same way humans do. Excretion applies to metabolic waste products that cross a plasma membrane.

Human Excretory System

Elimination is the removal of feces. Nitrogen wastes are a by product of protein metabolism. Amino groups are removed from amino acids prior to energy conversion. The NH 2 amino group combines with a hydrogen ion proton to form ammonia NH 3. Ammonia is very toxic and usually is excreted directly by marine animals.

Terrestrial animals usually need to conserve water. Ammonia is converted to urea, a compound the body can tolerate at higher concentrations than ammonia. Birds and insects secrete uric acid that they make through large energy expenditure but little water loss. Amphibians and mammals secrete urea that they form in their liver. Amino groups are turned into ammonia, which in turn is converted to urea, dumped into the blood and concentrated by the kidneys.

The excretory system is responsible for regulating water balance in various body fluids. Osmoregulation refers to the state aquatic animals are in: Animals, such as crabs, have an internal salt concentration very similar to that of the surrounding ocean. Such animals are known as osmoconformers , as there is little water transport between the inside of the animal and the isotonic outside environment.

Marine vertebrates, however, have internal concentrations of salt that are about one-third of the surrounding seawater. They are said to be osmoregulators. Osmoregulators face two problems: Fish deal with this by passing water out of their tissues through their gills by osmosis and salt through their gills by active transport. Cartilaginous fish have a greater salt concentration than seawater, causing water to move into the shark by osmosis; this water is used for excretion.

Freshwater fish must prevent water gain and salt loss. They do not drink water, and have their skin covered by a thin mucus. Water enters and leaves through the gills and the fish excretory system produces large amounts of dilute urine.

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