Chapter 51: Salt and Water Balance and Nitrogen Excretion Chapter 51 Salt and Water Balance and...
36
apter 51: Salt and Water Balance and Nitrogen Excretion Chapter 51 Salt and Water Balance and Nitrogen Excretion
-
Upload
liberty-gaskill -
Category
Documents
-
view
249 -
download
5
Transcript of Chapter 51: Salt and Water Balance and Nitrogen Excretion Chapter 51 Salt and Water Balance and...
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Chapter 51Salt and Water Balance and Nitrogen Excretion
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Chapter 51: Salt and Water Balance and Nitrogen ExcretionTissue Fluids and Water BalanceTissue Fluids and Water Balance
Distinguishing Environments and AnimalDistinguishing Environments and Animals in Terms of Salt and Waters in Terms of Salt and Water
Excreting NitrogenExcreting Nitrogen
The Diverse Excretory Systems of The Diverse Excretory Systems of InvertebratesInvertebrates
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Chapter 51: Salt and Water Balance and Nitrogen ExcretionVertebrate Excretory Systems Are Built Vertebrate Excretory Systems Are Built
of Nephronsof Nephrons
The Mammalian Excretory SystemThe Mammalian Excretory System
Control and Regulation of Kidney Control and Regulation of Kidney FunctionsFunctions
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Tissue Fluids and Water Balance• The problems of salt and water The problems of salt and water
balance and nitrogen excretion that balance and nitrogen excretion that animals face depend on their animals face depend on their environments, environments,
• In all animal excretory systems, there In all animal excretory systems, there is no active transport of water.is no active transport of water.
44
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Tissue Fluids and Water Balance
• All adaptations for maintaining salt All adaptations for maintaining salt and water balance and for excreting and water balance and for excreting nitrogen wastes employ filtration of nitrogen wastes employ filtration of body fluids and active secretion and body fluids and active secretion and resorption of specific ions.resorption of specific ions.
55
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Distinguishing Environments and Animals in Terms of Salt and Water• Marine animals can be Marine animals can be
osmoconformers or osmoregulators. osmoconformers or osmoregulators. • Freshwater animals must be Freshwater animals must be
osmoregulators and continually osmoregulators and continually excrete water and conserve salts. excrete water and conserve salts.
• All animals are ionic regulators to All animals are ionic regulators to some degree. some degree.
Review Figure 51.1Review Figure 51.1
66
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.1
Figure 51.1Figure 51.1
figure 51-01.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Distinguishing Environments and Animals in Terms of Salt and Water• On land, water conservation is On land, water conservation is
essential, and diet determines whether essential, and diet determines whether salts must be conserved or excreted. salts must be conserved or excreted.
• Marine birds excrete excess salt Marine birds excrete excess salt through nasal salt glands. through nasal salt glands.
Review Figure 51.2Review Figure 51.2
88
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.2
Figure 51.2 – Part 1Figure 51.2 – Part 1
figure 51-02a.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.2
Figure 51.2 – Part 2Figure 51.2 – Part 2
figure 51-02b.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Excreting Nitrogen
• Aquatic animals can eliminate Aquatic animals can eliminate nitrogenous wastes such as ammonia nitrogenous wastes such as ammonia by diffusion across their gill by diffusion across their gill membranes. membranes.
• Terrestrial animals must detoxify it by Terrestrial animals must detoxify it by converting it to urea or uric acid. converting it to urea or uric acid.
Review Figure 51.3Review Figure 51.3
1111
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.3
Figure 51.3Figure 51.3
figure 51-03.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Excreting Nitrogen
• Depending on the form in which they Depending on the form in which they excrete their nitrogenous waste excrete their nitrogenous waste products, animals are classified as products, animals are classified as
ammonotelic
ureotelic
uricotelic
1313
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Diverse Excretory Systems of Invertebrates• The protonephridia of flatworms The protonephridia of flatworms
consist of flame cells and excretory consist of flame cells and excretory tubules. tubules.
• Tissue fluid is filtered into the tubules, Tissue fluid is filtered into the tubules, which process the filtrate to produce a which process the filtrate to produce a dilute urine. dilute urine.
Review Figure 51.4Review Figure 51.4
1414
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.4
Figure 51.4Figure 51.4
figure 51-04.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Diverse Excretory Systems of Invertebrates• In annelid worms, blood pressure In annelid worms, blood pressure
causes blood filtration across capillary causes blood filtration across capillary walls. walls.
• The filtrate enters the coelomic cavity, The filtrate enters the coelomic cavity, and is taken up by metanephridia. and is taken up by metanephridia.
• As it passes through the tubules to the As it passes through the tubules to the outside, its composition is changed by outside, its composition is changed by active transport mechanisms. active transport mechanisms.
Review Figure 51.5Review Figure 51.5
1616
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.5
Figure 51.5Figure 51.5
figure 51-05.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Diverse Excretory Systems of Invertebrates• The Malpighian tubules of insects The Malpighian tubules of insects
receive ions and nitrogenous wastes by receive ions and nitrogenous wastes by active transport across the tubule cells. active transport across the tubule cells.
• Water follows by osmosis. Ions and Water follows by osmosis. Ions and water are resorbed from the rectum, so water are resorbed from the rectum, so the insect excretes semisolid wastes. the insect excretes semisolid wastes.
Review Figure 51.6Review Figure 51.6
1818
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.6
Figure 51.6Figure 51.6
figure 51-06.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Vertebrate Excretory Systems Are Built of Nephrons• The nephron is the functional unit of The nephron is the functional unit of
the vertebrate kidneythe vertebrate kidney• It consists of a glomerulus, in which It consists of a glomerulus, in which
blood is filtered across the walls of a blood is filtered across the walls of a knot of capillaries, and knot of capillaries, and
• A renal tubule, which processes the A renal tubule, which processes the filtrate into urine. filtrate into urine.
• A system of peritubular capillaries A system of peritubular capillaries serves the tubule. serves the tubule.
Review Figure 51.7Review Figure 51.72020
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.7
Figure 51.7Figure 51.7
figure 51-07.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Vertebrate Excretory Systems Are Built of Nephrons• Adaptations of marine fishes and Adaptations of marine fishes and
terrestrial animals to conserve water are terrestrial animals to conserve water are diverse. diverse.
• Bony fishes have few glomeruli and Bony fishes have few glomeruli and produce little urine. produce little urine.
• Cartilaginous fishes retain urea so the Cartilaginous fishes retain urea so the osmotic concentration of their body fluids osmotic concentration of their body fluids remains above that of seawater. remains above that of seawater.
• Amphibians remain near water or have Amphibians remain near water or have waxy skin coverings. waxy skin coverings.
• Reptiles have scaly skin, lay shelled eggs, Reptiles have scaly skin, lay shelled eggs, and excrete nitrogenous wastes as uric and excrete nitrogenous wastes as uric acid.acid.
2222
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Vertebrate Excretory Systems Are Built of Nephrons• Birds share the adaptations of reptiles.Birds share the adaptations of reptiles.
• They also can produce urine more They also can produce urine more concentrated than their tissue fluids. concentrated than their tissue fluids.
• Only birds and mammals can produce Only birds and mammals can produce such urine.such urine.
2323
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Mammalian Excretory System
• The concentrating ability of the The concentrating ability of the mammalian kidney depends on its mammalian kidney depends on its anatomy. anatomy.
Review Figure 51.10Review Figure 51.10
2424
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.10
Figure 51.10Figure 51.10
figure 51-10.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Mammalian Excretory System• The glomeruli and the proximal and distal The glomeruli and the proximal and distal
convoluted tubules are located in the convoluted tubules are located in the cortex of the kidney. cortex of the kidney.
• Certain molecules, salts, and water are Certain molecules, salts, and water are resorbed in bulk, and other molecules are resorbed in bulk, and other molecules are secreted in the convoluted tubules without secreted in the convoluted tubules without the urine becoming more concentrated. the urine becoming more concentrated.
• Straight sections of renal tubules (loops of Straight sections of renal tubules (loops of Henle) and collecting ducts are arranged Henle) and collecting ducts are arranged in parallel in the medulla of the kidney. in parallel in the medulla of the kidney.
Review Figure 51.11Review Figure 51.112626
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.11
Figure 51.11Figure 51.11
figure 51-11.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
The Mammalian Excretory System• The loops of Henle create a concentration The loops of Henle create a concentration
gradient in the extracellular fluids of the gradient in the extracellular fluids of the renal medulla by a countercurrent renal medulla by a countercurrent multiplier mechanism. multiplier mechanism.
• Urine flowing down collecting ducts to the Urine flowing down collecting ducts to the ureter is concentrated by osmotic loss of ureter is concentrated by osmotic loss of water caused by the concentration water caused by the concentration gradient in surrounding tissue fluid. gradient in surrounding tissue fluid.
Review Figure 51.12Review Figure 51.12
2828
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.12
Figure 51.12Figure 51.12
figure 51-12.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Control and Regulation of Kidney Functions
• Kidney function in mammals is Kidney function in mammals is controlled by autoregulatory controlled by autoregulatory mechanisms that maintain a constant mechanisms that maintain a constant high glomerular filtration rate even if high glomerular filtration rate even if blood pressure varies. blood pressure varies.
Review Figure 51.14Review Figure 51.14
3030
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.14
Figure 51.14Figure 51.14
figure 51-14.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Control and Regulation of Kidney Functions• An important autoregulatory An important autoregulatory
mechanism is renin release by the mechanism is renin release by the kidney when blood pressure falls. kidney when blood pressure falls.
• Renin activates angiotensin, which Renin activates angiotensin, which causes constriction of peripheral blood causes constriction of peripheral blood vessels, causes release of aldosterone vessels, causes release of aldosterone (which enhances water resorption), (which enhances water resorption), and stimulates thirst.and stimulates thirst.
3232
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Control and Regulation of Kidney Functions• Kidney function in mammals is also Kidney function in mammals is also
controlled by mechanisms responsive to controlled by mechanisms responsive to blood pressure and osmolarity. blood pressure and osmolarity.
• Changes in these influence release of Changes in these influence release of antidiuretic hormone, which controls the antidiuretic hormone, which controls the permeability of the collecting duct to water, permeability of the collecting duct to water, thus amount of water resorbed from urine. thus amount of water resorbed from urine.
• ADH stimulates expression of proteins ADH stimulates expression of proteins called aquaporins that serve as water called aquaporins that serve as water channels in the collecting duct cell channels in the collecting duct cell membranes.membranes.
Review Figure 51.15Review Figure 51.153333
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.15
Figure 51.15Figure 51.15
figure 51-15.jpg
Chapter 51: Salt and Water Balance and Nitrogen Excretion
Control and Regulation of Kidney Functions
• Hydrogen ions secreted by renal Hydrogen ions secreted by renal tubules are buffered in the urine by tubules are buffered in the urine by bicarbonate and other buffering bicarbonate and other buffering systems. systems.
Review Figure 51.16Review Figure 51.16
3535
Chapter 51: Salt and Water Balance and Nitrogen Excretion
51.16
Figure 51.16Figure 51.16
figure 51-16.jpg
