chpt 9.4-9.5 test Flashcards
(104 cards)
1
Q
The body’s internal environment of extracellular fluid must maintain a constant…
A
volume, solute content, and often temperature
2
Q
Osmotic pressure is
A
the pressure that results from a difference in solute concentration between the two sides of a selectively permeable membrane
3
Q
Hyperosmotic
A
the property of the solution on one side of a selectively permeable membrane that has the lower concentration of water
4
Q
Hypoosmotic
A
the property of the solution on one side of a selectively permeable membrane that has the higher concentration of water
5
Q
Isoosmotic
A
the property of two solutions that have equal water concentrations
6
Q
During osmosis, water molecules move from a region where they are – concentrated to a region where their concentration is –.
A
highly, lower
7
Q
The movement occurs across a selectively permeable membrane allows water but very few —- to flow through.
A
solute molecules
8
Q
Different water concentrations on the two sides of the membrane are produced by
A
different numbers of solute molecules
9
Q
Selective permeability is a key factor in osmosis because it helps to maintain
A
differences in solute concentration on the two sides of biological membranes, such as cell membranes
10
Q
— are among the most important solutes in establishing the conditions that produce osmosis
A
Proteins
11
Q
The greater the water concentration gradient, the greater the —– between the two sides.
A
osmotic pressure difference
12
Q
A solution with a higher concentration of solute molecules on one side of a selectively permeable membrane is said to be —- to a solution with a lower concentration of solutes on the other side. Water tends to move to the —- side.
A
hyperosmotic (hypertonic)
13
Q
The solution with a lower solute concentration is said to be —- to the solution with the higher solute concentration. Water tends to move from the —- solution.
A
hypoosmotic (hypotonic)
14
Q
Solutions with the same solute and water concentrations are
A
isoosmotic (isotonic)
15
Q
Water moves across the membrane when the two solutions have different water concentrations and tends to continue until the two solutions are —-.
A
isoosmotic
16
Q
Water still moves across the membrane even when the solutions are isoosmotic, but…
A
the water movement is equal in both directions so there is no net movement
17
Q
Hydrostatic pressure refers to
A
the pushing force on water due to the presence of more fluid in one region than another
18
Q
If the hydrostatic pressure on one side of a membrane is equal to the osmotic pressure on the other side of the membrane, there is no net flow of water. As water continues to cross the membrane, the internal hydrostatic pressure begins to build until it —-.
A
balances the external osmotic pressure and osmosis comes to a stop
19
Q
Osmotic and hydrostatic pressures are important for the – of plant cells
A
structure
20
Q
The water surrounding most plant roots is —– relative to the inside of the plant cells
A
hypo osmotic
21
Q
Therefore, water flows into the root cells and then into the cells of stems and leaves. This inflow of water causes the cells to —–.
A
expand and press against the insides of their cell walls
22
Q
Turgor pressure (hydrostatic pressure)
A
gives a plant its rigidity and allows it to stand erect.
23
Q
If the surrounding fluid becomes hyperosmotic in relation to the insides of the cells, or if there is a shortage of water…
A
there will be a drop in turgor pressure and the plant will wilt.
24
Q
Hydrostatic pressure cannot build in …
A
animal cells because they do not have strong cell walls
25
An animal cell that is surrounded by a very dilute, or hypoosmotic, solution, water molecules will
continue to enter the cell until it swells and bursts
26
Osmoregulation
is the process of actively regulating the osmotic pressure of bodily fluids and cells
26
An animal cell that is surrounded by a hyperosmotic solution, water molecules will
leave the cell by osmosis and the cell will shrink
27
Osmosis is a crucial and ongoing process in...
the establishment and maintenance of homeostasis
27
The concentrations of water and solutes, both inside and outside of the cells, must be kept in ---- and requires the continuous movement of water by --- and the movement of solutes by --- and --- into and out of the cells.
a constant balance, osmosis, diffusion, active processes
28
All organisms need to keep their intracellular and extracellular fluids ---
isosmotic
29
Many marine animals such as sponges, jellyfish, sea urchins, squid, and lobsters do not need to...
regulate the concentration of their extracellular fluid (concentrations of their intracellular and extracellular fluids are identical to concentrations in the environment)
29
Many animals require ---- to keep the concentrations of intracellular and extracellular fluids constant, but at levels different from the concentrations in the external environment.
more complex control mechanisms
29
Plants must keep a certain minimum osmotic and hydrostatic pressure within their cells to maintain ----.
rigidity and transport nutrients
30
The waste products of metabolism and cell functions are continuously ----
eliminated from the body to maintain aqueous homeostasis
31
To maintain homeostasis, cells regulate their...
osmotic concentration, ionic balance and pH balance.
31
Ions and toxic compounds (amino acids and nucleic acids) must be ----
eliminated
- the body’s aqueous internal environment acts as a solvent for these wastes
32
Animals maintain their ionic and pH balance through the process of
excretion
32
The maintenance of osmotic concentration while eliminating nitrogenous wastes can be difficult for most terrestrial animals since it requires...
significant amounts of water.
- may not be readily available depending on the season or geographical location
33
Excretion is the ---- and serves to maintain the ----
elimination of waste products and foreign matter from the body, ionic and osmotic equilibrium that is necessary for cell functions
33
As the body processes proteins during metabolism, it produces waste molecules, which the liver ---
converts into soluble metabolites
34
The body system that regulates the removal of wastes is the ---, and its main organs are the ----.
excretory (or urinary) system, kidneys and the bladder
34
The --- can filter out these metabolites and eliminate them from the body with other aqueous waste, maintaining the ---.
kidneys, water and pH balance of the internal environment
35
Bony fishes produce --- as nitrogenous waste
ammonia
35
Mammals and cartilaginous fishes such as sharks, skates, rays produce --- as nitrogenous waste
urea
36
Most birds produce --- as nitrogenous waste
uric acid
36
Most animals are able to form all three of these nitrogen compounds, but the primary method of excretion depends on a balance among ----
water conservation, toxicity, and energy requirements
37
the process of deamination (occurs in the liver)
-the amino group is removed from each amino acid that comes from the breakdown of a protein
-the amino group is then converted to ammonia and the rest, which is mostly carbon and hydrogen, is oxidized to produce energy.
37
Ammonia is a --- and animals with an abundant supply of water are able to secrete ammonia directly from the body in this very dilute form.
highly toxic substance
38
In mammals, some reptiles, and most amphibians, the --- combines ammonia with --- to create --- and can be eliminated from the body with less water, allowing --- to maintain their water balance.
liver, bicarbonate ions, urea, terrestrial animals
39
Birds and some terrestrial invertebrates produce --- as their nitrogenous waste product. Uric acid is ---. As urine is concentrated in its final stages, the uric acid forms --- that are expelled from the body with a --- amount of water.
uric acid, not toxic and has a low solubility, crystals, minimal
40
One of the main functions of the excretory system which is aided by osmoregulation is to...
concentrate wastes and expel them from the body
41
The second main function of the excretory system is to
regulate fluids and water within the body
42
(EA) Freshwater fish (trout)
- Tissues lower water concentrations than surrounding medium
- Takes in water by osmosis through gills (passive transport)
- Loses salt from tissues by diffusion (passive transport) from high to low
- Salt reabsorbed by gills and kidneys (active transport) from low to high concentration
- Much diluted urine is excreted to remove excess water
43
(EA) Marine Fish (cod)
- Tissues higher water concentration than surrounding salt water
- loses water by osmosis through gills (passive transport)
- replace water by drinking sea water, which leads to high salt concentration in tissues
- Extra salt excreted by gills (active transport) from low to high
- Kidneys reduce water loss by excreting small quantities of concentrated urine
44
(EA) Amphibian
- In water- tissues have low concentration of water and take in water by osmosis (passive transport)
- Kidneys excrete excess water in urine and reabsorb salt needed to survive (active transport)
- On land the tissues have a high concentration of water and tend to lose it by osmosis (passive transport)
- Kidneys reabsorb water from tissues and store in the bladder as a reserve
45
(EA) Reptile
- Tissues have a high-water concentration compared to surroundings
- Loses water by osmosis and evaporation (passive transport)
- Replaces water by drinking and eating
- Converts nitrogenous wastes to insoluble uric acid which can be excreted with little water loss (active transport)
- Reptiles that live in or around saltwater take in large quantities of salt with their food and rarely or never drink fresh water. These animals usually excrete excess salt through specialized salt glands located in the head.
- The salt glands remove salts from the blood by active transport and are secreted to the environment as a water solution, in which the salts are two to three times more concentrated than in body fluids.
- The secretion exits through the nostrils of lizards, and as salty tears from the eye sockets of sea turtles and crocodilians.
46
(EA) Bird
- Tissues have high water concentration compared to air
- Tends to lose water by osmosis and evaporation (passive transport)
- Converts nitrogenous waste to insoluble uric acid for excretion. Little water needed for excretion of uric acid and is reabsorbed and conserved by kidneys
- Birds that live in or around saltwater take in large quantities of salt with their food and rarely or never drink fresh water. These animals usually excrete excess salt through specialized salt glands located in the head.
- The salt glands remove salts from the blood by active transport and are secreted to the environment as a water solution, in which the salts are two to three times more concentrated than in body fluids.
- The secretion exits through the nostrils of birds.
47
(EA) Paramecium
- Have an internal environment that is hyperosmotic to their surroundings
- Need to maintain a fluid balance, or they can eventually burst
- To expel excess water, these protozoans have contractile vacuoles, which pump out water to maintain osmotic balance
- A contractile vacuole is a structure in a single-celled organism that maintains osmotic equilibrium by pumping excess fluid out of the cell.
48
(EA) Earthworm
- Have excretory organs called metanephridia that expel wastes from the body
- Metanephridium is an excretory organ in some invertebrates that is used to reabsorb and eliminate wastes
- In each segment of the earthworm, hemolymph which is a fluid that serves as both interstitial fluid and blood.
- Hemolymph flows into a pair of metanephridia, which are twisted into convoluted shapes to maximize their surface area.
- Ions and wastes are reabsorbed from the hemolymph and secreted (along with water) into a saclike organ called a bladder.
- Excess water and waste products are secreted to the external environment through a pore in the side of the worm’s body.
49
(EA) Grasshopper
- Excrete wastes using a set of organs called Malpighian tubules which are the main organ of excretion in insects, which is used to carry wastes to the intestine
- The closed ends of these organs are immersed in the hemolymph and the open ends empty into the intestines
- Uric acid and potassium and sodium ions are secreted into the tubules. As the concentration of these substances’ increases, water moves osmotically from the hemolymph into the tubule to form a dilute waste solution.
- Urine then travels to the intestines of the insect, where specialized cells reabsorb most of the potassium and sodium ions back into the hemolymph.
- Water then moves from the intestines back into the hemolymph by osmosis.
- Uric acid that is left behind forms crystals and is expelled with the insect’s digestive waste product
50
The excretory systems of all vertebrates, including humans, use specialized tubules, called ---, which regulate the water balance in the body and conduct excretion.
nephrons
51
A nephron is
the tiny functional unit of the kidney that filters wastes from the blood
52
nephrons are located in the
kidneys
53
The --- make up the human excretory system.
kidneys, ureters, bladder, and urethra
54
kidneys play a critical role in ...
removing wastes, balancing blood pH, and maintaining the body’s water balance
55
mammals have two kidneys, one on each side of the ---
vertebral column
56
in humans, the average kidney has a mass of about --- and receives about --- of the cardiac output (roughly -- L/min).
150 g, 25 %, 1.25
57
Blood is supplied to the kidney through the ---. Kidney filters the wastes from the blood, and the clean blood exits the kidney through the ---
renal artery, renal veins
58
outer layer of the kidney is called the ---
renal cortex
59
inner layer of the kidney is called the --- and is found beneath the ---
medulla, renal cortex
60
the --- is a hollow cavity that connects the kidney to the ---, through which urine passes to the ---
renal pelvis, ureter, urinary bladder
61
once the bladder is full (with roughly 300 to 400 mL of urine), the urine exits the body through the ---
urethra
62
Each kidney contains about --- nephrons
1 000 000
63
--- is a small folded structure in the human kidney that encircles the ---
Bowman’s capsule, glomerulus
64
The glomerulus performs ---. The glomerulus is a --- within the Bowman’s capsule
the first steps in the filtration of blood to form urine, network of capillaries
65
Blood is supplied to the glomerulus by the --- and, after being filtered, exits via the --- and is carried to a net of capillaries called the ---
afferent arteriole, efferent arteriole, peritubular capillaries
66
The --- are a net of capillaries in the nephrons that surround the tubules and carry away the urine and allow for the reabsorption of essential ions and minerals from filtered blood back into the bloodstream
peritubular capillaries
67
During the first steps of filtration, components of the unfiltered blood pass from the glomerulus into the --- and enter a ---, which lies in the renal cortex.
Bowman’s capsule, proximal convoluted tubule
68
The proximal convoluted tubule is the duct portion of a nephron that connects the ...
Bowman’s capsule to the loop of Henle
69
The loop of Henle is the U-shaped part of the duct that connects the --- to the ---
proximal convoluted tubule, distal convoluted tubule
70
The distal convoluted tubule is the duct portion of a nephron that connects the ...
loop of Henle to the ducts that lead to the renal pelvis
71
In mammals, urine is hypoosmotic to the surrounding body fluids and water tends to move from ...
urine into the body fluids
72
Features of the Nephrons:Q
▪interact to conserve nutrients and water
▪balance salts
▪concentrate wastes for excretion
73
Urine formation is the result of three interrelated processes:
▪ Filtration = occurs as body fluids move from the blood into the Bowman’s capsule.
▪ Reabsorption = transfers essential solutes and water from the nephron back into the blood.
▪ Secretion = transfers materials from the blood back into the nephron.
74
--- are too large to pass through the capsule and are retained in the capillaries
blood cells, platelets, and plasma proteins
75
The fluid that enters the Bowman’s capsule contains only ...
the smaller molecules which includes metabolic waste. It is an ultrafiltrate of the blood
76
Approximately --- of blood pass through the kidneys every day, and the Bowman’s capsules filter about --- of fluid from this blood.
1400 L, 180 L
77
The human body contains roughly --- of blood plasma and the kidneys filter the entire contents of the blood plasma -- times every day.
2.75 L, 65
78
Approximately about --- of the daily filtrate is excreted as urine while the rest consists primarily of water and is ---
1.5 L, reabsorbed into the nephrons.
79
The fluid enters the proximal convoluted tubule, where reabsorption occurs and water, ions, and nutrients are transferred back into the interstitial fluid via ---.
both passive and active methods
80
Active transport proteins which are embedded in the walls of the tubule reabsorb ...
the amino acids, glucose, and other nutrients out of the filtrate
81
Urea and other unwanted compounds are ---.
not reabsorbed
82
The inner walls of the tubule are covered with microscopic extensions called --- which greatly increase the total surface area that is available for the reabsorption of solutes.
microvilli
83
All of the reabsorption processes make the filtrate --- to the interstitial fluid and the water flows out of the tubule and into the interstitial fluid by osmosis.
hypoosmotic
84
water movement is facilitated by membrane proteins called ---, or water channels, which form passages for additional water molecules to flow out of the tubule.
aquaporins
85
Aquaporins ensure that ...
the maximum amount of water is removed from the tubule during the reabsorption process
86
The proximal convoluted tubule reabsorbs -- of sodium ions, potassium ions and chlorine ions, -- of water;-- of urea and --- of the amino acids, glucose, and other nutrients.
67 %, 65 %, 50 %, nearly all
87
Concentration of solutes increases with -- as fluid --- and there is more removal of water through the ducts which greatly increasing the concentration of the urine.
depth, descends into the medulla
88
Near the bottom of the medulla, the walls of collecting ducts contain ---, which allow some of the nitrogenous wastes to pass from the duct into the interstitial fluid. This urea adds significantly to the concentration gradient of solutes in the medulla
passive urea transporters
89
Collecting ducts descend from the cortex of the kidney and through the medulla. They are permeable to ...
water, but not to salt ions
90
Wastes are secreted at --- in the nephron
several points
91
Hydrogen ions are --- secreted, and the products of detoxified poisons from the liver are --- secreted.
actively, passively
92
--- into the filtrate helps to balance the acidity that is constantly generated in the body by metabolic reactions. It is coupled with the --- from the filtrate to the plasma in the peritubular capillaries.
Hydrogen ions secretion, bicarbonate ion reabsorption
93
After leaving the collecting ducts, urine flows ...
into renal pelvis, through ureters, into the urinary bladder and urine exits through the urethra into external environment
