osmoregulation and excretion Flashcards
1
Q
Indirectly how is water moved?
A
osmosis
2
Q
How is water moved indirectly in organisms?
A
The concentration of ions is moved and the water follows the ion concentration gradient
3
Q
What is ultrafiltration?
A
pressure mediated event that forces fluid across a permeable membrane that allows the filtering out of large proteins and molecules and is normally associated with the circulatory system in higher animals and in lower animals deals with pressures generated inside the body from movement of cilia and flagella
4
Q
What is the product of ultrafiltration?
A
an ultra-filtrate that is non discrimatent everything goes across
5
Q
WHat does active transport involve?
A
involves molecular pumps
6
Q
What are the two process of active transport in the basic process of secretion?
A
active secretion and active reabsorption
7
Q
What is active secretion?
A
Molecular pump enables specific compounds to be picked up from the blood and body fluids and transported to a tubular system and they are transported to the outside and secreted.
8
Q
WHat is active reabsorption?
A
Some molecules and ions will end up in the tubular system through the process of ultrafiltration in most cases and they will be actively transported back into the blood reabsorbed
9
Q
Some animals have only secretion organs not filtration or reabsorption?
A
true
10
Q
Who are the main animals that contain only secretory organs?
A
Insects
11
Q
Active reabsorption is always a result of what process?
A
ultrafiltration
12
Q
What are some of the common secretory organs in animals groups?
A
teleost fish gills, salt glands, malpigian tubules
13
Q
Teleost fishes are what fish?
A
modern lineage of fishes the bony fishes
14
Q
In the teleost gills what types of cells do they contain? Why are they called this and what are they properly known as?
A
chloride cells named so because they transport the ion of chloride. Many animals have these types of cells and mechanisms but the ion moved may be different so now they are called mitochondrial rich cells-MRC
15
Q
Mitochondrial rich cells are called so because?
A
they are highly active and energy consuming
16
Q
Metabolically speaking besides staying warm what is the next highest process that costs a lot of energy?
A
excretion
17
Q
What type of fish do chloride cells work in?
A
both saltwater and freshwater fish but it is more complicated process in the freshwater fish
18
Q
WHat is the major problem marine fish have?
A
marine fish live in saltwater. They have an ion content that is lower than the water they live in so they constantly lose water to their environment and gain salt.
19
Q
To make up for the loss of water marine fish do what? What is the issue they must deal with?
A
drink seawater constantly
must get rid of the salt
20
Q
WHo first determined the mechanism by which the chloride cells work? What did they propose?
A
Keys and Willmer
Chloride was the ion being actively transported
21
Q
Where are the chloride cells found in modern teleost fish?
A
in the gills
22
Q
What is the structure of the gill filaments in the teleost fish?
A
see paper
23
Q
WHere are the chloride cells found on the gill filaments?
A
At the base where the secondary lamellae meet the primary lamellae or the gill filament.
24
Q
The chloride cells have what particular arrangement?
A
columnar/cuboidal that gives them the maximum volume
25
What is the dimple called on the top of the chloride cell?
apical pit
26
diagram a chloride cell
see sheet
27
What is the basal surface of the chloride cell?
blood
28
The tubular system of chloride cells is very what? WHere is the tubular system found in the chloride cells?
Extensive and advanced like a sheet of saran wrap all cricked up has a massive amount of surface area. The tubular system permeates throughout the chloride cell.
29
The indentations and branching of the tubular system in the chloride cells allows what?
a tremendous amount of surface area for the sodium potassium pumps.
30
Where are the sodium potassium pumps primarily located in chloride cells?
On the basal surface
31
As you move from the basal end of the cell to the apical end of the chloride cell what happens to the amount of sodium potassium pumps?
As you move from the basal end of the chloride cell to the apical end of the chloride cell the concentration of sodium potassium pumps decreases
32
In addition to the sodium potassium pumps on the basal surface of the chloride cell what other pump is found?
NaKCl pump
33
When compared with the drawing the sodium potassium and chloride pumps are densely packed together in real life because of what?
the tubular system
34
What are the cells adjacent to the chloride cells but what is the nature of their connectivity?
Accessory cells are immediately adjacent and are loosely connected. Pavement cells are adjacent to the accessory cells and are tightly connected.
35
What does the entire chloride cell system depend on?
sodium potassium pump
36
Does the sodium potassium pump require ATP to function as an active molecular pump?
No it is the only main ATPase type of pump that instead exploits the sodium gradient created by the NaK pumps
37
In the sodium potassium pump what goes where?
3 Na out and 2 K in
38
In the chloride cells What molecule builds up and where does it build up?
Na+ builds up on the outside of the cell in high amounts bc the chloride cells have so many extensive pumps
39
Massive Na+ potential is buildup on the outside of the chloride cells. WHat does this buildup cause and where does it occur?
At the critical level sodium will be forced back across the membrane into the cell. This forcing of the sodium back into the cell will occur at the NaKCl pumps.
40
WHen Na+ is forced back into the chloride cell what ions will it drag along with it?
1 K+ and 2Cl- ions
41
What is the result of the Na+ forced back into the cell bringing one K+ and 2 Cl- along with it?
The sodium potassium pump will transport sodium back out of the cell. The potassium freely diffuses back outside the cell. The chloride will buildup inside the cell because the cell membrane is not permeable to chloride at all.
42
WHen the chloride builds up in the cell how is it finally released from the cell? WHat is also sometimes let out as well
specialized chloride channels will let chloride out and these channels are a little leaky to bicarbonate which is more important in freshwater fish
43
WHen chloride is released from the cell by the specialized chloride channels where does the chloride ions aggregate?
in the apical crypt
44
What is the general electrical potential on each side of the chloride cells and this is due to what ions? WHat does this allow?
Apical surface negative charge sue to the concentration of chloride cells and the basal surface positive charge due to the concentration of sodium cells. Because of the loose junction between the chloride cella and the accessory cell sodium will diffuse to the apical side to stabilize electrical charge across gill surface.
45
WHat is transcellular transport?
Actively moved through the cell. Chloride is actively pumped inside the cell and forced out
46
What is para-cellular transport?
Beside of. Sodium is going to follow passively along with it electrical gradient
47
What are the pavement cells used for?
structural cells
48
Which ion is transported out actively and which is transported out passively? And how are these processes done?
Chloride is actively transported out of the cell and sodium is passively diffused through the loose junction between the accessory and chloride cell based on the electrical gradient and the mechanical gradient.
49
Other vertebrates use a very similar system to the chloride cells found in marine fish. What is different?
the ions that needs to be transported out
50
WHat is some of the byproducts of the transport of chloride out of the chloride cell and what type of fish is this more important to?
bicarbonate and ammonia and it is more prudent to the freshwater fishes
51
How is can discrete secretory organs be created from chloride cells?
Take a whole bunch of chloride cells and make a flat sheet with them and with the flat sheet roll it into tubes--->tubular system use that make discrete organs.
52
In what organisms are salt glands found and where are they most active?
In many reptiles and birds; largest and most active in the marine groups
53
What part of the brain controls the salt glands? And what does this mean?
the hypothalamus
| They are under hormonal control with some intervention form the parasympathetic nervous system
54
What is the major advantage of salt glands over something like the human kidney?
Kidneys work all the time and because of that they are hugely expensive. On the other hand salt glands only work when they have to. The hormonal and nervous control systems can turn the salt glands on when the animal takes in a lot of salt and then when the salt load is reduced the salt gland can be turned off.
55
WHat is the difference in the size of salt glands and kidneys?
Kidneys are about the size of your fist they grow to a certain size and the stop growing. Slat glands however can atrophy reduce in size if not used.
56
Salt glands adjust their _____ according to their ______.
size, salt load
57
Can difference in salt gland size be variable across species?
Yes some birds of the same species may have different concentration of salt in their diet depending on the exact location of their habitat.
58
Salt glands are efficient for only what ions?
sodium and chloride
59
What are the most efficient excretory organs for sodium and chloride?
salt glands
60
Give an example of the efficiency and the fastness of the salt glands?
A seagull was given a liter of seawater and the salt was gone 2 and half hours later
61
Who was the first person to discover salt glands and their function?
Knut Schmidt Nielsen
62
WHat was the specific discovery made by Knut Schmidt Nielsen?
That chloride like cells are arranged in flat sheets and rolled up into tubes and the tubes are set up in a counter current extraction to blood flow.
63
How does the salt gland work in the counter current system?
Blood flow is one way and when salt load high the hypothalamus releases hormones open up blood flow capillaries and the blood flows into the salt gland tissue. The tubes themselves pick up the fluid and smaller tubules made of the chloride like cells empty into bigger tubules and bigger tubules until finally into central duct which s a collecting area. So there are many tubules following through the tissue all counter current to blood flow that makes it highly efficient and they drain out through a central duct.
64
WHen the salt glands are found what does their location depend on?
The organism in which they are found and the excretion site varies as well
65
Where is the salt glands found in the birds? And what are they called?
They are found in depressions above the eye and they are called supraoribital.
66
Where are the salt glands found in reptiles?
In some reptiles the salt glands are found above the eye and they are called orbital.
67
Where do the salt glands of birds drain?
Into the nares-looks like a runny nose
68
In sea turtles and marine iguanas where are the salt glands found? WHat are they called and where do they drain?
The salt glands are found in between the lower part of the eye and the nares itself. The sea turtle salt glands are nasal in location and empties through the posterior orbit of the eye. In marine iguanas the salt gland drain to the nares and have salty snot.
69
In the saltwater crocodile where are the salt glands?
lingual they are on the tongue and distributed across the tongue and have salty spit
70
WHere are the salt glands found in sea snakes and sea crates?
The salt glands are found sublingual under the tongue
71
What is the secretory structure found in insects and spiders?
malpigian tubules
72
Where are the malpigian tubules found in insects?
Always in the same spot found in the middle where the exoskeleton does not cover the organism mid and hindgut junction and thus is the only area where absorption can occur and ions can be removed from the hemolymph. In this area tubules are found freely in the hemolymph and are called malpigian tubules.
73
How do the malpigian tubules operate?
They are made of cells similar to the chloride cells but usually don't move sodium and chloride but move potassium because potassium have a hard time collecting potassium so they will absorb it and hang on to it.
74
Are there secretory structures that don t only secrete ions and molecules?
yes
75
WHat are the three secretory organs we discussed?
chloride cells
salt glands
malpigian tubules
76
What are protonephridia? And how do they work?
Most ancestral primitive form. There is a tubular arrangement with a bulb like closed end that contains a series of flagella that are continuously beating and they push fluid down the tubular system that creates a slight negative pressure inside the bulb relative to the outside body fluids. This pressure gradient will force fluid under negative pressure to flow across the membrane and that is the ultrafiltration part. The tube is made of the chloride like cells that continually pick up the salts that need to be reclaimed and the excretory product go outside.
77
Where are protonephridia mainly found?
in acoelomate and pseudocoelomate animals
78
Where are metanephridia only found
in eucoelomate animals
79
What is the key element in the pronephridia and what are they called?
The cilia that are continuous beating and move the fluid to create the negative pressure and when you examine them under a microscope they look like a candle and are called flame cells!
80
How do metanephridia differ from protonephridia?
They are more advanced and derived independently. The are funnel shaped and have bands of cilia that create the negative pressure.
81
Do all eucoelomate animals have metanephridia?
no
82
Metanephridia can be bundled up into what?
decrete organs
83
tubular system is responsibel for what?
reclamation
84
What animals are kidneys moslty found in and what other groups are they seen in?
Mostly found in the vertebrates but can be found in the mollusks and the cephalopods
85
Kidneys use what followed by what?
ultrafiltration followed by reabsorption
86
how much of our budget goes to running the kidney? and what is the advantage of the kidney?
20% of our left over budget after thermal regulation
We do this because the kidney excretes all the harsh molecules and ions we eat. In insects they use malpigian tubules and pick up only certain compounds and excrete them and can only eat certain types of plants etc. We can eat whatever we want because our kidney filter everything and we pick up what we want from it.
87
The vertebrate kidney works as what type of system?
filtration-reabsorption system but some things are not reabsorbed and are secreted
88
WHat is the outer region of the kidney called and what is located here?
The cortex and all the filtration units located here
89
The inner region of the kidney is called what?
medulla
90
What is the region in the center reffered to as?and what does the name mean?
calyx and renal pelvis
| The calyx is made of major and minor units and it means funnel in latin
91
what does the renal pelvis do?
wide region thats collects urine
92
WHat is the piping system in the kidney?
The minor calyx to the major calyx to the renal pelvis and then to the ureter to empty from the body
93
What is the striated region found within the calyx region in between the minor calyxes and what happens here?
renal pyramids
| they are the collecting ducts
94
What is the functional unit of the kidney?
nephron
95
What are the two parts of the nephron?
1. the circulatory system that creates the pressure
2.
96
What is a portal system?
arteriole-->capillary bed-->arteriole
97
What is the glomerulus?
a tangle of capillary beds in the kidney and acts as the filtration system
98
What does the bowmans capsule wrap around and bind to?
The glomerulus
99
What is the bowman's capsule?
a tubular system
100
In the majority of vertebrate kidneys with the exception of some birds and a lot of mammals what happens after the proximal convoluted tubule?
a straight segment followed by the distal convoluted tubule and then it collects to the collecting duct and that equals one nephron
101
What is the region containing the glomerulus and bowman's capsule called? and what occurs here?
The renal corpuscle and ultrafiltration happens here
102
Many collecting ducts come down and form what?
the renal pyramids
103
What is the most advanced kidney?
mammalian kidney
104
WHat generates the pressure in vertebrates to generate ultrafiltration?
circulatory system
105
What is larger the afferent arteriole or the efferent arteriole and why?
The afferent arteriole because the if you constrict the diameter of the efferent arteriole then the pressure in the capillaries will increase and the pressure can be controlled.
106
WHat is the purpose of controlling the pressure in the capillaries in the glomerulus?
Controlling the pressure by changing the diameter of the efferent arteriole allows us to control the rate of ultrafiltration.
107
If you reduce the diameter of the efferent arteriole what happens to the pressure inside the capillaries and the rate of ultrafiltration?
the pressure in the capillaries will increase thereby decreasing ultrafiltration. If you want more filtration you decrease the diameter.
108
What does the lymphatic system do in mammals?
It picks up the leakage from the capillary beds and returns it back to the circulatory system so we don't swell up like balloons
109
Glomerular capillaries are extremely large pores that make them what? WHy?
extra leaky
| to allow everything to pass through
110
What are the glomerular capillaries pores known as?
frenestraes-frenestrated capillaries very large and very leaky
111
WHat do frenestrated capillaries hold back?
red blood cells and platelets
112
WHat is the first part of ultrafiltration take place? what type of barrier is this?
frenestrated capillaries
| mechanical
113
What is the third barrier of ultrafiltration? Where does it take place?
Takes place on the inner wall of Bowman's capsule that connects to the glomerulus capillaries. The barrier is the podocytes. They wrap around the capillaries in the glomerulus and interdigitat like when you cup your hands together to carry water from a lake to a bucket.
114
What does the podocyte look like?
footlike fingerlike projections out of the cell
115
When the podocytes wrap around the glomerulus capillaries what do they create?
filtration slits designed to be leaky
116
WHat is filtration barrier number 2?
The fusion of the membranes of the glomerular capillaries and the podocytes creates the basement membrane that acts as barrier number 2
117
What type of barrier is filtration barrier number 3?
Mechanical
118
WHat determines what gets through in filtration barrier number one and three?
Mechanical barriers so:
the size of the frenestrae determines what gets through
the size of the podocyte decides what gets through
119
WHat type of barrier is filtration barrier number 2?
electrical
120
WHat is the fusion membrane (second filtration barrier) composed of and what is the charge?
Composed of proteins and the charge is negative
121
How the negative charge in the fused basement membrane between the frenestrae and the podocyte filtration slits act as an electrical barrier?
The negative charge of the membrane will repel the negative charge on proteins protease red blood cells platelets and stuff we want to hold on to
122
The renal corpuscle is made of what two systems?
circulatory the capillary beds and the tubular system the bowman's capsule
123
What role does the tubular system play in the kidneys?
It allows the reclamation of water
124
What cells is the proximal convoluted tubule made of?
Chloride like cells that push out sodium and chloride out passively.
125
Around the tubular system what concentration will build up? WHat will this cause?
high salt concentration
| Causes water to move out
126
Between the bowmans capsule and the straight segment(in most vertebrates we have the loop of henle) how much water is pulled out?
94-96% of the ultrafiltrated water
127
Most of the reuptake of water is done by what point and can terrestrial animals survive on that?
By the time you get through the PCT and no most terrestrial animals cant survive on that so they reabsorb water more
128
The pulling out of the fluid from the tubular system is sitting out in the interstitial fluid, how is that reclaimed?
From the efferent arteriole. The efferent arteriole will wrap all around the tubular system. The peritubular capillaries are water deprived form the pressure in the glomerulus so water will freely diffuse into the efferent capillary along with some salts and it will be returned to the main circulatory system.
129
where does active reabsorption and active secretion take place?
in the distal convolutes tubule
130
Is it possible for the nephron to concentrate salt content in the urine to a degree higher than in blood?
No
131
What is the trick for mammalian kidneys to increase their salt load in the kidney?
the loop of Henle
132
Humans are limited by using osmotic pressure to drive water in one direction or another so how does the loop of henle assist in this?
countercurrent magnification
133
What is the only part of the nephron that dips down into the medulla?
loop of henle and the collecting ducts
134
What does the collecting ducts empty into?
the calyx into the ureter into the bladder and out it goes
135
What are the three things that will result in countercurrent magnification in the loop of henle?
1. countercurrent flow
2. differential permeability
3. hairpin circulation
136
What is hairpin circulation?
arrangement of capillary that will loop down on itself and then back up so that the two are completely adjacent to one another
137
In the loop of henly what is the arrangement of capillary? and what is the arrangment called collectively?
long hairpins that will reach all the way down and back up
vasa recta
138
Counter current exchange is a good way to do what?
keep a high concentration of something in a specific area
139
What is concentrated around the loop of henly?
sodium and chloride
140
As you move from the cortex to the medullary region of the kidney what increase?
the salt concentration sodium and chloride
141
The passive side of the loop of henly is permeable to what mol?
permeable to H2o and salt
142
The active side of the loop of henly is permeable and impermeable to what?
impermeable to water
| impermeable to salt
143
What does the active side of the loop of henly do?
actively kicks salt out and water follows
144
At some point in the asending loop of henly the salt content os so high that what happens?
the pumps are saturated so it cant pump out anymore salt and thats the salt that is going to stay and there is no water in it-salt is concentrated at a higher level than in blood
145
the concentrating ability of the loop of henly depends on what?
the length of the loop-longer the loop higher concentrating ability of the kidney
146
The only nephrons with loops of henly are seen where?
In the boundary between the medulla and cortex the juxamedullary close to the medulla because thats the only place to build up the salt concentration
147
Collecting ducts are a place where the ultrafiltrate is processed a little further. How is the wall of the collecting duct altered?
Altered to be more or less permeable to water
148
how is the wall of the collecting duct made or les spermeable to water?
ADh-anti diuretic hormone is secreted and when it in a high level the walls of the collecting duct are very permeable so water is pulled out and conserved.
149
Up until the fluid leaves the collecting duct what is it called?
ultrafiltrate
150
WHen fluid enter into the calyx and leaves the collecting duct what is it called?
urine
151
What animals have the ability to absorb or lose water through the bladder?
reptiles and amphibians
152
WHen do ADH levels drop causing you to go to the bathroom because permeability levels are low?
cold hypothalamus and adh drops, after sex, and when you drink
153
WHat is significant about the bird kidney?
primitive nephron is found on birds and they have a few juxtamedullary nephrons like in mammals and then they have some intermediate forms and no one really understand why they have these nephron types because they don't use them because they have salt glands
154
What is the only kidney that can process higher salt content in the urine than in the blood is the ?
mammal kidney
155
What are some fish kidney characteristics?
They are very simple. Short PCT. lacking DCT.
156
What is the difference in the kidneys between the marine fish and the freshwater fish?
The marine fish are losing water constantly so they don't filter water out they are a glomerular and have lost their glomerulus.
157
What type of fish is a glomerular?
marine fish-most common in pipe fish sedentary fish
158
Can the marine fish's aglomerular kidney be considered a secretary organ?
yes it lacks the ultrafiltration ability
159
What are elasmobranchs?
They came up with a completely different set of physiologically rules. They don't reabsorb water they produce urea and they just dump that into the bloodstream and make up the gap between the osmolarity between the sea water and blood-osmotic gap.
160
ELasmobranchs are slightly hyper osmotic to seawater?
yes beacause they have a higher osmotic tension and absorb freshwater directly from seawater across skin and gill surface.
161
Why does the arctic fish lack a glomerulus?
They don't have hemoglobin and have to make room for the antifreeze compounds
162
Amphibians have primitive kidney alot like we see in fish with one exception?
No opportunity for the animals to get into salt water because they have permeable skin and so they absorb sea water and drop dead.
163
What is the exception to saltwater amphibians?
Grana kanakvora the crab eating frog. They get into saltwater they cant do ti all at once have to adapt
164
how does the crab eating frog regulate water balance and are saltwater frog?
They have adopted a stragety that take urea from the bladder
165
What is the excretion in reptiles?
They normally have a shortage of water and overabundance of salt-salt glands and have excretion of uric acid as well
166
What freed the reptiles from water?
the clydoic egg-enclosed egg and they are hard shelled release uric acid
167
How is uric acid stored?
low toxicity and with no water
168
WHat is the world record holder for maximizing the salt concentration in urine?
Australian mouse has the ability to concetrate salt in its tissue to 25-26 times found in blood
169
Can humans process seawater?
no because too high salt concentration and too high magnesium concentration
