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Human biology questions

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Skidous:
Hi anotherworld2b

Yes it would be good to talk about how blood maintains the concentration difference. This is because since the blood is constantly flowing towards or away from organs, nutrients is always being absorbed into the blood stream or into the organs. In the case of the alimentary canal, the blood flowing past the canal in the capillaries will maintain the concentration difference as new blood is always being passed by the canal, promoting the transport of nutrients via diffusion and osmosis (or active transport) into the blood so that it can be taken into other parts of the body.

Hope this helps out
Skidous

vox nihili:

--- Quote from: Skidous on July 22, 2016, 10:08:52 pm ---Hi anotherworld2b

Yes it would be good to talk about how blood maintains the concentration difference. This is because since the blood is constantly flowing towards or away from organs, nutrients is always being absorbed into the blood stream or into the organs. In the case of the alimentary canal, the blood flowing past the canal in the capillaries will maintain the concentration difference as new blood is always being passed by the canal, promoting the transport of nutrients via diffusion and osmosis (or active transport) into the blood so that it can be taken into other parts of the body.

Hope this helps out
Skidous

--- End quote ---

Just to add to this.

Such is the bloody flow around the alimentary canal (called the portal system btw), all the stuff that diffuses into the blood is taken away straight away, such that the concentration of the blood remains effectively constant.
You'll see this is a fairly common theme in biology. It's the movement of blood through the lungs that maintains the concentration gradient for oxygen, through the kidneys that allows urine to be concentrated etc etc.

anotherworld2b:

--- Quote from: Mr. T-Rav on July 22, 2016, 10:12:04 pm ---Just to add to this.

Such is the bloody flow around the alimentary canal (called the portal system btw), all the stuff that diffuses into the blood is taken away straight away, such that the concentration of the blood remains effectively constant.
You'll see this is a fairly common theme in biology. It's the movement of blood through the lungs that maintains the concentration gradient for oxygen, through the kidneys that allows urine to be concentrated etc etc.

--- End quote ---

I've tried to rewrite my response would this be better? All feedback is appreciated :D

Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.

Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.

In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into the blood. This is due to using ATP to go against the high concentration of these materials in the blood vessel from the low concentration in the lacteal.

Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal through passive transport from high concentration in the lacteal to a lower concentration in the lymph, The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.

The muscular movements of the intestinal wall constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach. The constant influx of nutrients from the consumption of food ensures that the concentration gradient is maintained as nutrients are diffused from the small intestines into the lacteal. This diffusion occurs due to the high concentration of nutrients in the small intestines diffusion into the lacteal with a low concentration of these nutrients. These nutrients that are diffused into the lacteal are then travel in lymph vesicles to lymph nodes. This ensures that a low concentration of these nutrients is maintained in the villi of the small intestines.

Blood is part of the circulatory system which maintains the concentration difference of substances in the alimentary canal. Blood is constantly circulated towards and away from organs allowing nutrients to be absorbed into organs and waste to be collected from the blood stream. In regards to the alimentary canal new blood is always being passed by the canal in the capillaries allowing the transport of nutrients through diffusion, osmosis and active transport into the blood. This is maintains the concentration of nutrients by the fact that the material diffused into the blood is circulated away and around the body allowing diffusion to occurring constantly retaining a constant concentration of the blood.

Skidous:

--- Quote from: anotherworld2b on July 23, 2016, 01:28:10 am ---I've tried to rewrite my response would this be better? All feedback is appreciated :D

Q1. Absorption of nutrients depends on concentration differences so that substances diffuse across the absorbing surface. Explain how the concentration difference is maintained in the parts of the alimentary canal where absorption occurs.

Concentration difference is maintained in the small intestine which consists of millions of lacteals. Inside the villus is a lymph capillary, called a lacteal, which is surrounded by a network of blood capillaries.The structure of a villus is ideally suited to its function of nutrient absorption. In the small intestine there is high surface area which allows for greater absorption into either lymph or blood vessels. This is due to the folding of lacteals allowing for a larger surface area to volume ratio (SA:V) within the small intestines allowing for more efficient absorption of nutrients.

In the lacteals there is active and passive transport of materials. Monosaccharides, amino acids, water soluble vitamins undergo active transport into the blood. This is due to using ATP to go against the high concentration of these materials in the blood vessel from the low concentration in the lacteal.

Osmosis involves the passive transport of water into blood.Osmosis must occur through a semipermeable membrane and mainly occurs in the large intestines. Concentration difference is maintained through the constant movement of concentrations of lacteal in the villi in the small intestine. The concentration difference is also maintained by the diffusion of fat soluble vitamins and fatty acids and glycerol into lacteal through passive transport from high concentration in the lacteal to a lower concentration in the lymph, The movement for passive transport is along the concentration gradient, as well as the fact that active transport is against the concentration gradient and requires energy in the form of ATP.

The muscular movements of the intestinal wall constantly brings the villi into contact with different parts of the intestinal contents, These contents are constantly changing as new material is emptied into the small intestine from the stomach. The constant influx of nutrients from the consumption of food ensures that the concentration gradient is maintained as nutrients are diffused from the small intestines into the lacteal. This diffusion occurs due to the high concentration of nutrients in the small intestines diffusion into the lacteal with a low concentration of these nutrients. These nutrients that are diffused into the lacteal are then travel in lymph vesicles to lymph nodes. This ensures that a low concentration of these nutrients is maintained in the villi of the small intestines.

Blood is part of the circulatory system which maintains the concentration difference of substances in the alimentary canal. Blood is constantly circulated towards and away from organs allowing nutrients to be absorbed into organs and waste to be collected from the blood stream. In regards to the alimentary canal new blood is always being passed by the canal in the capillaries allowing the transport of nutrients through diffusion, osmosis and active transport into the blood. This is maintains the concentration of nutrients by the fact that the material diffused into the blood is circulated away and around the body allowing diffusion to occurring constantly retaining a constant concentration of the blood.

--- End quote ---

Hey AnotherworldB

This response is MUCH better since the last response, however I do notice that you've done some copy-paste of the information that's been given by both myself and Mr T-Rave. Whilst that is good for the information, it isn't as good in responses if they aren't modified to make the sentences run smoothly. If the sentences don't run smoothly, it may place your response from full marks to just under full marks because it was not as cohesive and coherent as a full mark response should be.

To better this response, it is not about the information but your structure. Depending on the marks allocated to this question, the structure may differ.

If it is a 3-4 mark question, you need to immediately go onto the answer, and be concise with your information and get straight to the point. Unlike English, waffling in Bio will make it seem like you don't understand what is being asked. You should also make distinct arguments in your response, so if you want to talk about passive transport, make 2-3 sentence about passive transport only and then say something along the lines of "Active transport is also used..." and continue with active transport. Ensure that the information your given also links to the question.

5-6 Mark Question require a little more information but the structure is very similar (These are usually Assess or Discuss questions so cause and effect language will be needed and a judgment will be needed [but only for the assess question])

7-8 Mark Questions require planning on the structure and understanding where your information must go and being discerning with what information is relevant and what is not. Sometimes it may be better to draw a table, for this you must remember to use headings and draw a box around the table otherwise you will lose marks (I'm not kidding).

Since this appears to be a 3-4 mark question (since it is explain) I want you to try and condense the information as there is far too much for a 3-4 marker in the HSC or Trials

So try to answer this one without copy-paste from your previous response or the information given here

Explain how the differences in nutrient concentrations ensures that absorption will occurs in the alimentary canal. 4-Marks

anotherworld2b:
I will rewrite my response following your advice:D
I just wanted to put all the information I've received in one place before I lose track of what to include :)
I really appreciate all the help I've received :D

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