scilearner

It's ok I understand Thanks for the response. However I'm still bit confused. In this diagram I think discontinuous capillaries is what you mentioned, doesn't fenestrated capillary have holes inside the cell.

Hey I have, and I'm asking how cells can have holes like that, this is the first unhelpful response I have recieved from you.

Hello everyone, Since filtration occurs at the glomerulus, starling's law can be applied. Now I'm very confused with this. I understand the concept but starling's law is only for water molecules right? Now this is my question if water moves out of the glomerulus to be filtered, do solutes dissolved in it move out as well or is it just the water? Thanks

Hello everyone, In fenestrated capillary there are holes inside the endothelial cell, I don't understand how cells can have holes? Does this mean that individual holes in endothelial cells are covered by a lipid membrane? Can anyone tell how can there be holes in an individual cells when lipid membrane usually covers the whole cell. Thanks

Hello everyone, In electrophoresis the least dense one moved less (other factors been the same for every particle). I'm assuming this is due to higher volume and more resistance but, doesn't electrophoresis measure kinetic friction, so the one with lowest density should move further. What kind of resistance does electrophoresis refer to. Thanks

First of all thanks for the interest so far in the subject The book says if the lumen of EJV is kept open, air can enter in inspiration and cause fatal air embolism.

Thanks for all the replies but my question is actually from where does the air come from. Is it air dissolved in interstistial fluid or air inside your body. I'm thinking that air inside your body is covered by lungs right? I think I have some misunderstandig. Please correct me Thanks

Hello everyone, If external jugular vein is damaged and is kept open, air can enter upon inspiration. I thought in inspiration air only travels to through trachea to lungs, so how can air enter the vein in inspiration. When we breathe, air only passes through trachea right, our whole body doesn't get it right (I know later by capilllaries in lungs but directly I mean) ? Thanks

Thanks again So in the test tube platelets are damaged and release tissue factor. According to wiki Tissue factor, also called platelet tissue factor, factor III, thrombokinase, or CD142 is a protein present in subendothelial tissue, platelets, and leukocyte. So capillaries only have an endothelium, so if only the endothelium is damaged, what releases tissue factor?What are the cells that contain TF in the membran surface, I can only think of platelets in this case.

Thanks for all the answers I read the paths you have described however I'm still little bit off in my thinking. Ok so if you get some blood into a test tube, where does the trauma occur. I mean the surrounding vessel is not damaged, I just put some blood into a test tube, what creates the trauma and make platelets release tissue factor. Also a capillary is made only of endothelium, so how can platelets bind to sub endothelium collagen creating intrinsic pathway, in capillaries does extrinisic pathway take place. Thanks again

Ok Thanks

Hello everyone, If blood is taken to a tube it clots after a while. If the tube is glass, since it is a wettable surface the process is hastened, but my question is normally in the body when blood is flowing, anticoagulents are dominant over coagulents. Now if the blood is moving slow inside the body or out, why do coagulents become more dominant. Also in capillaries there is only endothelium right no collagen. So how do platelets bind if a capillary wall is damaged, platelets bind to collagen right? Thanks a lot

Hello everyone, I can't find a satisfactory answer in google. Abnormal red blood cells are destroyed inside capillaries, by what or who?

Hello everyone, When hookworm lives in your intestine and sucks your blood, what causes the main blood loss? Does the damaged blood vessels leak into the intestine and get excreted or hookworm itself causes more damage? Thanks

Hey thanks a lot for the answer That makes sense. Also just to clarfiy the last sentence, so iron is mainly lost via red blood cells right?

Hello everyone, I have found out that iron exists as plasma iron, plasma transferrin and plasma ferritin. Now what is plasma iron, I thought iron can not exist alone in the plasma it has to bind to something, is this wrong? Also ferritin is inside cells (eg liver cells) so why is there plasma ferritin. My main question is if we lose blood this can lead to iron deficiency anaemia, the thing is I'm confused how the iron is lost. If the iron is lost via plasma I'm confused due to above reasons I mentioned. Also iron is in red blood cells, so what contributes more to loss, loss of iron via red blood cells or plasma iron? Thank you

Thanks

Hello everyone, Partial pressure of oxygen at lungs is 100mmHg. Is this the oxygen dissolved in blood or oxygen bounded with haemoglobin. I think former is true, just to clarify. Thanks

Hello everyone, I'm struggling a little bit to understand the structure of haemoglobin. I have few questions to ask. 1.Ok so the top bit must be the proximal histidine and in haemoglobin rather than water bottom bit is attached to distal histidine when oxygen is not present right? Now my question is why iron atom able to make 6 bonds. For example if it is oxygen, I know it has 6 electrons in final outershell so it need 2 electrons meaning 2 bonds. (I know energy levels are bit more complicated but this is my level at the moment). Using the same prinicple iron has 26 electrons, that mean it has 16 electrons in its furthest shell so I don't understand where 6 bonds are coming? 2. When the iron atom in heme group is attached to 6 bonds, is it just an iron atom, is it when it has only 4 bonds it becomes ferrous atom (Fe2+). I don't understand the importance of ferrous atom for haemoglobin. This is the picture I got from wikipedia that show heme group? Where is the Fe2+ atom? 3. Is oxygen attached to the distal end of the histidine as well as the iron atom, or just the iron atom only? 4. What is the difference between tertiary structure and quaternary structure here? Is the 3 dimensional shape of 1 polypeptide chain called tertiary structure and many quaternary structure? Thank you so much

Ok thank you both

Hello everyone, First of all I have not seen a paranasal sinus for real, so I'm bit confused how it looks like. For example the maxillary sinus. So to see it you have to cut half of maxilla from front right. Then it is covered by mucous membrane, is this mucos membrane on top of bone. What I'm asking is do you have cut the maxilla from behind as well to see the sinus, or only from the front. Thank you I also don't understand the function of these sinuses. How do they reduce the weight of the front of the skull (the air filled cavities reduce weight is that it,rather than having bone). Also more importantly how do they resonate voice. When you speak how does air travel to them for resonance? Do they travel from trachea? Thanks

Hello everyone, When you swallow food I know nasopharynx closes and cricopharyngeus muscle relaxes. This means air can enter oesophagus easily right? Then why are we not burping all the time while eating. Thanks

Hello everyone, What is the function of the mucous membrane of the mouth. Ok if it is to trap infectious agents and keep everything moist, where does mucous drain to after it traps the pathogens. Do they fall down from the mouth. Also since the first thing that comes to mind when mucous pops up is obviously nasal mucous. So how does the actual mucous look like it. In the mouth why can't we see or feel the mucous like in the nose. Thanks

Thanks everyone My knowledge on this is very poor. I'll take this step by step. So from what you guys are saying, if there is a single tyre, I push it, it rolls rather than slide due to friction. Is that right? Ok then in a car what creates the initial push? With the tyre I pushed it, in a car what gives this initial push to the car? I think may be the question I should ask is why does a tyre roll? What makes it roll in one direction. So is the friction making the car move forward, or is it making the tyre roll? Also since I'm not sure about this I don't understand how friction helps braking. Isn't braking due to discs?

Hello everyone, When you go down a lift, are you actually falling down. Is the lift carrying you down, or are you falling down due to gravity towards the lift, if the lift goes too fast would your head crash? Sorry if my thinking is completely wrong. Ok now apparent weight is from the normal reaction force. Muscles pump blood up via veins and then they fall due to gravity and other factors. So when they fall and hit the interior of the foot, can't you feel it. So isn't apparent not just the normal reaction force. Thank you