Free Biology NEET Video Lectures for Excretory Products And Their Elimination

00:00:02 [Music] [Applause] [Music] [Applause] [Music] let's get started so um today we will discuss about excretory products and their elimination if we try to look into and see what is happening in the human body we have two distinct kind of processes going simultaneously in the body one we are calling anabolism this anabolism is a constructive process where where the small molecules are getting assembled to form a bigger molecule basically these are synthesis process something is getting built up something which are

00:01:11 getting manufactured something which are useful for the body useful for the digestive aspect useful for for the normal physiological aspect of the body are getting manufactured so these are called as anabolism and then there is another process simultaneously going on which is called catabolism catabolism which is nothing but a destructive process so the harmful products are getting produced by the actual disruption actual breakdown of the bigger component so anabolism is a constructive process and catabolism is a

00:01:55 destructive process and this catabolism in this catabolism process what we are getting is the production of harmful elements in the body and some of the harmful element we will try to discuss here in this topic so those excretory product are coming because of this catabolic processes and in biology if you combine this anabolism and catabolism you call it metabolism so this metabolism is another very important physiological uh consequences in the human body in order to make homeostasis homeo means constant environment inside

00:02:35 the body we can't do abrupt changes for example if you are feeling very hot during the summer weather what the what body is trying to do is to secrete the sweat and the sweat so this is just an example sweat is secreted out from the body during the heat condition now the whole purpose of this sweat coming out from the body is to cool the body down so this is a very good osmo regulatory aspect of the body in order to cool down the whole physiological aspect because body is showing alteration during the heat

00:03:15 condition so this is one such example we will discuss this whole process in in context of actual excretory aspect now this metabolism is very important and every person every human individual requires a constant amount of energy constant amount of threshold uh energy every day and that depends upon the basal metabolic rate of a human individual and in s sometime we called it [Music] BMR basal metabolic rate if the person's basal metabolic rate is very high that means the person is efficient if the

00:03:53 basil metabolic rate is down that means a person is little bit sluggish so VMR is very important which is that L linked to this metabolism which in which is indirectly linked to these two process anabolism and catabolism now probably we will try to discuss in this chapter mostly about this catabolic processes because these are creating some toxic element which are not at all required by the body and the body wants to throw it out so let's start the actual topic now uh if we see that what is happening

00:04:35 during the normal process so suppose we have food this food particles or food ingredients we are getting it inside the body by a process called ingestion so ingestion is nothing but taking the food particle or food ingredients inside the body through this mou which is a part of our Buckle cavity so this food particles are entering inside the body it is getting inside the stomach and then it is getting kind of uh metabolized and the ingredients and the other aspects are getting absorbed from the small intestine and then we are

00:05:20 getting energy now in this whole process what is happening the undigested food particles are getting out so there are some undigested material which are not required by the body which is above the threshold and these are not U actually The Wanted kind of material for the body so these are unwanted so these are just undigested food particles and this needs to be eliminated from the body system similarly in addition to food what we are taking is water also now water is also an ingredient which we which is

00:06:06 very important for our body look uh why water is important you just imagine a situation when the body get dehydrated once the body gets dehydrated what you are getting during the diarrhea or extreme water loss condition from the body uh during the burning and all in uh the water loss is huge in the body and just imagine uh what what the what are the kind of consequences a a person is getting uh if you don't have water so water is very important inrent but above a threshold water is also not required

00:06:42 right so water is needed in actual concentration if you have a stimulated a stipulated amount of uh water intake in the body you are fine excess water is again not required and that is to be thrown out in the form of urine right so these are the two important aspect of the uh digestive system which we are encountering every day whatever food we are taking undigested food is getting out in the form of faces and then water which are not at all utilized by the body is getting out in the form of urine we will

00:07:23 see this whole aspect in detail but I just wanted to give you guys a basic understanding of this secretory aspect why these are produced and how it is getting eliminated so all right we have now little bit understanding of this excretory and how the body is responding let's try to recall our last chapter number 17 which is breathing and exchange of gases which was nothing but we discussed all about O2 and CO2 so what is happening in the atmosphere where we are getting all different kind of ingredient in the form

00:08:03 of those oxygen carbon dioxide nitrogen and all some of them are utilized by the body and the one which is not required is getting excr out and what we learned in this whole chapter in that whole chapter that CO2 is The Unwanted one and we are excreting it out in the form of exhalation so CO2 is going out from the body system because accumulation of CO2 is toxic to body so the CO2 needs to be uh out from the body by certain mechanism and one such mechanism is exhalation so we will discuss this uh uh

00:08:45 again in detail but let's uh try to focus here that how this excretory products uh is important here what is happening uh we will try to imagine imagine a situation and we will try to focus our human body in order to understand this topic in a proper way now if we think about what are the normal openings in the body because this is these are the openings which are going to excrete out which are going to force out the stuff which are not wanted by our body okay now if we see the skull region the head Reon what is the first

00:09:26 opening you are getting I so the first opening which is there is I now I when you have certain emotions when we when you have certain uh kind of sorrow or some kind of emotions and all what you are getting is crying and this crying leads to production of Tears so tears unwanted tears are coming out from the area which is called eyeball now if we go and see the detail of this structure which is not a part of this whole chapter but the students uh uh whosoever is learning biology needs to understand this one that tears are

00:10:13 produced by a very specific gland and that gland is called lacrimal lacrimal gland is the producer of tears and this lacrimal gland and lacrimal ducts are there in the uh eye orbit eye ball socket but we have a duct called lacrimal duct and from this duck the tears are coming out through your eyes now uh there is a very fascinating aspect about this whole process when a person is crying something is coming out from the nostril also because crying is not associated always with tears but you are getting a dropping from the nostril

00:10:59 also that dropping is nothing but the tears only how it is possible there is a common duct which is coming both in the nostril and the lacrimal uh duct so it is called Nazo lacrimal duct and because of that reason when the tears are coming out some of the tears are coming from eyes and some of the tears are coming out from nostril so this is one opening and this is just a small example that we have some certain emotions and water is coming out of course this water is mixed with various kind of salts and all the

00:11:33 next opening is nose so this is another opening which is quite visual from outside naked eyes that you have nose as an opening and the classical example which we have gone through is CO2 The Unwanted CO2 which is not at all absorbed is coming out also uh from nostril when you have a a common cold when you have nasal sneezing and cuff and all kind of thing you always have a running nose and that running nose is nothing but some of the secretion which are produced in the nasal cavity or inside this respiratory uh aspect or

00:12:16 respir system which are which are nullifying the effect or because of this whole inflammatory process you are getting production of certain secretary mucus kind of secretions which are coming out the excess amount which is not at all required by the body is coming out through this nostril so nose is also an area which is kind of giving an exit point to the stuff which are not required by our human body now the second uh the third one is quite obvious you have your mouth which is another opening and now

00:12:57 very simple and uh if a lay man ask that what kind of stuff is coming out from the mouth if you take an example of a baby the one thing which is coming in the mind directly that baby saliva coming out from the baby mouth is quite common so saliva now this saliva is nothing but a mixture of lot of enzyme and what one such enzyme is called amyes so saliva contain contains amyes and this amyes is basically an enzyme that digest carbohydrates so carbohydrate digestion is required uh in in the Buckle cavity

00:13:39 because that enzyme very much important or very much required by uh the human body in order to degrade the carbohydrate so this saliva is also very important but excess saliva sometime when you are uh when you are getting some food particles which you really like that time you elevate a lot with mouth watering condition is nothing but secretion of excess saliva and this saliva we will see later on this is a very important ingredient that is related to the nitrogen excretion also so saliva is related to certain kind of

00:14:17 excretory aspect also so these are the three opening now the fourth opening is also available here and that is our ear so let's delete this three and we'll try to focus on the fourth one and the fourth one is ear now in ear you have let's draw a rough schematic kind of a diagram suppose this is an ear the outer of this ear is what you call P this p is nothing but this cartilagenous bone like structure which is hanging from hanging outside so but we are not concerned about that one we are

00:15:09 concerned about this area this is nothing but the canal we called it ear canal so this is nothing but the ear canal sometime it is called as a meters in biology it is called ERS but we are not going to go and look into uh the complex nen cature we will simp say ear canal now what is happening you have very small kind of hair like a structure throughout this canal so you have lot of hairs here uh in this canal and in the base of this hair follicle so suppose this hair follicles are here these are very sensitive area so um

00:15:52 there is a small glands which are situated in the base of this hair follicles and these glands are called as sasus gland sasus sasus glands and this sasus gland are the secretor of sebum this SE in Layman language it is called wax so Cassius I think this is Cassius sasus so sasus gland is nothing but the secretor of sebum so now this sebum is coming in the solary meters basically what is happening here this wax which we are otherwise called as seum is secreted in this particular area and which is

00:16:46 trapping the dust particle in order to prevent the damage of the eard drum so there is a very sensitive part which is called e drum there in at the end of this temp uh the whole ear canal which is very sensitive so nobody can touch this one and avoid to do that kind of uh mechanism the body is created this vxi envirment so as to trap the dust particles so as to trap in in order to make this particular area hygienic of course this is very sensitive part so one has to clean and every time once you

00:17:23 will clean you are getting some kind of a small wax kind of crambles and which is nothing nothing but the secretion of this cassus gland so this is the fourth opening situated in the top now we have this all opening discussed uh in the head area we will now move on to the next aspect uh our whole body the whole skin area the whole leg area whole body is having a small pores like structure so suppose this is is a body surface and this small kind of pores are there so the the hair follicle so suppose we are talking

00:18:07 about the the arm area so we have small hairs in the arm in the bottom hair follicles we are again having uh something called sweat gland sweat glands the next one is anus which is giving uh excretion or giving a passage to the undigested food particle in the form of stool or in the form of feces biologically what we call so anus is another opening that is giving uh excretion or kind of Passage to the undigested food particles uh from rectum now the other opening is uh is what we will discuss in great detail in this

00:18:57 chapter and that is our urinary system urinary system so this urinary system uh we will discuss the this one again in in our reproductive system to to certain extent so the opening is common for both urinary system as well as reproductive system so we are calling reproductive system as geneal system and reprodu urinary system as as a urin system but in in the passage the last opening uh where the the urinary system and the genital system are merging is called urogenital system Euro genital opening and this urogenital

00:19:42 opening is giving basically passes to urine so in nut cell these are some of the openings available in the human System since we need to understand this topic in in great detail so uh that's what uh uh we started here now if you go and check the slide again so these are some of the excretory products uh secreted out uh from the human body and uh not in human body Al also in uh vertebrate invertebrates and other uh living individuals so these excretory products are comprises of ammonia Uria uric acid

00:20:27 CO2 water and certain ions sodium potassium chloride phosphate sulfate uh Etc so these are some of the uh excretory products which are produced uh inside uh the the human body by by various processes going on uh in in every day-to-day activities so uh if we start looking into the actual component of this excretory products three are most important uh so we will discuss most mostly about ammonia UA and uric acid so uric acid Ura and ammonia are the three very very important excretory product in the human

00:21:23 body or other vertebrate or invertebrates which are produced by the body as a toxic ingredient these are not required uh in huge quantity uh in the body so they are getting excreted out by a process of excretion and there are various organs uh for the excretion avable right from the very lower uh invertebrates to the higher vertebrates like human beings uh we have a very specialized structure called kidney and we will discuss kidney in detail but let's try to focus here and understand the the basic mechanism behind this

00:22:02 three important toxic material ammonia Uria and uric acid if we see the uh the solubility aspect of these three ingredients ammonia requires a huge amount of water in order to ex it out so if a person is having or if an individual if a if if a living entity is having huge water reservoir or huge water content in the in the atmosphere or in in the area where they are surviving basically they are they are they are excreting ammonia so ammonia is excreted by those living entities which are having higher percentage of water

00:22:47 around them so uh if we go in the slide next slide what we are seeing here is uh there are three kind of uh excretory aspect available one is ammonotelic ureotelic and uricotelic which is nothing but related to the excretion of ammonia or UA or uric acid so the the organism which can secrete ammonia is called ammonotelic ammono telic the one which can excrete Uria is called ureotelic and the one which can excrete uric acid is called uricotelic now what we discuss is the water Affinity about this uh three individual

00:23:38 toxic material so they require huge amount of water this is kind of a moderate water so if the body is having moderate water condition they are ureotelic like human beings if we try to consider the smaller uh uh vertebra some of the some of the best examples are birds the these birds are having very less amount of water in their body reptiles they are having very less amount of water or they are kind of uh deprived of the water uh availability in in or they are living in an atmosphere which is which is not that aquatic in

00:24:17 nature so in that case the droppings if one can look into their uh the the the one which is dropping is coming out is nothing but a kind of a solid droplet and this droplets are nothing but the uric acid crystals which are coming out as an excretory product in birds and reptiles so birds reptiles and certain other animals also we are having uric acid as an excretory product and that's why we are calling it uricotelic so we will again go back to the slide and see that we have three distinct kind

00:24:54 of excretory aspect ammonotelic ureotelic and uriot talic and if you see the example these are some of the best example of amono talic so we have bony fishes we have aquatic amphibians we have insect now these species aquatic amphibians and aquatic insect which are living in water are having huge amount of water around them so that's why uh somehow their body system is evolved in such a way that they are ammonotelic in nature while mums terrestrial amphibians terrestrial amphibians means amphibians they can

00:25:34 adapt both in land as well as Waters terial amphibians we have this UA as an ingredient for exory system and then we have Marine fishes now Marine fishes is why we are discussing Marine fishes here and take an example because Marine fishes are living in a a very salty environment so the actual fresh water requirement or actual fresh water contain in the surroundings are very less and because of that reason the body system is evolved in such a way that this Marine fishes are excreting out UA uh while if we go back in the slide and

00:26:16 check once again the uricotelic examples are birds as what we discussed reptiles and insect not uh the the aquatic insect but the normal insect and the land snails so these are some of the species land snails are the one which are surviving or living in the land condition so these are all terrestrial examples which can preserve the water they don't want to leave the water in a different way so they are preserving and because of this preservation the body is adapted in such a way that the excretory

00:26:47 system is involved to excrete out ammonia excrete out Uria and excrete out uric acid and accordingly the animals are called as ammonotelic ureotelic and uralic based on the excretory aspect so let's try to discuss the actual uh Evolution aspect of the whole animal system we will try to understand from the basic uh lower invertive rates and then we'll try to see the gradual Evolution uh happened so we will now discuss the the lower invert rates and try to see how the how the excr system system got evolved in this smaller

00:27:31 animals so now we will discuss about taking an example of certain invertive rates so uh if we start looking the evolution uh of these animals um the the excretory system is started with a tube so there are lot of uh small duct or tube like structure so suppose if this is the typical body surface area of say for example a protozoa or any lower uh invert rate their excretory system of course there is no as such Advanced digestive system so there is no way they can they can produce uh some some very

00:28:12 toxic material in law but generally the water osmo regulation and water balance inside the body are controlled by a fine duct like structure so basically these are that ductal appearance so there will be one opening outside and there will be one one opening inside so something is getting kind of directed from inner side to Outer side so these are kind of Maintenance of an osmo regulation in this lower uh invertebrate so this this is a starting point in evolutionary aspect and gradually what happened this

00:28:49 small tubes are getting directed and evolved in such a way that instead of opening inside the body system they started getting open into to some normal collecting duct so say for example these are a small duct which are kind of collecting all this waste material and then after getting it collected they are draining out from the body cavity now here since we are trying to understand the whole excretory system in evolutionary terminology this is started with a tube like structure and this tube like structure is

00:29:29 called neia so these are a specific terminology which are which are used in order to depict any excretory organ tube like structure since we are talking about ancient very old we will add a prefix called Ary Ary is anything which is primitive in nature so Arin neia are basically these older ductlike structure available in these kind of species where the uh excreted product are directly uh going from inner to Outer Side by specific openings later on this kind of ductal system uh get evolved where the

00:30:15 the whole passages are coming into this ductal kind of structure and then this was another first uh advancement from Ary neia so these are called as Proto neia so this proton neia is nothing but the evolved form of the older primitive small ductlike structure now you have a ductal system and a very nice example of this ductal system is a we are getting in anela anela is a philm where we are uh discussing about the earthw and all so so since this species they are very specifically demarcating their body

00:31:04 structure in the form of segment so if you start drawing a earth form their body is like in segment and each segment is basically having a proton neia so basically this proton neia is collecting the West material and then basically these are having this ductal appearance so what is happening so these are having segment and each segment is having two lateral collecting duct area which is in converging in the lateral side to drain all the excretory material with a common point so somehow these are getting

00:31:43 involved and at certain point you have an external opening that is discarding the material and it varies this is not a fundamental rule but this is how things are evolved small duct ducting tube and then merging into an nice exterior opening where everything is raining out so here we have taken an example of proton neia which is coming from a very specialized philm analita because this was this is studied in great detail in this earthworms now there is a very nice species to understand this uh excretory system and that is called

00:32:25 planaria plaria is a species uh coming from Flat war and that flat warm is what we know as philm platti Hal menus so platus is a philm and the species name is plania the plania body since uh we discuss why they are calling a flat warm because the body cavity is not there so everything is squeezed you just considered like a field balloons for example they have air and all so basically if you squeeze it down there is nothing left out so uh the the body cavity is absent that's why they are called as flat warm so this flat warm

00:33:12 the example penia is nicely studied for this proton Neal kind of excretory system now what is there in these uh species are like they are they are having this flat like structure so they are they are roughly a flat organism and lateral laterally is something which is towards the periphery so lateral is this lateral is this so laterally they have a very nice Channel distributed throughout their body length so these channel are basically having a very specialized kind of cell very specialized kind of cell and

00:33:58 this cell are sometime called as flame cells so flame cells are kind of a protal system which are very specialized structure uh for this plal warm in order to excrete the uh materials so if you start looking so this is the ductal system and these are distributed throughout so everything is here also the same thing so this this warm is kind of so if we start looking into this kind of flame cell and if we start uh seeing what are the the content in the flame cell so basically they have a body like

00:34:39 structure and then they have Celia and then they have an exterior opening outside and they are basically these are collecting duct so this body so this is what we are gross uh we are just zooming it out so these are Celia so Celia we know that these are hairy like structure so basically things are coming from the body cavity and these are drained and basically these drained or these are coming from this collecting duct also and there is an opening which is kind of attaching to the outside area and this opening is

00:35:14 giving uh kind of excretion to this material so this is very specialized structure called Flame cell in platy helmus now this uh is in Gross these are all gross pictures that we are trying to discuss here now we will see a little advanced form of excretory system and that advanced form is coming from another film which is arthropoda arthropoda now this arthropoda as we know that these are also segmented body cavity so of course we have a protal kind of system but in gradual time Evolution this Proto Neal system is

00:35:58 getting disappeared and because of this disappearance the new organ system started one we just now saw flame cell the another one is in the Cockroach we know the cockroach is representative organism from this orthopod phum they have a very specific organ in their body taking part in excretory process and that is called malpan body Malian body so this malesian body is nothing but an excretory organ in case of uh cockroaches so and of course this phm oropa is not a very uh small philm it's a very big philm and a lot of species

00:36:42 are there so this is one modification we have malesian body in cockroach taking part in excor process there is another species we know is prawn prawn is a represented of class crustacea so prawn is Crustaceans so this is nothing but coming from a class called crusta but the philm isopoda now this prawn are having antenna so they have a very specialized antenna like structure where they can sense uh the the outside environment just in the base of antenna so suppose you have can't draw to scale but suppose this

00:37:32 is this is kind of a prawn they they have this leg and all so there is a tent specific antena just in the base of antena you have this gland called antinal gland antinal gland so this prawn is very specifically using this antinal gland to excrete out the waste material collected from our body cavity so we are just looking into the advancement see how these things are getting Advanced earlier it was like a small tube which is getting in a tubular form like in proton neia then we started with the flame cell then malpan body

00:38:12 antinal gland and then in case of another species so I'll just delete this part so we have another species spiders is SP ERS are organism from class arakida AR Nida so this arakida or ar needs uh um comprises of a spider and other various organism tis are there other very minute insects are there so this species are having a very specialized structure in their limb in the lower in the base of their limb they have a very specialized structure called coxal gland coxal gland so this coxal gland is

00:39:05 a very specialized excretal structure located in the base of the limb in this species particularly in the class ARA there are certain exceptions but I'm just giving an example that coxal gr is another modification of the excretory organ in case of spiders which is located in the base of the the limb region and also here we have got to antina gland sometime it is also called as green gland green gland green gland so antinal gland is also called as sometimes green gland and then you have a coxal gland which is uh

00:39:44 kind of excretory organ in oropa so we we are now looking that there is a great advancement of excretory system in this arthropodan species of course it is started with aror where we have a seg Ed body and the proton radial system is getting Advanced and getting more mged and evolved uh after flame cell so and then we have a specialized organ that is taking part in this whole process slowly advancement happened and now these all organs are completely dedicated for excretory system and in our case human

00:40:22 being we have a very specialized structure very specialized organ we call it kidney in our next class we'll discuss about kidney the human exory system