Mammals
Mammals are a special group in the animal kingdom - so can we define an animal.?
An animal is ...a Multi cellular organism, made of many cells - It is Heterotrophic (which means it feeds on the food Plant and/or animals of others) in its environment. It is capable of moving in response to factors or stimuli in their environment.
The word Mammal is derived from the scientific name for animals of the class Mammalia and is derived from the latin "mamma" meaning "teat"
A mammal is identified by having a special set of characteristics or features....
A Mammal has....
A vertebrate-a backbone
Three middle ear bones
Has a four chambered heart
Has Lungs for gas Exchange
Is Homeothermic - warm blooded
Has fur and/or Hair
Mammary Glands to feed young by producing young
Mammals are a special group in the animal kingdom - so can we define an animal.?
An animal is ...a Multi cellular organism, made of many cells - It is Heterotrophic (which means it feeds on the food Plant and/or animals of others) in its environment. It is capable of moving in response to factors or stimuli in their environment.
The word Mammal is derived from the scientific name for animals of the class Mammalia and is derived from the latin "mamma" meaning "teat"
A mammal is identified by having a special set of characteristics or features....
A Mammal has....
A vertebrate-a backbone
Three middle ear bones
Has a four chambered heart
Has Lungs for gas Exchange
Is Homeothermic - warm blooded
Has fur and/or Hair
Mammary Glands to feed young by producing young
Mammals and their need to consume:
Mammals need to consume food in order to carry out the 7 major Life Processes.
CARBOHYDRATES:
These include sugars and starches and give us ENERGY ! Most carbohydrates in a mammals diet comes from plants and in the form of sugars.
They are known as the "energy foods" and are divided into two sub-groups:
Complex Sugars eg:(starch) AND Simple sugars (eg: Glucose)
Fibre is also a "carbohydrate" and is found mostly in fruit, vegetables and some cereals (grains) Fibre is the indigestible part and is responsible for moving food through the intestine.
Starch (complex sugars) and Fibre are sugar polymers = hundreds of sugar molecules joined together.
Mammals need to consume food in order to carry out the 7 major Life Processes.
CARBOHYDRATES:
These include sugars and starches and give us ENERGY ! Most carbohydrates in a mammals diet comes from plants and in the form of sugars.
They are known as the "energy foods" and are divided into two sub-groups:
Complex Sugars eg:(starch) AND Simple sugars (eg: Glucose)
Fibre is also a "carbohydrate" and is found mostly in fruit, vegetables and some cereals (grains) Fibre is the indigestible part and is responsible for moving food through the intestine.
Starch (complex sugars) and Fibre are sugar polymers = hundreds of sugar molecules joined together.
'''Cellulose'''
Cellulose is the most common form of fibre on the planet. It is a major component of plant cells (the cell wall is mainly cellulose). Many herbivores rely on cellulose as a food source even though no mammals can digest it.
They rely on bacteria in the gut to help break down (digest) the cellulose for them.
Amylase cannot break the bond in this complex carbohydrate
Cellulose is the most common form of fibre on the planet. It is a major component of plant cells (the cell wall is mainly cellulose). Many herbivores rely on cellulose as a food source even though no mammals can digest it.
They rely on bacteria in the gut to help break down (digest) the cellulose for them.
Amylase cannot break the bond in this complex carbohydrate
PROTEIN:
What is Protein?
Proteins are large, complex molecules that play many critical roles in the body. They do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.
Proteins are made up of hundreds or thousands of smaller units called amino acids, which are attached to one another in long chains. There are 20 different types of amino acids that can be combined to make a protein. The sequence of amino acids determines each protein’s unique 3-dimensional structure and its specific function.
Protein is a source of energy but its main role in the body is growth and repair.
It helps in the formation of muscles, hair, nails, skin and organs, such as the heart, kidneys and liver. We all contain a significant amount of protein. For example, a 76kg man is made up of 12kg of protein (16%).
Protein is a nutrient needed by the human body for growth and maintenance.[1] Aside from water, proteins are the most abundant kind of molecules in the body.
Protein can be found in all cells of the body and is the major structural component of all cells in the body, especially muscle.[1][6] This also includes body organs, hair and skin. Proteins are also used in membranes.
Click here to learn more about Protein !!
LIPIDS- Fats and Oils:
A Lipid is non-soluble organic compound made up a Glycerol and a Fatty Acids. (see pic below for typical structure)
Lips are more commonly known as fats, play many important roles in your body, from providing energy to cell membrane development and producing hormones. You wouldn't be able to digest and absorb food properly without lipids.
Of course, eating more fat than you need can lead to weight gain, but in proper amounts lipids are a healthy part of your diet.
Plants and animals alike contain lipids which they depend on for energy. Gram for gram, a lipid contains more than twice the amount of energy found in carbohydrates
A Lipid is non-soluble organic compound made up a Glycerol and a Fatty Acids. (see pic below for typical structure)
Lips are more commonly known as fats, play many important roles in your body, from providing energy to cell membrane development and producing hormones. You wouldn't be able to digest and absorb food properly without lipids.
Of course, eating more fat than you need can lead to weight gain, but in proper amounts lipids are a healthy part of your diet.
Plants and animals alike contain lipids which they depend on for energy. Gram for gram, a lipid contains more than twice the amount of energy found in carbohydrates
Types and Functions of Lipids
There is some confusion between lipids and fats as while not all lipids are fats, all fats are lipids. There are several different types of lipids to discover before fully understanding the subject, which include the following:
1. TriglyceridesTriglyceride molecules are made from three molecules of fatty acids and one glycerol molecule. The fat can be either unsaturated or saturated. Triglycerides are able to float in a cell’s cytoplasm since they have a lower density than water and are non-soluble, as is the case with all lipids. A triglyceride will be classified as a fat if it becomes solid at a temperature of 20ºC, otherwise that are classified as oils. Triglycerides are crucial in the body for energy storage.
2. SteroidsSteroids have a structure that resembled four rings fused together which are made from carbon molecules. A few types of common steroids are cholesterol, testosterone, vitamin D2 and estrogen. Steroids benefit the body by helping determine and control the structure of plasma membrane.
3. PhospholipidsPhospholipids earn their name as their constitution is primarily phosphate groups. They contain molecules that both attract and repel water, playing a key role in constituting cell membranes.
4. GlycolipidsShort sugar chains form glycolipids, which can be found in a cellular membrane’s exoplasmic surface. They play an important role in boosting the body’s immune system.
5. LipoproteinsA lipoprotein is a combination of proteins and lipids found in a cell’s membrane – examples being antigens and enzymes. Lipoprotein help fat move around the body in the bloodstream and exist in the form of Low Density Lipoprotein (HDL) and High Density Lipoprotein (LDL).
6. WaxesAlong with a chain of alcohols, fatty acids are found in waxes. These are extremely common lipids and can be found on animal feathers, in human ears and even on the leaves of plants. Their primary function is one of protection.
There is some confusion between lipids and fats as while not all lipids are fats, all fats are lipids. There are several different types of lipids to discover before fully understanding the subject, which include the following:
1. TriglyceridesTriglyceride molecules are made from three molecules of fatty acids and one glycerol molecule. The fat can be either unsaturated or saturated. Triglycerides are able to float in a cell’s cytoplasm since they have a lower density than water and are non-soluble, as is the case with all lipids. A triglyceride will be classified as a fat if it becomes solid at a temperature of 20ºC, otherwise that are classified as oils. Triglycerides are crucial in the body for energy storage.
2. SteroidsSteroids have a structure that resembled four rings fused together which are made from carbon molecules. A few types of common steroids are cholesterol, testosterone, vitamin D2 and estrogen. Steroids benefit the body by helping determine and control the structure of plasma membrane.
3. PhospholipidsPhospholipids earn their name as their constitution is primarily phosphate groups. They contain molecules that both attract and repel water, playing a key role in constituting cell membranes.
4. GlycolipidsShort sugar chains form glycolipids, which can be found in a cellular membrane’s exoplasmic surface. They play an important role in boosting the body’s immune system.
5. LipoproteinsA lipoprotein is a combination of proteins and lipids found in a cell’s membrane – examples being antigens and enzymes. Lipoprotein help fat move around the body in the bloodstream and exist in the form of Low Density Lipoprotein (HDL) and High Density Lipoprotein (LDL).
6. WaxesAlong with a chain of alcohols, fatty acids are found in waxes. These are extremely common lipids and can be found on animal feathers, in human ears and even on the leaves of plants. Their primary function is one of protection.
VITAMINS and MINERALS
CELLULAR RESPIRATION:
Occurs in EVERY living cell.
It is an essential process that is carried out to meet the Energy demands of a mammal such as:
It is defined - as the breaking up of Glucose in the presence of oxygen to release Energy in the form of ATP along with CO2 and H2O.
It is controlled by ENZYMES every step of the way.
This cellular process occurs in the organelles called Mitochondria.
There are two types of Cellular Respiration: Aerobic and Anaerobic
Our circulatory system is how the Glucose (from digestion) and Oxygen (from gas exchange on the lungs) is transported to EVERY CELL in our body so they can respire - carry our cellular respiration!!
Occurs in EVERY living cell.
It is an essential process that is carried out to meet the Energy demands of a mammal such as:
- For muscle contraction - so the body can move, the heart can beat. chromosomes can be moved during cell divison, so organisms can grow or produce gametes
- For other chemical reactions-including enzyme activity for important metabolic processes eg: digestion
- Active Transport eg: absorbing digested food from the intestine, or reabsorbing Glucose in the kidneys,
It is defined - as the breaking up of Glucose in the presence of oxygen to release Energy in the form of ATP along with CO2 and H2O.
It is controlled by ENZYMES every step of the way.
This cellular process occurs in the organelles called Mitochondria.
There are two types of Cellular Respiration: Aerobic and Anaerobic
Our circulatory system is how the Glucose (from digestion) and Oxygen (from gas exchange on the lungs) is transported to EVERY CELL in our body so they can respire - carry our cellular respiration!!
MAMMALIAN DENTITION:
There are three main types of diets in the mammalian world:
Mammals that eat grass are called Herbivores, those that eat meat are called Carnivores and those that eat both are termed Omnivores.
Herbivore, Carnivore and Omnivore are reffered to as a mammals "trophic group" which comes from the Greek term trophikos meaning "nutrition".
Teeth play an important part of Ingestion = taking food into the mouth.
Teeth have 3 main roles- they are used to capture and subdue living prey, remove food from its source AND to increase the surface area of a food so that digestive enzymes and gastric chemicals can work more efficiently and effectively.
The structure of each tooth type is directly related to its role.
There are three main types of diets in the mammalian world:
Mammals that eat grass are called Herbivores, those that eat meat are called Carnivores and those that eat both are termed Omnivores.
Herbivore, Carnivore and Omnivore are reffered to as a mammals "trophic group" which comes from the Greek term trophikos meaning "nutrition".
Teeth play an important part of Ingestion = taking food into the mouth.
Teeth have 3 main roles- they are used to capture and subdue living prey, remove food from its source AND to increase the surface area of a food so that digestive enzymes and gastric chemicals can work more efficiently and effectively.
The structure of each tooth type is directly related to its role.
DIGESTION PROCESS: HUMANS:
Digestion is defined as the process that breaks down large food molecules into smaller molecules that can be absorbed and assimilated by our body
It Involves both Physical (mechanical) and Chemical digestion (enzymes)
Digestion.....Starts in the mouth - with the teeth and Saliva. Ingestion is the termed used for taking food into the mouth.
Involves the
Teeth -the physical chewing action of teeth termed mastication is an example of Mechanical digestion - mastication is a process that breaks up the food into smaller particles to increase the surface area available for exposure to digestive enzymes,
Saliva -Produced in salivary glands, saliva is 98% water, but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. The saliva and the digestive enzymes is termed a from of Chemical digestion. The other digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily.
Digestion is defined as the process that breaks down large food molecules into smaller molecules that can be absorbed and assimilated by our body
It Involves both Physical (mechanical) and Chemical digestion (enzymes)
Digestion.....Starts in the mouth - with the teeth and Saliva. Ingestion is the termed used for taking food into the mouth.
Involves the
- Teeth – physical/mechanical digestion – breaks down food into smaller particles increasing the SURFACE AREA available for ENZYME action
- Saliva – produced by the salivary glands – lubricates the food-Contains AMYLASE = starch digestion and MUCIN - the slimy substance.
- Tongue - helps to roll food up into a ball – bolus
Teeth -the physical chewing action of teeth termed mastication is an example of Mechanical digestion - mastication is a process that breaks up the food into smaller particles to increase the surface area available for exposure to digestive enzymes,
Saliva -Produced in salivary glands, saliva is 98% water, but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. The saliva and the digestive enzymes is termed a from of Chemical digestion. The other digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily.
The OESOPHAGUS – is a muscular tube that connects the throat (pharynx) with the stomach- transports food & fluid from mouth to stomach. It does this with Peristaltic wave action – alternating muscle contractions - involuntary
THE STOMACH......
A large, elastic muscular bag which can expand to hold many litres of liquid. Is a muscular sac that lies on the left of our body just below the diaphragm - food enters when the ring of muscle = sphincter relaxes.It functions to:
The cells in the stomach walls produce:
Gastric Juice which contains
*Pyloric Sphincter relaxes to let chyme enter the doudenum.
A large, elastic muscular bag which can expand to hold many litres of liquid. Is a muscular sac that lies on the left of our body just below the diaphragm - food enters when the ring of muscle = sphincter relaxes.It functions to:
- Store and gradually release food into the duodenum.
- Assist the Physical digestion of the food by constantly contracting and relaxing, breaking down the food , mixing and stirring the food with Gastric Juice to produce Chyme. (thick pea soup consistency
The cells in the stomach walls produce:
Gastric Juice which contains
- Protease enzymes to digest proteins eg: pepsin and
- HCL hydrochloric acid to aid in the digestion of foods eg: the acid causes proteins to denature so that enzymes can continue to digest protein chains into amino acids. It also sterilises the stomach contents and kills potential pathogens. It also provides the correct pH environment for Proteases to work in of PH 1-2 and stops the action of Amylase
- Mucus which acts as a protective layer from the effect of pH
*Pyloric Sphincter relaxes to let chyme enter the doudenum.
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DUODENUM:
The duodenum is the first and shortest segment of the small intestine. It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine.
In the duodenum the food leaving the stomach is mixed with fluids from the gall bladdder (bile) and the pancreas (pancreatic Juice)
The duodenum is the first and shortest segment of the small intestine. It receives partially digested food (known as chyme) from the stomach and plays a vital role in the chemical digestion of chyme in preparation for absorption in the small intestine.
In the duodenum the food leaving the stomach is mixed with fluids from the gall bladdder (bile) and the pancreas (pancreatic Juice)
THE PANCREAS:
Produces Pancreatic Juice which contains:
An Alkaline liquid of pH 7.5-8.0 that is produced by the Pancreas which contains the digestive enzymes:
•Protease – Trypsin - Polypeptide to Amino acids
•Lipase – Lipids to fatty acids and glycerol
•Amylase and Maltase - starch to glucose
•Glycogen and Insulin ( a hormone) to regulate sugar levels in the blood.
Produces Pancreatic Juice which contains:
An Alkaline liquid of pH 7.5-8.0 that is produced by the Pancreas which contains the digestive enzymes:
•Protease – Trypsin - Polypeptide to Amino acids
•Lipase – Lipids to fatty acids and glycerol
•Amylase and Maltase - starch to glucose
•Glycogen and Insulin ( a hormone) to regulate sugar levels in the blood.
THE GALL BLADDER:
Stores - BILE:
A yellow/green liquid which acts on lipids and is released into food that contains fat in the Duodenum.
It is Akaline with a pH of 7.5-8.0
It is produced by the Liver and stored in the Gall Bladder. It contains “salts” which play a vital role in emulsification. It functions to :
•To neutralise the acidity of the“Chyme” (from the stomach) in the duodenum
•To emulsify the Lipids to increase the surface area for the action of Lipases-increase the rate of lipase action.
Stores - BILE:
A yellow/green liquid which acts on lipids and is released into food that contains fat in the Duodenum.
It is Akaline with a pH of 7.5-8.0
It is produced by the Liver and stored in the Gall Bladder. It contains “salts” which play a vital role in emulsification. It functions to :
•To neutralise the acidity of the“Chyme” (from the stomach) in the duodenum
•To emulsify the Lipids to increase the surface area for the action of Lipases-increase the rate of lipase action.
THE LIVER:
Digested nutrients get assimilated here....
•Assimilation - Is the process in which products of digestion (ie: nutrients) are incorporated into and become part of the body cells and tissues.
•Occurs in the Liver (after digestions and absorption)
•The Liver receives nearly all the food absorbed into the bloodstream - so it participates in the breakdown of Carbohydrates, Proteins, Lipids.
•The Liver acts as the "sorting house" and ensures consistent delivery of nutrients to the blood- so it CONTROLS the amounts distributed to the cells depending on the bodies needs.
•It stores, sorts, re-directs, regulates or breaks down further the nutrients it receives.
Digested nutrients get assimilated here....
•Assimilation - Is the process in which products of digestion (ie: nutrients) are incorporated into and become part of the body cells and tissues.
•Occurs in the Liver (after digestions and absorption)
•The Liver receives nearly all the food absorbed into the bloodstream - so it participates in the breakdown of Carbohydrates, Proteins, Lipids.
•The Liver acts as the "sorting house" and ensures consistent delivery of nutrients to the blood- so it CONTROLS the amounts distributed to the cells depending on the bodies needs.
•It stores, sorts, re-directs, regulates or breaks down further the nutrients it receives.
THE SMALL INTESTINE: aka ILEUM
•Is the site of absorption = the taking in (absorbing) of digested nutrients (eg: Amino acids and Glucose) into the bloodstream so that cells can utilise them for Respiration and other life processes.
•It is a long narrow tube surrounded by rings of muscle that move the digested nutrients along by Peristalsis action:
– maximising the absorption across the Villi
- preventing any blockages
Its SURFACE:
- Is lined/covered with finger like projections called VILLI –which are covered by “microvilli”
Function to greatly increase the surface area available for absorption into the bloodstream and lacteals so increases the RATE of absorption.
Their surface is very THIN – to allow for rapid diffusion of nutrients into the bloodstream
& the Lacteals
•Is the site of absorption = the taking in (absorbing) of digested nutrients (eg: Amino acids and Glucose) into the bloodstream so that cells can utilise them for Respiration and other life processes.
•It is a long narrow tube surrounded by rings of muscle that move the digested nutrients along by Peristalsis action:
– maximising the absorption across the Villi
- preventing any blockages
Its SURFACE:
- Is lined/covered with finger like projections called VILLI –which are covered by “microvilli”
Function to greatly increase the surface area available for absorption into the bloodstream and lacteals so increases the RATE of absorption.
Their surface is very THIN – to allow for rapid diffusion of nutrients into the bloodstream
& the Lacteals
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THE LARGE INTESTINE: aka COLON
The large intestine takes about 16 hours to finish the digestion of the food.
Main role is for the reabsorption of any left over water (to keep cells hydrated ) AND absorption of any remainable absorbable nutrients from the food before sending the indigestible matter to the rectum
Structurally it is a shorter/wider tube (than small intestine)
Its Surface is fairly smooth and thin to promote efficient diffusion of H2O into the bloodstream to hydrate body cells
It is surrounded by a ring of muscle – Peristalsis ensures food is moved through at speed to maximise H2O absorption & also prevent it getting stuck !!
Food that enters here is largely waste matter which is indigestible such as Cellulose + plant fibres (the roughage) bacteria, mucus and dead cells.
Bacteria also breakdown this roughage further = gas = Flatulence !!
The large intestine takes about 16 hours to finish the digestion of the food.
Main role is for the reabsorption of any left over water (to keep cells hydrated ) AND absorption of any remainable absorbable nutrients from the food before sending the indigestible matter to the rectum
Structurally it is a shorter/wider tube (than small intestine)
Its Surface is fairly smooth and thin to promote efficient diffusion of H2O into the bloodstream to hydrate body cells
It is surrounded by a ring of muscle – Peristalsis ensures food is moved through at speed to maximise H2O absorption & also prevent it getting stuck !!
Food that enters here is largely waste matter which is indigestible such as Cellulose + plant fibres (the roughage) bacteria, mucus and dead cells.
Bacteria also breakdown this roughage further = gas = Flatulence !!
COMPARISON OF DIEGESTIVE TRACTS:
The HERBIVORE GUT system:
Like us Herbivore's can’t produce Cellulose digesting enzymes BUT instead they have Bacteria that release Cellulose digesting enzymes Cellulase and specialised and often enlarged structures to “house” them - a Caecum and appendix OR a special large 4 chambered gut.
Herbivores are largely broken into two:
- HINDGUT Herbivores - includes all rodents (rats and mice) as well as rabbits is characterised by a Large, well developed CAECUM.
- FOREGUT herbivores - includes all ruminants(cows sheep and goats) - characterised by a large and complex stomach
Caecum = role in digestion of Cellulose for the Hindgut herbivores = houses the bacteria that breakdown the Cellulose – ie: the billions of bacteria contain the cellulose digesting enzyme Cellulase to convert Cellulose to Glucose and then they respire using the Glucose as energy source – it is a Mutualistic relationship beneficial to the host (herbivore) AND the bacteria - bacteria get to keep warm, safe environment to grow, feed and reproduce.
Specialised structures are – relative to size of the organism ie: larger the herbivore the larger the caecum .
Even with the help of bacteria – digestion of the cellulose is still difficult –so herbivores generally have a long Small Intestine still to give more time for digestion
The Stomach is often smaller as it is not so much of a “storage” organ for Herbivores – food needs to get into the Caecum asap for bacteria action.
COWS and SHEEP (and goats) are referred to as Foregut Herbivores or Ruminants.
Their digestive system is distinguished by their specialised chambered stomach & chewing of the cud.
COWs and SHEEP spend most of their time chewing their cud and ruminating !!
WHY - because this physical digestion is necessary in order to break down the cellulose cell walls so as to make the most of the Enzyme action (chemical digestion) and the assimilation of nutrients into cells. It also increases the production of SALIVA which ensures that the RUMENS environment does not get to acidic so that the billions of Bacteria populations are maintained !
The SHEEPS specialised stomach - the stomach is a very important part of their digestion. The chemical digestion starts in the stomach and is the result of fermentation and enzymes.
1. ingestion of grass - the grass gets chewed (physical digestion) then it is taken into the RUMEN
2. The RUMEN is where bacteria start the digestion of the cellulose by fermentation and the release of cellulase which digests cellulose into glucose.Muscular contractions mix the grass with the billions of cellulose digesting bacteria (pH is 7.3- 5.7) weakly basic and acidic.
3.The RETICULUM then makes the partly digested grass into CUD to be regurgitated - cud is then taken up the oespohagus - then re-swallowed. (the rumen and reticulum are not completely separated)
4. The Omasum removes the water
5. The Obomasun- digestion by gastric juices - contains Pepsin
6. Then small intestine - Lipase - large intestine (very short) - rectum - anus
** ENZYMES -Both ruminants have Pepsin and Pipase involved in chemical digestion.
The COWS specialised stomach is very similar to the sheeps
Herbivore
Herbivores consume algae or plant matter such as seeds, leaves, and fruits. Because some of these materials are low in easily accessible energy, herbivores have evolved two alternatives for releasing the nutrients: foregut and hindgut gastric fermentation. Gastric fermentation utilizes bacteria that breakdown the hard to digest cellulose, the plant cell wall’s primary component.
In animals that use foregut (a.k.a. pre-gastric) fermentation, the stomach is modified into four chambers/compartments where the first chamber is the rumen. This rumen provides a place for the bacterial breakdown of food. Ruminants regurgitate the partially digested mass from their rumen, known as “cud,” and continue to chew the plant matter to break it down further. Examples of foregut ruminants include cows, sheep, camels, and deer. Camels are known to “spit” when angry, but in actuality, they projectile vomit their cud.In those animals that utilize hindgut fermentation (a.k.a. post-gastric) such as rabbits, rhinos, and horses, the microbial digestion occurs in the large intestine (colon) and/or alarge cecum. These organisms are known as monogastric animals, because they lack the multi-chambered stomachs of the ruminants. The post-gastric fermentation processis less efficient (20% – 65% fiber digestion) than pre-gastric fermentation (52% - 80%);therefore, some monogastric animals practice coprophagy (the consumption of feces) to increase the absorption from nutrients of the food that has already passed through their system. Because this process is not efficient, monogastric herbivores have to consume large amounts of food to meet their nutritional needs, sometimes spending up to 16 hours per day grazing.
Carnivore
Carnivores consume other organisms. Because meat is easily digested compared to plant material, the digestive system of a carnivore is typically shorter than an herbivore of comparable size. In carnivores, the caecum is sometimes reduced and may bepartially replaced by the appendix. Because meat is so easily digested, carnivores and omnivores have lost the ability to synthesize some amino acids. These amino acids, building blocks of proteins, which cannot be synthesized, are known as “essential” amino acids. True carnivores lack enzymes in their saliva to help them digest food. They cannot “chew” by moving their jaws side to side but instead rip the meat into smaller pieces when possible and swallow their food quickly. When the food reaches the stomach, digestive enzymes in the stomach begin to break down the food into absorbable units. The food then moves to the small intestine where most of the absorption occurs and then through the large intestine where waste is eliminated.
Omnivore
Omnivores consume both plant and animal matter. The length of their digestive system more closely resembles that of an herbivore as compared to a carnivore. However, omnivores lack the fermenting vats found in herbivores. Examples of omnivores include humans, pigs, and bears.
Herbivores consume algae or plant matter such as seeds, leaves, and fruits. Because some of these materials are low in easily accessible energy, herbivores have evolved two alternatives for releasing the nutrients: foregut and hindgut gastric fermentation. Gastric fermentation utilizes bacteria that breakdown the hard to digest cellulose, the plant cell wall’s primary component.
In animals that use foregut (a.k.a. pre-gastric) fermentation, the stomach is modified into four chambers/compartments where the first chamber is the rumen. This rumen provides a place for the bacterial breakdown of food. Ruminants regurgitate the partially digested mass from their rumen, known as “cud,” and continue to chew the plant matter to break it down further. Examples of foregut ruminants include cows, sheep, camels, and deer. Camels are known to “spit” when angry, but in actuality, they projectile vomit their cud.In those animals that utilize hindgut fermentation (a.k.a. post-gastric) such as rabbits, rhinos, and horses, the microbial digestion occurs in the large intestine (colon) and/or alarge cecum. These organisms are known as monogastric animals, because they lack the multi-chambered stomachs of the ruminants. The post-gastric fermentation processis less efficient (20% – 65% fiber digestion) than pre-gastric fermentation (52% - 80%);therefore, some monogastric animals practice coprophagy (the consumption of feces) to increase the absorption from nutrients of the food that has already passed through their system. Because this process is not efficient, monogastric herbivores have to consume large amounts of food to meet their nutritional needs, sometimes spending up to 16 hours per day grazing.
Carnivore
Carnivores consume other organisms. Because meat is easily digested compared to plant material, the digestive system of a carnivore is typically shorter than an herbivore of comparable size. In carnivores, the caecum is sometimes reduced and may bepartially replaced by the appendix. Because meat is so easily digested, carnivores and omnivores have lost the ability to synthesize some amino acids. These amino acids, building blocks of proteins, which cannot be synthesized, are known as “essential” amino acids. True carnivores lack enzymes in their saliva to help them digest food. They cannot “chew” by moving their jaws side to side but instead rip the meat into smaller pieces when possible and swallow their food quickly. When the food reaches the stomach, digestive enzymes in the stomach begin to break down the food into absorbable units. The food then moves to the small intestine where most of the absorption occurs and then through the large intestine where waste is eliminated.
Omnivore
Omnivores consume both plant and animal matter. The length of their digestive system more closely resembles that of an herbivore as compared to a carnivore. However, omnivores lack the fermenting vats found in herbivores. Examples of omnivores include humans, pigs, and bears.
OUR CIRCULATORY SYSTEM:
The circulatory system includes the heart, blood vessels and blood, and is vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance). The system's main function is to transport blood, nutrients, gases and hormones to and from the cells throughout the body.
It is an organ system that transports material in blood such as food or oxygen to every cell in the body and removes waste such as carbon dioxide. Blood transports various substances from one part of the body to another by continuous flowing through a closed system of blood vessels known as the circulatory system. The blood flow is known as blood circulation. Blood is moving by means of an organ known as the heart, which is a muscular pump that draws blood in when it relaxes and pushes it out at great force when it contracts.
Blood vessels are responsible for the transportation of blood from the heart around the body and vice versa. This intricate network includes:
1. arteries
2. veins
3. capillaries
Arteries:
They carry the blood away from the heart.
Veins:
On the other hand, veins convey blood towards the heart.
Capillaries:
The microscopic thin-walled blood vessels which carry blood from a small artery to a small vein.
Fun fact about these vessels.......
If you were to lay out all of the arteries, capillaries and veins in one adult, end-to-end, they would stretch about 100,000 kilometers. What's more, the capillaries, which are the smallest of the blood vessels, would make up about 80 percent of this length.By comparison, the circumference of the Earth is about 25,000 miles (40,000 km). That means a person's blood vessels could wrap around the planet approximately 2.5 times
The circulatory system includes the heart, blood vessels and blood, and is vital for fighting diseases and maintaining homeostasis (proper temperature and pH balance). The system's main function is to transport blood, nutrients, gases and hormones to and from the cells throughout the body.
It is an organ system that transports material in blood such as food or oxygen to every cell in the body and removes waste such as carbon dioxide. Blood transports various substances from one part of the body to another by continuous flowing through a closed system of blood vessels known as the circulatory system. The blood flow is known as blood circulation. Blood is moving by means of an organ known as the heart, which is a muscular pump that draws blood in when it relaxes and pushes it out at great force when it contracts.
Blood vessels are responsible for the transportation of blood from the heart around the body and vice versa. This intricate network includes:
1. arteries
2. veins
3. capillaries
Arteries:
They carry the blood away from the heart.
Veins:
On the other hand, veins convey blood towards the heart.
Capillaries:
The microscopic thin-walled blood vessels which carry blood from a small artery to a small vein.
Fun fact about these vessels.......
If you were to lay out all of the arteries, capillaries and veins in one adult, end-to-end, they would stretch about 100,000 kilometers. What's more, the capillaries, which are the smallest of the blood vessels, would make up about 80 percent of this length.By comparison, the circumference of the Earth is about 25,000 miles (40,000 km). That means a person's blood vessels could wrap around the planet approximately 2.5 times
OUR BLOOD....
Did you know we make about 2.4 millions Red Blood cells every second....Blood makes up around 7% of the weight of a human body.
Did you know we make about 2.4 millions Red Blood cells every second....Blood makes up around 7% of the weight of a human body.
- Blood contains red blood cells, white blood cells and platelets.
- These blood cells float in a yellow liquid called blood plasma. Blood plasma is made up of 90% water and also contains various nutrients, electrolytes, gases, proteins, glucose and hormones.
- Blood plasma can be separated from the cells by spinning blood in a device known as a centrifuge until the cells collect at the bottom of the tube.
- Red blood cells have the important job of carrying oxygen around the body. They also contain a protein called hemoglobin. Hemoglobin contains iron which combines with oxygen to give hemoglobin and our blood, a red color.
- Red blood cells develop in bone marrow and circulate in the body for around 120 days.
- White blood cells are an important part of the body’s immune system. They defend against certain bacteria, viruses, cancer cells, infectious diseases and other unwanted materials.
- Platelets help blood clot in order to limit bleeding when your skin is cut. Blood clots can occasionally have negative effects, if they form in blood vessels going to the brain they can cause a stroke while clotting in a blood vessel going to the heart can lead to a heart attack.
- As well as delivering important substances to our cells, blood also helps take away unwanted waste products
- The human body manufactures 17 million red blood cells per second. If stress precipitates a need the body can produce up to 7 times that amount. (That’s up to 119 million red blood cells per second.)
- A red blood cell is around 7 microns in size. (A micron is one millionth of a metre).
- It only takes 20 to 60 seconds for a drop of blood to travel from the heart, through your body, and back to the heart again
ARTERIES VEIN AND CAPILLARIES:
How DO Capillaries work ??.......
OUR HEART:
Valves:
Valves function to prevent blood from flowing backwards.
Between each atrium and ventricle is an atrioventricular valves (AV Valves)
On the right side of the heart they are called the "Tri-cupsid valve" because it has
Valves function to prevent blood from flowing backwards.
Between each atrium and ventricle is an atrioventricular valves (AV Valves)
On the right side of the heart they are called the "Tri-cupsid valve" because it has
Heart Attack v Cardiac Arrest
Our GAS EXCHANGE system
To supply the cells of our body with a continuous supply of oxygen for respiration and to remove the carbon dioxide generated by respiration, we have evolved a specialised exchange surface for gas exchange within the breathing system. The efficiency of this system is further improved by ventilation of this exchange surface and by having an efficient blood supply - both of which maintain a suitable concentration gradient.
The lungs are part of the breathing system which is adapted for two functions:
Beneath the lungs is a muscular sheet called the diaphragm. This separates the lungs from the abdomen of the body and also plays a role in ventilating the lungs.
Within the lungs is a network of tubes through which air is able to pass. Air is firstly warmed, moistened and filtered as it travels through the mouth and nasal passages. It then passes through the trachea and down one of the two bronchiand into one of the lungs.
After travelling into the many bronchioles, it finally passes into some of the millions of tiny sacs called alveoli, which have the specialised surfaces for gas exchange.
To supply the cells of our body with a continuous supply of oxygen for respiration and to remove the carbon dioxide generated by respiration, we have evolved a specialised exchange surface for gas exchange within the breathing system. The efficiency of this system is further improved by ventilation of this exchange surface and by having an efficient blood supply - both of which maintain a suitable concentration gradient.
The lungs are part of the breathing system which is adapted for two functions:
- ventilation – the movement of air into and out of the lungs
- gas exchange – the 'swapping’ of gases between the alveolar air and the blood
Beneath the lungs is a muscular sheet called the diaphragm. This separates the lungs from the abdomen of the body and also plays a role in ventilating the lungs.
Within the lungs is a network of tubes through which air is able to pass. Air is firstly warmed, moistened and filtered as it travels through the mouth and nasal passages. It then passes through the trachea and down one of the two bronchiand into one of the lungs.
After travelling into the many bronchioles, it finally passes into some of the millions of tiny sacs called alveoli, which have the specialised surfaces for gas exchange.
ALVEOLI: - a specialised surface for gas exchange
Structural Adaptations of the alveoli to maximise the efficiency of gas exchange, the alveoli have several adaptations:
Structural Adaptations of the alveoli to maximise the efficiency of gas exchange, the alveoli have several adaptations:
- They are folded, providing a much greater surface area for gas exchange to occur.
- The walls of the alveoli are only one cell thick. This makes the exchange surface very thin - shortening the diffusion distance across which gases have to move.
- Each alveolus is surrounded by blood capillaries which ensure a good blood supply. This is important as the blood is constantly taking oxygen away and bringing in more carbon dioxide - which helps to maintain the maximum concentration gradient between the blood and the air in the alveoli.
- Each alveolus is ventilated, removing waste carbon dioxide and replenishing oxygen levels in the alveolar air. This also helps to maintain the maximum concentration gradient between the blood and the air in the alveoli.
Ventilation...The Mechanics of BREATHING:
When you inhale:
When you inhale:
- The intercostal muscles contract, expanding the ribcage outwards and upwards.
- The diaphragm contracts, pulling downwards to increase the volume of the chest.
- Pressure inside the chest is lowered and air is sucked into the lungs.
- The intercostal muscles relax, the ribcage drops inwards and downwards.
- The diaphragm relaxes, moving back upwards, decreasing the volume of the chest.
- Pressure inside the chest increases and air is forced out.