Module 2: Animal Nutrition, Gas Exchange and Transport Flashcards
What is the largest organ in the human body?
The skin.
What is the role of the skin?
A protective barrier for our bodies.
How is death cell used beneficially in the epidermis tissues?
The dead cells form a thick, scaly mesh that is waterproof. This acts a barrier to microbes entering the body.
What is the outer layer of the skin?
The epidermis.
Are salts organic?
No.
What is the role of salts in the body?
They help nerves to function.
Are carbohydrates organic?
Yes.
Are lipids organic?
Yes.
Are proteins organic?
Yes.
Are vitamins organic?
Yes.
What is the role of carbohydrates in the body?
Energy.
What is the role of lipids in the body?
Energy storage, phosopholipids for cell membranes, insulation.
What is the role of proteins in the body?
Growth and repair of the body.
What is the role of vitamins in the body?
Help enzymes function, regualte all activities, assist metabolism and growth.
Why can you not just eat sugar?
Although sugar is very important for having energy, your body needs many other substances derived from foods that are not just sugar. A balanced diet is essential for healthy function.
Why is our digestive system like a donut?
The digestive system is essentially a hole going straight through our bodies, similar to the hole of a donut.
What substances are found in saliva?
Water, amylase (enzyme that digests carbohydrates), mucus.
What do muscles in the stomach do?
Churn up the food.
What do HCl and pepsin do inside the stomach?
HCl creates an acidic environment, pepsin breaks down proteins.
What organ releases bile salts?
The gallbladder.
Why are bile salts important?
They surround lipids to emulsify fats.
How is food absorbed into the body from the small intestine?
Capillaries in vili and microvilli absorb it predominantly through active transport.
What happens in the large intestine?
Reclaiming water from wastes, release vitamins into the body.
Why is the appendix larger in herbivores?
Because it contains many vital enzymes that are able to break down cellulose.
What is chemical disgestion?
The use of chemical reactions to break down food. Digestive enzymes catalyse many of these chemical reactions.
What is physical disgestion?
Breaking food down into smaller pieces without making chemical changes.
What role does the mouth play in chemical digestion?
Releasing saliva containing enzymes.
What role does the mouth play in chemical digestion?
Teeth cut and grind food, increasing surface area.
What role does the stomach play in chemical digestion?
Releases acid and enzymes.
What role does the stomach play in physical digestion?
Muscles churn the food.
What role does the small intestine play in chemical digestion?
Contains many different enzymes to break down down food.
What percentage of faeces is water?
75%
What percentage of faeces is live bacteria, dead cells, salts, mucus, fats, and proteins?
9%
What percentage of faeces is indigestible fibres?
8%
What percentage of faeces is dead bacteria?
8%
What organ store faeces before it is excreted?
The rectum.
Why is faeces brown?
The bilirubin from broken down red blood cells is processed by bacteria in the intestines, turning it a brown colour.
Why do doctors treat some patients with fecal transplants?
Diverse microflora in the gut is vital for healthy function. Doctors will transfuse microbes from a healthy person to an unhealthy one to increase the biodiversity in their gut.
What are microbes?
Bacteria, viruses, archaea, and unicellular fungi.
Why is diversity of microbes important for health?
They aid digestion and help prevent diseases.
Why do cows have four stomach chambers?
They had to adapt in order to successfully digest the tough cellulose in their high fibre diets.
What are ruminants
Animals with four stomach chambers. These are grazing herbivores such as sheep and cows.
Why does the length of digestive systems in different mammals vary according to their diet?
The length increases dependant on how difficult it is to digest the substances they consume. The longer the digestive system, the more difficult it is to digest the substances in their diet.
What are the names of cows’ four stomach chambers?
The rumen, reticulum, abomasum, and omasum.
What is the role of rumen and reticulum in the cows’ digestive system?
They contain microbes that are able to break cellulose.
Why do cows regugitate their food after passing through the first two stomach chambers?
So they are able to chew it further before it enters the second two chambers.
What is the role of omasum and abomasum in the cows’ digestive system?
Water is removed in the omasum and the abomasum contains digestive enzymes that further break it down.
Why do the microbes living in the rumen/reticulum are helpful to ruminants in gaining nutrition?
They break the cellulose down into smaller, less complex molecules that can be absorbed in the small intestine.
Rank each type of mammal from most easily digested diet to least easily digested diet.
Nectar-feeding herbivore, carnivore, omnivore, grazing herbivore.
What is the caecum?
A digestive organ that contains the nessesary enzymes for breaking down cellulose. It is also called the appendix in humans.
How is a carnivore’s digestive system different to that of a grazing herbivore’s?
It will have a much smaller caecum as it does not require the digestion of any cellulose.
How is the caecum different in humans to rabbits?
The rabbit’s caecum is much larger because, as a grazing herbivore, it is required to break down a lot more cullulose than humans.
What type of animal would benefit from an enlarged caecum?
Grazing herbivores.
Why does removing the appendix from humans not affect their digestive system?
Because our diets do not contain a lot of cellulose, so our appendix (caecum) is relatively inactive.
What is the epiglottis?
The flap that ensures gases pass into the trachea rather that the oesophagus.
What is the trachea?
The tube that enters the lung. It then splits into two (one going into each lung).
What are the bronchi?
The two tubes that stem from the trachea and go into each separate lung.