Animal nutrition Flashcards
Describe the swallowing process
- The teeth & salivary glads digest the food into a bolum
- The tongue pushes the bolus backwards into the mouth
- The UES opens up the oesophagus
- The epiglottis covers up the trachea/windpipe (to stop choking)
- The soft palate closes up the nasal cavity
- The bolus is swallowed
What are the relevant features of the mouth for swallowing?
You must know where each one is situated
- Teeth
- Salivary glands
- Mucus
- Amylase
- Water - Tongue
- Upper oesophagal sphincter (UES)
- Nasal Cavity
- Epiglottis
- Soft Palate
What is the Oesophagus?
Muscular organ that transports food to the stomach
What is the stomach?
Muscular organ where digestive enzymes break down the food
What is the small intestine?
Where food is mixed up with digestive enzymes & bile
Where digested food is absorbed into the bloodstream
What is the liver?
Where bile is produced
What is the gall bladder?
Where bile is stored
What is the pancreas?
Where enzymes are produced
What is the large intestine?
Where water is reabsorbed from the undigested waste
What is the Rectum?
Where faeces is stored
What is the anus?
Where faeces leaves the body
Which enzyme breaks down starch and glycogen, what it breaks them down to, and where it is produced.
Amylase, in the salivary glands, breaks down to Maltose
Which enzymes break down protein, what they break them down to, and where they are produced.
Protease (Pepsin in the stomach), (trypsin in the pancreas) breaks down to amino acids
Which enzyme breaks down lipids, what it breaks them down to, and where it is produced.
Lipase, in the pancreas, breaks down to glycerol and fatty acid chains
Which enzymes break down disaccharides, what they break them down to, and where they are produced.
Sucrose, Maltose, Lactose, in the pancreas, break down to simple sugars i.e. glucose
What is the alimentary canal?
The pathway through which food travels, including undigested waste, from the mouth to the anus
What is Mastication?
The process of cutting up and mixing food.
How does the oesophagus move food?
The oesophagus moves food using the longitudinal and circular muscle contractions. The process is called peristalsis. This also happens in the small intestine.
What is the purpose of the hydrochloric acid in the stomach?
It kills pathogens (bacteria) and establishes the right pH for pepsin to develop.
What chemicals are released into the intestines and why?
Enzymes such as amylase, protease (specifically trypsin) and lipase are released to break down nutrients. Bile is added to the mixture to emulsify fats (separate them). In addition, sodium hydrogen carbonate is released into the small intestine to balance the acidity from the stomach.
How do the small soluble molecules of nutrients move into the blood from the small intestines?
In the ileum, the biological molecules pass through the wall, so are absorbed, into the bloodstream, if they are small enough. The water moves by diffusion, osmosis and active transport.
Def. Ingestion
The process of taking food into the mouth
Def. Digestion
- Mechanical
- Chemical
Process where nutrients are broken down from large insoluble to small soluble molecules
Mechanical - Food is broken down physically. (No chemical change in the nutrients)
Chemical - Food is broken down by enzymes. (Chemical change, Polymers are broken down into monomers)
(to be absorbed into the bloodstream)
Def. Absorption
The movement of nutrients from the small intestine to the bloodstream
Def. Assimilation
Process of body cells taking in biological molecules (lipids, glucose, protein), into cells to be used in cell processes.
e.g. glucose for respiration
Def. Egestion
Removal of undigested waste
Name the body parts involved in the digestive system
- Mouth
- Salivary glands
- Oesophagus
- Liver
- Stomach
- Pancreas
- Gall bladder
- Small intestine (duodenum & ileum)
- Large intestine
- Anus
How many teeth of each type does a human have?
32 teeth in total
- Incisors x8
- Canines x4
- Premolars x8
- Molars x12
What are the characteristics and uses of Incisors?
Sharp: To cut and slice harder food (e.g. apples)
Has 1 root
What are the characteristics and uses of Canines?
Sharp: To tear/rip, and hold onto meat
Has 1 root
What are the characteristics and uses of Premolars?
Ridged: To chew and grind (increases food surface area)
Has 2 roots
What are the characteristics and uses of Molars?
Wide & ridged: To chew and grind (increases food surface area)
Has 3 roots
What are the different parts of the human tooth?
- Enamel
- Dentine
- Pulp
- Gums
- Cement
- Nerves
Def. Enamel
Hardest tissue in the body, produced by tooth forming cells. Cannot be renewed.
Def. Dentine
Major part of tooth. Hard and made of calcium salts deposited on collagen fibres. Series of canals extend to pulp cavity.
Def. Cement
Similar to dentine but no canals. Anchors the teeth to the jaw.
Def. Gum
Covers junction between enamel and cement.
How can you prevent tooth decay?
- Eating low sugar foods
- Regular & effective teeth brushing to prevent build up of plaque
- End meals with vegetables or fruit and water
What does fluoride do, and why is it put in water? Why do people not like this?
- Reduces risk of tooth decay
- Dental costs fall, and general health improves
- Can make people develop grey or brown spots on teeth
What are the steps to tooth decay and what causes them?
1) Healthy tooth with plaque - Bacteria use sugars for respiration and make a sticky substance to trap food, to form a plaque
2) Decay in enamel - Bacteria conerts sugar to acids to remove calcium. Happens slowly and is painless as enamel is solid
3) Decay in dentine - Happens faster as dentine is softer, and is more painful
4) Decay in pulp - Acids reach nerve, very painful
What are the 7 components of a balanced diet
- Carbohydrates
- proteins
- vitamines (A, C, D)
- minerals (Iron, magnesium, calcium)
- lipids
- fibres
- water
Give the reasons why we need :
Carbohydrates
To produce fast energy to make the body function.
Give the reasons why we need :
lipids
Store of energy, helps build cell membrane
Give the reasons why we need :
Vitamin A
We need it for better vision, growth, cell division, reproduction and immunity
Give the reasons why we need :
Vitamin C
What would a deficiency of this cause?
Essential part to making collagen protein (to make gums, skin, hair and bones)
A deficiency causes scurvy.
Give the reasons why we need :
Vitamin D
What would a deficiency cause?
Helps the body absorb calcium, which is required for strong bones and teeth
Deficiency causes rickets.
Give the reasons why we need :
Iron
What would an over/underdose cause?
Needed to make haemoglobin
deficiency -> anemia
Give the reasons why we need :
Magnesium
Muscle and nerve function and production
Give the reasons why we need :
Calcium
Needed for strong teeth and bones
Give the reasons why we need :
Fibre
Provides bulk for large intestine to push waste through itself. Therefor helps food travel smothly through large intestine.
Give the reasons why we need :
Water
Neded for chemical reactions to take place in cells
Give the reasons why we need :
Protein
Growth and repair
Def. Nutrition
Taking in (absorption) of nutrients (organic substances) and mineral ions (from materials). These are used for energy, growth and tissue repair and health.
They have to be absorbed and assimilated.
What does a balanced diet consist of?
All food groups in correct proportions
Def. Malnutrition
Deficiency or excess of key nutrients
Which factors affect a balanced diet?
- Activity level
- pregnancy or breastfeeding
- age
- money
- dietary restrictions such as :
- religion
- choice/personal conviction
- medical, such as :
- intolerances
- allergies
- diabetes - gender
- muscle mass
- job/occupation
What are the 2 functions of Bile?
1) Neutralise stomach acid (to make the pH level suitable for enzymes)
2) Emulsifies fats (turns fat into fat droplets)
How does the process of breaking down fats (lipids) work?
- Bile emulsifies fats, turning them into fat droplets (mechanical)
- Lipase can now efficiently break don the lipids into fatty acid and glycerol (chemical)
Why do fats need to be emulsified?
Fats do not mix well with watery liquids (and our body is mainly composed of water), so the fats need to be separated apart (emulsified) so that the lipase can break down the fats without a problem.
What are Villi?
Many upright structures that line the walls of the small intestine and help take in nutrients.
They increase the surface area of the small intestine.
Def. Microvilli
On the top of each Villus, increases surface area even more (20 times)
Def. Microvilli
On the top of each Villus, increases surface area even more (20 times)
Def. Goblet cell
Secretes mucus to protect lining from body‘s own digestive fluids
Def. Epithelium
1 cell thin membrane (includes microvilli and golbet cells) to let nutrients pass.
Def. Capillary network
Connects to the bloodstream and transports glucose and amino acids
Def. Lacteal
A tube that transports fatty acids and glycerol
Def. Gland
Group of cells that work together produce digestive enzymes
What are the three methods of absorbtion in the Ileum?
- Osmosis
- Diffusion
- Active transport
What is rickets?
Poor bone development caused by lack of vitamin D.
Symptoms: Weak bones/underdeveloped bones/soft bones
Treatment: Vitamin D (Via sunlight and foods e.g. eggs, fish and butter) and calcium
What is scurvy?
It is a vitamin C deficiency.
Symptoms: Gum pain, exhaustion, tooth loss
Treatment: Vitamin C supplements
What is starvation?
Taking in less energy than is used up, causing the body to use it’s long term energy supplies, and everntually muscles and bones.
What is constipation?
Lack of fibre in a diet, increases risk of diseases in intestine
What is obesity and what can it cause?
Taking in more energy than is used. Extra energy is stored as fat, causing weight gain and increasing chance of diabetes.
What is Kwashiorkor and what is Marasmus?
Both caused by lack of protein.
Symptoms of Kwashiorkor: Underweight, swelled abdomen
Marasmus is also caused by the lack of energy.
Symptoms of Marasmus: Extremely low body weight, very feeble
