human nutrition Flashcards
what is nutrition
obtaining organic substances and mineral ions from which organisms gain their energy and raw materials for growth and tissue repair
define balanced diet
contains all 7 classes of food in correct amounts and proportions
provide right amount of energy to meet daily requirements
what is basal metabolic rate
energy consumed in a day to carry out basic processes like breathing
why do pregnant women need more energy
need protein for growing baby and iron to make new blood cells
why would a breast feeding mother need more energy
need enough energy for both baby and mom
need more protein, vitamins, minerals and liquid
name some foods included in vitamin A, its uses and its deficiency
carrots milks; good eyesight and health skin; poor night vision, unhealthy skin and sore eyes
name some foods included in vitamin B, its uses and its deficiency
yeast, cereals ; healthy nerves and growth ; beri-beri and retarded growth
what are the symptoms of survey and what causes it?
easy bruising and poor wound healing, gum bleeding and loosening teeth; vitamin c includes oranges which helps for tissues repair and resistance to disease
rickets is caused by the lack of _____. examples of this would be
vitamin D; butter and milk
causes strong bones
what are some examples and what does iron and what deficiency does is cause?
red meat; healthy rbc; rickets
what deficiency does calcium cause and what are examples of calcium
stiff brittle bones; milk and green vegetables
lack of —- gives the deficiency of goitre, and its symptoms are
iodine ; hyperactivity, weight loss despite increased in appetite
what is peristalsis?
rhythmic contraction of muscles that ripple along a tube
how does fibre prevent constipations?
good Bactria feed on fibre
bulk helps food moving down alimentary canal
muscles of gut wall contract squeezing the food along
lack of protein causes what deficiency
kwashiorkor and marasmus
symptoms of kwashiorkor
underweight, swelling in feet, thinning hair, flocky skin
symptoms of marasmus
chronic diarrhoea, dizziness, fatigue, rapid weight lost
symptoms of beri-beri
lethargy, weight loss, weakness and pain in limbs
how does having too much fats cause heart attack?
fatty acids deposits in arteries, walls become stiff and narrows, not enough blood can get through causing heart to run short of oxygen
another word for coronary heart disease is
atherosclerosis
what does obesity cause
heart disease, diabetes , strokes
join problems due to weight placed on legs
how to decrease chances of getting obesity
lower energy intake and increase output
define ingestion
taking of substances into body through mouth
define digestion
breakdown of large insoluble molecules into small molecules
what are the 2 types of digestion and define them
mechanical digestion: breakdown of large food particles into smaller pieces of food particles
chemical digestion: breakdown of large food molecules by action of enzyme
descrive the 4 types of teeth
incisor: chiseled shaped, sharp edge
canine: slightly more pointed than incisors
permolar: 2 points/cups, 1-2 roots
molar: 4-5 cups, 2-3 roots
what are the function of the 4 types of teeth
incisor and canine biting pieces of food
premolar: tearing and grinding
molar: chewing and grinding food
describe the tooth structure
hard layer of calcium call enamel, followed by a softer layer dentine
pulp is under structures with blood vessels and nerve - they supply cytoplasm in the dentine with food and oxygen
cementum is the connective tissue that binds roots of tooth to jaw
describe how tooth decay happens
caused by bacteria living on food residue in mouth. they form plaque
bacteria feed on sugar residue and respire, which causes them to produce acid
acid dissolves the enamel layer making the exposed dentine easier to dissolve
cavity is formed
describe and name the 2 gum diseases
gingivitis: irritation, redness and swelling of gingiva. caused by bacteria plaque that spread to gum and enamel
periodontist: gum infection that damages tissues and destroy bones that support teeth, can cause tooth loss
how to prevent tooth decay
avoid high intake of sugar at frequent intervals, frequent visits to dentist, brush teeth 2 times a day using fluoride toothpaste, rinse mouth regularly with mouthwash, use dental floss
how does teeth help with digestion?
breaks food into smaller pieces causing larger surface area. easier for enzymes to work on food in digestive system, helps soluble part of food dissolves
what enzyme is in saliva?
amylase
what does the mucus in saliva do?
help lubricated the passage of food bolus down the throat, helps food bind tgt to form bolus
where is mucus made?
goblet cells, which usually occur a long alimentary canal
what does the sphincter muscle do?
they close part of the alimentary canal to allow food to stay is 1 part of the tube before its allowed to move to the next
what muscle is used to stop food from entering the lungs?
epiglottis
where is saliva made and what is it made of
salivary glands; mucus and amylase
amylase breakdown what into what
starch into maltose
why does starch not get digested in the mouth
food is not in the mouth for a long enough time
what is peristalsis
rhythmic contractions of muscles that ripples along a tube
what is the use of the tongue
mix food with saliva and form food into bolus shape
helps with swallowing process by pushing the food to the back of the throat
what does the oesophagus do in the alimentary canal
takes food down the stomach
where is the oesophagus found
in front of the trachea
what does the epiglottis do
the piece of cartilage covers entrance of trachea to prevent food going into lungs
what makes peristalses easier
fibber bc makes bolus bulky
what is the stomach
it is a muscular bag with a lining that contains digestive glands
what does the glands of the stomach produces
hydrochloric acid, mucus, pepsin and rennin
what is chyme
it is the mixture of food and gastric juices
what is the use of mucus
protect the walls of the stomach from gastric juices
what is the use of hydrochloric acid in the stomach
to kill bacteria and provides acidic medium for action of enzymes
what is the word equation for digestion of protein
protein –> (pepsin) amino acid
what is the word equation for milk
caseinogen –> (rennin) casein
what happens to chyme?
it squeezes past a ring of muscles at the end of the stomach called the pyloric sphincter and enters the duodenum
what happens in the small intestine
digestion of food is completed
what are the 2 secretion and its uses that enter the duodenum
pancreatic juice- contains lipase , amylase and trypsin to break down fat starch and protein
bile juice- contains bile to emulsify fats to increase SA for action of lipase to work on and contains hydrogen carbonate to help neutralise acid from the stomach
where is bile produced and stores
liver; gallbladder
what happens in the ileum
enzyme - maltose, lactose and sucrose break down further into glucose
why do the enzyme break down into glucose for absorption
glucose can go through the membrane
what are the structures involved in absorption
villus, ileum, blood capillaries and lacteal
how does vile have large surface area
microvilli, a lot of villi, large network of capillaries, one cell thick, lacteal for absorption of fat soluble system
how is the small intestine adapted to its function
its very long which gives time for digestion and absorption
how is the blood capillaries adapted to its function
contains monosaccharides, amino acid, water minerals and vitamin to be taken to the liver????????
how is the lacteal adapted to its function
part of lymphatic system- fat absorbed into lacteal
what process is involved in absorption
osmosis, diffusion and active transport
what does capillaries do
absorb water soluble substances such as amino acid, glucose
what does lacteal do
partway for fat soluble substances to be absorbed
what is the pathway of digested nutrients once taken up by blood
small intestine - blood- hepatic portal vein - liver - hepatic vein - heart - aorta -body
what happens in the large intestine
left only water and fiber
travels through caecum into colon where more water and salt are absorbed
when it reaches rectum most substance which can be absorbed are in blood
food bacteria and dead cells from as faeces and passed out through the anus
what are the effects of diarrhoea
loss a lot of water and salt, causes tissues to stop workings and causes kidney failure and dehydration
ways to treat diarrhoea
oral rehydration therapy: replaces water and salt
and iv fluid: regulates temp and medium for biochemical reactions
how does cholera work
bacteria produces toxin that simulates cell lining of intestine to secret chloride ions
chloride ion accumulate in lumen of small intestine
water moves out of blood and into lumen of intestine
reabsorption due to osmosis
large quantities of water are lose by watery faeces
