Nutrition in humans
Modes of nutrition
autotrophic heterotrophic
autotrophs heterotrophs
photosynthesis chemosynthesis holozoic saprophytic parasitic
- green - some - animals - fungi - animals
plants, bacteria - herbivores - putrefying - plants
algae @deepoce - carnivores bacteria - fungi
- bacteria w/ an - omnivores (external - bacteria
chlorophyll (H2S as energy (take in digestion: (obtain nutrient
(CO2 and H2O source) complex food, absorb soluble and shelter from
as energy internal nutrients thru host)
source) digestion) body surface)
Process of human nutrition
1. Ingestion: take in food thru mouth
2. Digestion: complex large insoluble molecules > simple small soluble molecules
- significance
- humans intake large complex molecules (starch, proteins, lipids) > need to be
broken down before cells can use
- differentially permeable cell membrane
- large complex food molecules X pass thru
- need to be broken down into small soluble molecules to enter
cells
- food molecules structurally diff from molecules make up our body
- need to break down, use the small molecules to build our own
molecules (eg. human proteins)
3. Absorption: digested food molecules enter circulatory system blood
4. Assimilation: absorbed food molecules used for metabolism @cells
5. Egestion: undigested unabsorbed material removed from body as faeces
, Nutrition in humans
Alimentary canal Digestive glands
- Long muscular - Produce
tube (mouth digestive
>...> anus) juices
- Food pushed in - Released into
1 direction alimentary
- Digested + canal to aid
absorbed digestion
- Undigested
unabsorbed
> egested
Ingestion
Mastication: chewing action by teeth in mouth cavity
- Break down solid foods into smaller pieces mechanically
- ↑ SA for digestive enzymes to act on
- facilitate swallowing
Types of teeth in humans
- Upper jaw and Lower jaw: nos + types + arrangement are the same
- upper jaw: fixed VS lower jaw: movable (attached w/ joint)
- LHS and RHS: arrangement is symmetrical (midline between incisors)
Incisor (4 upper, 4 lower) Canine KEENAI (2 upper, 2 lower)
- 1 root - 1 root
- Chisel-shaped with flat sharp edges - Pointed and curved
- For biting and cutting food - For tearing flesh
- Carnivores (lions and tigers)
have well developed canines
- pointed: killing prey
- curved backwards:
holding prey and
tearing flesh
- carnassial teeth
Premolar (4 upper, 4 lower) Molars (6 upper, 6 lower)
- 1 or 2 roots - 2 or 3 roots
- Broad chewing surface with cusps - Broader chewing surface than
- For crushing and grinding food premolar with more cusps
- The largest in size
- For crushing and grinding food
Modes of nutrition
autotrophic heterotrophic
autotrophs heterotrophs
photosynthesis chemosynthesis holozoic saprophytic parasitic
- green - some - animals - fungi - animals
plants, bacteria - herbivores - putrefying - plants
algae @deepoce - carnivores bacteria - fungi
- bacteria w/ an - omnivores (external - bacteria
chlorophyll (H2S as energy (take in digestion: (obtain nutrient
(CO2 and H2O source) complex food, absorb soluble and shelter from
as energy internal nutrients thru host)
source) digestion) body surface)
Process of human nutrition
1. Ingestion: take in food thru mouth
2. Digestion: complex large insoluble molecules > simple small soluble molecules
- significance
- humans intake large complex molecules (starch, proteins, lipids) > need to be
broken down before cells can use
- differentially permeable cell membrane
- large complex food molecules X pass thru
- need to be broken down into small soluble molecules to enter
cells
- food molecules structurally diff from molecules make up our body
- need to break down, use the small molecules to build our own
molecules (eg. human proteins)
3. Absorption: digested food molecules enter circulatory system blood
4. Assimilation: absorbed food molecules used for metabolism @cells
5. Egestion: undigested unabsorbed material removed from body as faeces
, Nutrition in humans
Alimentary canal Digestive glands
- Long muscular - Produce
tube (mouth digestive
>...> anus) juices
- Food pushed in - Released into
1 direction alimentary
- Digested + canal to aid
absorbed digestion
- Undigested
unabsorbed
> egested
Ingestion
Mastication: chewing action by teeth in mouth cavity
- Break down solid foods into smaller pieces mechanically
- ↑ SA for digestive enzymes to act on
- facilitate swallowing
Types of teeth in humans
- Upper jaw and Lower jaw: nos + types + arrangement are the same
- upper jaw: fixed VS lower jaw: movable (attached w/ joint)
- LHS and RHS: arrangement is symmetrical (midline between incisors)
Incisor (4 upper, 4 lower) Canine KEENAI (2 upper, 2 lower)
- 1 root - 1 root
- Chisel-shaped with flat sharp edges - Pointed and curved
- For biting and cutting food - For tearing flesh
- Carnivores (lions and tigers)
have well developed canines
- pointed: killing prey
- curved backwards:
holding prey and
tearing flesh
- carnassial teeth
Premolar (4 upper, 4 lower) Molars (6 upper, 6 lower)
- 1 or 2 roots - 2 or 3 roots
- Broad chewing surface with cusps - Broader chewing surface than
- For crushing and grinding food premolar with more cusps
- The largest in size
- For crushing and grinding food
