Digestive system Flashcards
DIGESTIVE SYSTEM
the alimentary canal along with other digestive organs is known as the digestive system
STEPS IN NUTRITION
ingestion digestion absorption assimilation excretion
digestion in higher organisms
specialised organs are present for digestion
digestion in single-celled organisms
all the steps take place in a single cell. eg amoeba
INGESTION
process of taking in food. occurs through the mouth in humans
DIGESTION
breakdown of complex food particles into simple molecules with help of enzymes.
WHAT ARE ENZYMES?
special molecules which help in the breakdown of food into simpler molecules during digestion.
ABSORPTION
the process by which digested food passes through the walls of the intestine and enters the blood
ASSIMILATION
the utilisation of absorbed food by the body for energy growth and repair
the absorbed food is carried to all parts of the body by
blood
EGESTION
the process of removal of undigested food from the body. in humans it occurs through the anus
TEETH
hard structures present in the mouth cavity specialised for holding prey and breaking food.
DENTITION
arrangement of teeth in the jaw
TYPES OF DENTITION
heterodont- all teeth have the same shape and size. eg. fish, reptiles, amphibians.
homodont- teeth are or different shapes and sizes. eg. humans, mammals.
TYPES OF TEETH AND FUNCTION & NO.
- incisors- 4- cutting and biting
- canines-2- tearing
- premolars- 4- chewing and grinding
- molars-6- chewing and grinding
STRUCTURE OF TOOTH
- crown- the part of the tooth above the gum
- neck- part of the tooth level to the gum
- root- part buried in the gum
ENAMEL
the white part of the tooth which is the hardest substance present in the body.
contains calcium salts
DENTINE
solid tissue present inside the enamel. contains strands of cytoplasm passing through it
PULP CAVITY
CAVITY CONTAINING BLOOD CAPPULARIES AND NERVES ENCLOSED IN THE DENTINE.
CEMENT
the thin layer of bonelike material covering the dentine. hold the tooth firmly in the jaw.
ORGANS OF THE DIGESTIVE SYSTEM
- mouth
- oesophagus
- stomach
- small intestine
- large intestine
- anus