HUMAN NUTRITION Flashcards
What is nutrition?
The way in which an organism obtains and uses it’s food.
Autotroph
An organism that makes its own food.
Heterotroph
An organism that consumes food from the environment.
What are the three groups of heterotrophs?
Carnivore
Herbivore
Omnivore
What is an carnivore?
Only eats meat
What is an herbivore?
Only eats plants
What is an omnivore?
Eats both plants and meat
What is digestion?
Physical and chemical breakdown of food into soluble particles.
What is the digestive system?
It’s where food breakdown and absorption occurs.
What are the glands that secrete digestive juices?
Salivary glands, pancreas and liver.
What are the main events in nutrition?
Ingestion
Digestion
Absorption
Egestion
What is ingestion?
Food is taken in through the mouth.
What is absorption?
Digested food passes into the bloodstream (through the walls of the intestines)
What is egestion?
Removal of unabsorbed waste from the body.
Describe physical digestion in the mouth.
Teeth and chewing physically break down food.
How many teeth does an adult have?
32
What are the 4 types of teeth and where are they located in the mouth/shape and what is their function?
Incisors - front of the mouth, cut food
Canines - pointed, grip, and tear food
Premolars - large flat surface, crush, and grind food
Molars - large flat surface - crush, and grind food
What is the dental formula?
I 2/2 C 1/1 P 2/2 M 3/3 = 16
Describe how you’d draw the teeth.
Incisor = half square
Canine = V
Premolar = gentle W
Molar = larger gentle W
Describe chemical digestion in the mouth.
Salivary glands produce saliva that is made of water, enzymes (amylase), mucus, and salt.
What else does saliva contain?
Lysozyme that kills bacterial cells.
What is the optimum Ph in the mouth?
7
What does mucus and water do?
Moisten food and make it easier to swallow.
What does salivary amylase do?
Begins digestion of starch in the mouth.
What is food chewed into?
A ball called bolus.
What is the oesophagus?
A muscular tube that carries food from the pharynx to the stomach. Muscular contractions carry the food down.
What is peristalsis?
Contraction and relaxation of the muscular wall of the gut to move food along.
How does mechanical digestion occur in the stomach?
Peristalsis mixes the food with HCI and digestive enzymes (food is churned)
Peristalsis in the small intestine.
A slower rate allows food more contact time with enzymes and walls of the intestine for absorption.
Peristalsis in the large intestine.
Vey slow peristalsis to allow more absorption of water.
