05- nutrition in humans

Question 1

definition of nutrition

Answer 1

process by which organisms obtain food and energy for growth, repair and the maintenance of the body.

Question 2

nutrition processes in humans

Answer 2

1. feeding/indigestion - consuming food
2. digestion - large food molecules are broken down into smaller, soluble molecules that can be absorbed into the body cells
3. absorption - nutrients more from the small intestine into the bloodstream
4. assimilation - nutrients are used by cells to provide energy or to make new cytoplasm for growth
5. egestion - undigested matter is removed from the body

Question 3

function of the mouth and buccal cavity

Answer 3

• helps to break large pieces into smaller pieces (increases surface area of the food so that enzymes can act on it)
• tongue mixes the food with saliva and moves the food to the back of the mouth during swallowing

*buccal cavity is inside the mouth, beginning of the alimentary canal.

Question 4

what is the pharynx?

Answer 4

the part of the alimentary cana that connects the buccal cavity to the oesophagus and the larynx (voice box)
- also leads to the trachea (windpipe)

Question 5

function of the oesophagus

Answer 5

passes through the thorax (chest) and joins the mouth to the stomach

-contains 2 muscles: longitudinal (outer) & circular (inner)
- both sets of muscles produce long and slow contractions which move food along the guy via peristalsis

Question 6

what is peristalsis?

Answer 6

peristalsis is the rhythmic wave-like muscular contractions in the wall of the alimentary canal

Question 7

functions of the peristalsis

Answer 7

• allows food to be mixed with digestive juices, and also punches/propels the food along the gut