Digestion

Question 1

Intercellular digestion:

Answer 1

Food particles are engulfed by endocytosis and digested within food vacuoles.

Question 2

Extracellular digestion:

Answer 2

Is the breakdown of food particles outside cells.

Question 3

The four stages of food processing:

Answer 3

1. Ingestion
2. Digestion
3. Absorption
4. Elimination

Question 4

Ingestion:

Answer 4

• The act of eating.

Question 5

Digestion:

Answer 5

• Break down food into m.s small enough to absorbed.

- Involves enzymatic hydrolysis of polymers into their monomers.

Question 6

Absorption:

Answer 6

• Uptake is nutrients by body cells.

Question 7

Elimination:

Answer 7

• Undigested material passes out of the digestive compartment.

Question 8

The mammalian gastrointestinal tract (GI):

Answer 8

• Consists of alimentary canal and various glands that secrete juices.
• Food is pushed down digestive tract by peristalsis, rhythmic waves of contraction of smooth muscles in canal wall.
• Digestion begins in oral cavity.

Question 9

1. Oral cavity, 2. pharynx, 3. esophagus:

Answer 9

1. Food is lubricated. Digestion begins.
   - Teeth chew food into small particles that are exposed to salivary amylase, initially the breakdown of glucose polymers.
2. Throat region, junction opening both esophagus & windpipe (trachea).
3. Conducts food from pharynx down to stomach by peristasis.

Question 10

Nerve tissues:

Answer 10

• Built yo of neutrons.
• Senses stimuli and transmits signals throughout the animal.
• Consists of CNS, PNS & nerve cells.

Question 11

Muscle tissue:

Answer 11

• 40-50% of adult weight.
• Composed of muscle fibres capable of contracting in response to nerve signals.
• Three types: skeletal, cardiac and smooth.

Question 12

1. Skeletal, 2. Smooth, 3. Cardiac:

Answer 12

1. Attached to bones and skin through connective tissue.
2. Found in blood vessels, in digestive organs etc.
3. Found only in the heart.

Question 13

Different types of tissues:

Answer 13

1. Epithelial tissue
2. Connective tissue
3. Muscle tissue
4. Nerve tissue

Question 14

Epithelial tissue:

Answer 14

• Covers outside of body and lines cavities within body.
• Protects against microorg. and mechanical damage, prevents water loss.
• Makes food easier to slide down to gut, makes throat slippery.
• Keeps lungs clean, by having cilia in airways.

Question 15

Connective tissue:

Answer 15

• Supports and connects tissues and organs.
• Has packed cells, cartilage, bone and fat tissues.
• Collagen is important in these tissues.

Question 16

1. Tendons, 2. Ligament:

Answer 16

1. Connect bones to muscle.

2. Connect bones to bones, contains a lot of collagen threads.