Digestive systems

What type of digestion does Hydra perform?

A combination of extracellular and intracellular digestion.

What is the main function of the gastrovascular cavity in flatworms?

It allows for digestion and absorption of food products throughout the organism.

What are the two openings of a tube gut in higher order animals?

One opening for ingestion and another for egestion.

What is the function of salivary amylase?

It breaks down starch into maltose.

What initiates peristalsis in the oesophagus?

Waves of contraction of muscles within the gut wall.

What is chyme?

A semi-liquid produced in the stomach at the end of digestion.

What do zymogenic cells secrete?

Pepsinogen, which is converted to pepsin for protein digestion.

What is the role of Brunner's glands in the duodenum?

They secrete alkaline fluid and mucus to neutralize acid chyme.

What is the main site of absorption in the human digestive system?

The ileum.

What do the villi in the small intestine do?

They increase the surface area for digestion and absorption.

What happens in the colon of the large intestine?

Water and mineral salts are absorbed, and vitamins produced by microorganisms are absorbed.

What stores bile produced by the liver?

The gall bladder.

What is one of the endocrine functions of the pancreas?

Secreting hormones like insulin and glucagon.

What does the liver store excess glucose as?

Glycogen.

What is the role of sphincter muscles at the anus?

They control the timing of defecation.

What is the role of mucus in the stomach?

To protect the stomach lining from self-digestion by gastric juice.

How do food fragments enter the cells lining the gut in Hydra?

By phagocytosis.

What is the primary chemical digestion in the stomach aided by?

Enzymes and hydrochloric acid.