In this type of writing the authors main purpose is to inform the reader about a topic. which type of text is this

 Non-fiction or factual texts, writing in a expository way.

Explanation:

Non-fiction or factual texts include a wide range of texts in many forms. They can be: discussion texts, procedural texts, explanatory texts, persuasion texts, non-chronological reports or reccounts. In these type of texts, writing in a expository way wants to inform the readers about facts. Its aim is not to persuade or influence them. Descriptive writing can inform too, but it goes deeper describing many items for the audience to experience.

the aorta is the large artery leaving the heart branches into smaller arteries, which eventually branch into capillaries.the arteries carry oxygen and nutrients away from your heart, to your body's tissues. the capillaries are small, thin blood vessels that connect the arteries and the veins. the statement that arteries carry oxygen-rich blood to capillaries is true. veins on the other hand are blood vessels that take oxygen-poor blood back to the heart.