Tell about PNS using a Concept Map, express your opinion (if you know any interesting facts about PNS you may also share with your class-mates)

 

Summary

Look through the text quickly. Does it contain any interesting information for you?

What is the main idea of the text? Is it reflected in the title of the text?

Read the text. Divide it into logical parts. Give the title to each part.

Cerebrospinal fluid

The space surrounding the organs of the CNS is filled with a clear fluid known as cerebrospinal fluid (CSF). CSF is formed from blood plasma by special structures called choroid plexuses¹. The choroid plexuses contain many capillaries lined with epithelial tissue that filters blood plasma and allows the filtered fluid to enter the space around the brain.

Newly created CSF flows through the inside of the brain in hollow spaces called ventricles and through a small cavity in the middle of the spinal cord called the central canal. CSF also flows through the subarachnoid space² around the outside of the brain and spinal cord. CSF is constantly produced at the choroid plexuses and is reabsorbed into the bloodstream at structures called arachnoid villi³.

Cerebrospinal fluid provides several vital functions to the central nervous system:

1. CSF absorbs shocks between the brain and skull and between the spinal cord and vertebrae. This shock absorption protects the CNS from blows or sudden changes in velocity (speed), such as during a car accident.
2. The brain and spinal cord float within the CSF, reducing their apparent weight through buoyancy⁴. The brain is a very large but soft organ that requires a high volume of blood to function effectively. The reduced weight in cerebrospinal fluid allows the blood vessels of the brain to remain open and helps protect the nervous tissue from becoming crushed under its own weight.
3. CSF helps to maintain chemical homeostasis within the central nervous system. It contains ions, nutrients, oxygen, and albumins that support the chemical and osmotic balance of nervous tissue. CSF also removes waste products that form as byproducts of cellular metabolism within nervous tissue.

¹choroid plexus – хороидноесплетение

²subarachnoid space – подпаутинное (субанархноидальное) пространство

³arachnoidvilli – анарохнаидальные грануляции (пахионовы грануляции)

⁴buoyancy – плавучесть, выталкивающая сила

 

 

 

Underline key word (word combinations) in each abstract.

What sentences in each abstract can be missed without changing the general meaning of the abstract?

Complete the conceptual map with key words from the text.

 

 

Choose several verbs from the text you can use for making summary.

44. Using the conceptual map of the text and key words tell about CSF using the following chart and expressions:

The title of the article.

The text is headlined…

The headline of the text I have read is…