Intro to Infectious Disease CNS Pathology

Question 1

What does a neutrophil look like?

Answer 1

Light pink body with dark purple lobes

Question 2

What is the difference between acute and chronic infection?

Answer 2

Acute happens right away after injury and goes to 48 hours (consists of neutrophils). Chronic is everything after 48 hours.

Question 3

What changes happen in the vessels during acute inflammation?

Answer 3

-They become larger, more engorged, more leaky and it helps neutrophils leave vessel and enter tissue

Question 4

What is pus?

Answer 4

Neutrophils (can be seen on surface of meningitis brain)

Question 5

What does acute inflammation look like on the slide?

Answer 5

• Neutrophils that look like Mickey Mouse hats
• Looks very busy/many cells!
• Many different shapes/sizes of black dots

Question 6

What does a lymphocyte look like on a slide?

Answer 6

Large, egg shaped nucleus with no lobes

Question 7

When do lymphocytes enter the story?

Answer 7

After acute inflammation - during chronic inflammation

Question 8

What happens during chronic inflammation?

Answer 8

Consists of mononuclear cells like lymphocytes, monocytes, macrophages and plasma cells

Question 9

What three things can happen after acute infection?

Answer 9

1. You can heal
2. Neutrophils can stick around to form an abscess
3. Can progress to chronic inflammation

Question 10

What does chronic inflammation look like on a slide?

Answer 10

Uniform, round nuclei (dispersed equally)
Looks more uniform than acute
-Uniform, round, very dark spots
-Can see lymphocytes running along meninges, looks like a stamp
-Predominant cell = lymphocyte

Question 11

What is an abscess?

Answer 11

Circumscribed collection of pus - contains neutrophils and debris - exception to the rule that you only see neutrophils in the first 48 hours
-Looks greenish (neutrophils look green in abscess)

Question 12

What does an abscess look like on a microscopic level?

Answer 12

Dark purple containing neutrophils on one side, necrotic tissue to the right of that (mid-slide)
Right hand side - compressed brain tissue with engorged vessels running through it

Question 13

What is the primary cell that reacts to injury?

Answer 13

Astrocytes!

Question 14

What do astrocytes do after injury?

Answer 14

-Bulk of rebuilding following injury
-Carries nutrients into tissue
-Reforms meshwork after destruction
{process is called gliosis}

Question 15

Gliosis:

Answer 15

• Astrocyte reaction to injury

- Proliferation of astrocytes in response to injury

Question 16

What can you see better in astrocytes in gliosis?

Answer 16

Processes of astrocytes become more eosinophilic

Question 17

What is a microglial nodule?

Answer 17

• Microglia cells can proliferate in response to injury

- Microglial cells proliferate around nodules of tissue/neurons that are dying off

Question 18

What is the pathway of CSF?

Answer 18

-Created by choroid plexus cells, goes through all ventricles, goes through foramina of majondbie and bushka, then exits into superior sagittal sinus and gets reabsorbed through arachnoid granulations on cortex

Question 19

What is hydrocephalus? (communicating and noncommunicating?)

Answer 19

-Blockage anywhere in the CSF pathway
Communicating - block near arachnoid granulations, whole system will be enlarged
Noncommunicating - Block within ventricular system, part of system may be enlarged

Question 20

What can cause a hydrocephalus?

Answer 20

CNS infection/meningitis
-As meningitis was healing, it blocked the arachnoid granulations and made it difficult for the CSF to get out, so CSF backed up into ventricles and whole system enlarges