Lecture 8-Neurocytology 2

Question 1

What does a dark staining nucleus on the Golgi stain signify?

Answer 1

Less activity-DNA is tightly wound

Question 2

What are the leptomeninges?

Answer 2

the arachnoid and pia mater together

Question 3

What separates the dura mater from touching the periosteum of the vertebral arches?

Answer 3

epidural fat (adipose tissue)

Question 4

Where is the epidural space located in the spinal cord?

Answer 4

between the dural mater and periosteum of the vertebrae

Question 5

Where is the epidural space found in the skull?

Answer 5

between the skull and its periosteum

Question 6

Where is the subdural space found?

Answer 6

between the dura mater and the underlying arachnoid mater

Question 7

Tearing of bridging vein is most likely to cause hemorrhaging into what space?

Answer 7

subdural space

Question 8

Hemorrhaging of the middle meningeal artery is most likely to cause what type of hematoma?

Answer 8

epidural hematoma

Question 9

What cells are responsible for immunological surveillance and patrol in the brain?

Answer 9

microglia

Question 10

What type of glial cell are phagocytitic?

Answer 10

microglia

Question 11

What type of glial cell is activated by injury and quickly migrates to the site of damage to mediate the inflammatory reaction?

Answer 11

microglia

Question 12

Which type of glial cell produces myelin for the CNS?

Answer 12

oligodendrocyte

Question 13

How many cells can one oligodendrocyte myelinate in the CNS? What about Schwann cells in the PNS?

Answer 13

CNS- 1 Oligodendrocyte can myelinate several cells

PNS- 1 Schwann cell can only myelinate one cell

Question 14

What is the function of an astrocyte?

Answer 14

• provide structural support
• monitor ionic environment around neurons
• form scar in regions of CNS damage
• form the glial limitans

Question 15

What glial cell contains the Glial Fibrillary Acidic (GFAP) intermediate filaments?

Answer 15

astrocytes

Question 16

What is the glial limitans?

Answer 16

the astrocyte lining around blood vessels and pial surfaces in the brain

Question 17

What type of glial cell lines blood vessels in the brain?

Answer 17

astrocytes

Question 18

List the types of neuroglia.

Answer 18

Microglia- immune response
Macroglia
astrocytes-structural support, monitor env.
oligodendrocytes- myelinate

Question 19

What are the 2 layers of the dura mater?

Answer 19

periosteal layer

meningeal layer

Question 20

Which meningeal layer IS pain sensitive?

Answer 20

dura mater

Question 21

What creates the dural sinuses?

Answer 21

separations in the periosteal and meningeal layers of the dura mater

Question 22

What is the name for the dura between the two cerebral hemispheres?

Answer 22

falx cerebri

Question 23

What is the name for the dura between the cerebrum and the cerebellum?

Answer 23

tentorium cerebelli

Question 24

What passes through the tentorial notch in the tenorium cerebelli?

Answer 24

brain stem

Question 25

What meningeal layer follows the contour of the brain?

Answer 25

pia mater

Question 26

What is a cistern?

Answer 26

a large subarachnoid space | caused by discontinuities b/t the arachnoid/dura contour and the pia/brain contour

Question 27

List 3 cisterns found in the brain.

Answer 27

interpeduncular pontine magna (inferior to cerebellum)

Question 28

What is the function of the CNS?

Answer 28

cushions the brain in response to external forces

Question 29

What is the function of the ependymal cells and where are they found?

Answer 29

ependymal cells line the cerebral ventricles and central canal of the spinal cord move their cilia to contribute to the flow of CSF

Question 30

What is the choroid plexus?

Answer 30

specialized vascular structure that secretes CSF

Question 31

Where are the 4 choroid plexuses found?

Answer 31

1 in each of the lateral ventricles 1 in the third ventricle 1 in the forth ventricle

Question 32

What is the function of the arachnoid granulations?

Answer 32

transport CSF into the dural sinuses

Question 33

How is CSF drained into the venous system?

Answer 33

via the arachnoid granulations

Question 34

Describe the flow of CSF.

Answer 34

lateral ventricles->3rd ventricle->cerebral aqueduct->4th ventricle->cerebellomedullary cistern->arachnoid granulations-> dural sinuses

Question 35

Where does CSF go after it leave the 4th ventricle?

Answer 35

cerebellomedullary cistern

Question 36

Where are the foraminae of Luschka Magendie found?

Answer 36

between the 4th ventricle and cerebellomedullary cistern

Question 37

What can decreases in flow or blockages in CSF lead to?

Answer 37

hydrocephalus

Question 38

What is meant by a circumventricular organ?

Answer 38

regions in the brain where there is no blood brain barrier (pineal body, pituitary gland, area postrema and the subfornical region)

Question 39

List the 4 areas of the brain where the BBB does not exist.

Answer 39

pineal body pituitary gland area postrema subfornical region (aka circumventricular organs)

Question 40

What are tanycytes?

Answer 40

specialized ependymal cells that surround and isolate the circumventricular regions where there is no BBB

Question 41

List 4 areas in the brain where tanycytes would be found?

Answer 41

1. Pineal body 2. Pituitary gland 3. Area postema 4. Subfornical region (these are the circumventricular regions that lack a BBB)

Question 42

What forms the BBB?

Answer 42

- Endothelial cells joined by tight junctions - Pericytes in the basement membrane to contribute to the structural integrity - Astrocytic and feet that create the glial limitans surround the blood vessels

Question 43

What types of substances can diffuse through the BBB?

Answer 43

lipophilic substances

Question 44

What type of substances used facilitated transport to get through the BBB?

Answer 44

glucose

Question 45

What types of substances use active transport to get through the BBB?

Answer 45

everything except lipophilic substances and glucose

Question 46

What is the area postrema?

Answer 46

area of the medulla that monitors blood, detects toxins and initiates vomiting reflex (circumventricular organ surrounded by tanycytes)

Question 47

What is the function of the subfornical organ?

Answer 47

monitor osmolarity of blood (one of the 4 circumventricular organs in the brain surrounded by tanygytes)

Question 48

List the 3 Brain barriers.

Answer 48

Arachnoid Barrier- tight jxn in arachnoid lining cells Blood-CSF Barrier- tight jxn b/t choroid plexus cells Blood-Brain Barrier-tight jxn b/t endothelial cells

Question 49

Why is sleep beneficial to waste removal from neurons?

Answer 49

New research has shown that neurons shrink during sleep which allows more room for CSF to flow and remove waste from neurons