Lecture 12 - Nervous System Organization

Question 1

What is the cerebrospinal fluid (CSF) and where is it located?

Answer 1

It circulates from the ventricles into the subarachnoid space. It cushions the brain and cleans the tissue

Question 2

Cerebrospinal fluid (CSF) circulation

Answer 2

1. CSF production occurs in the ventricles (by ependymal cells)
2. CSF drains wastes (toxins, poisonous buildup) from CNS tissue through glymphatic pumping
3. It then enters the subarachnoid space, cushioning the impact between the CNS and skull
4. The CSF then returns to the bloodstream

Question 3

Blood brain barrier (BBB)

Answer 3

Restricts the transport of water and molecules between the blood and CNS because of its tight epithelium

Only lipophilic or hydrophilic molecules with dedicated transport proteins can reach the CNS

Question 4

Functional MRI (fMRI)

Answer 4

Scan estimates activity in different CNS locations by measuring the relative amount of local blood flow under different conditions

More blood flow = area “lights up” on scan

Question 5

Cervical

Answer 5

Responsible for upper limb

Question 6

Thoracic

Answer 6

Responsible for trunk

Question 7

Lumbar

Answer 7

Responsible for lower limb

Question 8

Sacral

Answer 8

Responsible for lower limb/ano-genital region

Question 9

Dorsal root (afferent axons)

Answer 9

Carry information from sensory receptors found all over the body towards the central nervous system

Question 10

Ventral root (efferent axons

Answer 10

Carry motor information away from the central nervous system to the muscles and glands of the body in order to initiate an action