BIO 201 - Study Guide :Central Nervous System

18.What region comprises the bulk of the volume of the human brain?
 The CEREBRUM comprise 83% of the bulk of the volume of the human brain
19. Explain the difference between a gyrus and a sulcus.
 Gyrus – folds; mountain
 Sulcus – grooves; valley
20.What is a fissure in the brain?
 Fissure – divides cerebral hemispheres in half
21. Explain the difference between nuclei and tracts in the brain.
 Nuclei – deeper masses of gray matter
 Tracts – bundles of axons (white matter)
22. Compare and contrast grey and what matter in the brain.
 Gray matter = neuron cell bodies, dendrites, and synapses
o Forms cortex over cerebrum and cerebellum
o Forms nuclei deep within the brain
 White matter = bundles of axons
o Forms tracts that connect parts of brain
23. List the three meninges and the two spaces. Which of these three is located deepest
(closest to the brain)? Under which layer does CSF circulate? Under which of these
are the dural sinuses located? Where would a subdural hematoma occur if someone
got hit in the head?
 Dura mater – outermost, tough membrane
o Outer periosteal layer against bone
o Where separated from inner meningeal layer forms dural venous sinuses
draining blood from brain
o Epidural space filled with fat in low back
 Epidural anaesthesia during childbirth
 Subdural space
 Arachnoid layer
o Subarachnoid space
o The Cerebrospinal fluid (CSF) circulates here
 Pia mater
o Deepest layer
 A subdural hematoma would occur in the space between the dura mater and the
arachnoid layer of the meninges
24. Describe the pathophysiology of meningitis? Make sure to include where you would
insert a needle during a spinal tap.
 Meningitis
o Inflammation of the meninges
o Usually a disease of infancy and childhood – between 3 months and 2
years of age
o Bacterial and virus invasion of the CNS by way of the nose and throat
o Signs include high fever, stiff neck, drowsiness and intense headache and
may progress to coma
o Diagnose by examining the CSF
 Lumbar puncture (spinal tap)
 A needle is injected posteriorly into the epidural space at the C7 level