Lecture 12 & 13 Questions (few ? q's) Flashcards
draw and label the organization of the CNS at 3 weeks, 4 weeks and 11 weeks
• At the 3rd week of development, the
human brain starts as a hollow tube
• By 4th week it specializes in the anterior
end
- ~4-6 weeks - MASSIVE increase in the # of cells & they are starting to move/migrate around into these new structures
- ~11 weeks - all of this has REALLY started to enlarge & start to BEND & there is a massive increase in the # of cells in the cerebrum
what’s the difference between white and grey matter?
• Grey matter: Unmyelinated cell bodies, axon terminals
and dendrites. Neuronal cell bodies are most often
found clustered together in groups called nuclei, or on
the outer surface of the brain as the cerebral cortex.
• White matter: Myelinated axons.
Where is each (white & grey matter) located in the brain? The Spinal cords?
Brain:
- white matter - inside
- grey matter - outside
Spinal Cord:
- white matter - outside
- grey matter - inside
what are the 4 main support/protective systems for the CNS?
- Bony skull and vertebral column
- Wrapped by three protective and
nourishing membranes called MENINGES - Cerebrospinal fluid (CSF)
- Blood-Brain barrier
Draw and label a cross section (coronal section) of the brain and skull, including the 3 meninges
3 meninges:
- Pia matter
- Arachnoid membrane
- Dura matter
diagrams in notes
list 3 places bleeding can occur between the skull and brain
Traumatic head injury can cause:
– epidural bleeding (between the skull and dura)*
– subdural bleeding (between the dura and arachnoid)
– subarachnoid bleeding (between the arachnoid
membrane and the pia mater)
what are the ventricles filled with?
Cerebrospinal fluid
what produces this (cerebrospinal fluid) substance?
produced by CHOROID PLEXUS in the ventricles
describe the pathway taken by this (cerebrospinal fluid) substance
- Produced by choroid plexus in the ventricles
- Exits brain thru foramen of Magendie and
foramen of Luschka (median and lateral) - Some circulates around the spinal cord, some
circulates into subarachnoid space - Enters arachnoid villi (granulations), and
crosses into venous blood.
what does the cerebrospinal fluid do?
- Helps maintain proper solute concentrations in the interstitial fluid surrounding neurons
- Helps remove waste
- Provides a cushion for the brain
What is the blood brain barrier
• Barrier between the interstitial fluid of the
brain and the plasma.
– Due to the specialized anatomy of blood
vessels in the CNS
– Keeps unwanted materials out, keeps wanted
materials in.
what glia cells help make the BBB
endothelial cells & astrocyte endfeet ?
Is heroin likely to be hydrophobic or hydrophilic?
“Heroin is lipophilic (“lipid-loving”), which means that it can cross the blood-brain barrier more efficiently than its hydrophilic (“water-loving”) metabolite, morphine. Heroin’s lipophilicity manifests itself as rapid Central Nervous System (CNS) absorption, leading to fast onset of effects.” ?
How does glucose get from the plasma to the extracellular fluid in the brain?
Glucose from blood enters the brain by a transport protein. Glucose is the primary energy substrate of the brain. Glucose transport protein (GLUT-1) is highly enriched in brain capillary endothelial cells. These transporters carry glucose molecules through the blood brain barrier. ?? ASK
what kinds of information are processed at the level of the spinal cord
Spinal cord has its own internal circuitry to mediate simple reflexes and generates complicated control programs, such as rhythmic patterns used for walking.