Brain Pt 1. Flashcards
How many total neuroglia are found in the brain?
10-50 trillion.
How many neurons are there in the brain?
100 billion.
How many synapses does each neuron form with another neuron in the brain?
1000 for a total of 10^15 synapses.
What does the average human brain weigh?
3 lbs. .
*2% of body weight.
What composes the CNS along with the brain?
The spinal cord.
Number of cranial nerves?
12.
What embryonic structure did the brain develop from?
Neural tube.
What are the 3 early embryonic portions of the brain?
- Prosencephalon (Forebrain).
- Mesencephalon (Midbrain).
- Rhombencephalon (Hindbrain).
What is the function of the cranial meninges?
To surround and protect the brain.
*Continuous with spinal meninges.
What are the 3 cranial meninges?
- Dura mater.
- Arachnoid mater.
- Pia mater.
Where is the dura mater located?
Innermost meninge and in direct contact with the brain.
What are the 3 extensions of the dura mater?
- Falx cerebri.
- Falx cerebelli.
- Tentorium cerebelli.
What does the falx cerebri separate?
The two hemispheres of the cerebrum.
What does the falx cerebelli separate?
The two hemispheres of the cerebellum.
What does the tentorium cerebelli separate?
The cerebrum from the cerebellum.
What are the 4 major parts of the brain?
- Brain stem.
- Cerebellum.
- Cerebrum.
- Diencephalon.
What is the BBB made up of?
Specialized brain capillaries and astrocytes.
What is the function of the BBB?
Prevent the passage of potentially harmful substances and pathogens from the blood to the CSF and brain.
What type of connections maintains the BBB?
Tight junctions.
What passes through the BBB via active transport?
- Glucose.
- Some water soluble molecules.
What passes through the BBB via passive transport?
- Alcohol.
- Anesthetic agents.
- CO2.
- O2.
*Lipid soluble substances.
What cannot passes through the BBB?
- Proteins.
- Antibiotics.
What % of O2 and glucose does the brain consume?
20%.
What is the main, almost exclusive, energy source of the brain?
Glucose.