Flashcards in Functional Brain Systems Deck (21):
What is the LIMBIC SYSTEM?
A ring of structures around CORPUS CALLOSUM and THALAMUS
- Center of emotion and learning
- Connects logic, thoughts (PREFRONTAL CORTEX) with: emotions (HYPOTHALAMUS, AMYGDALA), memory and learning (HIPPOCAMPUS), and visceral well-being (HYPOTHALAMUS)
What is RETICULAR FORMATION and what does it do?
- Web of GREY MATTER that runs throughout the BRAIN
- Filters out 99% of signals to prevent sensory overload
- Stimulates CORTEX, keeps consciousness
- Inhibited by sleep centers
- Depressed by alcohol and tranquilizers
- Damage can result in irreversible coma
What 4 things help to protect the BRAIN?
4) BLOOD-BRAIN BARRIER
What does the MENINGES do?
- Covers and protects CNS
- Protect blood vessels, enclose sinuses
- Contain CSF
- Form partitions
What is the MENINGES made up of?
3 layers of connective tissue membranes, the:
- FALX CEREBRI
- TENTORIUM CEREBELLI
- FALX CEREBELLI
What does the FALX CEREBRI do?
It separates hemi's and attaches to CRISTA GALLI
What does the FALX CEREBELLI do?
It separates CEREBELLAR HEMI'S
What does the TENTORIUM CEREBELLI do?
It's in the TRANSVERSE FISSURE and it covers the CEREBELLUM
What is the function of the DURAL SINUS?
CSF and venous blood drain into veins here.
What is the structure and function of the ARACHNOID VILLI?
They are little projections of ARACHNOID MATER. Their function is to return CSF to venous blood in DURAL SINUS
What can be found in the SUBDURAL SPACE?
What is typically found in the SUBARACHNOID SPACE?
CSF and large blood vessels
What is ARACHNOID MATER?
A middle membrane made of loose, web-like anchors
What are the 2 layers of the DURA MATER?
1) PERIOSTEAL LAYER
2) MENINGEAL LAYER
They are fused together *EXCEPT* at the DURAL SINUS
What is the function of the PERIOSTEAL LAYER?
It attaches to the SKULL
What is the function of the MENINGEAL LAYER?
It covers the BRAIN
What is the structure and function of the PIA MATER?
It's a delicate membrane that organizes capillaries. It is the deepest membrane and it follows *every* convolution of the surface of the BRAIN
What is CSF and where is it found?
- Found in ventricles of the BRAIN and central canal of SPINAL CORD
- Reduces weight
- Cushions and absorbs shock and blows
- Removes waste and maintains environment around NEURONS
- Similar to PLASMA but less protein, glucose, K+, Ca+, more Na+ and Cl-, no hormones.
How is CSF formed?
Fluid leaves permeable capillaries of CHOROID PLEXUS (L= wall of ventricles) and is filtered by ependymal cells connected by tight junctions
Explain CSF circulation.
- CSF forms, enters, flows through ventricles
- Exits ventricles via medial and 2 lateral apertures of 4th ventricle
- Enters SUBARACHNOID SPACE, bathes BRAIN and SPINAL CORD
- Enters ARACHNOID VILLI
- Transferred to DURAL SINUS
- Returned to blood via jugular vein