PHAR 308: Flashcards 10 - Central Nervous System

What are the two structures which contribute to the CNS

Brain and Spinal Cord

How many cranial nerves in the CNS?

12

How many spinal nerves in the CNS?

31

What are 3 layers of the meninges? what is the role of the meninges?

Role: To protect the brain 

1. Dura mater 

2. Arachnoid

3. Pia Mater

What is the general distribution of the white and grey matter in the spinal cord?

white matter on the outside

grey matter on the inside

What is the general role of the spinal cord in CNS communication?

Allows the communication between the brain and peripheral nervous system

What is the organization of the signalling pathwayd?

tracts in the white matter for fast conduction speeds

Do reflexes occur in the spinal cord?

Yes, autonomic and somatic reflex processing 

What is the signalling between neurons like in the CNS?

Use of action potentials and NT

What is the importance of the cerebrum?

largest part, used for conscious thought, memory and voluntary movement

What are the 4 regions of the cerebrum?

1. Frontal lobe 

2. Occipital Lobe 

3. Parietal lobe 

4. Temporal Lobe 

What is the function of the occipital lobe?

Processes visual information

What is the purpose of the frontal lobe?

Perform executive functions such as decision making and problem solving

What is the function of the parietal lobe?

Sensory information and orienation 

What is the function of the temporal lobe?

Auditory info and memory

What is the purpose of the cerebellum

To coordinate movement

What are the three structures which make up the brainstem?

1. Midbrain

2. Pons

3. Medulla oblongata

What is the purpose of the brainstem

Maintain homeostasis

What is the purpose of the neuron in the CNS

Transmission of information in the brain

What is the point of the astrocyte in the CNS?

Ensures proper extraneuronal environment however is reactive and can form scar tissue

What is the function of a microglial cell in the CNS

An inflammatory cell (similar to monocyte/macrophage) which removes foreign material, presents antigens and produces cytokines for an inflammatory response 

What is the function of an oligodendrocyte

Generates myelin sheaths in the CNS (similar to a schwann cell)

What is an ependymal cell?

Lines the ventricles to generate CSF

What is a schwann cell?

A cell that generates myelin sheaths in the PNS 

How does CSF protect the brain?

Prevents brain tissue smashing against skull

How do the meninges protect the brain

Prevent a nice layer between the brain and outside layer w many barriers

How does the Choroid Plexus protect the brain?

Forms the Blood-CSF barrier to filter CSF components

How does the blood brain barrier protect the brain

Prevent foreign material from invading the brain

What does it mean that the brain is immune privelaged?

Prevents access of inflammatory cells to the brain so inflammation does not damage tissue 

• in serious situations the immune cells can access the brain 

What cells make CSF and where are they located?

Ependymal cells in the Choroid Plexus

What is the process that the ependymal cells perform to make CSF?

Filter the blood plasma to remove proteins and foreign material — fluid + ions remain

What are the three features of the Blood-CSF Barrier (BCSFB) what are their contributions?

1. Arachnoid Barrier: regulate movement of molecules  

2. Blood Vessels in subarachnoid space: More selective barriers  

3. Epithelium cells of the Choroid Plexus: Regulate CSF composition 

What are the four features of the Blood-Brain Barrier (BBB)

1. Glycocalyx

2. Tight Junctions Between endothelial cells (no paracellular transport)

3. Continuous Basement Membrane 

4. Astrocyte Cells 

They all restrict movement of molecules 

What are the properties of the Endotheliall endothelium of the BBB?

1. Tight junctions

2. Low transcellular permeability

3. Efflux transport

4. Selective solute transporters

5. Immune Modulation