Show:
Clinical Effects
AP Propagation
Synapses
Organization of NS
Brain
100
TTX blocks
Voltage gated Na+ channels
100
What makes an AP fast?
large fiber diameter, myelin, and longer fiber
100
How are electrical synapses maintained?
Through gap junctions
100
How is the CNS protected?
- Cranium and vertebral column - Meninges - CSF
100
What is the function of medulla oblongata?
-autonomic functions ( heart, blood pressure, digestion) - breathing, swallowing, coughing, sneezing - involuntary homeostasis
200
TEA blocks
voltage gated K+ channels
200
How does myelin speed up AP conduction?
Myelin is an insulator so APs occur at nodes of Ranvier only and jump from node to node and this is known my Saltatory Conduction
200
What's the role of Ca2+
Stimulates vesicles to translocate and bind to plasma membrane via SNARE proteins
200
What are the three layers of meninges?
- Dura matter - Arachnoid matter - Pia matter
200
What is the function of pons?
- signal relay and breathing - bridge
300
Inhibiting voltage gated Na+ channels results
AP not generated which stops the heart and cause ventilation failure
300
How is unidirectionality maintained in a fiber?
Refractory period prevents AP generation
300
How is a neurotransmitter cleared from a synapse?
- Diffusion away from cleft - Degradation by enzymes - Reuptake into pre-synaptic cells for reuse
300
How is the CSF produced and where?
It is produced using certain components of blood in choroid plexus inside the ventricles by ependymal cells
300
Midbrain?
Eye movement control
400
Inhibiting voltage gated K+ channels results
AP can be generated
400
Why is myelin important?
It speeds the AP, reduces metabolic cost, and saves room in the Nervous system
400
Where are all EPSPs and IPSPs summed?
at the Trigger zone
400
What constitutes the dorsal root ganglia of the spinal cord?
Sensory neurons
400
Reticular formation?
arousal, sleep , pain, and muscle tone
500
What's the effect of local anesthetics
They block voltage gated Na+ channels so that AP aren't generated and sensation of pain is reduced
500
Nodes of Ranvier are concentrated in
voltage gated Na+ channels and membrane pumps
500
What is the role of autoreceptors
give feedback and modulate further release of neurotransmitter from presynaptic cell
500
How are the gray matter and white matter distributed in the spinal cord? brain?
in spinal cord, middle is gray matter and outer is white matter in brain, the cortex is gray matter and myelinated axons constitute the white matter
500
What's the function of hypothalamus?
- thermostat - controls food intake - controls body osmolarity - secretes trophic hormone that control release of hormones from anterior pituitary gland