Nervous System Organisation Flashcards
What kind of nerves go from periphery to CNS?
Afferent (sensory)
What kind of nerves go from CNS to periphery (PNS)?
Efferent (motor)
What is the most coming NT for excitatory neurones?
Glutamate
What is the most coming inhibitory NT?
GABA (gamma-amino butyric acid)
What is an axon collateral?
Branches off axon (enable single neurone to communicate with many others)
A collection of neuronal cell bodies in the CNS is called a…?
Nucleus
A group of functionally related axons in the CNS is called a ….?
Tract
A bundle of axons in the PNS is a…?
Nerve
A collection of neuronal cell bodies in the PNS is a…?
Ganglion
SOMATIC NS: efferent (motor) neurones
- Cell body located in CNS/PNS?
- Myelination of axons is?
- Neurotransmitter?
Cell body: CNS
Axons are HEAVILY myelinated
NT: Ach
SOMATIC NS: afferent (sensory) neurones
- Cell body located in CNS/PNS?
- Myelination of axons is?
- Neurotransmitter?
Cell body in PNS
Axons are myelinated/unmyelinated
NT: Glutamate
SYMPATHETIC NS: Ganglia close to...? Preganglionic fibres? Postganglionic fribres? Postganglionic NT?
CNS
Short and myelinated
Long and branch extensively
NA
PARASYMPATHETIC NS: Ganglia close to...? Preganglionic fibres? Postganglionic fribres? Postganglionic NT?
Target
Long and myelinated
Short and branch minimally
Ach
Myelinating glial cells of the PNS are?
Myelinating glial cells of the CNS are?
Schwann cells
Oligodendrocytes
Supporting glia of:
- CNS is….?
- PNS is…?
- Astrocytes
* Satellite glia
Microglia are…?
Scavengers
Immune cells of CNS
Phagocytose debris
Golgi Type I neurones have ____ axons?
Golgi Type II neurone have ____ axons?
Golgi type I: LONG axons, extend to other parts of brain.
Golgi type II: SHORT axons, don’t extend beyond cell body (interneurones)
What brain regions make up the FOREBRAIN?
Cerebrum
Thalamus
Hypothalamus
What function does the MIDBRAIN have?
Process visual and auditory data
Reflexive somatic motor responses
Maintainence of consciousness
What functions does the pons have?
Relays sensory info to thalamus and cerebellum
Subconscious somatic and visceral motor centres
The PROSENCEPHALON divides into which secondary brain vesicles and which brain regions?
Telencephalon —> cerebrum
Diencephalon —> thalamus + hypothalamus
The RHOMBENCEPHALON divides into which secondary brain vesicles and forms which brain regions?
Metencephalon —> cerebellum + pons
Myencephalon —> medulla oblongata
Explain the function of these midbrain regions:
- Substantia nigra
- Superior colliculus
- Periaqueductal grey matter
- Red nucleus
- DA containg, motor system
- Receives visual input, focus eyes to attention
- Pain and fear pathways
- Motor control
Explain the function of these hindbrain/brainstem regions:
- Reticular formation
- Raphe nuclei
- Area postrema
- Locus coeruleus
- Alertness, CV function (HR)
- Contains 5-HT
- Chemoreceptor trigger zone
- NA +ve cells
Which is the innermost layer if ye meninges?
Pia matter
What is the space between the Dura and Arachnoid matter called?
Subdural space
The LATERAL ventricles are located in the____ and separated by the _______?
Cerebral hemisphere (one in each hem) Septum pellucidum
Where is the THIRD ventricle located?
Diencephalon
Which ventricle is continuous with the central canal of the spinal cord?
Fourth
What connects the 3rd and 4th ventricles?
Cerebral aqueduct
What 4 factors determine resting membrane potential?
- -ve charged intracellular PROTEINS
- Na/K pump (3 Na out, 2 K in)
- K+ ions (electrical force IN, greater concentration grad force OUT)
- Na+ ions (small inward force, electrical + conc)
What is the “electrical potential difference that balances the ionic concentration gradient”?
Equilibrium potential (E ion)
What is the ionic driving force?
Difference between membrane potential (Vm) and equilibrium potential (Eion).
= Vm - Eion
Why is GHK (Goldman-Hodgkin-Katz) eq use to calculate membrane potential, not Nernst eq?
GHK takes into account different ion permeabilities
Where in neurone is an AP generated?
Axon hillock
How long does one action potential last?
6 ms
Which phases of AP are in the ABSOLUTE refractory period?
Therefore, which phases = RELATIVE refractory period?
Depolarization and repolarization (the spike)
Hyperpolarization
The CNS is derived from which type of tissue?
Ectoderm
The PNS is derived from what type of tissue?
Neural crest
