Flashcards in Neuroscience Deck (429)
What are the three divisions of the nervous system?
Central nervous system
Peripheral nervous system
Enteric nervous system
What is the difference between CNS and PNS?
CNS - the structures of the brain and the spinal chord
PNS - nerves and cell bodies to and from the brain and spinal chord
What is the enteric nervous system?
The neural cells of the viscera and is often classified as the PNS
How many peripheral nerves are there?
What is a nerve?
Bundle of axons/neurone processes
Does not contain dendrites
No neuronal cell bodies
What does mixed mean (in terms of nerves)?
Has both motor and sensory roles
What are the layers in the nerve?
Each individual axon is surrounded by endoneurium
These are bundled together by perineurium into fascicles
Fascicles are bound together by epineurium
How many pairs of cranial nerves are there?
Are cranial nerves mixed, sensory or motor?
All of them
What is the most common cranial nerve?
Vagus nerve (cranial nerve 10) - 80% of PNS outflow
How many spinal nerves are there?
31 pairs (5 sets of pairs)
Are spinal nerves mixed, sensory or motor?
Are spinal nerves branched?
What are dermatomes and what is their clinical use?
The patterns of innervation of spinal nerves.
Help neurologists identify sites of damage
What are the sub-divisions of the PNS?
Somatic (voluntary) and visceral (involuntary)
These are split into afferent and efferent
Efferent visceral is Autonomic which is split into sympathetic and parasympathetic
Difference between somatic and autonomic? (in terms of motor axons)
Somatic - motor axons go straight to muscle
Autonomic - motor axons synapse with another cell in the ganglion and then to the muscle
Which are axons are usually myelinated?
Pre ganglionic axons are usually myelinated and post are not
What are the differences between the parasympathetic and the sympathetic nervous system?
- Both para and sympathetic use acetyl choline and sympathetic uses noradrenaline as well.
-Sympathetic ganglia lie closer to target as axons are shorter
- sympathetic axons can connect to multiple ganglion
Name some key historical figures in the study neuroscience
Huong Ti - canon of internal medicine
Galen - First to use animals
Aristotle - heart
Al Hazen - eye as an imaging system
Al - Zahrawi - Neurosurgery
How and why has the use of the squid giant axon improved neuroscience?
Allowed the determination of ion flows in action potentials
It has a large diameter and is easy to dissection
How and why has the use of worms (C.elegans) improved neuroscience?
The model system for developmental cell death (apoptosis)
They are fully mapped
How and why has the use of flies (Drosophila) improved neuroscience?
Identification of gene regualting (e.g. pax-6 development)
How and why has the use of frogs (Xenopus) improved neuroscience?
- Nerve conduction velocity
- Ca2+ release
- How axons grow
- How nerves pathfind
How and why has the use of chicks (Gallus) improved neuroscience?
Allowed development in transplantation and understanding of nerve growth factor
Allows easy embryonic manipulation
How and why has the use of birds improved neuroscience?
Behavioural studies e.g.. imprinting
How and why has the use of mammals improved neuroscience?
- Dogs to map motor cortex, chemical neurotransmission and behaviour (pavlovian classical conditioning)
- Cats dogs and apes used to understand reflexes and motor control
- Cats dogs and rabbits used to formulate the autonomic nervous system
- Rats used for operant conditioning by skinner
- Mice - Molecular dissection of behaviour and disease
Name some neural tube defects
Spina Bidfida - failure of the neural tube to close ( a mild form is dimples at the bottom of the spine)
How can you prevent most neural tube defects?
Folic acid - mother needs to take at very start of pregnancy for an effect
What are the primary brain vesicles? (draw it)