T1 L4 Neural tissues Flashcards
What does an afferent neuron do?
Transmits sensory information to the brain/spinal cord
What does an efferent neuron do?
Motor neurons transmitting information from the brain to effector organ i.e. a muscle
What is a ganglion?
Group of cell bodies outside the CNS
Give an example of a sensory ganglion
Dorsal root ganglion
What is dorsal?
Towards the spine/back
What is ventral?
Towards the belly
What is caudal?
Towards the tail
What is rostral?
Towards the nose
What is caudal?
Towards the tail
What are brodmann areas?
System for naming cortical areas. Each area has a particular set of inputs & outputs & often a specific function.
What is brodmann area 4?
Primary motor cortex
What is Brodmann area 17?
Primary visual cortex
How many Brodmann areas are there?
52
What does myelin do?
Electrically insultates
Increases conduction velocity
What classifies a bipolar neuron?
One dendrite
One axon
Less of them
Sensory neutrons such as the retina
What is divergent?
A single neuron sends its output signal to many neurons
What is convergent?
Multiple inputs influence a single neuron
What are interneurons?
Found only in CNS
Not motor or sensory
Process signals
Can be excitatory or inhibitory
How much of the brain are interneurons?
80%
What are glia?
Have no action potentials
Are able to divide
Do not form synapses
Form myelin sheathes
What are oligodendrocytes?
Production / maintenance of myelin sheath in CNS
One oligodendrocyte myelinates multiple axons
Where are oligodendrocytes found?
CNS
What are astrocytes?
Star shaped
Support neurons
Assist neuronal development / growth
Protects neutrons from harmful substances
Its feet influence blood flow & blood-brain barrier
Where are astrocytes found?
CNS
What are microglia
Immune cells Protect neutrons from disease Migrate to injury sites Engulf microbes / debris Mesodermal origin
Where are microglia found?
CNS
What are ependymal cells?
They line the brain ventricles & central canal of spinal cord
Form CSF
Have cilia & microvilli
Where are ependymal cells found?
CNS
What are Schwann cells?
Produce / maintain myelin sheath
PNS regeneration
Similar to oligodendrocytes in the CNS
Where are Schwann cells found?
PNS
What are satellite cells?
Support neurons
Regulate exchange of materials between neutrons & interstitial fluid
Similar to astrocytes in CNS
Where are satellite cells found?
PNS
What glial cells are found in the central nervous system?
Astrocytes
Oligodendrocyte
Ependymal cell
Microglial cell
What glial cells are found in the peripheral nervous system?
Schwann cells
Satellite cells
What is a glioma?
Largest group of primary tumours derived from glial cells
Usually highly malignant
Grow rapidly
Difficult to remove completely with surgery
Usually inside cranium
What is a neuroblastoma?
Tumour Most common in children & infants Outside cranium Derived from neural crest cells from sympathetic nervous system Increased catecholamine levels
What is the prognosis for neuroblastomas?
Initial prognosis is typically good
Often develop neurological problems around 30 years later
What are the most common source of tumours in the nervous system?
Glia
Give examples of post-synaptic cells
Neuron
Myocyte
Gland
What are pyramidal cells?
Main neuron in neurocortex
Where are purkinje cells found?
In the cerebellum
Where are dorsal root ganglion found?
Just outside the spinal cord
