Neuroanatomy January Flashcards
What is NG2?
Neural-glial antigen 2 expressed on oligodendrocyte progenitor cells, also called NG2 cells. These are highly branched, highly distributed, can become oligodendrocytes, and are involved in physiology and repair.
How many dorsal arteries are there?
2
How many ventral arteries are there?
1 large
What types of cells are found around the central canal?
Stem cells
What is a bundle of fibres called in CNS and in PNS?
CNS - tract
PNS - nerve
What is a collection of neuron cell bodies called in CNS and PNS?
CNS - nucleus
PNS - ganglion
Does the amacrine cell in the retina have an axon?
No
Do sensory neurons have axons and dendrites?
They do not have dendrites and have no synapses on cell body
What are satellite cells?
Glia found around neuron bodies in ganglia
What is a Remak cell?
Schwann cells which do not myelinate, but rather surround unmyelinated peripheral nerve fibers
What occurs in MS?
loss of oligodendrocyte myelination in CNS
What is contained within subarachnoid space?
CSF
Is there a subdural space?
No unless bleeding occurs there
In which week of human development does primary neurulation occur?
4th week
Closure occurs first, near hind brain - spinal cord boundary. progresses in anterior and posterior directions, closing caudal neuropore last of all.
Where is CSF made and transported?
Largely made by choroid plexuses in lateral ventricles, passes to third ventricle via interventricular foramina.
Does myelination occur before or after birth?
Both.
Many tracts eg corticospinal tracts myelinated after birth.
What is the diencephalon?
region of the embryonic vertebrate neural tube that gives rise to anterior forebrain structures including the thalamus, hypothalamus, posterior portion of the pituitary gland, and pineal gland.
What is another name for the Sylvian fissure?
Lateral fissure
What are the arachnoid villi?
Granulations which act as one way valves for flow of CSF into venous blood, stimulated by hydrostatic pressure.
What is a cause of hydrocephalus?
blockage of cerebral aqueduct -> swelling of ventricles, squashing brain
What are the names of enlargements in spinal cord near to limbs?
cervical enlargement, for upper limb
lumbosacral enlargement, for lower limb
Which dermatome is at the belly button/umbilicus?
T10
What is the grey matter of spinal cord divided into?
Rexed laminae
Which lamina is named substantia gelatinosa?
II
this is larger, full of small unmyelinated neurons
Which laminae are the superficial dorsal horn laminae?
I and II
related to pain
Where are motor neuron cell bodies found?
Ventral horn lamina IX
What are intrafusal muscle fibres responsible for?
Resetting muscle spindle so it can continue to detect stretch
What is poliomyelitis?
Virus that causes flaccid paralysis
Where are primary afferent cell bodies found?
DRG
Are primary afferents excitatory or inhibitory?
Excitatory
What is the Babinski sign?
reflex when instrument run down lateral sole of foot causes big toe extension.
in normal adults the big toe points down. with upper motor neuron lesion, big toe points up.
in babies big toe also points up because corticospinal tracts not yet myelinated.
What is the role of cerebellar peduncles?
Connect cerebellum with CNS.
How many cerebellar peduncles are there?
6; 3 on each side. They are found on each side of the midline. Superior peduncle --> midbrain Middle --> pons Inferior --> medulla
What are the colliculi?
Small swellings in midbrain roof involved in vision, hearing. Part of the tectum.
Superior colliculi - eye movements.
Inferior colliculi - relay station in auditory pathway
What is the name of grey matter surrounding cerebral aqueduct?
Periaqueductal grey.
primary control center for descending pain modulation.
What is the crus cerebri?
Cerebral peduncle. Part of the midbrain that links the remainder of the brainstem to the thalami and thereby, the cerebrum. They are the most anterior structure in the midbrain and contain the large ascending and descending tracts that run to and from the cerebrum.