Case 6 Flashcards
Where is the cerebral aqueduct found?
Passes through the midbrain
Connects the third and fourth ventricles
What is a commissure?
Connection of fibres between similar points on left and right sides of the CNS
What is the corpus callosum?
The largest commissure.
Connects the two cerebral hemispsheres.
What makes up the diencephalon?
Thalamus
Hypothalamus
Epithalamus
Where is the neurotransmitter Dopamine found?
Neurones of the substantia nigra and Ventral tegmental parts of the midbrain
What is a fasciculus?
A tract or bundle of nerve fibres (axons)
What is the fornix? What does it connect?
Tract below the corpus callosum.
Connects hippocampus to mammilary body.
What is the main inhibitory neurotransmitter in the CNS?
GABA
What is the main excitatory neurotransmitter in the CNS?
Glutamate
What makes up grey matter?
Nervous tissue –> cell bodies and dendrites.
Where is the hippocampus found?
Floor of inferior horn of lateral ventricle in the temporal lobe.
Part of the limbic system.
What is the neurotransmitter serotonin involved in? Where are its cell bodies located?
Involved in anti-nociception.
Cell bodies containing 5-HT are found in the raphe nuclei of the brainstem.
What is the internal capsule? Function?
Large mass of white matter lying between the…
Lentiform nucleus, Thalamus and head of Caudate nucleus.
Function - conveys tracts to and from the cerebral cortex.
What is the function of microglia?
The respond to injury or infection of the CNS.
Where is the neurotransmitter Noradrenaline normally found?
Neurones in the locus coeruleus of the upper pons.
Where is the somatosensory cortex located? Where does it recieve sensory information from?
Parietal lobe
Post central gyrus. Thalamus.
Name some special senses.
Vision
Hearing
Balance
Taste
Smell
What is the Thalamus?
Large bilateral mass of grey matter in the diencephalon.
Recieves somatosensory, visual and auditory input.
What makes up white matter?
Nervous tissue composed of mainly myelinated nerve fibres.
What part of the brain is responsible for controlling distal musculature and fine skilled movement?
Primary motor cortex
What part of the brain is responsible for controlling proximal musculature and sequencing of movements?
Premotor cortex
What part of the brain is involved in initiating and planning movement?
Supplementary motor area
Which part of the brain is responsible for motor sequence learning?
Basal Ganglia - it converts a silent movement into an actual movement.
E.g. learning to walk during infancy.
What three structures control movement?
Motor cortex
Cerebellum
Basal Ganglia
Label the apex and the base of the basilar membrane.
State the properties of the base and the apex -
Wide? Narrow? Stif? Floppy?
Apex is wide and floppy.
Base is narrow and stiff.
What part of the basilar membrane detects HIGH frequency?
What part of the basilar membrane detects LOW frequency?
HIGH frequency @ base (bottom)
LOW frequency @ apex (top)
Think opposites!
Low freq waves can travel further than High freq waves.
What unit of measurement is sound measured in and what is the range humans can hear?
Hertz
20 - 20,000
What is the name of the space between:
a) the pericranium and dura mater
b) the arachnoid and dura mater
c) the arachnoid and pia mater
a) Extradural space
b) Subdural space
c) Subarachnoid space
How many layers of outer hair cells and inner cells are there?
Number of each?
Function?
Outer hair cells:
3 layers. 12,000 in total. Cochlear Amplification.
Inner hair cells:
1 layer. 3500 in total. Pitch determination.
Where are the two groups og cholinergic neurones found in the brain?
Functions of each group?
- Substantia Niagra & Subthalamic nucleus in midbrain.
–> stereotype movements.
- Forebrain cholinergic neurons.
–> memory
The safe exposure time for listening to noise at 85dB is 8 hours.
A 3dB increase = __ reduction in safe exposure time
A 3dB rise = reduction in safe exposure time by a half
What is the safe exposure time for a person listening to 120dB?
Cacluate it in seconds.
120 - 85 = 35dB
35/3 = 11.67
8 / 2^11.67 = hours
hours x 60 x 60 = seconds
roughly 8 seconds.
In terms of dB for sound pressure (dB SPL),
what does a 6dB increase mean?
20dB increase mean?
6dB increase = doubling in pressure
20dB increase = tenfold increase in pressure (times by 2 ten times)
What enzyme converts glutamate into GABA
What enxyme converts glutamine into glutamate?
Cystolic glutamic acid decarboxylase
Glutaminase
Where are GABA neurones found in the brain?
GABA is made in the nucleus accumbens.
What is a Stapedectomy?
used to treat otosclerosis - insertion of prosthetic stapes to replace calcified stapes causing conductive hearing loss
What type of epithelium is the ependymal cells that line the ventricular system?
Simple cuboidal ciliated
