Case 6

Question 1

Where is the cerebral aqueduct found?

Answer 1

Passes through the midbrain

Connects the third and fourth ventricles

Question 2

What is a commissure?

Answer 2

Connection of fibres between similar points on left and right sides of the CNS

Question 3

What is the corpus callosum?

Answer 3

The largest commissure.

Connects the two cerebral hemispsheres.

Question 4

What makes up the diencephalon?

Answer 4

Thalamus

Hypothalamus

Epithalamus

Question 5

Where is the neurotransmitter Dopamine found?

Answer 5

Neurones of the substantia nigra and Ventral tegmental parts of the midbrain

Question 6

What is a fasciculus?

Answer 6

A tract or bundle of nerve fibres (axons)

Question 7

What is the fornix? What does it connect?

Answer 7

Tract below the corpus callosum.

Connects hippocampus to mammilary body.

Question 8

What is the main inhibitory neurotransmitter in the CNS?

Answer 8

GABA

Question 9

What is the main excitatory neurotransmitter in the CNS?

Answer 9

Glutamate

Question 10

What makes up grey matter?

Answer 10

Nervous tissue –> cell bodies and dendrites.

Question 11

Where is the hippocampus found?

Answer 11

Floor of inferior horn of lateral ventricle in the temporal lobe.

Part of the limbic system.

Question 12

What is the neurotransmitter serotonin involved in? Where are its cell bodies located?

Answer 12

Involved in anti-nociception.

Cell bodies containing 5-HT are found in the raphe nuclei of the brainstem.

Question 13

What is the internal capsule? Function?

Answer 13

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.

Question 14

What is the function of microglia?

Answer 14

The respond to injury or infection of the CNS.

Question 15

Where is the neurotransmitter Noradrenaline normally found?

Answer 15

Neurones in the locus coeruleus of the upper pons.

Question 16

Where is the somatosensory cortex located? Where does it recieve sensory information from?

Answer 16

Parietal lobe

Post central gyrus. Thalamus.

Question 17

Name some special senses.

Answer 17

Vision

Hearing

Balance

Taste

Smell

Question 18

What is the Thalamus?

Answer 18

Large bilateral mass of grey matter in the diencephalon.

Recieves somatosensory, visual and auditory input.

Question 19

What makes up white matter?

Answer 19

Nervous tissue composed of mainly myelinated nerve fibres.

Question 20

What part of the brain is responsible for controlling distal musculature and fine skilled movement?

Answer 20

Primary motor cortex

Question 21

What part of the brain is responsible for controlling proximal musculature and sequencing of movements?

Answer 21

Premotor cortex

Question 22

What part of the brain is involved in initiating and planning movement?

Answer 22

Supplementary motor area

Question 23

Which part of the brain is responsible for motor sequence learning?

Answer 23

Basal Ganglia - it converts a silent movement into an actual movement.

E.g. learning to walk during infancy.

Question 24

What three structures control movement?

Answer 24

Motor cortex

Cerebellum

Basal Ganglia

Question 25

Label the **apex** and the **base** of the basilar membrane. State the properties of the base and the apex - Wide? Narrow? Stif? Floppy?

Answer 25

Apex is wide and floppy. Base is narrow and stiff.

Question 26

What part of the basilar membrane detects HIGH frequency? What part of the basilar membrane detects LOW frequency?

Answer 26

HIGH frequency @ base (bottom) LOW frequency @ apex (top) Think opposites! Low freq waves can travel further than High freq waves.

Question 27

What unit of measurement is sound measured in and what is the range humans can hear?

Answer 27

Hertz 20 - 20,000

Question 28

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

Answer 28

a) Extradural space b) Subdural space c) Subarachnoid space

Question 29

How many layers of outer hair cells and inner cells are there? Number of each? Function?

Answer 29

*_Outer hair cells:_* 3 layers. 12,000 in total. Cochlear Amplification. *_Inner hair cells:_* 1 layer. 3500 in total. Pitch determination.

Question 30

Where are the two groups og cholinergic neurones found in the brain? Functions of each group?

Answer 30

1. ***_Substantia Niagra & Subthalamic nucleus_*** in midbrain. --\> stereotype movements. 2. ***_Forebrain cholinergic neurons_***. --\> memory

Question 31

The safe exposure time for listening to noise at 85dB is 8 hours. A 3dB increase = __ reduction in safe exposure time

Answer 31

A 3dB rise = ***reduction*** in safe exposure time by a ***half***

Question 32

What is the safe exposure time for a person listening to 120dB? Cacluate it in seconds.

Answer 32

120 - 85 = 35dB 35/3 = 11.67 8 / 2^11.67 = hours hours x 60 x 60 = seconds roughly 8 seconds.

Question 33

In terms of dB for sound pressure (dB SPL), what does a 6dB increase mean? 20dB increase mean?

Answer 33

***_6dB increase = doubling in pressure_*** 20dB increase = tenfold increase in pressure (times by 2 ten times)

Question 34

What enzyme converts glutamate into GABA What enxyme converts glutamine into glutamate?

Answer 34

Cystolic glutamic acid decarboxylase Glutaminase

Question 35

Where are GABA neurones found in the brain?

Answer 35

GABA is made in the ***_nucleus accumbens_***.

Question 36

What is a Stapedectomy?

Answer 36

used to treat ***otosclerosis*** - insertion of _prosthetic stapes_ to replace calcified stapes causing conductive hearing loss

Question 37

What type of epithelium is the ependymal cells that line the ventricular system?

Answer 37

Simple *_cuboidal_* ciliated