CNS

Question 1

__________ receptors have broader temperature range, they fire between ____________degrees.

Answer 1

Cold; 20-30

Warm: higher than 30 degrees

Question 2

______ fibres are thinly myelinated for acute pain. While ________ fibers are unmyelinated for chronic pain.

Answer 2

A-delta;

C

Question 3

Locus coeruleus secretes ____________ involving in what reticular formation functions?

Answer 3

Noradrenaline;

pain, arousal

Question 4

Periaqeuductal gray secretes ____________ involving in what reticular formation functions?

Answer 4

acetylcholine;

micturition and pain

Question 5

Pontine reticular formation is responsible for ___________ function, to cerebellum for the pontine-cerebellar thalamic loop

Answer 5

Micturition and continence

Decision to urintate >pontine reticular formation stimulatory neurons > parasympathetic neurons > contract detrusor muscles to allow micturition;

stimulate inhibitory interneurons to increase inhibition on motor neurons to relax sphincter urethrae

Question 6

What is the PPRF for?

Answer 6

VOR and saccades from frontal eye field;

projects to CN6 > nucleus next to CN6 that projects to CN3 via MLF

Question 7

What is the lateral medullary reticulospinal tract for?

Answer 7

inhibit the extensors (allow smooth contraction)

Question 8

Raphe nuclei secretes __________ involving in what reticular formation functions?

Answer 8

5-HT;

Pain, arousal

Question 9

Ventral tegmental area secretes __________ involving in what reticular formation functions?

Answer 9

dopamine;

reward (to nucleus accumbens), arousal

Question 10

Lesion at dorsal column - medial lemniscus system.

Answer 10

1. Sensory ataxia - no 2-point discrimination, fine touch, proprioception
2. Romberg’s sign: inability to maintain stability when eyes closed
3. Stamp and stick gait: due to impaired muscle coordination.

Question 11

Lesion at anterolateral system - spinothalamic tract.

Answer 11

Syringomyelia: a fusiform cyst around the central canal at visceral region: compress and degeneration of cells in the anterior white commissure

Question 12

Lesion at corticospinal tract.

Answer 12

1. Loss of inhibition on reflex loop (constantly activated) so all muscles contact at the same time, spasm and paralysis
2. Spastic gait: flexed upper limb but extended lower limb
3. UMNL
   - clonus hyper reflexis
   - +ve Babinski’s sign: dorsiflexed big toe when stroked on plantar surface
4. LMNL
   - degeneration of the ventral horn motor neurons > flaccid, complete paralysis

Question 13

Possible reasons for lesion of the corticospinal tract?

Answer 13

• Tumor compression on primary motor area
• Haemorrhage of internal capsule
• Damage to brainstem or spinal cord
• resulting in denigration of neurons

Question 14

Lesion in supplementary motor area (area 6)?

unilateral and bilateral

Answer 14

• Unilateral lesion: akinesia of contralateral side = difficulty in initiating movements
• Bilateral lesion: total akinesia (persist muscle tone but unable to move, including speech initiation)

Question 15

Lesion in somatosensory association area (area 5) and posterior parietal cortex (area 7)?

Answer 15

Astereognosis;

Loss of ability to recognize 3D objects

Question 16

Lesion in the posterior parietal cortex?

Answer 16

• Contralateral visual neglect, delayed and inaccurate saccades and reaching movements
• Especially obvious if lesion at right side, because attention to the right is by both left and right PPC, but attention to left is only by right lobule
• lesion to left is compensated by the right lobule

Question 17

Inferior parietal cortex (area 40)/ supra marginal gyrus function + afferents?

Answer 17

• Contains a body schema, awareness of existence and spatial relationships of body parts
• receive inputs from 3,1,2: especially proprioceptive signals

Question 18

Lesion in inferior parietal cortex (area 40)/ supra marginal gyrus?

Answer 18

• Contralateral visual hemineglect - ignore opposite side of the body unless attention is drawn to it
• Right hemisphere: spatial relation
• Left hemisphere: Visual details

Question 19

Functions of angular gyrus? (area 39)

Answer 19

initiates learned movements, connects with premotor area, prefrontal cortex and motor cortex ;

neurodictionary

Question 20

Angular gyrus dominance? Lesion?

Answer 20

Dominant on the left side.
Lesion: Ideomotor apraxia (failure to perform learned movement) /
Alexia (cannot read)/ Agraphia (cannot write)

Question 21

Wernicke’s area (area 22) location and lesion?

Answer 21

Location: superior temporal gyrus;
Receptive aphasia, accompanied by auditory comprehension, able to speak fluently but cannot understand

*larger temporal plane on the left side

Question 22

Lesion in medial prefrontal and orbitofrontal-amygdala area?

Answer 22

anxiety, phobia, depression, schizophrenia, autism , PTSD

Question 23

Central/posterior visual field is the most posterior at the occipital lobe.

Answer 23

Central

Question 24

Main function of prefrontal cortex?

Answer 24

Personality, decision making (especially orbitofrontal cortex) > consider future consequences of actions

Question 25

Functions of fusiform cortex (at base of temporal lobe)?

Answer 25

face recognition and color processing V4

Question 26

What is lingual gyrus (function and lesion) ?

Answer 26

Visual association area posterior to the parahippocampal gyrus; Lesion: snowflake vision

Question 27

Olfactory bulb is near?

Answer 27

septal area (reward, pleasure), hypothalamus (emotion), primary olfactory cortex in the uncus (fear, anxiety in amygdala)

Question 28

Superior temporal gyrus important structures?

Answer 28

Wernicke's area and primary auditory cortex

Question 29

Which brain structure is for recognising places and for daydreaming?

Answer 29

Hippocampus (place and grid cells); source of theta waves

Question 30

Location and function of Broca's area (area44/45)?

Answer 30

Inferior frontal gyrus; | motor component of speaking

Question 31

Damage to CA1 in hippocampus? | CA2?

Answer 31

CA1: Alzheimer's CA2: social cognition

Question 32

Korsakoff Syndrome? | Signs?

Answer 32

Atrophy of the mammillary body that involves in the papez circuit for memory formation. 1. Loss of recent memory 2. Confusion 3. Confabulation 4. Hallucination (sensory signals from entorhinal area)