CNS Flashcards
(102 cards)
1
Q
What is the general function of the mesencephalon? (5)
A
- Hearing
- motor control
- sleep/wake
- arousal
- temperature regulation
2
Q
What is the general role of the pons? (4)
A
- arousal
- autonomic function
- relay sensory info between cerebellum and cerebrum
- sleep centre
3
Q
What is the general role of the medulla?
A
- Autonomic function
- Relay nerve signals from the brain and spinal cord
- Coordinate body movement
4
Q
Which cranial nerve nuclei are found in the midbrain?
A
3,4,5
5
Q
Which cranial nerve nuclei are found in the medulla
A
5,7,9,10,12
6
Q
Which cranial nerve nuclei are present in the pons?
A
5,6,7,8,9
7
Q
Name the subdivisions of the diencephalon
A
- epithalamus
- hypothalamus
- thalamus
8
Q
Which part of the diencephalon contains the pineal gland?
A
epithalamus
9
Q
What is the role of the pineal gland? (2)
A
- secrete melatonin
- role in circadian and seasonal rhythm
10
Q
What is the general function of the thalamus?
A
Relay information to the cerebral cortex
11
Q
State three important nuclei of the thalamus
A
- Lateral geniculate
- Medial geniculate
- Ventrolateral
12
Q
Via which thalamic nucleus does the tract from the eye to visual cortex travel through?
A
Lateral geniculate
13
Q
Via which thalamic nucleus does the tract from the inner ear to auditory cortex travel through?
A
medial geniculate
14
Q
Via which thalamic nucleus does the tract from the cerebellum to motor cortex travel through?
A
ventrolateral
15
Q
Where in the brain can the pituitary gland be found?
A
ventral to the hypothalamus
16
Q
What is the role of the pituitary?
A
secrete hormones into the blood stream, its the connection between the nervous and endocrine systems
17
Q
Name the most important nuclei of the hypothalamus and their functions (3)
A
- paraventricular-oxytocin and ADH
- Lateral - arousal and feeding
- mammilary - memory
18
Q
What is proprioception?
A
the systems response for detection changes in the position of the limbs trunk and head. it is the sense of position and movement
19
Q
What is the difference between conscious and unconscious proprioception?
A
Unconscious involves projections from receptors to the cerebellum via the spinocerebellar tract. conscious involves projections from receptors to the somesthetic cortex via the cuneate/gracile tract.
20
Q
What is the general function of the dorsal funiculus?
A
fine conscious mechanoception and proprioception
21
Q
What is the general function of the lateral funiculus?
A
proprioception, course conscious mechanoception, noicioception
22
Q
What is the general function of the ventral funiculus?
A
sensation
23
Q
What tracts can be found in the dorsal funiculus?
A
gracile and cuneate
24
Q
What tracts can be found in the lateral funiculus?
A
spinothalamic, spinocervicothalamic, dorsal and ventral spinocerebellar, spinomedullary
25
What tracts can be found in the ventral funiculus?
spinoreticular, spinovestibular, spinomesencephalic,spinoolivary,trigeminothalamic
26
Which tract is found most medial the gracile or cuneate?
Gracile
27
Which tract transmits pain and touch from the hindimbs and which from the forelimbs?
Forelimbs cuneate, hindlimb gracile
28
Describe the route of the gracile/Cuneate tract (3)
- First neurone ascends in Dorsal funiculus to the medulla
- Second neurone decussates in the medial lemiscus to thalamus
- third neurone travels from thalamus to general sensory cortex
29
Where in the body would a lesion to the right gracile tract in C1 effect?
right hindlimb
30
What is the role of spinothalamic tract?
nocioception, touch and temperature
31
Describe the general route of the spinothalamic tract (3)
- first neurone from receptors to dorsal column grey M
- Second neurone decussates from DCGM to tract in lateral funiculus where it ascends to the thalamus
- third neurone from thalamus to general sensory cortex
32
What is the role of the spinocervicothalamic tract?
nocioception
33
Where in the body would a lesion to the right spinothalamic tract in the medulla affect?
Left side of the body
34
Describe the general route of the spinocervicothalamic tract (4)
- First neurone from receptors to dorsal route G to DCGM
- second neurone from DCGM to dorsolateral funiculus and ascends to lateral cervical nucleus C1/3
- The third neurone decussates and heads to the thalamus
- The fourth neurone goes from the thalamus to the general sensory cortex
35
What is the role of the dorsal spinocerebellar tract?
unconscious proprioception
36
Describe the route the dorsal spinocerebellar tract (2)
- first neurone from receptors, through spinal nerves caudal to thoracic limb
- Second neurone from DCGM to lateral funiculus in tract and then ascends and travel through the caudal peduncle to the cerebellum
37
What is the pyramidal system?
a collection of tracts that originate from the cortex and pass and cross through the pyramids of the medulla
38
What are the two tracts that make up the pyramidal system?
- corticospinal
| - corticobubar
39
What is the corticospinal tracts main function?
voluntary body movement
40
There are two corticospinal tracts, where do they cross?
The one that innervates the trunk crosses in the medulla pyramids, the one that innervates the limbs crosses in the spinal cord
41
What is the corticobulbar spinal tract responsible for and where does it cross?
Head movement and eye movement and crosses in the medulla.
42
What is the extrapyramidal system?
A collection of tracts that originate from the reticular formation of the pons and medulla and don't cross through the pyramids
43
Name the four extrapyramidal tracts
- tectospinal
- rubospinal
- reticulospinal
- vestibulospinal
44
What are the extrapyramidal tracts responsible for?
Involuntary movements
45
Where does the vestibulospinal tract cross?
It doesn't
46
What ligament holds the vertebrae together?
the ligaments flavum
47
What is the intervertebral sagittal ratio?
The minimum sagittal diameter of the vertebral foramen divided by the maximum sagittal diameter of the vertebral body
48
What would a low intervertebral sagittal ratio indicate?
Foramen narrowing so high chance of wobblers syndrome if horses
49
What is the medical term for wobblers syndrome?
cervical stenotic myelopathy
50
What are some treatments for wobblers syndrome? (4)
- disc prosthesis
- hydrotherapy
- anti-inflammatory
- exercise modification
51
What are the two main divisions of the forebrain?
- telencephalon - most cranial
| - Diencephalon
52
What is another name for the midbrain?
Mesencephalon
53
What are the two main divisions of the hindbrain?
Mesencephalon
| Myelencephalon
54
What two important regions are found in the mesencephalon?
tectum and tegmentum
55
what two important structures are found in the mesencephalon?
Cerebellum and pons
56
what is another name for the myencephalon?
Medulla oblongata
57
Where in the brain can the limbic system be found?
telencephalon
58
Where in the brain can the basal ganglia be found?
Telencephalon
59
What part of the brain contains the hippocampus?
Limbic system
60
What 6 layers can be found in a histological slide of the cerebral cortex?
Molecular, external granular, pyramidal, inner granular, ganglionic, multiform
61
What are the 8 causes of seizures?
- Vascular
- Inflammation
- Toxic/trauma
- Anomalous
- Metabolic
- Infection
- Neoplastic
- Degenerative
62
What other conditions could be confused for a seizure? (3)
- Convulsions
- muscle spasms
- sleeping/dreaming
63
What is a seizure?
any abnormal electrical activity in the body
64
What mechanisms cause a seizure? (5)
- influx of extracellular calcium which opens sodium channels
- sustained neuronal depolarisation
- burst of action potentials
- rapid depolarisation and hyperpolarisation
- Too much excitement with little inhibition
65
What is the term used to describe the burst of action potentials with rapid depolarisation and hyper polarisation in seizures?
Paroxysmal depolarising shift
66
What is epilepsy?
A group of neurological disorders characterised by recurrent episodes of paroxysmal depolarising shifts, which causes a predisposition to epileptic seizures.
67
Describe the development of the cerebellum
upward growth of alar lamina which fuse together
68
What is the the middle section between the two hemispheres of the cerebellum called?
The vermis
69
What are the three lobes of the cerebellum called from cranial to caudal
rostral, caudal, floculonodular
70
What are the histological layers of the cerebellum called from outside to inside? (3)
molecular layer, Purkinje cell layer, granular layer
71
What afferent tracts run through the rostral peduncle of the cerebellum?
ventral Spinocerebellar, tectocerebellar
72
What afferent tracts run through the middle peduncle of the cerebellum?
corticopontocerebellar
73
What afferent tract runs through the caudal cerebellum?
dorsal spinocerebellar
74
What are mossy fibres?
afferent fibres from the brainstem and spinal cord involved in proprioception, they excite granule cells and inhibit Purkinje cells
75
What are climbing fibres?
Afferent fibres from the olivary nucleus of the medulla, they excite Purkinje fibres
76
What are Purkinje fibres?
Efferent inhibitory fibres from the cerebellum to the Cortex
77
Whats the general function of the flocculonodular lobe?
Balance an equilibrium, contains vestibular system
78
What is the general function of the rostral lobe?
truncal and limb coordinated movements
79
What is the general function of the caudal lobe?
Skilled movements
80
What is ataxia?
Disturbance that alters the direction and extent of voluntary movements
81
What is abiotrophy?
A postnatal loss of Purkinje cells
82
What are some general features of cerebellar defects? (3)
- vestibular signs
- uncoordinated movements
- exaggerated reflexes
83
What efferent projections run through the rostral peduncle?
projections through the thalamus to the cerebral cortex
84
What efferent tracts run through the middle peduncle?
none
85
What efferent tracts run through the Caudal peduncle?
cerebellovestibular, cerebelloreticular
86
What is the ARAS?
The ascending reticular activating system is a collection of interconnected nuclei in the brain responsible for sleep-wake transition, relaying information to higher centres for approval
87
What tract passes through the ARAS that is not responsible for sleep? And what is its function?
Spinoreticular - pain
88
What can a destruction of the ARAS cause?
Coma
89
Where in the brain is the sleep centre said to be?
In the ventrolateral preoptic area of the hypothalamus
90
If the VLPOA of the hypothalamus is inhibited are you awake or asleep?
Awake
91
When the ARAS is inhibited are you awake or asleep?
Asleep
92
How is orexin involved in sleep?
Orexin maintains wakefulness by stimulating the ARAS
93
How is the Suprachiasmic nucleus involved in sleep?
When it is light signals are sent which cause inhibition of vlPOA and stimulation of orexinergic neurones, maintaining wakefulness
94
Why do you fall asleep if you have been awake too long?
Adenosine accumulates slowly and stimulates the vlPOA to make you sleep
95
How can the amygdala be involved in sleep?
The amygdala has connections to the thalamus in the area where REM sleep in controlled. during REM sleep
96
What separates the Dura matter from the periosteum?
Epidural space
97
What is the Pia matter?
A thin layer of connective tissue that is adherent to the underlying brain or spinal cord and blends fibres with the arachnoid matter
98
What is the arachnoid matter?
A fine layer between the Pia and dura matter
99
What spaces are found between the meninges?
Epidural space, subdural space, subarachnoid space
100
What is the function of the meninges?
- protection
- containment of CSF
- Support
- maintanance of BBB
101
What structure connects the hypothalamus and the pituitary gland?
The infundibulum, a stalk which is part of the posterior lobe
102
What structures run through the connection between the hypothalamus and pituitary?
Neuronres and a portal system of vessels
