CNS Flashcards
1
Q
What two tissues does the CNS comprise of?
A
Grey and white matter
2
Q
What does grey matter contain?
A
Nerve cell bodies, dendrites and synapses
3
Q
What does white matter contain?
A
Axons of nerves
4
Q
What are clusters of cell bodies in the CNS called?
A
nuclei
5
Q
What causes the colour of white matter?
A
The fat in the myelin sheaths
6
Q
How is white matter organised in the CNS?
A
organised into bunches called tracts
7
Q
Where is the grey and white matter in the spinal cord?
A
grey matter is contained inside white matter on the periphery
8
Q
Where is grey and white matter in the cerebral hemispheres?
A
Grey matter forms an outer cortex and white matter a central mass
9
Q
Where and what is the basal nuclei?
A
In the deep part of the cerebral hemispheres and is interwoven grey and white matter
10
Q
What is the basal nuclei also know as?
A
Corpus striatum
11
Q
What is the CNS made up of?
A
Brain and spinal cord
12
Q
What are ridges and furrows in the cerebral cortex called?
A
ridges- gyri
furrows- sulci
13
Q
What are the two cerebral hemispheres separated by?
A
longitudinal fissure
14
Q
How is the cerebrum and cerebellum separated?
A
Transverse fissure
15
Q
What is the major sulcus which crosses longitudinal fissure called?
A
cruiciate sulcus
16
Q
What are folds of the cerebellum called?
A
Folia
17
Q
What is the major gyrus on the lateral aspect called?
A
sylvan gyrus
18
Q
What is the cortex of the cerebellum made of?
A
Outer cortex is made up of grey matter with central nuclei
19
Q
Where is the cerebellum found?
A
caudal to the cerebral hemispheres
20
Q
What does the organises white matter look like?
A
resembles a tree
21
Q
What is the white matter of the cerebellum often referred to as?
A
arbor vitae
22
Q
How many lateral hemispheres does the cerebellum have?
A
2
23
Q
What is the central part of the cerebellum called?
A
Vermis
24
Q
How does the cerebellum connect to the brainstem?
A
by three peduncles
25
What fluid surrounds the brain and spinal cord?
Cerebrospinal fluid (CSF)
26
What does the CSF circulate round the brain in?
A series of ventricles
27
Describe the flow of CSF
Two lateral ventricles in the cerebral hemispheres communicate with a single third ventricle which surrounds the thalamus, the third communicates with the fourth ventral to the cerebellum and connects to the spinal cord
28
How can the cerebral hemispheres be divides according to bones of the skull?
Frontal, parietal, temporal, occipital
29
How can the cerebral cortex be divided according to function?
visual cortex in occipital lobe, motor cortex rostral to cruciate sulcus, somatosensory cortex next caudal sulcus and auditory in temporal
30
What is the function of the rhinencephalon?
Smell (olfaction)
31
What part of the brain is the rhinoncephallon found?
The ventral aspect part of the cerebellum
32
What is the most rostral part of the brain?
Olfactory bulb
33
What part of the brain is responsible for conscious thought?
Cerebral cortex
34
What part of the brain is responsible for decision making, planning, judgement and motivation
The frontal cortex
35
What is in the diencephalon?
Thalamus and hypothalamus
36
What is responsible for personality and social behaviour?
Pre-frontral cortex
37
What is the limbic system responsible for?
emotion, learning and memory
38
What is the basal nuclei responsible for?
planning and executing movements
39
What information does the thalamus receive?
All sensory other then olfactory
40
What does the hypothalamus do?
Connects the nervous and endocrine system
41
What do the brainstem and medulla oblongata control?
basic functions of live (cardiovascular),
42
What is the cerebellum responsible for?
Organises and refines motor function in the body
43
How many segments are initially in the head?
7
44
What does each of the 7 segments consist of initially?
Ectoderm, Somites, Endoderm, Lateral plate mesoderm, segmental arteries, neuraxis, nerves
45
What is the function of the ectoderm?
Forms outer epithelial covering, somatic sensation
46
How are segments marked externally in development?
Lateral indentations which are pharyngeal clefts
47
What is different about the ectoderm in segments 1 and 2?
Deeply invaginated into segments 1 and 3, forming oral opening
48
What is the function of the endoderm?
Forms inner epithelial covering, sensation from autonomic efferents and autonomic efferents for motor
49
What does the cephalic part of the fore-gut become?
Pharynx
50
What is the lateral plate mesoderm?
Belt of skeletal muscle that surrounds pharynx in all segments but 1
51
What is each belt of lateral plate mesoderm called?
Pharyngeal arch
52
What do the lateral plate mesoderm form?
Special visceral muscle of the gut tube
53
What innervates the pharyngeal arch?
Special visceral efferents
54
What are the functions of somites?
Form striated muscle in eyeballs and tongue
55
What innervates the somites?
Somatic efferents
56
How many somites does each segment have?
a pair
57
What parts of the trunk are obliterated?
Somites 4/5, Pharyngeal arch 5, arterial arch 1/2, pharyngeal cleft 5/6, ectoderm 6/7
58
What part of the head fails to develop further?
Endoderm arch 2, ectoderm 5-5
59
What migrates in the development of the head?
somites 6 and 7
60
How does the oral and nasal cavity form?
Paired nasal pits form, breaks through to oral cavity, palatine process grows
61
How does the tongue form?
Front of tongue from ectoderm of arch 1, back of tongue endoderm of arch 3, muscle is somites 6 and 7
62
How does the pituitary gland form?
Anterior lobe from ectoderm of arch 1 (rathkes pouch), posterior from brain stem
63
What does the thyroid develop from?
Diverticulum of arch 2
64
What does the larynx, trachea and lungs develop from?
Depression in floor of arches 4 and 6
65
What does cleft 1 form?
External ear
66
What does pouch 1 form?
middle ear cavity
67
What does pouch 2,3 and 4 form?
2- palatine tonsil
3- parathyroid and thymus
4- parathyroid and thymus
68
What does ectoderm 1-5 develop into?
1-skin on top
2-rest of skin
3/4/5-small area skin in external ear
69
What do somites 1-3 form?
1-3 extrinsic muscles of the eye
70
What do somites 4/5 form?
Nothing disappear
71
What do somites s6/7 form?
Muscles of the tongue
72
What do the arches form?
1- chewing, 2- facial muscles, 3- stylopharyngeus, 4- pharyngeal muscles, 5- disappears, 6- laryngeal muscles
73
What are the function of meninges?
Physical protection, facilitate flow of CSF, framework of blood vessels
74
What layers does the dura mater have?
Outer- endosteal
| Inner- meningeal
75
Where are the two layers of the dura mater distinguishable?
Between the cerebrum and cerebellum where inner layer folds in
76
What does the arachnoid mater look like?
Spider web
77
What separates the arachnoid and dura mater?
Potential space
78
What part of the meninges is pain sensitive?
Dura mater
79
Is the arachnoid mater and Pia meter vascular or avascular?
Avascular- arachnoid
| Vascular- pia meter
80
What is between the arachnoid mater and Pia mater?
CSF and blood vessels
81
What does the Pia mater adhere to?
Underlying tissue
82
How does the layers in the spinal cord differ?
Indura mater an epidural space is filled with fat
83
What is the area called where the nerve leaves the meninge?
Cuff zone
84
What are the functions of the CSF?
provides nutrition, acts as cushion, volume buffer, maintains environment, movement of neurotransmitter
85
Where is CSF produced?
In ventricles by the choroid Plexi
86
What cells produce CSF in the choroid Plexi?
Transporting ependymal cells
87
What is the composition of CSF?
cell/protein free, low amino acid, low K+, low glucose
88
What lines ventricles and central canal to move CSF?
Cilia
89
Where does CSF circulate?
Subarachnoid space, ventricles of brain, central spinal cord
90
How does CSF drain?
Re-absorption into circulation at arachnoid villi (extensions of arachnoid membrane)
91
Where can CSF be sampled from?
Behind skull or bottom of spine
92
What does all arterial supply come from in the brain?
Cerebral arterial circle?
93
Where is the cerebral arterial circle found?
Ventral surrounding hypothalamus
94
What are the three pairs of arteries to cerebral from arterial circle?
Caudal, middle, rostral
95
What are the two pairs of arteries to cerebellum from arterial circle?
Rostral and caudal
96
What arteries feed the cerebral arterial circle?
internal carotid, basilar, maxillary, vertebral
97
How do the arteries supplying the circle supply the blood?
Either difextlt or rete mirabile (net) to cool and slow down blood
98
What supplies a dog and horse arterial circle?
Internal carotid, basilar
99
What arteries supply arterial circle in sheep and cat?
Mainly maxillary via rete miraile
100
What supplies a cows arterial circle?
Maxillary, vertebral via 2 rete meribile
101
Why is a blockage in the brain catastrophic?
Very little arterial-anatomoses and collateral circulation
102
How is the spinal cord supplied with blood?
Branch of vertebral artery cranially and aorta caudally, enter through intervertebral foramina giving off two branches- one in dorsal root and ventral spine artery
103
Why is there potential for a tumour of infection in the venous drainage of CNS?
System is slow, bidirectional and intermittent blood flow
104
Where does the brain tissue first drain into?
Venous sinuses- dorsal and ventral
105
Where is the ventral sinuses positioned?
Within falconers cerebri and tentorium cerebelli
106
Where do the dorsal sagittal sinus and straight sinus receive veins from?
Sagittus- cerebral hemispheres
| Straight- deeper veins
107
What sinuses run into the tentorium cerebelli?
dorsal sagittus, straight sinus, left/right transverse
108
Where are the ventral sinuses found?
Between the layers of the dura mater
109
What to sinuses receive blood from the face, nose and orbit?
Cavernous sinus and inter-cavernous sinus
110
What do the cavernous sinuses drain into?
Dorsal and ventral petrosal sinuses
111
What does the petrosal sinuses drain into?
Ventral into basilar then internal vertebral plexus
| Dorsal- to transverse confluence of sinuses to systemic circulation
112
What are the three branches of the trigeminal nerve?
Opthalmic, Maxillary, Mandibular
113
Which area does each branch of trigeminal branch innervate and receive info from?
Ophthalmic- upper eyelid and above
Maxillary- between lower eyelid and top lip
Mandibular- lower lip and below
114
Why does the ophthalmic and maxillary branches only have somatic afferent sensation?
Segment 1 in the head loses its pharyngeal arch- only has ectoderm
115
Which nerves of the ophthalmic branch innervate the forehead skin, cornea, dorsal turbinates and medial eyelid?
Frontal/zygomatictemporal, long ciliary nerve, ethmoidal nerve, infratrochlear nerve
