Nervous System - Autonomic Nervous System Flashcards
1
Q
What is the motor part of the somatic nervous system concerned with?
A
Innervation of skeletal muscle.
2
Q
What does autonomic control?
A
- Involuntary functions.
- Visceral motor.
- Visceral sensory.
3
Q
What makes up the peripheral nervous system?
A
- Somatic.
- Autonomic.
4
Q
What does somatic control?
A
- Somatic sensory fibres.
- Somatic motor fibres.
- Voluntary actions.
5
Q
Where are the cell bodies in the somatic nervous system?
A
- Motor nuclei of cranial nerves.
- Anterior horn cells of the spinal cord.
6
Q
How is the nervous system broken up?
A
- Central nervous system.
- Peripheral nervous system.
7
Q
Where do the nerve fibres go in the somatic nervous system?
A
Run un-interrupted straight to the muscles, ending as end plates of th muscle fibres.
8
Q
What is the motor part of the autonomic nervous system concerned with?
A
Innervation of cardiac and smooth muscle and glands.
9
Q
What is the pathway for nerves in the autonomic system?
A
The nerves are classically interrupted by synapses in a ganglion.
10
Q
What is pre-ganglionic and post-ganglionic autonomic fibres?
A
This is when there are two nerves in the autonomic nervous system that are broken up by synapses in ganglions.
11
Q
Where do the preganglionic cell bodies lie?
A
Within the central nervous system.
12
Q
Where do sympathetic preganglionic cell bodies lie?
A
Lateral horn cells of all thoracic and upper two lumbar segments of the spinal cord - thoracolumbar outflow.
13
Q
Where do parasympthetic preganglionic cell bodies lie?
A
Certain cranial nerve nucle in and in lateral horn cells of sacral segments of the spinal cord - craniosacral outflow
14
Q
Where do postganglionic cell bodies lie?
A
Peripheral nervous system.
15
Q
Where do sympathetic postganglionic cell bodies lie?
A
- Sympathetic trunk - paravertebral ganglia.
- Collateral ganglia e.g. coeliac ganglia.
16
Q
Where do parasympathetic postganglionic cell bodies lie?
A
Terminal ganglia - within the walls of viscera OR in four ganglia (head and neck).
17
Q
What are the outcomes when preganglionic fibres have reached the sympathetic trunk?
A
- Synapse with cell bodies in a trunk ganglion.
- Leave the trunk ganglion without synapsing and to pass to a collateral ganglion for synapse.
- leave the trunk without synapsing and pass to the suprarenal gland, where certain cells of the medulla can be regarded as modified ganglion cells (small number of cells).
18
Q
Where will you not find sympathetic outflow?
A
- Cervical part of the cord.
- Lower lumbar and sacral parts.
19
Q
Where do the preganglionic fibres go to where there is no sympathetic flow?
A
These fibres ascend in the sympathetic trunk to cervical ganglia, and lower lumbar/sacral nerves descend in the trunk to lower lumbar and sacral ganglia.
20
Q
What are the spinal levels of sympathetic preganglionic cells that supply the heart?
A
T1-5.
21
Q
What are the spinal levels of sympathetic preganglionic cells that supply the upper limb?
A
T1-6.
22
Q
What are the spinal levels of sympathetic preganglionic cells that supply the head salivary glands?
A
T1-3.
23
Q
What are the spinal levels of sympathetic preganglionic cells that supply the eye?
A
T1-2.
24
Q
What are the spinal levels of sympathetic preganglionic cells that supply the oeosphagus?
A
T4-6.
25
What are the spinal levels of sympathetic preganglionic cells that supply the lungs?
T2-6.
26
What are the spinal levels of sympathetic preganglionic cells that supply the stomach/liver/gallbladder/pancreas?
T7-9.
27
What are the spinal levels of sympathetic preganglionic cells that supply the small gut?
T9-10.
28
What are the spinal levels of sympathetic preganglionic cells that supply the appendix/colon?
T10-11.
29
What are the spinal levels of sympathetic preganglionic cells that supply the gonads?
T10-11.
30
What are the spinal levels of sympathetic preganglionic cells that supply the supra-renal?
T10-L1.
31
What are the spinal levels of sympathetic preganglionic cells that supply the lower limb
T11-12.
32
What are the spinal levels of sympathetic preganglionic cells that supply the bladder/rectum/uterus?
T12-L2.
33
What are the spinal levels of sympathetic preganglionic cells that supply the kidney?
T12-L1.
34
What are the spinal levels of sympathetic preganglionic cells that supply the ureter?
L1-2.
35
Where does the sympathetic trunk extend?
Alongside the vertebral column from the base of the skull to the coccyx. This theoretically forms a ganglion for each nerve.
36
Describe the ganglions and fusion?
Fusion occurs classically in the cervical region:
1. Upper four ganglion form = superior cervical ganglion.
2. 5-6th ganglion form = middle cervical ganglion.
3. 7-8th ganglion form = inferior cervical ganglion.
There is usually one ganglion less than the number of nerves e.g. 11 thoracic.
37
Where do the fibres from the lateral horn cells of each segment leave?
Anterior nerve root - with the axons of the anterior horn cell. They go to reach the spinal nerve and its anterior ramus.
38
What are rami communicantes?
Connecting links to the sympathetic trunk and its ganglia.
39
What are the type of rami ocmmunicantes?
1. White ramus communicans.
2. Grey ramus communicans.
40
Describe the features of the white ramus communicans?
- More distal of the two fibres.
- Contains preganglionic fibres (myelinated - so called white).
41
Describe the features of the grey ramus communicans?
- More proximal of the two fibres.
- Contains post-ganglionic fibres (unmyelinated).
42
How are the fibres in the grey ramus communicans distributed?
Via the branches of the spinal nerve to the following structures:
- Blood vessels.
- Sweat glands.
- Arrector pili muscles (vasomotor, sudomotor, pilomotor).
43
What does every spinal nerve receive?
Grey ramus.
44
What spinal nerves give off white rami?
1. Thoracic nerves.
2. L1-2.
45
What spinal nerves give off grey rami?
All of them.
46
Why do the cervical, L3-5 and sacral nerves not have white rami?
No sympathetic outflow from these segments of the cord.
47
What does each sympathetic trunk ganglion have?
Collateral or visceral branch.
48
What is the collateral/visceral branch called?
1. Splanchnic nerve - thoracic, lumbar and sacral regions.
2. Cardiac brach - cervical region (it proceeds to the cardiac plexus).
49
Where do the visceral branches arise?
High up and descend steeply to form plexuses for hte visera.
50
Where do cardiac branches arise from?
Three cervical ganglia.
51
Where do the cardiac branches descend into?
Go into the mediastinum to the cardiac plexus. The plexus is supplemented by fibres form upper thoracic ganglia.
52
What is the pathway of the lower thoracic ganglia?
The three splanchnic nerves pierce the diaphragm ot reach the coeliac plexus.
53
What is the pathway of the upper lumbar (L1-2) ganglia?
The lumbar splanchnic nerves descend to the superior hypogastric plexus.
54
What does the superior hypogastric plexus divides into?
Left and right inferior hypogastric plexuses.
55
What do the inferior hypogastric plexuses form?
Pelvic plexus.
56
What joins the inferior hypogastric plexuses?
Visceral branches from all the sacral ganglia - sacral splanchnic nerves.
57
What is the difference between sacral splanchnic nerves and pelvic splanchnic nerves?
Sacral splanchnic - sympathetic.
Pelvic splanchnic - parasympathetic.
58
What are sympathetic visceral plexuses joined by?
Parasympathetic nerves.
59
How do mixed visceral plexuses reach the viscera?
Branches that hitch-hike along the relevant arteries.
60
What do all trunk ganglia give off?
Vascular branches to adjacent large blood vessels.
61
What do the cervical ganglia give branches to?
Carotid arteries. Their branches (internal carotid nerve) runs upwards on the artery of that name to form the internal carotid plexus on the artery as it enters the skull.
62
What do the thoracic and lumbar ganglia give?
Filaments to the various parts of the aortic plexus and its derivatives (common iliac and median sacral arteries). Branches from the sacral ganglia pass to the lateral and median sacral arteries.
63
Where do limb vessels get their sympathetic innervation from?
Nerve fibres that run with the adjacent peripheral nerves before passing to the vessels. The fibres do not run long distances along the vessels themselves.
64
Where do the nerve filaments to the vessels of the tip of a finer or toe run?
They run with the digital nerves, not with the digital arteries, and the the leave the nerve near the actual site of innervation.
65
Describe afferent sympathetic fibres?
They hitch hike along sympathetic efferent pathways.
66
What can afferent sympathetic fibres form?
Afferent limb for unconscious reflex activities, others with visceral pain.
67
Where do afferent sympathetic fibres have their cell bodies?
Posterior root ganglia of the spinal nerve (not in sympathetic ganglia) at the same segmental level as the preganglionic cells.
68
What is the peripheral processes of the sensory cells?
1. Structure receives efferent innervation (usually vascular).
2. Run through any plexus or colalteral ganglion in which the efferent fibres were involved.
3. The fibres enter the sympathetic trunk.
4. The fires reach the spinal nerve via the white ramus communicans.
5. Join the posterior root ganglion, from which central processes enter the spinal cord by the posterior nerve root.
69
Where do visceral pain fibres enter?
Posterior horn.
70
What is the visceral pain fibres pathway?
First they enter the visceral horn then the pathway is the same as that for spinal nerve pain fibres.
71
What does the grey ramus communicans contain?
Only efferent post-ganglionic fibres.
72
What is a sympathectomy?
Parts of the sympathetic trunk are removed with the appropraite ganglia, this is to abolish the normal sympathetic influence.
73
What is removed in a cervical sympathectomy for the upper limb?
The 2nd and 3rd thoracic ganglia and their rami and the intervening part of the trunk are removed.
74
Why is the first thoracic ganglion not removed?
The pre-ganglionic fibres for the upper limb do not arise above T2 level, the removal would result in horner's syndrome.
75
What is removed in a lumbar sympethectomy?
3rd and 4th lumbar ganglia and the intervening trunk are removed, pre-ganglionic fibres do not arise below L2.
76
Why should the first lumbar ganglion be preserved?
Ejaculation can be compromised.
77
What is the distribution of the parasympathetic supply?
Wholly visceral and not to trunk or limbs.
78
What viscera are not innervated by the parasympathetic nervous system?
Suprarenal glands and gonads.
79
Where do the cell bodies of the preganglionic fibres of cranial origin lie?
1. Accessory oculomotor nucleus.
2. Superior and inferior salivary nuclei.
3. Dorsal motor nucleus of the vagus.
80
Where do the postganglionic cells of the accessory oculomotor nucleus, superior and inferior salivary nuclei occur?
In the four parasympathetic ganglia.
81
Where do the vagal fibres synapse with the postganglionic cell bodies?
In the walls of the viscera supplied:
1. Heart.
2. Lungs.
3. Gut.
82
Where do the preganglionic fibres of sacral origin arise from?
Cells in the lateral grey horn of sacral segmenets 2-4 of the spinal cord.
83
What constitutes the pelvic splanchnic nerves?
The preganglionic fibres of sacral origin.
84
What is the pathway of the preganglionic fibres of sacral origin?
1. Leve the anterior rami of the appropriate sacral nerves near the anterior sacral foramina.
2. Pass forwards to enter into the formation of the inferior hypogastric plexuses (pelvic plexus).
3. Run to pelvic viscera and to the hindgut as far up as the splenic flexure.
4. They reach the viscera either by running along their blood vessels or making their own way retroperitoneally.
5. Synapse around the postganglionic cell bodies in the walls of these viscera.
85
What are the four cranial parasympathetic ganglia?
1. Ciliary.
2. Pterygopalatine.
3. Submandibular.
4. Otic.
86
What does each of the four cranial parasympathetic ganglia have?
1. Parasympathetic.
2. Sympathetic.
3. Sensory roots.
4. Branches of distribution.
87
Describe the pathway of the parasympathetic root?
Carries the preganglionic fibres form the cells of origin in a brainstem nucleus.
88
Where do the fibres in the parasympathetic root synapse?
In the root of the ganglion. All other root simply pas through the ganglion without synapse.
89
What does the sympathetic root contain?
Post-ganglionic fibres from the superior cervical ganglion.
90
Where are the superior cervical ganglion preganglionic cell bodies?
In the lateral grey horn of cord segments T1-3.
91
What does the sensory root contain?
Peripheral processes of cell bodies in the trigeminal ganglion.
92
What do the branches of each ganglion carry?
Post-ganglionic parasympathetic fibres to the particular structures that require this kind of localised motor innervation e.g. salivary glandds form the submandibular and otic ganglia.
93
Describe the parasymapthetic root of the ciliary ganglion?
Edinger-westphat part of the oculomotor nucleus , by a branch from the nerve to the inferior oblique muscle.
94
Describe the sympathetic root of the ciliary ganglion?
From the superior cervical ganglion by branches of the internal carotid nerve.
95
Describe the sensory root of the ciliary ganglion?
From a branch of the nasociliary nerve, with cell bodies in the trigeminal ganglion.
96
Describe the branches of the ciliary ganglion?
Short ciliary nerves to the eye.
97
Describe the parasympathetic root of the pterygopalatine ganglion?
Goes from the superior salivary nucleus by the nerve of the pterygoid canal + greater petrosal nerve from the nervus intermedius part of the facial nerve.
98
Describe the sympathetic root of the pterygopalatine ganglion?
From the superior cervical ganglion by the internal carotid nerve + deep petrosal nerve + nerve of the pterygoid canal.
99
Describe the branches of the pterygopalatine ganglion?
The branches go to the lacrimal gland via the zygomatic and lacrimal nerves. They also go the mucous glands in the nose, nasopharynx and palate via maxillary nerve branches. A few fibres are taste fibres from the palate, running in the greater petrosal nerve with cell bodies in the geniculate ganglion of the facial nerve.
100
Describe the parasympathetic root of the submandibular ganglion?
From the superior salivary nucleus by the nervus intermedius part of the facial nerve and the chorda tympani, joining the lingual nerve.
101
Describe the sympathetic root of the submandibular ganglion?
From the superior cervical ganglion by fibres running with the facial artery.
102
Describe the sensory root of the submandibular ganglion?
From a branch of the lingual nerve, with cell bodies in the trigeminal ganglion.
103
Describe the branches of the submandibular ganglion?
They go to the submandibular and sublingual glands via branches of the lingual nerve.
104
Describe the parasympathetic root of the otic ganglion?
From the inferior salivary nucleus by the glossopharyngeal nerve and its tympanic branch to the tympanic plexus and then to the lesser petrosal nerve.
105
Describe the sympathetic root of the otic ganglion?
From the superior cervical ganglion by fibres running with the middle meningeal artery.
106
Describe the sensory root of the of the otic ganglion?
From the auriculotemporal nerve with cell bodies in the trigeminal ganglion.
107
Describe the branches of the otic ganglion?
They go to the parotid gland via filaments of the auriculotemporal nerve.
108
What does the otic ganglion have that the other 3 do not?
An additional somatic motor root, from the nerve to the medial pterygoid, the fibres pass through (without synapse) to supply tensor tympani and tensor palati.
109
Where do parasympathetic afferent fibres run?
With the glossopharyngeal and vagus nerves. The cell bodies are in the inferior ganglia of these nerves and their central processes pass to the nucleus of the tractus solitarius. There are connexions with other parts of the brainstem for reflex control of respiration/HR/BP/GI activity.
