6 Flashcards

1
Q

What are some features of the autonomic (visceral) nervous system?

A
  • Part of the peripheral nervous system
  • Central control is from hypothalamus
  • controls body functions not under conscious control
  • maintains and fine tunes internal environment; like an accelerator and brake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two main components of the autonomic nervous system? How are ganglion involved?

A
  • divided into sympathetic and parasympathetic components

- consists of preganglionic and postganglionic nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the usual target tissues of the ANS?

A
  • smooth muscle: action is involuntary and frequently found in viscera
  • smooth muscle in blood vessels
  • glands (sweat, lacrimal, mucosal and salivary)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the difference between what the sympathetic and parasympathetic innervate?

A

Sympathetic

  • smooth muscle of blood vessels, eye lid (tarsal muscle) and iris (dilator pupillae, which will dilate pupil)
  • sweat glands
  • Arrector pili muscles (hair follicles)
  • decreases secretions from salivary and lacrimal glands (smaller volume but higher protein, so more viscous)

Parasympathetic

  • smooth muscle of iris (sphincter pupillae) and muscle in ciliary body (controls thickness of lens)
  • lacrimal glands (tears)
  • salivary and mucosal glands
  • smooth muscle of the respiratory and GI tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where in the spinal cord do the sympathetic and parasympathetic nerves arise from?

A

Sympathetic

  • thoracolumbar outflow
  • segments T1-L2 of spinal cord only
  • cell bodies within lateral horn of grey matter of spinal cord

Parasympathetic

  • craniosacral outflow
  • Cranial (four cranial nerves): supplies parasympathetic innervation to head and neck, thorax and abd
  • Sacral (S2-S4): pelvic splanchnics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name the collective name of the top 3 ganglion of the sympathetic chain, and their individual names

A
  • Collectively known as cervical ganglion
  • Superior cervical ganglion (most important)
  • middle cervical ganglion
  • inferior cervical ganglion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Explain how sympathetic outflow to head and neck works

A
  • nerves to head and neck region arise from T1/T2 spinal segments
  • preganglionic fibres ascend from thorax, up the sympathetic chain
  • they synapse with one of the cervical ganglia, mainly superior and middle
  • postganglionic then follow common carotid into the external and internal carotid arteries
  • they HITCH-HIKE onto the blood vessels
  • follow internal carotid to supply the eye (through opthalmic artery)
  • follow external carotid to supply sweat glands and vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How do the common carotid arteries and the lung apex relate to sympathetic nerves innervating head and neck, especially in pathology?

A
  • patient will usually present with Horner’s syndrome
  • partial ptosis, anhydrosis, miosis
  • pathology involving apex of lung and common carotid artery and its branches can cause autonomic dysfunction in the eye and face
  • may involve pancoast tumour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a pancoast tumour?

A

-tumour that occurs in the apex of the lung

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Horner’s syndrome?

A
  • involves partial ptosis, miosis and anhydrosis
  • partial ptosis: partial drooping of eyelid, not complete because levator papillary superioris is helping to elevated it
  • miosis: constriction of pupil
  • anhydrosis: lack of sweating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which cranial nerves “carry” parasympathetic fibres from the brainstem?

A

-CN 3, 7, 9, 10

Oculomotor, facial, glossopharyngeal, vagus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the general pathway of parasympathetic innervation to head and neck

A

Rule of 4s

  • Arise from brainstem from parasympathetic nuclei
  • hitch-hike on to one of 4 CNs
  • parasympathetic ganglia (4)
  • hitch hike on to branches of CN V (trigeminal, very short distance; exception is CN x)
  • goes to target tissues
  • none of these CNs carry sympathetic fibres, those come from a different route
  • postganglionic fibres travel and hitch-hike on branches of trigeminal nerve (is a short route)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the pathway for the parasympathetic innervation of CN 3?

A
  • Arise from Edinger Westphal
  • goes to CN 3
  • goes to ciliary ganglia
  • hitch hikes on CN Va
  • goes to smooth muscle (sphincter pupillae: constricts pupil) and (ciliary muscle: controls and alters shape of lens)
  • parasympathetic fibres run OUTSIDE of oculomotor nerve
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the pathway for the parasympathetic through CN 7?

A
  • arise from superior salivary
  • goes to CN 7
  • goes to submandibular ganglion
  • goes to CN V branches
  • ends at lacrimal gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the pathway for the parasympathetic of CN 9?

A
  • arises from inferior salivary
  • goes to CN 9
  • goes to pterygopalatine ganglia
  • hitch hikes on CN V branches
  • ends at mucosal gland in nasal/oral mucosa/resp. Tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the pathway for the parasympathetic of CN 10?

A
  • arise from dorsal motor
  • go to CN 10
  • goes to optic ganglion
  • ends at salivary glands
  • preganglionic fibres will meet ganglion in or at the target tissue

Target tissues are:

  • mucosal glands in pharynx/larynx and smooth muscles of oesophagus and trachea
  • smooth muscle and mucosal glands within rest of resp. And GI tract
  • heart
17
Q

How do pupillary light reflexes work?

A
  • shine light in (ex. Left) eye
  • optic nerve senses the light (sensory AFFERENT)
  • communication from optic tract to brainstem telling how much light there is
  • this info is relayed to Edinger Westphal nucleus on both sides
  • pre-ganglionic parasympathetic fibres then bring back info through oculomotor nerve on BOTH eyes
  • pre-ganglionic synapse at ciliary ganglion to become post-ganglionic
  • reach sphincter pupillae muscle of the iris
  • as a result, the pupils constrict
  • direct light reflex: eye in which light is shone
  • consensual light reflex: opposite eye
18
Q

What two branches of CN 7 do the parasympathetic fibres hitch-hike on to get to the target tissues?

A
  • Greater petrosal
  • Chorda tympani
  • both arise in petrous bone
19
Q

What are the two associated parasympathetic ganglia of CN 7?

A
  • Greater petrosal runs over foramen lacerum and goes to PTERYGOPALATINE GANGLIOn which is found in the PTERYGOPALATINE FOSSA
  • post-ganglionic goes to lacrimal and mucosal glands
  • Chorda tympani goes to SUBMANDIBULAR GANGLION which is found beneath the tongues
  • innervates submandibular gland and carries taste to anterior 2/3 of tongue
  • post-ganglionic parasympathetics then run with distal branches of the trigeminal (lingual nerve)
20
Q

Describe the parasympathetic fibres of CN 9

A

-exits through jugular foramen with CN 9 but at this point, splits into a number of branches:
-tympanic nerve which supplies sensory to middle ear
-parasympathetic fibres run with the tympanic nerve initially (hitch-hike)
-then parasympathetics exit middle ear as lesser petrosal nerve
-synapses in otic ganglion (in infratemporal fossa)
-postganglionic parasympathetics then hitch-hike on branch of CN Vc (auriculotemporal)
-supply parotid gland
See diagram in session 6 lecture slide 25

21
Q

What is exophthalmos?

A

Retraction of eyeballs

22
Q

What is the difference between hyperthyroidism and Grave’s disease?

A
  • hyperthyroidism is an umbrella term

- Grave’s disease is an autoimmune condition which causes hyperthyroidism, so you will have exophthalmos

23
Q

Between which two layers does an extradural haemmorhage occur?

A

Inter table of periosteum and periosteal layer of dura

24
Q

How can we treat an extradural haemorrhage?

A
  • drain the blood

- go through layers of scalp but not periosteal layer of dura