4.a) Visceral pain Flashcards Preview

Anatomy of the abdomen, pelvis and perineum > 4.a) Visceral pain > Flashcards

Flashcards in 4.a) Visceral pain Deck (29)
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1
Q

What is the point in the enteric nervous system?

A

Enables the GI tract to perform reflex functions of secretion, absorption, mixing and gut movements without the influence of the CNS or ANS

2
Q

How is the ENS arranged?

A

In ganglionated plexuses with interconnecting bundles of unmyelinated nerve fibres

3
Q

How does the CNS communicate with the intrinsic neurones of the ENS?

A

Via sympathetic and parasympathetic nerves

Brings about modulation of GI tract functions

4
Q

What do axons of the intrinsic neurones of ENS project to?

A
Sympathetic ganglia
Pancreas
Gall bladder
Trachea
Spinal cord
Brain stem
5
Q

Where are the 2 plexuses in the GI tract?

A

Submucosal plexus: Meissner’s plexus

Myenteric plexus: Auerbach’s plexus

6
Q

Describe the distribution of the Enteric Nervous System

A

The intrinsic network of neurons of the ENS is situated in the tissues of the gut wall from oesophagus to anus.

7
Q

Where do the sympathetic nerves arise?

A

T1-L2

= Thoracolumbar

8
Q

Where do the parasympathetic nerves arise?

A

Cranial: III, VII, IX and X (occulomotor, facial, glossopharyngeal and vagus)
Sacral: S2-S4

9
Q

What are the roles of efferent autonomic nerve fibres in the abdomen?

A

Motor to smooth muscle

Secretomotor to glands

10
Q

What are the roles of afferent sympathetic and parasympathetic nerve fibres?

A

Sympathetic: mediates pain
Parasympathetic: specific functional sensation e.g. stretch

11
Q

Describe the arrangement of the splanchnic nerves.

A

All the splanchnic nerves (greater, lesser and least) arise in the thorax and descend into the abdomen.
Greater splanchnic = T5-T9
Lesser splanchnic = T10 + T11
Least splanchnic = T12

12
Q

Describe the parasympathetic innervation of organs of the

abdomen and pelvis

A
Vagus nerve (X)
Sacral outflow (S2-4)
13
Q

Describe the distribution of autonomic nerves to peripheral vessels and skin (sympathetic only)

A

Sympathetic nerves run with somatic nerves to the same region

14
Q

Describe the distribution of autonomic nerves to organs (lacking somatic innervation).

A

Most nerves run with the arteries to the same organs

There are a few cases where autonomic nerves run separately

15
Q

State the autonomic abdominal ganglia in order from top to bottom.

A
(Anterior left vagal trunk)
Coeliac trunk and ganglion 
Superior mesenteric ganglion 
Renal plexus and ganglion 
Inferior mesenteric ganglion 
Sympathetic trunk and ganglion
Superior and inferior hypogastric plexuses
16
Q

How are autonomic nerves to the abdomen routed?

A

Via plexuses surrounding the aorta and its branches

17
Q

Where do sympathetic nerves of the abdomen synapse?

A

At ganglia associated with plexuses that surround the aorta and its branches

18
Q

Where do the testicular/ovarian arteries arise?

A

Arise below the superior mesenteric artery and above the inferior mesenteric artery (closer to the SMA).

19
Q

State the nerves that travel to the organs supplied by the main branches of the aorta and the important abdominal plexuses.

A

Coeliac artery: greater splanchnic (T5-T9) + X
Superior mesenteric artery: lesser splanchnic (T10-T11) + X
Renal arteries: lesser and least splanchnic (T10-T12) + X
Testicular/Ovarian arteries: lesser splanchnic (T10-T11) + X
Inferior mesenteric artery: T12-L2 + S2-S4
Superior and inferior hypogastric plexuses: T12-L2 + S2-S4

20
Q

Why can’t the brain localise pain sensation from visceral organs and the diaphragm?

A

The cerebral cortex of the brain has no ‘sensory map’ for visceral organs and the diaphragm
Pain is referred regions of skin supplied by nerves with the same segmental supply (dermatomes)

21
Q

Dermatome

A

An area of skin supplied by a single spinal nerve (i.e. single segment of the spinal cord)

22
Q

Why might a disruption in one nerve not cause any major changes in sensation on the skin?

A

Because adjacent dermatomes overlap so that on the trunk, at least 3 spinal nerves would have to be blocked to produce a region of complete anaesthesia.

23
Q

Which vertebrae has no dermatome?

A

C1

24
Q

State the regions where pain from the foregut, midgut and hindgut is referred to
State the nerves that innervate these regions

A

Foregut: Epigastric (T7/T8)
Midgut = Umbilical (T10)
Hindgut = hypogastric (T12 - L1/2)

25
Q

What structures may cause pain in the epigastric region?

A
Stomach
Proximal duodenum
Pancreas
Liver
Gall bladder
26
Q

What structures may cause pain in the umbilical region?

A

Midgut structures (from duodenal papilla to splenic flexure) including inflamed appendix (usually colicky- intermittent with bowel contractions)

27
Q

When would pain due to an inflammed appendix be felt in the inguinal region?

A

When the inflammation spreads to the surrounding peritoneum - then the pain will become localised and constant at the right inguinal region

28
Q

What would elicit pain from an inflamed appendix?

A

Movement of the hip joint

Coughing

29
Q

What structures may cause pain in the suprapubic/ hypogastric region?

A

Hindgut structures

Descending colon to anal canal