Thoracoabdominal Nerves

These nerves are the ventral rami of the thoracic spinal nerves T7-T11 and subcostal nerves T12. They supply the anterolateral muscles and overlying skin. These nerves are supplemented by the anterior terminal branches of the subcostal nerves and by a branch of the iliohypogastric nerve (L1) of the lumbar plexus after passing through the muscles, they are sensory nerves of the skin.

Gallbladder Anatomy

Located in the RUQ, the gallbladder is a small organ that aids in digestion.  It secretes bile into the cystic duct where it is joined by the common hepatic duct and forms the common bile duct which empties into the duodenum when fat is being digested.  The gallbladder consists of three parts: the fundus, body and neck. It is supplied by the cystic artery. It is innervated by the vagus nerve and celiac ganglia.

Zolpidem

Zolpidem is a nonbenzodiazepene hypnotic that binds to and activates allosteric benzodiazepine sites of GABA-a receptors. It is used primarily as treatment for sleep disorders such as insomnia. In the US, it is marketed as Ambien and Ambien CR.

Organophosphate Poisoning

Organophosphates inhibit acetylcholinesterase. This results in an increase of Ach buildup in the cholinergic synapses. The physiological effect is over-stimulation of the PS nervous system and excessive cholinergic symptoms.  A common acronym is SLUDGE:

salivation, lacrimation, urination, defecation/diaphoresis, gastric secretion and emesis.

When sympathetic neurons innervate sweat glands, they become cholinergic neurons and secrete Ach.  This is the only occurence of adrenergic transdifferentiation in the body. 

Reflex Sympathetic Dystrophy

RSD is a chronic progressive disorder characterized by pain, swelling, cutaneous discoloration, sudomotor disturbances and other dystrophic changes in the skin of extremities. Sympathetic nerves of the body wall viscera are affected.  Usually caused by trauma or surgery.

Pheochromocytoma

Pheochromocytoma is a tumor of the adrenal gland.  It results in increased production of E & NE by the chromaffin cells. The result is sympathetic hyperactivity.

Key presentations of pheochromocytoma include high BP, racing heart & diaphoresis.

Functions of Adrenergic Receptors

alpha (activated by NE)

• a1 – postsynaptic excite (constriction)  => vasoconstrict
• a2 – presynaptic inhibit (dilation) => inhibit NE release, vasodilate, ↓BP

 

beta (activated by E)

• b1– postsynaptic excite => ↑ heart fxn & metabolism
• b2 – postsynpatic inhibit => bronchodilation, relax uterine muscle, ↑ eye pressure, relax muscles

Horner’s Syndrome

Main symptoms:

• partial tsosis
• pupil constriction
• decrease facial sweat
• enophtalmosis (retraction of eye)
• dilation of facial blood vessels = redness, nasal congestion, excessive lacrimation

Muscarinic Poisoning

Muscarine mimics the activity of Ach at muscarinic receptors.  It has profound impacts on the parasympathetic nervous system.  Symptoms include abdominal pain, profuse sweating, diarrhea, hypotension and bradycardia.

Adrenergic Receptors

Adrenergic receptors are postganglionic receptors found on cells in target organs of autonomic stimulation.

There are 2 main types: alpha & beta.

alpha (activated by NE)

• a1 – postsynaptic excite (constriction)
• a2 – presynaptic inhibit (dilation)

beta (activated by E)

• b1- postsynaptic excite
• b2 – postsynpatic inhibit