Morphine will be described in detail and other opioid analgesics principally in so far as they differ. Morphine acts mainly on the opioid p,-receptor (analgesia, euphoria, dependence) and p2-receptors (respiratory depression, reduced gut motility). The principal actions of morphine may be summarised:
On the central nervous system:
• Depression, leading to: analgesia, respiratory depression, depression of cough reflex, sleep
• Excitation, leading to: vomiting, miosis, hyperactive spinal cord reflexes (some only), convulsions (very rare)
• Changes of mood: euphoria or dysphoria
• Dependence; affects other systems too.
Peripheral nervous system:
• Analgesia, some anti-inflammatory effect
Smooth muscle stimulation:
• Gastrointestinal muscle spasm (delayed passage of contents with constipation)
• Biliary tract spasm
• Dilatation of resistance (arterioles) and capacitance (veins) vessles.
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Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.