Here's a UK study on blood-pressure:

The research centres on endocannabinoids - natural substances produced by the body - which are chemically similar to the active ingredients in the drug.

These substances are known to make blood vessels relax, which can reduce blood pressure by allowing blood to flow more freely.
http://news.bbc.co.uk/1/hi/health/244086.stm

"Laurie [iii] reported that in a few cases 'anxiety, which may approach panic, often associated with a fear of death or an oppressive foreboding is infrequently seen, usually giving way to an increasing sense of calmness... to euphoria'. Grinspoon refers to the initial state as a 'happy anxiety' where the experience is internally redefined as pleasurable. Rosenthal et al [iv] report that panic reactions and anxiety are rare, and most commonly found with overdose (particularly from oral preparations), in naĆ?ve users, or in those who do not like the effects of marijuana, and attributed the incidence of anxiety reports with Marinol (dronabinol - pure THC) to the lack of CBD within the preparation. "
http://www.idmu.co.uk/canstressdepres.htm