Search found 17 matches

by angelo
Mon Mar 01, 2010 4:31 am
Forum: General Discussion
Topic: Why do neurons form into clusters?
Replies: 0
Views: 1779

Why do neurons form into clusters?

What causes nerve cells to form into clusters/ganglia, and what are the advantages of cell clusters?
by angelo
Sun Jul 23, 2006 7:41 am
Forum: Human Biology
Topic: homeostasis vs. memory
Replies: 5
Views: 2765

I like that question. I will get back to you in about 20 years when I have the answer. Are you a student?
by angelo
Thu Feb 09, 2006 4:10 pm
Forum: Physiology
Topic: Difference between opiate and opiod
Replies: 4
Views: 15800

is it correct?

"opioid An opioid is any agent that binds to opioid receptors, found principally in the central nervous system and gastrointestinal tract. There are four broad classes of opioids: endogenous opioid peptides, produced in the body; opium alkaloids, such as morphine (the prototypical opioid) and c...
by angelo
Sun Jan 22, 2006 2:45 pm
Forum: Human Biology
Topic: How does the heart work?
Replies: 11
Views: 6754

yes, they have so called If-Ca(2+)-channels which depolarize when e membrane potential of -60 mV is reached, resulting in contraction cycles. Ok. So at the time of action potential, the Ca(2+) channels are letting calcium flow into the cell. The refractory period is relatively long. Why is it so lo...
by angelo
Sat Jan 21, 2006 10:03 pm
Forum: Human Biology
Topic: How does the heart work?
Replies: 11
Views: 6754

Ok (thanks). So I suppose that the chemical properties of cells in the SA node and their enviroment are generating action potentials in the cells. But what makes them fire so slowly, and in such a rythmic manner?
by angelo
Sat Jan 21, 2006 12:31 am
Forum: Human Biology
Topic: How does the heart work?
Replies: 11
Views: 6754

How does the heart work?

How does the heart work? I mean, is every beat mediated by an electrical signal from the brain? If so (or not) , where does the signal originate? What creates it, and what keeps it from stopping? (How could it be so robust?)
by angelo
Sat Jan 21, 2006 12:27 am
Forum: Human Biology
Topic: SNS dilation of blood vessels
Replies: 1
Views: 2913

SNS dilation of blood vessels

The sympathetic nervous system contracts blood vessels, causing a higher blood pressure. But how does an increase in pressure prime the body for a response?

And is the contraction purely by activation of smooth muscle tissue at the blood vessel?
by angelo
Fri Jan 20, 2006 7:28 am
Forum: Physiology
Topic: Defining pleasure.
Replies: 11
Views: 8693

oki.

Ok. Sensual gratification. How could I define this term in biological terms?
by angelo
Fri Jan 20, 2006 7:25 am
Forum: Physiology
Topic: Muscular pain
Replies: 6
Views: 5285

yep

It's not a problem, I'm just interested in the mechanism mediating the sensation of pain.

Ok, lactic acid. But is this directly causing the firing of nociceptive neurons? And if so, how?
by angelo
Thu Jan 19, 2006 8:08 am
Forum: Physiology
Topic: Defining pleasure.
Replies: 11
Views: 8693

Defining pleasure.

What is pleasure?
by angelo
Thu Jan 19, 2006 8:06 am
Forum: Physiology
Topic: Muscular pain
Replies: 6
Views: 5285

Muscular pain

During a rigorous workout, my muscles might start to hurt. What causes this? Is the depleated tissue releasing substances that activate nociceptive neurons?
by angelo
Thu Jan 19, 2006 8:02 am
Forum: Physiology
Topic: Receptors in joints.
Replies: 4
Views: 6038

Receptors in joints.

What kind of receptors give feedback on the position of joints? Are they similar to the stretch receptors in muscles?