The "fight or flight" mechanism is one of the best-known physiological responses. It increases our ability to respond to stressful situations. One way to look at exercise – physiologically -- is as a non-life-threatening example of a stressful situation. Think about it: When we exercise, our heart and breathing rates rise rapidly and blood vessels in our limbs dilate in order to deliver more oxygenated blood to our working muscle cells. The rapid rise in blood flow to the periphery -- especially to the legs -- can create a "heady" feeling, which reflects a temporary drop in blood pressure. This stimulates sympathetic nerves throughout the body to release substances that constrict blood vessels, even those vessels that feed working muscles.
Blood vessels in our leg muscles must respond to both dilating and constricting substances to meet the competing demands of muscle oxygen delivery and maintenance of bodily blood pressure, so we don’t faint! It’s a balancing act that could change with advancing age.
David Proctor and Urs Leuenberger and physiology student Dennis Koch, researchers at Pennsylvania State University and Hershey Medical Center, studied this possibility by manipulating the activity of the sympathetic nervous system in healthy older and younger men undergoing a moderate level of leg (cycling) exercise. They used a simple, but powerful sympathetic stimulus -- plunging a hand into a bucket of ice while still cycling -- and compared the blood vessel reactions in the legs of both age groups.
Mayer Resnick | EurekAlert!
Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg
New potential cancer treatment using microwaves to target deep tumors
12.10.2016 | University of Texas at Arlington
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences