Increasing stimulation of the parasympathetic nervous system decreases heart rate and blood pressure as well as the size of the pupil. At the same time, it increases digestion, urination, defecation and sexual arousal. The parasympathetic nervous system governs activities that involve relaxation.Know More
The parasympathetic nervous system controls body functions that do not require immediate action. These include digestion and sexual arousal. It also promotes urination by moving urine down the tubes that connect the kidneys to the bladder, and causes the bladder to contract and relaxes the sphincter that allows urination. Defecation is aided by the movement of feces along the intestine and relaxation of the anal sphincter. Sexual arousal is dependent on the engorgement of sexual organs by blood, and stimulation of the PNS allows this to occur. In the female, PSN stimulation assists the movement of eggs from the fallopian tube to the uterus.
The PSN increases secretions, such as saliva, and this aids digestion. Mucous production is increased while the muscles of respiration relax.
Stimulation of the PSN decreases heart rate. It decreases blood pressure by causing dilation of the blood vessels. This is often seen in athletes who have a low resting heart rate and a fast recovery time. Runners and bicyclists are good examples of this.Learn more about Biology
Fungi range in size from a single-celled organism, such as yeast, to a 3.5-mile-wide mushroom located in Oregon's Malheur National Forest. This honey mushroom covers more than 2,200 acres of the forest floor and is dubbed "the humongous fungus."Full Answer >
According to Nature Education, restriction enzymes are used to cut DNA into smaller pieces that can then be separated by size via gel electrophoresis. Typical restriction enzymes cut DNA at four or six base pair recognition sites, resulting in very small pieces of DNA.Full Answer >
Because mean corpuscular volume, or MCV, measures the size of a patient's red blood cells, or RBCs, a low MCV number indicates smaller-than-normal RBCs. Small RBCs indicate a condition known as microcytic anemia, which has numerous causes, the most common being iron-deficient anemia.Full Answer >
To identify an unknown flowering shrub, consider the size and shape of the leaves and the color, size and shape of the flower. Use these characteristics to search for a match in a plant database or consult an expert at a nearby garden center or nature preserve. To locate databases of plants likely to grow in the area, consult state agriculture organizations, nearby nature preserves or local university extension programs.Full Answer >