Healthy Beginnings

Nerve Function and How it Impacts Your Health

In parts one and two of this series, we discussed the effects of the nerves and their function in the neck and thoracic, or mid-back area. In this article, we will be discussing the nervous system of the lumbar, or low-back area.

The spinal cord comes o the base of the brain, and runs throughout the cervical and thoracic spine. The spinal cord ends in the lower thoracic area, and o the cord comes nerve roots for the lumbar and sacral levels that look like a horse’s tail, which is called cauda equina. The nerves then exit the spine at different levels, and are named for the level at which they exit.

Upon exiting the vertebral canal, the spinal nerves of the lower back form into two networks known as the lumbar and sacral plexuses. The lumbar plexus supplies nerves to the skin and muscles of the lateral abdominal region, thigh, anterior thigh and external genitals. The sacral plexus similarly supplies nerves to the skin and muscles of the posterior thigh, leg and foot.

The sciatic nerve is the largest and longest single nerve in the human body, about as big around as a man’s thumb at its largest point, and it carries a major portion of the nerve signals from the sacral plexus into the leg before separating into many smaller branches. The sciatic nerve supplies sensation and strength to the leg, as well as the re exes of the leg.

The spinal nerves of the lower back also carry many neurons of the autonomic nervous system (ANS) that maintain the vital involuntary processes of the digestive, urinary, endocrine and reproductive systems.

The parasympathetic division of the ANS is also represented in the abdomen and pelvis through the vagus nerve and the sacral nerves. The vagus nerve is a cranial nerve that wanders from the base of the brain parallel to the spinal cord to stimulate digestion in the liver, stomach and intestines. Parasympathetic neurons in the spinal cord pass through the sacral nerves in the lower back to reach the pelvic organs such as the bladder and reproductive organs to control their functions.

The human body has a built-in threshold to help us so we’re not in pain all the time. If the nerves exiting the spine are being pinched or irritated a little or a lot, it will depend on your symptoms. If the nerves’ irritations are under the threshold, you can still be having problems but you might not even realize anything is happening or wrong because there is no pain. When a nerve is irritated it will do one of two things:

  1. Make the body part work sluggish.
  2. Be in a state of irritation.
If either occurs, we will look at what happens with each of the lumbar nerves’

function, and if they are irritated, we examine each of the following:

  • L1:  Helps control the large intestine. If irritated, possible constipation, colitis, diarrhea, hernias.
  • L2:  Helps control the appendix, abdomen and upper leg. If irritated, possible cramps, di cult breathing, acidosis and varicose veins.
  • L3:  Helps control sex organs, uterus, bladder and knees. If irritated, possible bladder troubles, menstrual troubles such as painful or irregular periods, miscarriages, bedwetting, impotency, change of life symptoms and knee pain.
  • L4:  Helps control prostate gland, muscles of the lower back, and sciatic nerve. If irritated, possible sciatica, lumbago, di cult painful or too frequent urination, and backaches.
  • L5:  Helps control lower legs, ankles and feet. If irritated, poor circulation in the legs, swollen ankles and arches, cold feet, weakness in the legs and leg cramps.

Sacrum: Helps control hip bones and buttocks. If irritated, low back pain and spinal curvature.

Coccyx: Helps control rectum and anus. If irritated, hemorrhoids (piles), pruritis (itching) and pain at the end of spine on sitting.

Our spine is a wonderful thing, and we only have one, so please take good care of it. When all of our body parts and tissues are communicating together at a 100 percent, we can expect optimum health. So take the time to keep your nervous system and spine in the best condition you can by getting it checked to rule out any nerve irritations or unseen problems. A chiropractor is highly trained to see if you have any pinched or irritated nerves that might be setting you up for problems. So enjoy a healthy and happier life, with a happy spine and nervous system.

For more information, call Jensen Chiropractic at 775-323-1222 or visit