Final answer:
Block anesthesia is used on the mandibular teeth and involves injecting an anesthetic near the mandibular foramen to numb the mandibular nerve, effectively reducing sensation in the lower teeth region.
Step-by-step explanation:
Block anesthesia is frequently used on the mandibular teeth and is injected near a major nerve that numbs the entire area served by that nerve branch.
During dental procedures such as tooth extraction, the dentist injects an anesthetic into the area around the mandibular foramen to numb the mandibular nerve. This important nerve is responsible for the sensory innervation of the lower teeth. The injection is made into the lateral wall of the oral cavity, targeting the area before the nerve enters the mandibular foramen. By doing this, the entire nerve branch is affected, resulting in a lack of sensation throughout its distribution. This type of anesthesia is considered a local anesthetic, which means the effect is limited to the region where the drug is applied and does not affect consciousness.
Local anesthetics block nerve conduction by interfering with the movement of ions across the nerve cell membranes, thus preventing the initiation and transmission of nerve impulses. This blockade is reversible, and normal sensation returns once the anesthetic wears off.