Centrally acting muscle relaxants reduce muscle tone and tension by interfering with the postsynaptic reflexes in the central nervous system.
Centrally acting drugs are classified into spasmolytic and antispasmodic drugs. Spasmolytic drugs such as baclofen, diazepam, and tizanidine inhibit spinal motor neurons and decrease muscle tone. Spasmolytic drugs are administered for severe and chronic spasms due to multiple sclerosis, cerebral palsy, stroke, and spinal cord and muscle injuries. However,...

Skeletal muscle relaxants are used to relax muscle tone and alleviate painful muscle contractions. However, the choice of skeletal muscle relaxants depends on the duration of the surgical procedure in order to minimize potential side effects. Skeletal muscle relaxants like neuromuscular blocking agents [NMBAs] are commonly employed as adjuvants alongside general anesthetics in clinical settings. NMBAs are also used to maintain controlled ventilation during surgery of the larynx or pharynx...

Skeletal muscle relaxants can target the central nervous system [CNS] to reduce muscle tension or act directly at the neuromuscular junction to induce temporary paralysis. These two classes of muscle relaxants are called centrally acting muscle relaxants and peripherally acting muscle relaxants. They differ in their action, mechanism, administration route, and clinical uses.
Centrally acting muscle relaxants can be further divided into spasmolytic and antispasmodic drugs. Spasmolytic...

The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open....

Directly acting muscle relaxants like dantrolene and botulinum toxin (BoNT) have distinct mechanisms and applications. Dantrolene, a hydantoin derivative, acts on the ryanodine receptor (RYR1) in skeletal muscle cells. RYR1 are calcium channels present at the sarcoplasmic reticulum membrane. In response to excitation, they release calcium ions from the sarcoplasmic reticulum to the cytosol. Calcium promotes actin-myosin-mediated contraction of muscles.
The binding of dantrolene to the RYR1...

Palpation is a crucial tactile examination method for assessing abdominal organs and detecting conditions like tenderness, distention, masses, or fluid. It involves both light and deep palpation techniques, each serving specific diagnostic purposes. Light palpation helps identify tenderness and other surface-level indicators, while deep palpation locates and assess abdominal masses and organ boundaries. A skilled professional can gather valuable insights through palpation, including evaluating...