Defining sagittal imbalance in axial spondyloarthritis: considerations beyond C7 sagittal vertical axis

Homeostasis is the maintenance of a stable internal environment within the body, which is crucial for the proper functioning of cells, tissues, organs, and organ systems. The body has various control mechanisms that work together to regulate various physiological parameters such as temperature, blood pressure, pH balance, and fluid balance, to name a few. These control mechanisms are based on feedback loops that can be either positive or negative.
However, sometimes these feedback loops fail,...

The heart's primary function is to pump blood throughout the body, maintaining a balance between blood sent out (cardiac output) and blood returning (venous return). If this balance is disrupted, it can result in congestive heart failure (CHF), a severe condition where the heart becomes an inefficient pump, leading to inadequate blood circulation.
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send...

Hyperthermia occurs when the body's temperature becomes unusually high, often due to heat exposure, intense physical activity, or certain illnesses. This condition can create a dangerous cycle where elevated body temperature increases the metabolic rate, generating more heat and potentially leading to organ failure and brain damage. A severe form of hyperthermia, called heat stroke, can raise body temperature to life-threatening levels. Fever, on the other hand, is a controlled form of...

Skeletal muscles, the key players in our body's movement, can be classified into two groups based on their location and function: axial muscles and appendicular muscles. These classifications reflect the primary roles the muscles play in the body's structure and movement.
Axial Muscles
Axial muscles, situated along the body's midline, are intricately connected to the axial skeleton, which includes the skull, spine, ribs, and sternum. These muscles facilitate facial expressions and...

The response to stress—be it physical or psychological, acute or chronic—involves activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis. The HPA axis is part of the neuroendocrine system because it involves both neuronal and hormonal communication. Its function is to regulate homeostatic systems—metabolic, cardiovascular, and immune—providing the necessary means to respond to a stressor.

Vertical curves provide the transition between two roadway grades, ensuring safety, comfort, and functionality. Calculating elevations at specific stations along the curve involves several systematic steps based on the curve's geometry and provided design parameters.The vertical curve is defined by its length, grades, Point of Vertical Intersection (P.V.I.) location, and P.V.I. elevation. The stations of the Point of Vertical Curvature (P.V.C.), where the curve begins, and the Point of Vertical...