Retraction is the shrinking or retraction of a tissue, organ, or other anatomical structure. Physiologically, for example, maternal tissues contract during child birth to allow passage of the pushing head. The concept of retraction is also relevant pathophysiologically, for example, retraction of the nipple in carcinoma in situ.
What is retraction?
Retraction is, for example, the shrinkage or retraction of a tissue. Physiologically, when a baby is born, for example, maternal tissue contracts to allow the pushing head to pass through. “Retrahere” is a Latin verb and literally means to pull back. Accordingly, the term retraction is a loanword from Latin and is associated with various meanings in medicine. As a rule, any medical process of retraction has the meaning of retraction, which can refer to various tissues. Thus, a retraction in medicine implies the retraction or shrinkage of tissues, organs or other structures of the organism. The opposite of retraction is understood to be protraction, which in anatomy is associated with an advancement of body parts or other structures. For example, the mandible can advance and thus has completed a protraction. In contrast, when the mandible retracts, it retracts backward, i.e., it pushes backward. In different contexts, retraction also stands medically for a regression of tissues, as is relevant above all in the context of diseases. Basically, the term retraction is used more in pathophysiology than in physiology. That is, retraction is most often associated with disease processes than with natural body processes.
Function and task
Wholly natural retraction in a healthy organism occurs, for example, during wound healing. When the body’s vascular system is injured, the coagulation cascade prevents blood leakage and thus stimulates hemostasis (hemostasis). The coagulation system thus corresponds to an endogenous protection against bleeding and the resulting blood loss. Accordingly, hemostasis is a vital bodily function. Three steps are involved in blood clotting. Vasoconstriction, i.e. contraction of the vascular musculature in the injured vessel, occurs as a result of the release of serotonin and thromboxane. Slowed flow velocity is now present in the injured blood vessel, which activates platelet aggregation. In the third step of the coagulation cascade, the injury closes with an aggregate consisting of fibrin polymers and platelets. A thrombus forms, so that the escape of blood is inhibited. Once the thrombus retracts as part of the subsequent wound healing process, the medical term for this is retraction of the thrombus. The reduction in size of blood clots should be understood as an active service provided by the blood platelets (thrombocytes) within hemostasis. Many other, physiological processes offer use to the term retraction. Among others, this applies to typical bodily processes during the birth of a child. The tissue retracts during each contraction, for example, over the downward pushing head of the child. This retraction of tissue is also a retraction. In addition, the physician sometimes refers to retraction of the testicle. This process is present in the context of anomalies such as the pendulous testis, which temporarily retracts into the inguinal canal due to contraction of the cremaster muscle. The pendulum testis has descended into the scrotum (scrotum) and therefore is not necessarily a pathological malformation. Pendulous testicles therefore do not in themselves have any manifest pathological value or malposition. Nevertheless, in the case of a particularly lively cremasteric reflex, they temporarily change their localization and lie abnormally. In this context, retraction is therefore not to be evaluated as a manifest pathological phenomenon, but as a temporary positional anomaly. In the context of many diseases, however, the term retraction has more pathological connotations.
Diseases and complaints
Sometimes, when there is a pathologic retraction of the eyeball into the orbit, the term retraction is used. This retraction is a malformation that may refer to diseases such as Duane syndrome.Similar to this use of the term, retraction of the nipple also indicates disease. In the case of such a retraction, the physician assumes a ductal carcinoma in situ. Even more pathological is the retraction of a lung segment. This refers to the collapse of a single lung segment, the lobe of the lung, or the lobes of the lung toward the hilus. Retraction of the lung in this context is associated with pulmonary collapse and, accordingly, should be understood as a medical emergency. Not only as a pathological symptom of single disease incidents the term retraction is used within pathophysiology. The physician also uses the term for subsequent phenomena after certain pathological processes. This applies, for example, in the context of prolonged functional disorders of the auditory tubes, which may cause retraction of the eardrum. Such regression of the tympanic membrane is called tympanic membrane retraction. This type of tissue retraction is particularly common in the setting of seromucotympanum. In dentistry, the term retraction is also applied to the retraction of the gums. This retraction may occur in the context of periodontitis or may be artificially induced, for example, with therapeutic removal of the gum from the cervical region. Therapeutically, retraction is also associated with the placement of an artificial bowel outlet. Thus, for patients with colorectal cancer, an artificial bowel outlet may be relevant to treatment, whereby the bowel is sutured under the abdominal wall. In this context, the retraction of the bowel thus sutured below the patient’s skin level is referred to as retraction.
