Category: P

  • Pilosis

    A condition in which someone has an unusual amount of hair or where hair is present in an unusual place.  

  • Pilosebaceous

    Referring to the hair follicles and the glands attached to them. To a hair follicle and its sebaceous gland.  

  • Pilonidal sinus

    A small depression with hairs at the base of the spine. A hairy bump in the cleft of the buttocks in tissue near the tailbone; also known as a pilonidal cyst. A pilonidal sinus can become infected and form a painful abscess (pus-filled sac). Treatment is with antibiotics and, as necessary, either surgical incision and…

  • Pilonidal cyst

    A cyst containing hair, usually found at the bottom of the spine near the buttocks. Hair that has been encapsulated in a dermal cyst. A cyst most often in the sacrococcygeal region, usually at the upper end of the intergluteal cleft. It is due to a developmental defect that permits epithelial tissue to be trapped…

  • Pilonidal

    Relating to a cyst or cavity which has a growth of hair. Containing hairs; most often seen in a dermoid cyst, especially in the saccrococcygeal region. Containing hair. This term typically refers to cysts, believed to develop when surface skin becomes embedded deep in the tissues due to a congenital mistake. Within these cysts, the…

  • Pilomotor reflex

    A reaction of the dermal papillae of the skin to cold and fear which causes the hairs on the skin to become erect. Erection of the hairs of skin in response to emotional stress, skin irritation, or cold; also called goose bumps; gooseflesh. Piloerection when skin is cooled or as a result of emotional reaction.…

  • Pilomotor nerve

    A nerve which supplies the arrector pili muscles attached to hair follicles. Sympathetic nerves that supply muscle fibers in the skin, around the roots of hairs. Activity of the sympathetic nervous system cause the muscles to contract, raising the hairs and giving the ‘gooseflesh’ effect of fear or cold. A motor nerve that innervates the…

  • Pill-rolling

    Nervous action of the fingers, in which the person seems to be rolling a very small object, associated with Parkinson’s disease.  

  • Pillow

    A soft cushion on a bed which the head lies on when the person is lying down. A postsurgical cushion or support for a body part (e.g., the head, chest, hip, or knee). Therapeutic pillows are used as buttresses or wedges to relieve stress on parts of the body that have been operated on. Chest…

  • Pillar

    A part that is long and thin. An elongated apparently supportive structure. For example, the pillars of the fauces are folds of mucous membrane on either side of the opening from the mouth to the pharynx. An upright support, column, or structure resembling a column.