extrinsic aging

Examples of extrinsic aging in the following topics:

• Effects of Aging on the Integumentary System

  • The integumentary system undergoes intrinsic and extrinsic cutaneous aging, primarily involving the dermis.
  • Intrinsic and extrinsic aging are terms used to describe cutaneous aging of the skin and other parts of the integumentary system.
  • Of all extrinsic causes, radiation from sunlight has the most widespread documentation of negative effects on the skin.
  • Because of this, extrinsic aging is often referred to as photoaging, defined as skin changes caused by chronic exposure to UV light.
  • Wrinkles form due to intrinsic (loss of collagen) and extrinsic (photodamage) aging.

• Asthma

  • Asthma may also be classified as atopic (extrinsic) or non-atopic (intrinsic).
  • Strict reduction of dust mite allergens, for example, reduces the risk of allergic sensitization to dust mites, and modestly reduces the risk of developing asthma up until the age of 8 years old.

• Muscles that Cause Movement at the Foot

  • Although many extrinsic muscles attach within the dorsal compartment, there are only three intrinsic muscles which act on the foot and two extrinsic muscles which act on the foot rather than the ankle.
  • Extensor Digitorum Longus - The extensor digitorum longus is a deep-lying extrinsic muscle that lies runs down the length of the tibia.
  • Extensor Hallucis Longus - The extensor hallucis longus is a deep-lying extrinsic muscle lying beneath the extensor digitorum longus.

• Coagulation

  • The coagulation cascade is classically divided into three pathways: the contact (also known as the intrinsic) pathway, the tissue factor (also known as the extrinsic pathway), and the common pathway.
  • The main role of the extrinsic (tissue factor) pathway is to generate a "thrombin burst," a process by which large amounts of thrombin, the final component that cleaves fibrinogen into fibrin, is released instantly.
  • The extrinsic pathway occurs during tissue damage when damaged cells release tissue factor III.
  • When factor X is activated by either the intrinsic or extrinsic pathways, it activates prothrombin (also called factor II) and converts it into thrombin using factor V.

• Gastrointestinal Reflex Pathways

  • The digestive system functions via a system of long reflexes, short reflexes, and extrinsic reflexes from gastrointestinal (GI) peptides working together.

• Hypersensitivity

  • High magnification micrograph of hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis.

• Hypoglossal (XII) Nerve

  • The hypoglossal nerve is the twelfth cranial nerve (XII) and innervates all extrinsic and intrinsic muscles of the tongue, except for the palatoglossus.

• Muscles that Cause Movement at the Ankle

  • Extensor Digitorum Longus - The extensor digitorum longus is a deep-lying extrinsic muscle that runs the length of the tibia.
  • Extensor Hallucis Longus - The extensor hallucis longus is a deep lying extrinsic muscle beneath the extensor digitorum longus.

• Muscles of the Wrist and Hand

  • Muscles of the forearm that act on the wrist and hand are referred to as extrinsic muscles, or external to the hand.
  • The extrinsic muscles of the hand are responsible for the larger scale, stronger movements of the wrist and hand.
  • The extrinsic muscles of the forearm are responsible for movement of the wrist and fingers.

• Aging and the Urinary System

  • As with other organs, kidney function may be slightly reduced with aging.
  • As the kidneys age, a number of events occur.
  • The bladder wall changes with age.
  • Under usual conditions, kidney function remains normal in an aging person, although sometimes kidneys in an aging person may function more slowly than those of a younger person.
  • Summarize the changes that may occur in the urinary system with aging