Chapter 6 Integumentary Sx.

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Chapter 6 - Integumentary Sx.

• The Skin and Accessory Structures

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Integumentary Sx.

• The skin is one of the largest organs in the body
  and serves many functions. Chief among them is
  protection. It also prevents water loss and
  regulates body temperature. It also acts as a
  general sense organ for the sense of touch and
  tactile input.

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Integumentary Sx.

• The skin has three layers
• Epidermis composed primarily of stratified
  squamous epithelium.
• Dermis thicker than the epidermis, this layer
  is composed of connective tissue, smooth muscle,
  nervous tissue and blood vessels.
• Hypodermis aka subcutaneous layer, the
  hypodermis is composed of areolar tissue and
  adipose.

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Integumentary Sx.

• The Epidermis
• The lowest level of cells in this layer is the
  foundation of the entire layer. This layer of
  cells is called stratum basale and sits atop the
  basement membrane. These cells are closest to
  the underlying blood supply in the area and thus
  receive the best nourishment. These cells are
  almost always undergoing cell division and new
  cells are pushed up and away from the blood
  supply. This rise in successive levels removes
  the cells farther from the blood supply and in
  time they die.

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Integumentary Sx.

• As these epithelial cells rise in layers many of
  them undergo the process of keratinization.
  During this process the cytoplasm of the cell is
  replaced by a fibrous waterproofing protein
  called Keratin.

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Integumentary Sx.

• The successive layers of the epidermis are as
  follows
• Stratum Basale bottom most layer, mitosis is
  ongoing
• Stratum Spinosum
• Stratum Granulosum keratinization is taking
  place, these cells are dying
• Stratum Lucidum
• Stratum Corneum completely keratinized, these
  cells are all dead and ready to be shed.

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Integumentary Sx.

• Calluses are a thickening of the epidermis due to
  regular friction or pressure.
• Melanocytes are specialized cells in the
  epidermis that reside in the stratum basale.
  They produce a pigment called melanin that
  provides skin color.
• Melanocytes are stimulated by ultraviolet
  radiation to produce melanin that absorbs some of
  that form of radiation.

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Integumentary Sx.

• Skin Cancer
• Skin cancer is the most common form of cancer
  and usually poses the least threat to life and
  health. If caught early it is usually very
  easily treated and exhibits very little incidence
  of return.
• Basal Cell Carcinoma the most common form of
  skin cancer, this lesion is benign and very
  seldom metastasizes (spreads) to distant sites.
• Squamous Cell Carcinoma the next most common
  form of skin cancer, this carcinoma is almost as
  reluctant to metastasize as the previous
  mentioned condition.
• Malignant Melanoma making up only a very small
  minority of skin cancers (about 5 or less), but
  is one of the most dangerous forms of any cancer
  known. Caught early it is similar in treatment
  to the above forms. However, metastasis of
  melanoma can be very fast, and once this happens
  the survival rate after treatment plummets
  greatly.

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Integumentary Sx.

• The Dermis
• The Dermis is largely composed of connective
  tissues with a lot of collagen and elastic
  fibers. The dermis has many accessory structures
  of the skin located in it.
• Nerve endings scattered throughout the dermis are
  responsible for the variety of sensation
  available thru the skin.
• The papillary layer of the dermis is responsible
  for fingerprint patterns.

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Integumentary Sx.

• Accessory Structures
• Hair Follicles Hair grows from epidermal cells
  found in the dermis. Growth of hair starts at
  the root where blood vessels nourish the hair.
  The shaft of hair is made up of keratinized
  epithelium.
• Hair color is determined by genetics. The more
  melanin a person produces, the darker their hair
  is.

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Integumentary Sx.

• A bundle of smooth muscle cells called arrector
  pili is attached to each hair follicle. This
  muscle is responsible for making the hair stand
  up at times and thus for goose bumps. Arrector
  pili are under autonomic control.
• Nails these structures are made of a special
  keratinized epithelium. Each nail has a free
  edge, nail plate, nail bed, a lunula and a root
  or matrix.

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Integumentary Sx.

• Skin Glands the glands in the dermis are
  considered exocrine glands as they possess a duct
  for secretory purposes.
• Sebaceous Glands these glands secrete body oil
  known as sebum. These glands are usually
  associated with a hair follicle. Sebum helps the
  body by keeping the skin and hair soft, pliable
  and waterproof. An underproduction will result
  in dry skin and brittle hair.

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Integumentary Sx.

• Sudoiferous Glands There are two types of sweat
  glands
• Eccrine these are the smallest and most
  numerous sweat glands. They are found body wide
  with few exceptions.
• Apocrine larger than eccrine glands, these
  glands also secrete sweat. Found only in the
  axilla, groin, and around the nipples, apocrine
  glands do not become active until puberty. They
  usually have a small amount of melanin associated
  with them, thus areas containing these glands are
  slightly darker in color.

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Integumentary Sx.

• Regulation of Body Temperature
• Normal body temperature ranges from 96.5-99.5
  degrees F. Average body temperature is 98.6
  degrees F. or 37 degrees C.
• Heat in the human body is a product of metabolic
  reactions and muscle contractions.

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Integumentary Sx.

• Heat is lost from the body in a number of ways
• Radiation loss of heat in the form of infared
  energy from a warm surface to cooler
  surroundings.
• Conduction loss of heat from the body into an
  object that is in direct contact with the body.

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Integumentary Sx.

• Convection The loss of heat from the body due
  to the movement of cooler air over the body.
• Evaporation the loss of heat from the body by
  way of moisture as it leaves the surface of the
  body as a gas.
• The body may retain or release heat thru the
  action of the blood vessels. By constricting the
  diameter of the superficial vessels the warmth of
  the blood is conserved in the bodys core areas
  such as the torso and head. Pallor and perhaps
  cyanosis can result in this situation. On the
  other hand, if the blood vessels are dilated,
  then more blood reaches the skin and is loss by
  means of radiation and flushing will probably
  result.

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Integumentary Sx.

• Hypothermia is a condition where the core body
  temperature falls below a manageable level. A
  gradual re-warming of the body is called for in
  order to restore homeostasis.
• Hyperthermia is a condition where the core body
  temperature rises above a manageable level. Two
  types are noted
• Heat Exhaustion a condition that may be easily
  managed by cooling of the body as well as the
  replacement of body fluids and needed
  electrolytes.
• Heat Stroke a condition that is considered a
  medical emergency as it poses a threat to life.
  The tx. is the same as above, but will likely
  need to be done in a medical setting as the
  fluids are often administered via IV therapy.

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Integumentary Sx.

• Skin color is due to a variety of factors.
  Included are genetics (heritage), environmental
  factors (sun exposure or lack of), and
  physiological factors (such as flushing and
  cyanosis).
• The three pigments playing into skin color are
  melanin, carotene (found in certain foods), and
  hemoglobin (found in red blood cells).
• Albinism is a condition where a persons body
  does not make any of the melanin pigment.

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Integumentary Sx.

• Inflammation is a response of tissue to injury.
  The five signs of inflammation are
• Reddening
• Swelling
• Heat
• Pain
• Loss of Function

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Integumentary Sx.

• Burns
• Burns may be classified into catagories by the
  depth to which they penetrate the body
• First degree burns are also called superficial
  partial thickness burns. They are characterized
  by a slight reddening of the skin. The damage
  does not pass beyond the epidermis and usually
  heals within a few days.
• Second degree burns are also called a deep
  partial thickness burn. These are characterized
  by blisters. Second degree burns penetrate thru
  the epidermis into the dermis but no farther.
  Blistering is due to damaged capillary vessels.
  These burns are usually quiet painful. Healing
  time will usually be at least two weeks, but may
  take longer depending on how extensive the damage
  to the skin.

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Integumentary Sx.

• Third degree burns are also called full thickness
  burns. These burns penetrate thru the epidermis,
  thru the dermis, into the hypodermis and possibly
  much deeper. Charring of the tissues is evident
  in a third degree burn, but the are of the third
  degree burn is without pain as the nerve endings
  in the area are destroyed. Healing time can be
  quite extensive and surgical grafts are
  frequently used to assis in the process.

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Integumentary Sx.

• Burn patients are assessed using the rule of
  nines. This is a system by which the body is
  assigned an amount of surface are based on size.
  See chart p.187.