AMA 171 - Anatomy PhysiologyMedical TerminologyPathology 2 - PowerPoint by cmb14063


									AMA 171 - Anatomy &
 2 Skin and Senses
    Skin: (Integumentary System)
Interesting fact: weighs 8-10lbs and covers an
  area of 22 square feet (in an average adult)
   Covers and protects the internal organs and
   Produces important secretions: oil and sweat
    to lubricate and cool the body
   Contains nerves that are receptors for
    sensations such as pain, temperature,
    pressure and touch
   Thermoregulation of the body
    Structure (layers of the skin):
   Epidermis: outermost layer made of squamous
    epithelial cells; the basal layer of the epidermis is
    always growing and multiplying

   Dermis: middle layer composed of blood and lymph
    vessels, nerve fibers and accessory organs, such as
    hair follicles, sweat and sebaceous glands

   Subcutaneous: deepest layer specializing in the
    formation of fat; important in the protection of the
    deeper tissues of the body, as a heat insulator and
    for energy storage
    Accessory organs: hair, nails &
   Hair: fibers composed of keratin, a hard protein

   Nails: hard keratin plates covering the last bones of each toe
    and finger

 Sebaceous (oil): found almost everywhere, except hands and
   feet. Lubricate the skin through the hair follicle and minimize
   water loss from the body; influenced by sex hormones

   Sweat: most numerous on hands and feet but found on almost all
    body surfaces. Almost pure water with dissolved materials such
    as salt; odor comes from bacteria, not sweat. Sweat
    (perspiration) cools the body as it evaporates into the air.
    Sense Organs: Receptors that are
       activated by stimuli from the
     external or internal environment.

   Eye: light rays enter the eye and are
    sent to the cerebral cortex of the
    brain, fusing to form a visual sensation
    with three-dimensional effect

   Ear: sound waves are received by the
    ear and sent to the auditory region of
    the brain in the cerebral cortex
            Structure of the eye
   Cornea: fibrous tissue covering pupil and iris, light enters here first, is bent or

   Anterior chamber: contains aqueous humor a fluid produced by the ciliary body
    to nourish the eye and help maintain its shape

   Pupil: dark center of the eye, light rays enter here after passing through the

   Iris: colored portion of the eye, contains muscles that constrict pupil to regulate

   Conjuctiva: membrane that lines the eye and eyelids; clear and colorless unless

   Sclera: white of the eye, provides nourishment via blood vessels

   Choroid: dark brown membrane inside of sclera, contains blood vessels

   Lens: changes shape to refract light and to flatten or round the lens for
    distance or close vision (accommodation)
    Structure of the eye cont…
   Ciliary body: muscles that control the lens

   Vitreous humor: jelly-like fluid that helps maintain eye’s shape

   Retina: sensitive nerve layer of the eye, contains rods and cones
    that are receptor cells responsible for color and central vision

   Optic nerve: chemical change from rods and cones cause nerve
    impulses to send visual signal to brain through this nerve

   Optic disc: region where optic nerve meets the retina

   Macula: area that contains the fovea centralis

   Fovea centralis: depression in macula that is the location of the
    sharpest vision in the eye
Structure of the ear: three regions
                      of waves ear
 Outer ear: conducts sound
   Pinna (auricle): flap of the ear
   External auditory meatus (auditory canal): ear canal that
    secretes ceruman (ear wax)

Middle ear: conducts sound waves
 Tympanic membrane (eardrum): sounds waves make this
 Ossicles: three small bones that are vibrated by the sound
  on the tympanic membrane: Maleus, Incus & Stapes
 Oval window: vibration from stapes touches this membrane
  that separates the middle and inner ear

Inner ear (labyrinth): receives auditory waves and relays them
   to the brain
 Cochlea: looks like a shell; contains liquids that transmit the
   sound waves/vibrations
 Auditory nerve fibers: connect the cochlea to the brain so
   the brain “hears” sounds

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