more notes for ch 5

dermal circulation

blood contains RBC filled w/ pigment hemoglobin- when bound to oxygen, hemoglobin is bright red giving capillaries in the dermis a reddish tint that can be seen in pale skin.

hemoglobin

responsible for transporting oxygen in the bloodstream

what pigment is carried in blood?

hemoglobin

what does hemoglobin attach itself to?

oxygen

dark red vs. light red

dark- lack of oxygen; light- with oxygen

cyanosis

reduction in circulatory supply -> oxygen levels decline -> hemoglobin releases oxygen and turns darker red -> skin takes on bluish coloring (lack of oxygen=blush coloring

examples of cyanosis

heart attack, severe asthma, response to extreme cold

jaundice

liver unable to excrete bile (the liver produces bile which is stored in the gal bladder- breaks down fat) , yellowish pigment accumulates in body fluid

tumor affecting pituitary gland

results in the secretion of large amounts of melanocyte- stimulating hormone MSH causing darkening of skin

Addison disease

pituitary gland secrets large quantities of ACTH causing a darkening of the skin

Vitiligo

individual looses their melanocytes- blotchy or irregular pigment found on skin

basal cell carcinoma

originates in the stratum germinativum; most common skin cancer

malignant melanoma

extremely dangerous; growing rapidly; metastasize through lymphoid system

ABCD for cancer

A= asymmetry - irregular in shape, raised & may ooze or bleed; B= border- irregular; C= color- tan, brown, black, pink, white, and blue tones; D= diameter- any skin growth more than 5mm or 0.2 in is dangerous

2 types of fibers

collagen and elastic (in the dermis/ reticular)

collagen fibers

very strong and resist stretching but are easily bent or twisted

elastic fibers

permit stretching and recoiling

cutaneous plexus

network of arteries that form in the subcutaneous tissue along the reticular layer of the dermis

papillary plexus

branching network covers the blood supply from the papillary layer of the dermis into the epidermis

contusions

breaking of those blood vessels/ blood leaks into dermis/ area develops black and blue color (bruise)

subcutaneous tissue

interwoven w/ the fibers of the dermis/ stabilize position of the skin to underlying tissue (skeletal muscles or other organs)