Integumentary System Flashcards
Describe the homeostatic mechanisms of body temperature regulation
To stay warm: Hair stands on end, muscles fire(shivering) to create heat, blood vessels pull away from the skin’s surface (what happens when we turn blue when cold), blood stays in proximal part of the body (to keep important organs alive)
To cool down: sweat glands secrete sweat, blood vessels dilate near the surface (makes us blush/turn red)
Most importantly, what chemical does the skin keep in?
water
What materials do not pass through intact skin?
water and water soluble molecules
What materials may pass through intact skin? Why?
salt, urea, and moisture in sweat. helps regulate body temp
What is the origin of the upper layers of epidermal cells?
Epidermal layers of epithelial cells are created at the basal-most layer (just above the connective tissue) called the strata basale. These cells are pushed up by new epithelial cells being formed beneath them
Why is the structure and function of epidermal cells different in the different strata?
Strata Basale: base layer, cell division
Strata spinosum: flexibility, and “spines” are the beginnings of desmosomes being formed
Strata Granulosum: water proofing/preventing water loss
Strata lucidim: in hairless skin
Strata corneum: tough outer protection
Describe the dermis
Connective tissue layer composed of collagen & elastic fibers, fibroblasts, macrophages & adipocytes
Contains hair follicles, glands, nerves & blood vessels
Major regions of dermis
papillary region
reticular region
Describe the location of the following
injections: subcutaneous (SQ), hypo-
dermic, intradermal (ID), and
intramuscular (IM).
Subcutaneous: “below skin”, into layer of tissue between skin and muscle
Hypodermic: also seems to be subcutaneous tissue layer
Intradermal: into dermis layer
Intramuscular: into muscle
Differentiate between calluses and
pressure (decubitus) ulcers.
Calluses form due to friction placed against the cells.
Pressure ulcers are caused by constant pressure being applied to one area (such as people in care homes- and why nurses need to turn patients over). Usually forms over a bony prominence such as a hip.
How are sweat glands and ceruminous glands similar?
Sweat gland- tubular gland in the skin that secretes sweats to cool the body, there are two kinds of sweat glands eccrine and apocrine, both secrete sweat in response to stress as well as heat. Ceruminous are modified sweat glands of the apocrine glands (ducts that open into hair follicles, produce a special kind of sweat consisting of fatty substances and proteins, along with normal components of sweat glands) that line the external ear canal, their product is ear wax.
What is the relationship between hair, nails and the epidermis?
All three are full of keratin, are made of dead cells, and are secreted by the dermis.
What is sebum?
Oily substance secreted by the sebaceous glands comprised of triglycerides and other fat-producing cells. Functions to keep skin and hair of mammals waterproof and well lubricated.
Skin cancer
- basal cell carcinoma (rarely metastasize)
- squamous cell carcinoma (may metastasize)
- malignant melanomas (metastasize rapidly)
