chemical

-atomic

-molecular

cellular

tissue

organ

system

organism

provides protection and support

houses cells that will become red blood cells, white blood cells, and platelets

consists of named skeletal muscles, as well as smooth muscle and cardiac muscle.

-facilitate movement

-maintain posture

-generates heat to maintain a constant body temp

consists of the brain, spinal cord, nerves, and sensory organs.

-senses and responds to body conditions through nerve impulses

consists of hormone-producing cells and glands scattered throughout the body

-regulates the body through chemical mechanisms(by releasing hormones into the blood)

consists of the heart, blood, and blood vessels.

-carries blood and nutrients to specific locations

-regulates body temperature, and water balance

consists of the lymphatic fluid, lymph nodes, and lymphocytes--and the other associated organs of the immune system like the tonsils, spleen and thymus gland.

-transportsfats and proteins to the cardiovascular system

-filters blood and protects against disease

consists of the upper airways, the trachea and major bronchi, and the lungs.

-extracts O2 and eliminates CO2

-in conjunction with the kidneys, regulates acid/bases balance

consists of the esophagus, stomach and intestines, and the accessory digestive glands (salivary glands, liver, and gallbladder).

-accomplishes the physical and chemical breakdown of food and waste elimination

consists of kidneys, ureters, bladder and urethra.

-involved in the collection and excretion of waste products in urine, and the regulation of fluid, electrolyte, and acid/base balance

-epidermis: outer thinner layer. avascular, consists of EP

-dermis: inner, thicker layer. vascular, consists of CT

-SubQ:located under dermis, consists of loose areolar/adipose CT that attaches skin to underlying tissues and organs

-make up 90% of the cells

-produce keratin: a tough fibrous protein that provides protection

stratum basale

stratum spinosum

stratum granulosum

stratum lucidum

stratum corneum

the replacing of viable cells in the stratum basale with more and more keratin protein as cells move from the deepest layer to the surface layer.

-constant friction stimulates keratinization causing a callus(thicker buildup of keratinocytes in the stratum corneum)

-dandruff is an excess of keratinized cells shed from the scalp

brown pigment produced by melanocytes

-absorbs UV radiation protecting DNA in stratum basale cells from damage

chronic disorder that causes depigmentation patches in the skin.

-pathogenesis/cause unknown, but it is likely a combination of genetic factors coupled with autoimmune disease

contains collagen and elastic fibers

-contains blood vessels-supply surrounding tissue with nutrients

-consists of two regions: papillary region and reticular region

lies just below the epidermis

consists of areolar connective tissue containing thin collagen and elastic fibers

lines of cleavage are tension lines in the skin that indicate the predominant direction of underlying collagen fibers.

surgery: minimize scarring

-epidermal ridges reflect countours of the underlying dermal papillae and form the basis for fingerprints(and foorprints)

-increase firmness of grip by increasing friction

dermatoglphics: study of epidermal ridge patterns

-attaches the skin to underlying tisssues and organs.

-contains blood vessels and nerves in transit to more superficial layers

-contains pacinian (lamellates) corpuscles

-detect external pressure applied to the skin

multiple layers in the skin allow for specialization.

-epidermis:fast turn over, resists damage and offers protection to underlying tissues.

-dermid:provides temperature stability and dehydration

-subcutaneous:insulate, store fat, and anchor the skin

the epidermis develops from the ectoderm.

-nails, hair, and skin glands are epidermal derivatives

-the dermis develops from the mesoderm

pili; present on most surfaces except palms and soles. composed of dead, keratinized, epidermal cells

genetics determines thickness and distribution

helps with touch sensations

protects the body from sun and heat loss

arrector pili muscle

shaft:above skin surface

root: penetrates into the dermis

follicle:below level of skin

lanugo:fine, nonpigmented hair that cover a fetus

vellus: short, fine pale hairs barely visible to naked eye

terminal hairs:long, coarse, heavily pigmented

color is determined by amount and type of melanin

are epithelial cells that secrete a substance

-endocrine, exocrine, merocrine, apocrine, holocrine

have ducts and include the following kinds of glands:

merocrine, apocrine, holocrine

watery secretion released by exocytosis

-saliva

-sweat

a partion of the glandular cell pinches off and becomes part of the secretion

-mammary glands

-apocrine sweat glands

-ceruminous glands

whole cell becomes secretion

-sebaceous gland

sebaceous (oil gland)

sudoriferous (sweat) gland

-eccrine

-apocrine

ceruminous gland (modified sweat gland)

mammary gland (modified sweat gland)

are connected to hair follicles

-they secrete an oily substance called sebum:

-prevents dehydration of hair and skin

-inhibits growth of certain bacteria

-most numerous

-secrete a watery solution (merocrine)

-cool the body and eliminate small amounts of waste

-release sweat in response to an emotional stress such as fear or embarassment "cold sweat"

-located mainly in the skin of the axilla, groin, areolae, and bearded facial region of adult males (puberty)

-secrete a slightly viscous sweat

-located mostly in subQ layer, excretory duct opens into hair follicles

-sweat secreted during emotional stress and sexual excitement

-much of body odor is due to apocrine sweat

modified sweat glands located in the ear canal.

-alng with nearby sebaceous glands, they produce cerumen providing a sticky barrier preventing entry of foreign bodies into the ear canal

are composed of hard, keratinized epidermal cells

epidermal wound healing

-occurs follwing superficial wounds that affect only the epidermis.

-return to normal function

-injury extends to the dermis and subQ layer

-loss of some function and development of scar tissue

occurs when tissues are damaged (including clot formation)

-vascular and cellular response in preperation for tissue repair

-mobilizes body's defenses

-isolates and destroys microorganisms

-removes damaged cells so repair can proceed

redness

heat

swelling-edema

pain

-loss of function(variable)

-histamine (from mast cells)

-prostaglandins (from damaged cells)

1. during inflammation, a blood clot forms to wall off site of injury from rest of body

-clot is formed from the protein, fibrin, which comes from the blood

-surface of clot forms the scab

2. phagocytosis to clear area for repair

-neutrophils arrive as part of inflammation response

3. macrophages remove dead neutrophils and cellular debris

3. scar formation-fibroblasts from surrounding migrate to the clot to synthesize scar tissue.

4. damaged blood vessels begin to regrow

5. extensive growth of ep cells beneath scab occurs

involves only epidermis

-no blisters, skin function remains intact, heals in two to three days, no scarring

damage to epidermis and dermis

-blisters

-pain

-epidermis regenerates from edge of burn

-2-3 weeks to heal 

-may result in some scarring

-2nd degree is critical if >30% of surface area is burned

epidermis, dermis, hair follicles, sweat glands, pain receptors, subQ layer all destroyed

-painless but life threatening bc of fluid loss and bacterial infection

-skin regenerates from edges, skin grafts may be necessary

-critical if >10% of surface is burned

78% of all skin cancers

-arises from abnormal growth of stratum basale in which cells lack ability to produce keratin

-generally does not metastasize

20% of all skin cancers

-arises from stratum spinosum

-may metastasize

3% of all skin cancers, but most dangerous

-metastasizes rapidly

-arises from melanocytes of preexisting moles