four types of tissues - epithelial, muscle, nervous, connective

epithelial tissue - tissue meant for covering

muscle tissue - tissue meant for movement

nervous tissue - tissue meant for control

connective tissue - tissue meant for support

EPITHELIAL TISSUE

epithelial cell layers types - simple, pseudostratified, stratified

epithelial cells shape types - squamous, cuboidal, columnar

CONNECTIVE TISSUE

• most abundant tissue by weight

consists of cells surrounded by an extra-cellular matrix

ECM (Extra-cellular matrix) - ground substance (may be fluid, semi fluid, gelatinous or calcified) + fibres (e.g. collagen, elastin, etc.).

classes of connective tissue - connective tissue proper, cartilage, bone, blood

loose connective tissue - areolar, reticular, adipose

Dense connective tissue - regular, irregular, elastic

fibroblasts adipocytes - major cell type of loose connective tissue. semi-fluid GS.

Fibroblasts - major cell type of dense connective tissue. very little GS.

Cartilage types - hyaline, fibrocartilage, elastic

Chondrocytes - major cell type of cartilage. Stiff gelatinous GS.

osteocytes - major cell type of bones. Calcified GS.

erythrocyte - major cell type of blood. Fluid GS.

SKIN

cyanotic - blue skin

jaundiced / icteric - yellow skin

erythema - red skin

pallor - white skin

INTEGUMENTARY SYSTEM

integumentary system - consists of skin and accessory organs. two layers: epidermis, dermis

epidermis - composed of 5 strata. corneum, lucidum, granulosum, spinosum, basale.

length of epidermis process - 4-6 weeks

corneum - 25-30 layers of dead cells

lucidum - only present in thick skin

granulosum - 3-5 layers of cells; living dead transition zone; Keratohyalin; Lamellar granules

spinosum - 8-10 layers; keratin intermediate filaments; cells joined by desmosomes;

basale - from which all other laers are derived from

cell types in the epidermis KLMM - keratinocytes, langerhan cells, melanocytes, merkel cells,

keratinocytes - 90% epidermal cells; produces keratin

keratin - protects from heat, abrasion, microbes, chemicals)

langerhan cells - only in living parts of the epidermis; intraepidermal microphage; Phagocytosis; stratum spinosum

melanocyte - 8% of epidermal cells; produce melanin; stratum basale

merkel cell - detect touch sensations; stratum basale

epidermal ridges - gives rise to finger prints; inc surface area of epidermis; inc contact b/w dermis + epidermis; epidermal peg supported by dermal papilla (see image in notes)

melanin - yellow-red / brown-black pigment; responsible for skin and hair colour

We all have the same number of melanocytes but different amounts of melanin

albinism - no melanin produced

vitiligo - loss of pigment in patches

freckles/moles - aggregation of melanin/melanocytes

melanoma - cancerous mole

ABCDE’S of malignant melanomas - Asymmetrical, Borders uneven, Colours - two or more, Diameter larger than 6mm, Elevated/Evolving

Dermis - location of BVs, nerves, hair follicles, and skin glands; contains collagen and elastic fibres that provide support for the skin; divided into papillary and reticular regions

types of skin glands - sebaceous, apocrine, eccrine, ceruminous

sebaceous skin glands - responsible for the oils in our skin

apocrine skin glands - responsible for creating sweat

eccrine skin glands - responsible for creating sweat; regulated by the SNS

ceruminous skin glands - responsible for the waxy

functions of the skin - thermo-regulation, blood reservoir, protection for the environment, cutaneous sensations, excretion and absorption, synthesis of vitamin D (make sure to know how to explain all of them)