1. the structure of the cells
2. the composition of the extracellular matrix (ECM)
3. the function of the cells

1. epithelial tissue
2. connective tissue
3. nervous tissue
4. muscle tissue

• defined as a sheet of cells that cover a body surface or lines a body cavity
• composed of almost entirely close-packed cells
• occurs in the body as: (1)covering and lining epithelium and (2)glandular epithelium 

• forms the outer layer of skin
• dips into and lines the open cavities of the cardiovascular, digestive and respiratory systems
• covers the walls and organs of the closed ventral body cavity

• cells have an apical surface (a free surface exposed to the exterior) a lateral surface and an attached basal surface
• all cells are supported by and rest upon connective tissue (called a basement membrane) which help it to resist stretching and tearing, and defines the epithelial boundry

• desmosomes: strong bonds between the lateral surfaces
• hemidesmosomes: similar to desmosomes, except at the basement membrane
• adhesion belt: "glue-like" protein, similar to desmosomes, but weaker
• gap junction: small, specialized spaces between cells that allow communication

1. protection: skin epithelium protects underlying tissue from chemical and mechanical injury and bacterial invasion
2. acts as a barrier: prevents substances from moving through it
3. permits passage of substances: via either diffusion or filtration
4. secretion: various glands and certain tissues of various organs will secrete mucous or enzymes
5. absorption: plasma membranes within regulate absorption of various materials
6. filtration: epithelium in the kidneys

1. simple epithelia: a single layer of cells from the basement membrane to the apical surface 
2. stratified epithelia: more than 1 layer of cells, only the basal layer attaches to the basement membrane

1. simple squamous
2. simple cuboidal
3. simple columnar
4. pseudostratified columnar

1. stratified squamous
2. stratified cuboidal
3. stratified columnar
4. transitional

description: flattened laterally with sparse cytoplasm; thin and permeable

functions: filtration, diffusion and secretion

locations: kidney glomeruli, air sacs of lungs, blood vessels, lining of ventral cavity, lymphatic vessels

description: single layer of cuboidal cells (shaped like a cube)

functions: secretion and absorption

locations: ducts and secretory portions of small glands; kidney tubules

description: single layer of tall cells with oval nuclei; some may contain cilia and/or mucus-secreting unicellular cells

functions: absorption, secretion of mucous, enzymes and other substances; ciliated type propels mucus and reproductive cells by ciliary action

locations: non-ciliated type lines most of the digestive tract, gallbladder and some glands; ciliated type lines small bronchi in lungs, uterine tubes, and some portions of the uterus

description: single layer of cells differing in height; irregular appearance; some ciliated

functions: secretion, especially of mucous; prospulsion of mucus

locations: non-ciliated type in the ducts of large glands, some of the male urethra;ciliated type in most of the upper respiratory (ie. trachea)

description: think membrane composed of several cell layers; basal cells or cells closest to the basement membrane are cuboidal or columnar; the specific keratinized form contains surface cells full of keratin (a protective protein)

function: protects underlying tissues in areas subjected to abrasion

locations: non-keratinized for found in the moist lining of the esophagus, mouth and vagina; keratinized (durable, moisture) form forms the epidermis of the skin

description: generally two layers of cubed cells

function: protection

locations: largest glands or sweat glands. mammary glands and salivary glands

description: several cell layers; basal cells usually cuboidal; superficial cells elongated and columnar

functions: protection and secretion

locations: rare in the body; small amounts in the male urethra and some large glands

basically anything not grouped above

description: resembles both stratified squamous and stratified columnar

functions: stretches readily and permits distention of urinary organ by contained urine

locations: lines the ureters, urinary bladder and part of the urethra

description: one or more cells that make and secrete a particular substance is called a secretion

classification: (1) endocrine glands are ductless glands that produce hormones that released directly into the blood or lymphatic fluid and (2) exocrine glands secrete their substance through a duct onto the body surface or into a body cavity -> sweat, salivary, the liver and pancreas

• found everywhere in the body and is the most abundant of the primary tissue types
• differs from other tissues because of its increased amounts of ECM

• enclose and separate other tissues
• connect tissues to one another
• support and move parts of the body
• storage
• cushioning and insulation
• transportation
• protection

• adipose tissue
• cartilage
• tendons and ligaments
• collagen = tendons and ligaments which are strong and flexible but NOT elastic-y

CT's are mostly composed of a ________ which separates the living cells of the tissue; because of this, it is able to bear _______ and ______

this is also known as ______

• non-living ECM
• bear weight and endure abuse
• ground tissue

• think of the screen in front of front door
• fiber can withstand pulling

elastic fibers 

ground substance

•  
• most common in connective tissue

1. atypical CT
2. loose CT (CT proper subtype)
3. dense CT (CT proper subtype)
4. cartilage

• bone (osseous tissue; vascular tissue with collagen fibers)
• blood (blood cells surrounded by fluid matrix called plasma)

• decrease amount of protein fibers (more squishy)
• areolar (most abundant CT; under the epithelium; wraps/ cushions organs; binds body parts toger while allowing them to move freely; involved in inflammation; contains fluid - excess fluid here results in "edema")
• adipose tissue (fat; under skin)
• reticular (lymph nodes) -> tissue that makes up bone marrow (meshy)

dense CT (CT proper subtype)

• dense regular (tendons, ligaments) - highly organized
• dense irregular (dermis of the skin) - random arrangement, resists stress, opposite of loose CT
• lots of protein fibers 
• most of dermis protective capsule (skin)

• hyaline cartilage (ends of the long bones, cartilage of nose, trachea, and larynx; costal cartilage of ribs 
• elastic (external ear or pinna)
• fibrocartilage (bones)
• chondroblasts, lacunae, chondrocytes, avascular

• spongy (inner part) - light but strong
• compact bone (outer) - rigid, solid

• makes up the nervous system - the brain, spinal cord and nerves
• composed of 2 cell types: neurons and supporting cells

• highly cellular, well-vascularized tissues that are responsible for most types of movement
• 3 types: skeletal, cardiac, and smooth

• attached to the bones of the skeleton
• form the flesh of the body
• contains many nuclei
• considered voluntary muscle because contraction or movement is under our control
• segmented pattern = striation 
• voluntary!

• occurs only in the walls of the heart
• its contractions help propel blood through the blood vessels to all parts of the body
• contain only one nucleus
• considered involuntary muscle
• striations