chapter 4.txt

epithelial tissue

covers outer body surface, inner lining of heart, blood vesssels and lymph vessels (endothelium), forms the layer of serous membrane of the heart (pericardium), lungs (pleura) and abdomin (peritoneum) (mesothelium), and also secrets glands

3 fxns of epithelial tissue

- regulate substances coming in and out of the body- serve as secretory surfaces that release products to the free surface- barrier to influences of the environment

features of epithelial cells

apical surface - is the free surace of the celllateral surface - surface between cellsbasal surface - point of connection of cells to the basement membrane, adhere to the extracellular materials

features of basement membrane

basal laminareticular laminaconnective tissue

connective tissue

involved in protection, support and binds organs, also stores fats and provides immunity

types of connective tissue

fibroblasts - secrets fibers which are on the ground substance of extracellular matrix (material b/w cells)adipocytes - stores fats (triglycerides)mast cells - produce histamine which dilate blood vessels during inflammation responsewhite blood cells - enter connective tissue during infection (neutrophils) or allergies (eosinophils) (immune responses)plasma cells - make antibodies, formed from b-lymphocytesmacrophages - engulf bacteria and cell debris by phagocytosis

muscular cells

provide the force needed for body movement (by using ATP) and help generate body heat

types of muscle cells and characteristics

cardiac - have INTERCALATED discs, striated, 1-2 nuclei/cell, involuntary skeletal - attaches to bones, striated, multinuclei/cell, voluntarysmooth - on walls of hollow internal structures (blood vessels, airways of lungs, stomache) non-striated, 1 nucleus/cell, involuntary

nerve cells

transmit information through nerve impulses (when there is a change in the body)


neurons: consist of action potentials - electrical signals neuroglia: do not generate nerve impulses but are involved in supportive fxns

4 types of cell junctions

tight junctions - have impermeable membrane between cells - involved in protection (ie: in stomach, intestines, urinary bladder to prevent transfer of organs from leaking to surroundings)adherens - have adhesion belt (plaque) that are connected through the cells' microfilaments and cadherins (glycoproteins) which connect cells like a rope - used to help cells stick together during contracting activities, such as when digesting food through intestinesdesmosomes - same as adherens, but the plaque is connected through the cells' intermediate filaments, which contain keratin - these are found on epidermis and cardiac muscles of heartgap junctions - have membrane proteins (connexons) that allow travel between cells - enable nerve impulses to spread among cells

exocrine glands

secretes products into ducts which are transported and released from the body (sweat glands, mucus, saliva, oil)

endocrine glands

secretes products directly into bloodstream where it acts on body (these are hormones)


connective tissue is highly vascular, epithelial tissue is avascular. Both supplied with nerves (except cartilage...has no blood or nerves)


involved in the extracellular matrix between cells-collagen fibers: strong and resistant pulling forces, made of collagen, help support and strengthen (in BONE, cartilage, tendons and ligaments)-reticular fibers: from fibroblasts, branch and provide strength and support (in soft organs such as spleen and lymph)-elastic fibers: made of elastin, helps to stretch without breaking (in SKIN, blood vessels)


loose connective tissueareolar, adipose and reticulardense connective tissuedense regular, dense irregular and elasticcartilage-hyaline, fibrocartilage and elastic cartilagebone tissueliquid connective tissue-blood and lymph

BONE tissue

compact: has osteons (haversian systemspongy: contains trabeculae - spaces in between these are filled with red bone marrow


hyaline cartilage: most abundant in body, provides FLEXIBILITY and SUPPORT (anterior of ribs, nose)fibrocartilage: strongest type of cartilage, found in INTERVERTEBRAL DISC (between vertebrae)elastic cartilage: provides STRENGTH and ELASTICITY (in ears)

CARTILAGE growth types

interstitial - grow by chondrocytes dividing in the cell (within the tissue itself)appositional - grown by chondrocytes at outer surface of the tissue near


blood tissue: connective tissue with types of cells in an extracellular matrix - blood plasmaLymph: similar to the extracellular matrix of blood plasma

OSTEOCLASTS vs OSTEOBLASTS and role in Ca+ content

osteoclasts - working when there is low blood calcium, break down bones to increase Ca in blood. Osteoblasts are active when there is high blood Ca, and they will produce bone to store the Ca and decrase calcium in blood.

ATP - active and passive transport - pump used K and Na

wants to be more K out of cell, so when there is more K in the cell and K wants to go in, it needs to be crossing against the concentration gradient, requiring ATP. Na wants to be into the cell, so when there is less Na into the cell for example, Na will be able to move passively into the cell.