Term | Definition |
Growth | normal expansion of size as produced by the accretion of tissues similar to that of the original tissue or organ |
Hypertrophy | process in which cells increase in size |
Hyperplasia | addition of more cells |
true growth | increase in amount of muscle of bone and fat |
Fattening | accumulation of fat |
Development | gradual progression from a lower to higher state of complexity |
Average daily gain | daily increase in weight |
Which performance trait is a direct reflection of an animal's ability to grow | average daily gain |
Growth rate | speed at which animals grow |
Current market animals possess less fat than those produced earlier. T/F? | True |
Paylean | compound added to swine diets to improve production efficiency |
Meat | rich source of high-quality protein, iron, and essential B-vitamins |
Sir John Hammond | conducted some of the earliest documented research showing how animals grow and develop under different environmental and nutritional conditions |
Rex Butterfield and Roy Berg | demonstrating growth and development patterns in tissue subsets |
Growth hormone | used in a lot of processes and has been applied to promote milk production in dairy cattle |
Leptin | capable of modulating whole body fat accretion |
Double muscling | genetic condition in cattle that results in greatly exaggerated muscle growth |
Transgenic | genetic material that has been introduced to an organism from an unrelated organism |
Tissues | groups of closely associated cells that act synergistically to perform specific functions |
What are the four primary tissues? | muscle tissue, connective tissue, nervous tissue, and epithelial tissue |
Epithelium | thin layer of tissue that covers all free surfaces of they body; acts as barrier between the underlying tissue it covers and its environment |
Endothelium | type of epithelium that covers innermost surfaces of capillaries; allows nutrients to cross and enter adjacent tissue while cellular metabolites diffuse across and re-enter circulation for removal as blood flows through capillary beds |
Secretory cells | contain extensive endoplasmic reticulum that is responsible for packaging and transporting various products to cell surface for release |
Protenaceous | contains high proportion of protein |
Simple epithelium | single layer of cells; nuclei appear to line up in a straight line; located in places where maximal secretion or absorption is needed |
Stratified epithelium | consists of many layers of cells which routinely shed when challenged by environment; found where there is a lot of friction by hostile environment |
Epithelium consists of different cell types. T/F? | True |
Squamous cells | very thin and flat in one dimension but broad in other two dimensions |
Cuboidal cells | possess a box-like structure where all dimensions are relatively equal |
Columnar cells | slender and elongated; nucleus is positioned toward base of the cell |
Basement membrane | layer of fibers and filaments that serve to attach to epithelium to under-lying connective tissues |
Transitional epithelium | resembles stratified cuboidal epithelium, but changes dramatically with distension of the underlying tissue; found in bladder and other parts of urinary tract |
Cilia | provide cell with 2 functions: improving absorptive and secretory abilities and aiding in movement of materials along their border |
Microvilli | allows for movement across surface of epithelium; enables cells to have 20 times more surface area |
Connective tissue proper | extracellular substance which ranges form a semi-solid, glue-like substance to a rigid, amorphous material |
Ground substance | viscous solution in which proteinaceous fibers are imbedded |
Macrophages | small ameboid cells which move around within tissue consuming damaged cells and foreign substances that gained access to body |
Mast cells | move freely within connective tissues and responsible for release of histamines; wandering cells |
Histamines | convey inflammatory response |
Fibroblasts | cells that are somewhat anchored in connective tissue matrix and responsible for production of fibrous proteins that reinforce amorphous structure; fixed cells |
What are the primary reinforcement proteins in connective tissue? | collagenous, reticular, and elastic fibers |
Proteoglycans | proteins linked to carbohydrates |
Ground substance | fluid-like structure of connective tissue that contains proteoglycans |
What are the most prominent carbohydrates attached to these proteoglycans? | chondroitin sulfates and hyaluronic acid |
Chondroitin sulfates | abundant in cartilage and tendons |
Hyaluronic acid | very viscous and supplies lubrication in form of synovial fluid to most articulations(joints) of skeletal system |
Depolymerization | reduces viscosity and results in increased friction in articulations |
Collagen | most abundant protein found in animals; comprises 20 to 30% of animal's body |
Alpha chain | primary sequence of collagen |
Pyrole rings | cause amino acids in collagen to coil into a left-handed helix |
Procollagen | secreted from fibroblast; precurser to collagen |
Pentafibrils | ultimate structure of collagen; where collagen fibrils are arranged in a staggered formation that yields highly organized fibers |
Lathyrism | poor collagen cross-linking leading to muscle weakness |
Reticular fibers | smaller and more delicate than collagen fibers and results in somewhat loose type of connective tissue |
Elastin | can be reversibly stretched to nearly twice their length; abundant in blood vessels, ligaments, and skin |
What is precursor molecule to elastin? | tropoelastin |
Loose connective tissue | highly flexible structure; provides structure to blood vessels and nerves; highly vascularized and contains a lot of cells |
Dense connective tissue | provides maximum strength with little flexibility |
What are the two types of dense connective tissue? | dense regular and dense irregular |
Hematopoietic tissue | specialized connective tissue that contains mostly fluid, such as blood and lymph |
What do white blood cells consist of? | lymphocytes, macrophages, and microphages |
What does extracellular fluid of blood consist of? | plasma, lymph, and interstitial fluid |
Cartilage | connective tissue that provides structural support for other tissues |