Chapter 4 Organization and Regulation of Body Systems What is a tissue A collection of cells of the same type that perform a common function There are 4 major tissue types in the body Connective It binds and supports parts of the body It has specialized cells ground substance and protein fibers Ground substance is non cellular and ranges from solid to fluid Ground substance and protein fibers together make up the matrix of the tissue There are 3 main types of connective tissue o Fibrous There are 2 types dense and loose but both contain fibroblast cells with a matrix of collagen and elastic fibers Loose fibrous tissue is found supporting epithelium and Adipose tissue is a special loose fibrous tissue where fat many internal organs is stored o Supportive Cells are in chambers called lacunae Matrix is solid but flexible Example Cartilage and there are 3 distinguished types of fibers Hyaline cartilage fine collagen fibers Location Nose ends of long bones and fetal skeleton Elastic cartilage more elastic fibers than cartilage fibers Fibrocartilage strong collagen fibers Location Disks Location Outer ear between vertebrae Example Bone its solid and rigid matrix is made of collagen and calcium and there are 2 distinguished types by the type of fibers Compact made of repeating circular units called osteons which contain the hard matrix living cells and blood vessels Location Shafts of long bones Spongy an open latticework with irregular spaces Location Ends of long bones Example Blood Made of a fluid matrix called plasma contained in vessels and 3 cellular components that are called 3 formed elements Red blood cells erythrocytes cells that carry oxygen Red because of hemoglobin protein White blood cells leukocytes cells that fight infection Platelets thrombocytes pieces of cells that clot blood Production of antibodies Prevent loss of blood o Fluid Example Lymph It s matrix is a fluid called lymph contained in lymphatic vessels White blood cells congregate in those lymph nodes Muscular It allows for movement in the body It is made of muscle fibers cells and protein fibers called actin and myosin There are 3 types of muscle tissue in humans o Skeletal o Smooth o Cardiac Appearance long cylindrical cells multiple nuclei striated fibers Nature voluntary movement Location attached to bone for movement Appearance spindle shaped cell with one nucleus lacks striations Nature involuntary movement Location walls of digestive organs and blood vessels Appearance branched cells with a single nucleus striations with darker striations called intercalated disks between cells Location heart Nature involuntary movement Nervous It allows for communication between cells through sensory input integration of data and motor output It is made of 2 major cell types o Neurons o Neuroglia They are made of dendrites a cell body and an axon Dendrites carry information toward the cell body Axons carry information away from the cell body They are a collection of cells that support and nourish neurons They outnumber neurons 9 1 Examples are oligodendrocytes astrocytes Schwann cells and microglia Epithelial It is a group of cells that forms a tight continuous network It lines body cavities covers body surfaces and is found in glands Cells are anchored by a basement membrane on one side and are free on other side We name epithelial tissue by their shape and quantity of layers It is named after the appearance of cell layers and the shape of the cells There is transitional epithelium that changes in appearance in response to tension o Number of layers Simple one layer of cells Pseudostratified appears to have multiple layers but only has one layer Stratified more than one layer of cells o Shape Cuboidal cube shaped Columnar column shaped Squamous flattened What does epithelial tissue look like Moving from tissue to organs and organ systems An organ is 2 or more tissue types working towards a particular function An organ system is a combination of organs that work together to carry out a particular function Homeostasis It is the ability to maintain a relatively constant internal environment in the body The nervous and endocrine systems are key in maintaining homeostasis Changes from the normal tolerance limits result in illness or even death The key mechanisms to maintainig homeostasis are Negative feedback the output of the system resolves or corrects the original stimulus The primary mechanism for maintaining homeostasis Has 2 components sensor and control center Positive feedback increases change in the same direction as the original stimulus An example is the secretion of oxytocin during birth to continually increase uterine contractions Can be harmful such as when a fever is too high and continues to rise Body Cavities ORGAN SYSTEMS
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