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Cells are organized into tissues Epithelial- protection, secretion, absorption surfaces (of body, organs) glands Connective- support, adhesion widely distributed Muscle- movement heart; internal organs; attached to bone Nervous- sensory input and output
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Cells are organized into tissues Epithelial- protection, secretion, absorption surfaces (of body, organs) glands Connective- support, adhesion widely distributed Muscle- movement heart; internal organs; attached to bone Nervous- sensory input and output brain, spinal cord, peripheral nerves
Epithelial tissues “sheets of cells” form barriers Secretion (exocrine glands) Absorption (specialized membrane) Transport Classified by shape
Squamous epithelium Simple- single layer of flattened cells diffusion (alveoli) filtration (blood vessels)
Simple cuboidal Cells are more “cubelike” than squamous cells Cover ovaries; line kidney tubules; various endocrine glands Secretion, absorption
Simple columnar epithelium Uterus, digestive tract Absorption (of food) Secretion (of digestive enzymes, acids, etc.) Goblet cells secrete mucus May have microvilli Glandular epithelium generally is columnar or cuboidal (exocrine, endocrine)
Pseudostratified columnar epithelium Cilated; also contains goblet cells Lines respiratory passageways Specialized to trap and remove airborne particles
Stratified epithelium Where “wear and tear” occur Stratified squamous outer layers are keratinized in skin not on internal surfaces: mouth, throat, vagina, anus Stratified cuboidal- certain glands Straitified columnar- urethra, vas deferens Transitional epithelium- bladder allows bladder to stretch
Connective tissues are the most diverse in form and function Generally a few cells scattered in an extracellular matrix Matrix: fibers and ground substance, either fluid, flexible or rigid (Fluid: blood, lymph Flexible: loose connective tissue, adipose, dense Rigid: bone, cartilage)
Fibroblasts: produce fibers that anchor the matrix Macrophages, mast cells- involved in immune response What kind of fibers? collagen, esp. in tendons and ligaments elastic fibers- in “stretchy” parts of body reticular fibers
Loose connective tissue Underneath most epithelium Well vascularized
Dense connective tissue Tendons, ligaments, deep layers of skin Poorly vascularized
Adipose tissue Energy storage, insulation, cushioning
Cartilage Hyaline-associated with bones Elastic cartilage- larynx, ears Fibrocartilage- vertebrae, knees, pelvis
Bone-matrix is mineralized Well nourished nonetheless
Membranes comprised of epithelium and connective tissue (usu. loose) Cutaneous- outermost membrane (skin) Serous- sealed body cavities (thoracic, abdominal, etc.) Mucous- line structures with access outside the body (respiratory, digestive, repro- ductive Synovial- between/within joints
Blood- liquid matrix Supportive, in a way Important for homeostasis
Muscle is specialized for contraction Three types- skeletal, smooth voluntary Differ in distribution, mechanism of contraction and regulation
Smooth muscle- internal organs Involuntary, not striated
Cardiac muscle Cells are branched and striated Involuntary control
Nervous tissue Neurons, glial cells Neurons transmit electrical signals Glial cells provide support functions
Organs contain all the tissues Epithelium- protective surface, absorption, secretion where appropriate Connective tissue- hold organ together Muscle (depending on organ) – whatever type of contraction or movement Nervous- sensory and motor response