Tissues of vertabrates Premedical 22 Tissues = cells of same shape and the same function extracellular matrix 1. Epithelia – ectoderm, mesoderm, endoderm 2. Connective tissue - mesoderm 3. Muscular tissue - mesoderm 4. Nervous tissue - ectoderm Basement membrane - thin sheet of fibers that underlies the epithelium, which lines the cavities and surfaces of organs, or the endothelium, which lines the interior surface of blood vessels 1. By fusion of endothelial and epithelial cells / kidneys and alveoli two laminae: lamina densa, lamina lucida 2. Epithelial cells with fibrous tissue: lamina densa and reticularis http://www.thefullwiki.org/Basement_membrane 1. Epithelia – form from one or more layers of cells covering an external surface or lining a cavity http://www.thefullwiki.org/Squamous_epithelium Single layer of squamous flat cells Single layer of cuboidal cells (sweat, digested food) Single layer of columnar cells - may function to absorb substances Single layer of columnar cells with microvili - help move substances over their surface Stratified e. of cuboidal cells Stratified Squamous Epithelium (non-keratinized) Stratified Squamous Epithelium (keratinized) Transitional e. with cells range from flat to tall cells Pseudostratified Ciliated Columnar Epithelial Tissue Simple squamous epithel (2) - capillary Simple columnar epithel – gal gladder Vesica fellea Hematoxylin-Eozin Single layer of columnar cells (2) with microvili (3)- oviduct 1 - lamina propria, 4 – gland cells Stratified e. of cuboidal cells with microvilli (2) - trachea 1 - submucosa Stratified Squamous Epithelium (1) (non-keratinized) Uterus :2 - submucosa Stratified Squamous Epithelium (keratinized) – Cutis- Skin Transitional Epithelium (2) (urinary bladder) 1 – lumen of vesica urinaria, 3 - Lamina propria mucosae Function of epithelial tissue • protection and cover - the skin - protect underlying tissue from mechanical injury, harmful chemicals, invading bacteria and from excessive loss of water • sensation - specialized epithelial tissue containing sensory nerve endings is found in the skin, eyes, ears, nose and on the tongue • secretion – glands - epithelial tissue is specialized to secrete specific chemical substances such as enzymes, hormones and lubricating fluids • resorption, absorption - certain epithelial cells lining the small intestine absorb nutrients from the digestion of food [lining inside surface of hollow organs] • respiratory, diffusion - simple epithelium promotes the diffusion of gases, liquids and nutrients. Because they form such a thin lining, they are ideal for the diffusion of gases (eg. walls of capillaries and lungs). Glands - secretion Secretion : merocrine (pancreas) / exocytose apocrine (lacteal gland) holocrine (sebaceous gland) Gland: •Exocrine - secrete chemicals into ducts – outlets •Endocrine –without outlets – directly to body fluids pancreas lacteal gland sebaceous gland 2. Connective tissue play a central part in the support and repair of almost every tissue and organ and the adaptability of their differentiated character is an important feature of the responses to many types of damage Collagen is the main protein of connective tissue in animals, making up about 25% of the total protein content Proper fibrous tissue Cartilage Bone Embryonic connective tissue Connective-tissue cells: Fibroblasts Cartilage cells (chondrocytes) Bone cells (osteoblasts and osteocytes) Fat cells (adipocytes) Mast cells Macrophages Leucocytes Fiber types as follows: collagenous fibers elastic fibers reticular fibers Fibroblasts with dark nuclei [A] are seen here along with thick collagen fibers [B], thin elastic fibers [C] and very fine reticular fibers [D]. Loose fibrous tissue - Areolar loosely organized fibers Fibers are collagenous, but elastic and reticular fibers are also present, in many serous membranes - Reticular a network of reticular fibers, made of type III collagen - Adipose white, brown Dense fibrous tissue Dense regular connective tissue (Ligament, Tendon, Aponeurosis) Dense irregular connective tissue (Submucosa, Dermis) Embryonic connective tissue - mesenchymal Specialized Bone Cartilage white, brown adipose tissue Vertical section of duodenum: 1 - Tunica mucosa, 2 - Tunica submucosa, 3 – Brunner gland Tendon Cartilage – the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs. • chondrocytes that produce a large amount of ECM composed of collagen fibers, rich in proteoglycan, and elastin fibers • elastic cartilage - epiglottis • hyaline cartilage • fibrocartilage hyaline cartilage elastic cartilage - epiglottis 1 – elastic cartilage, 2 - perichondrium, 3 – seromucin glands, 4 - Tunica mucosa Bone produce red and white blood cells – red marrow - in long bones store minerals and fatts (yellow) most notably calcium and phosphorus (calcium phosphate 2/3, calcium hydroxyapatit 1/3) Ossification (or osteogenesis) Intramembranous ossification is the direct laying down of bone into the primitive connective tissue (mesenchyme), while endochondral ossification involves cartilage as a precursor. 1. periosteum 2. compact bone 3. spongy bone 4. Bone marrow – medulla • Diaphysis • Epiphysis http://doctorsgate.blogspot.com/2010/11/compact-vs-spongy-bones.html 3. Muscular tissue – contractility upon stimulation skeletal muscle long, multinucleated syncytial cells by fusion of myoblast cells their nuclei are located peripherally adjacent to the plasma membrane (sarcolemma). Controll by our will, spinal (medullary) and cerebral nerves, cortex Skeletal and muscles of tongue and pharynx smooth muscle composed of sheets or bundles of relatively short, spindle-shaped cells not striated, and have a single central nucleus are interconnected by gap junctions. Muscles of digestive system, uteri, gall bladder, dermis, Controll by autonomic [vegetative] nerves cardiac muscle composed of branching and anastomosing chains of cardiac muscle cells are joined to their neighbours by intercalated discs, which contain anchoring and gap junctions. The anchoring junctions (adherens junctions and desmosomes) physically connect the cytoskeletons and contractile apparatuses of the neighboring cells. Control by autonomic [vegetative] nerves Muscle - structure A.Muscle with fascia e. tendon f. bundle of fibers B. Fiber C. Myofibril from sarcomers g. actin h. myosin Composed of actin (thin) and myosin (thick) filaments and associated proteins is organized into myofibrils The regular repeating segments (sarcomeres) of myofibrils give skeletal and cardiac muscle cells transverse striations. In smooth muscle cells, actin and myosin filaments form contractile fibers, which do not appear as highly organized as myofibrils 4. Nervous tissue composed of cells with long processes, which may run in bundles of parallel fibers. The cells are divided into excitable cells (called neurons, lead impulses ) and the more numerous supporting cells (called neuroglia or glial cells) Molecular Biology of the Cell. 4th edition. Alberts B, Johnson A, Lewis J, et al. neuron • Centripetal fibers - dendrits • centrifugal fibers – neurits – axons neuroglie Schwann cells - origin of neurolemma which cohere with sheath myelin Nerve grey and white fibers with or without Thank you for your attention Campbell, Neil A., Reece, Jane B., Cain Michael L., Jackson, Robert B., Minorsky, Peter V., Biology, Benjamin-Cummings Publishing Company, 1996 – 2010.