Tissues PDF - Human Anatomy & Physiology

1. Tissues Human Anatomy & Course Physiology Status Complete Materials 2. Tissues - Slides Date @August 29, 2024 Table of Contents...

1. Tissues Human Anatomy & Course Physiology Status Complete Materials 2. Tissues - Slides Date @August 29, 2024 Table of Contents Building Blocks for Functional Body Types of Tissues Epithelial Tissue Glands Connective Tissue Fat or Adipose Dense Regular Cartilage Bone Loose or Areolar Dense Irregular Blood Muscle Tissues 1. Tissues 1  Cardiac muscle Skeletal Muscle Tissue Smooth muscle Nervous Tissue What makes a cell a tissue cell? Membranes Building Blocks for Functional Body 1. Coverings Protection: Creates a boundary between environments using tightly fitting cells (e.g., skin prevents desiccation). Interaction with the Outside Environment: Diffusion: Thin, single-layer cells allow gas exchange (e.g., O₂ and CO₂ in the lungs). Secretion: Produces enzymes (e.g., for digestion) or fluids like sweat, oils, and mucus (e.g., lubrication). Absorption: Facilitates nutrient uptake during digestion. Adaptations: Multiple layers for durability under wear and tear (e.g., skin). Smooth surfaces to reduce friction (e.g., lining of chambers and tubes). 2. Movement: Cells shorten in length to pull on levers (bones), generating movement. 3. Connection and Support: Cells connect and bind to form strong, moveable multicellular structures, providing: Rigid support for shape and form. Cushioning for protection. Fluid conduits for distribution. Bindings to tie structures together. 1. Tissues 2  4. Cells that can communicate (coordinate and regulate other tissue cells) Types of Tissues Epithelial: covers Connective: connects and binds or is the building or packing material Muscle: contracts Nervous: communicates Epithelial Tissue Function: is to cover (protection, Epithelia is classified based on cell absorption, secretion, filtration, shape and number of layers excretion, senses) Squamous: or thin flat cell Location: body surface or lining a for diffusion (lungs) body cavity creating a smooth, frictionless surface lining chambers and blood vessels Columnar: Column or rectangular shape for absorption and secretion Found in the Digestive & respiratory tract 1. Tissues 3  Cuboidal: box-like shape for absorption and secretion kidney tubules Structure: Tightly packed cells with no spaces Polarity in cell structure Apical end: is exposed to a free surface Basal end: is attached to underlying connective tissue (basement membrane) Glands Avascular Glands: one or more cells that secrete cell products Regenerates or active cell division Endocrine Glands: Can be organized into glands cell products are secreted into (endocrine or exocrine) interstitial fluid and picked up and distributed by blood Lack ducts Exocrine glands: 1. Tissues 4  cell products are secreted onto a cell surface Via a duct Connective Tissue Structure: Functions: connects, supports and Common origin in the embryo protects body parts (is the packing Cells: or building material of the body) Secrete ground substance Binds: (ligaments, tendons, & extracellular fibers i.e. membranes) create their environment Protects: Membranes Few cells, space between Cushions: Areolar, Adipose, cells dominate Cartilage (extracellular space or fluid called matrix). Rigid Support: Bone Types: Insulates: Adipose Blast: young cell that is Transports: blood and lymph active in secreting ground substance and fibers (forming the matrix) Cyte: mature cell involved in maintenance and repair of matrix 1. Tissues 5  Less active in synthesis and cell division Properties of tissue due to nature of matrix, not cells Matrix: composed of extracellular fibers and ground substance Builds the body into a 3-D ECF referred to as a matrix structure that can move without because it is synthesized damaging delicate internal by the cells structures fluid, viscous fluid, water- soaked gel or rigid solid Classified based on the nature of the ground substance: liquid, gel Extracellular fibers are: or solid Collagen fibers for strength Elastic fibers for elasticity Reticular fibers are net-like structure composed of single collagen fibers Ground substance: composed of secreted proteins Vascularization varies Fat or Adipose Loose or Areolar Function: reserve energy supply 1. Tissues 6  insulates Function: /cushions organs Soft wrapping for organs Structure: matrix is reduced, cells Fluid media for cells of immune with fat droplets dominate, system vascularized Reservoir for water and fat is the bubble wrap Structure: thickened fluid Location: Surrounds organs and (hyaluronic acid) with many cells under skin and all three fibers is a soft packing material Dense Regular Location: Around organs and under skin Dense Irregular also called fibrous connective is sheet-like Function: handles stresses in Function: used to handle tensions many directions in one direction like a rope Structure: Densely packed but Structure: few fibroblast cells with random arrangement of collagen parallel collagen fibers filling and elastic fibers matrix Location: under skin and in avascular membranes Location: tendons aponeuroses, ligaments Cartilage 1. Tissues 7  Function: shock absorption, tough but flexible Structure: water-soaked gel, is rubber-like ground substance composed of chondroitin sulfite and hyaluronic acid, 80% water, avascular nutrients diffuse from adjacent tissues, no nerves Collagen fibers in gel ground substance, chondrocytes in lacunae Blood Location: ends of bone, ear, nose Bone Function: that acts as a transport medium to distributes nutrients Function: is rigid for support and respiratory gases Structure: calcified matrix Structure: a fluid matrix called containing collagen fibers and plasma calcium and phosphate salts 1. Tissues 8  Location: osteocytes lie in lacunae Contains white blood cells, red and are connected to blood blood cells, platelets vessels via canaliculi & canals Plasma is made up of ground substance and unpolymerized protein subunits No fibers but has ability to form fibers Skeletal Muscle Tissue Muscle Tissues Function: contraction Structure: parallel, elongated cells highly cellular vascularized Types: Function: attaches and moves Skeletal bones Cardiac Structure: Smooth Not a true cell but a mega cell: many fused cells i.e. Cardiac muscle multinucleate Striations or stripes indicating ordered arrangement of contractile elements Innervated and voluntary control Function: pumps blood Smooth muscle Structure: 1. Tissues 9  Mononucleated cells Some branching Striations Involuntary control Intercalated discs or gap junctions between cells Function: squeeze fluids through tubes Structure: Mononucleate Single tapered cells with no striations Involuntary control Nervous Tissue Function: communicates (regulates) Structure: cell body + processes (axons and dendrites) Two types of cells Neuron: conducts electrical signals Neuroglia: helps and supports neuron What makes a cell a tissue cell? 1. Cells are specialized 1. Tissues 10  a. Differentiation: step-wise process that restricts function by gene repression in the embryo and results in specialization of structure and function. b. Cells can not function independently 2. Cells are connected by junction proteins a. referred to as anchorage or attachment 3. The cell cycle is highly regulated to ensure that cells act as a unit and cooperatively. Chemical signals regulate and coordinate activities. a. Need growth factors from adjacent cells to divide (density dependent) b. Need to be attached to divide (attachment or anchorage) c. Regulation includes internal and external signals (growth factors, cell cycle regulatory factors, transcription factors) Cancer: the loss of a cell’s ability to be a tissue Loss of anchorage: cells can divide without attachment to other cells Cells can migrate and divide (metastasis) Loss of specialization (structure and function) Cells are immortal and can divide indefinitely (normal tissue cells can divide 20-30 times i.e. are mortal) Loss of cell cycle regulation results in uncontrolled cell division resulting in large masses called tumors (No longer show anchorage or density dependent inhibition or regulation by growth factors) Is the result of an accumulation of gene error in factors that regulate cell cycle and division: (growth factors, transcription factors , cell cycle regulatory factors, DNA repair mechanisms, anchorage proteins, telomere formation) Membranes 1. Tissues 11  Membranes: organs consisting of sheets of epithelial and connective tissues that form protective layers Types: Mucous (viscous secretions) Serous (watery secretions) Skin (dry) Synovial (joints) fluids 1. Tissues 12