230 likes | 256 Views
Tissues. Mr. Hill Anatomy. Contents. Tissues. Epithelial Tissues. Epithelial Tissue - Simple. Epithelial Tissue - Stratified. Epithelial Tissue - Glandular. Connective Tissue. Connective Tissue – Cell Types. Connective Tissue - Fibers. Connective Tissue - Types. Muscle Tissue.
E N D
Tissues Mr. Hill Anatomy
Contents Tissues Epithelial Tissues Epithelial Tissue - Simple Epithelial Tissue - Stratified Epithelial Tissue - Glandular Connective Tissue Connective Tissue – Cell Types Connective Tissue - Fibers Connective Tissue - Types Muscle Tissue Nervous Tissue
Tissues • Cells are organized into tissues. Cells within a tissue are similar. • Usually, tissue cells are separated by nonliving, intercellular materials - solid, semi-solid, or liquid. • The human body has 4 major types of tissues: • epithelial • connective • muscle • nervous
Epithelial Tissue • Widespread throughout the body. • Covers organs, forms inner lining of body cavities, and lines hollow organs. • Epithelial tissue is anchored to underlying connective tissue by a thin basement membrane. • Usually lacks blood vessels (nutrients diffuse via the basement membrane). • Protective barrier, secretion, absorption, excretion. • Classified by shape and number of layers of cells. Single layer: simple. Two or more layers: stratified. Shapes: squamous (flat), cuboidal (cube), columnar (elongated).
Epithelial TissueSimple Squamous • Single layer of flattened cells. • Substances pass easily through simple squamous epithelium – common at sites of diffusion and filtration. • Lines alveoli (in lungs), walls of capillaries, lines inside of blood and lymph vessels, lines body cavities. • Easily damaged.
Epithelial TissueSimple Cuboidal • Single layer of cube-shaped cells. • Centrally located, spherical nuclei. • Covers the ovaries, lines the kidney tubules and ducts of the salivary glands, pancreas, and liver. • Secretion and absorption.
Epithelial TissueSimple Columnar • Single layer of elongated cells. Thick and protects underlying cells. SCE also secretes digestive fluids and absorbs nutrients. • SCE lines the uterus and digestive tract. • Ciliated or nonciliated. • May have microvilli to increase surface area for absorption. • Often glandular cells (goblet cells) are scattered among SCE. These cells secrete a protective fluid called mucus
Epithelial TissueStratified Squamous • Many layers (thick). Cells at the surface are flattened (squamous). Deeper cells are cuboidal or columnar. • Outermost layer of the skin (epidermis). SSE also lines the oral cavity, throat, vagina, and anal canal.
Epithelial TissueTransitional • Specialized to change in response to increased tension. From many layers to only a few layers when the organ is distended. • Lines the urinary bladder, the ureters, and part of the urethra.
Epithelial TissueGlandular • GE is composed of cells that are specialized to produce and secrete substances into ducts or into body fluids. • Glands that secrete into tissue fluid or blood are called endocrine glands. • Single cells, simple or compound.
Connective Tissue • Comprise much of the body and are the most abundant type of tissue. • Bind structures, provide support and protection, fill spaces, store fat, produce blood cells, protect against infection, and help repair tissue damage. • Cells are not adjacent but have a matrix between them. The matrix binds, supports, and provides a medium. • CT has a variety of cell types.
Connective TissueCategories • Adipose (fat) tissue Certain cells within CT store fat within their cytoplasm. • Lies beneath the skin, between muscles, around the kidneys, in the abdomen, and around the heart. • Energy storage. Cushions joints and some organs. Insulates beneath the skin.
Connective TissueCategories • Dense CT consists of closely packed, thick, collagenous fibers, a network of elastic fibers, and a few fibroblasts. • Regular dense CT has strong collagenous fibers to withstand pulling forces. Tendons, ligaments. Blood supply poor. • Irregular dense CT is randomly organized. Can withstand tension from many directions. Dermis.
Connective TissueCategories • Elastic CT consists mainly of yellow, elastic fibers. • Between these fibers are collagenous fibers and fibroblasts. • Found in attachments between vertebrae and within the walls of the heart, larger arteries, and the larger airways.
Connective TissueCategories • Cartilage is a rigid connective tissue. Largely composed of collagenous fibers in a gel-like ground substance. • Support, frameworks, attachments, protects underlying tissue, forms structural models for many developing bones. • Cartilage cells (chondrocytes) occupy chambers called lucunae. • Cartilage lacks a direct blood supply.
Connective TissueCategories • Bone is the most rigid connective tissue. Hardness is due to mineral salts (calcium phosphate and calcium carbonate). Also contains a large amount of collagen for toughness. • Bone supports, forms blood cells, and protects. • Bone matrix is deposited by osteocytes (bone cells), which form concentric patterns called an osteon.
Connective TissueCategories • Blood is composed of cells suspended in a fluid called blood plasma. • Cells are red blood cells, white blood cells, and cellular fragments called platelets. • RBCs transport gases. WBCs fight infection. Platelets are involved in blood clotting.
Muscle Tissue Skeletal Muscle • Muscle tissues are contractile. Muscle fibers can shorten and thicken. • Skeletal muscle tissue forms muscles that we control by conscious effort. (Voluntary). • Can be long (to 40 mm) and narrow (0.1 mm). Have alternating light and dark cross markings called striations. • Each cell has many nuclei.
Muscle TissueSmooth Muscle • Smooth muscle tissue lacks striations. Cells are shorter and have one nucleus. • Involuntary. • In walls of hollow internal organs. (Stomach, intestines, urinary bladder, blood vessels.
Muscle TissueCardiac Muscle • Cardiac muscle tissue is only in the heart. Striated cells are branched and form complex networks. Single nucleus. • Where cells join forms an intercalated disk. • Involuntary. Can function without nerve impulses.
Nervous Tissue • Nervous tissues are found in the brain, spinal cord, and peripheral nerves. • Nerve cells are called neurons. Very specialized cell. • Also includes neuroglia, which support neurons. Neurons • Neurons sense changes in the environment and respond by transmitting nerve impulses. • Neurons coordinate, regulate, and integrate many body functions.
Nervous tissue Neuroglial Cells • Neuroglial cells (glial) support neurons. • There are many types of neuroglial cells, each has a different function. • Neuroglial cells lack the ability to transmit Impulses. Astrocytes