Chapter 5 Tissues

Epithelial Covers the body surface and organs, lines the inner cavities, glands External- protects from drying out, injury, and bacteria Internal-protection, secretions, specialization (mucus, cilia, microvilli) Cells packed tightly together, little matrix Lack blood vessels Anchored to underlying tissue at basement membrane Squamous, cuboidal, columnar Simple (single layer) Stratified (several layers)

Simple Squamous Flattened cells Single layer Found in the body where the layer of cells must be thin to permit efficient diffusion and filtration Thin, delicate, easily damaged EX: blood vessels (capillaries) alveoli (lungs) body cavities

Simple Squamous Epithelial

Simple Cuboidal Single layer, cubed shaped cells kidneys, liver, ovaries, glands (salivary, thyroid), pancreas

Simple Cubodial Epithelial

Simple Columnar Elongated, single layer Frequently secrete a product, also absorption May be ciliated (fallopian tubes) or non-ciliated May have microvilli for absorption (intestines) Wall of the uterus, stomach, small intestines

Simple Columnar Epithelial

Stratified Squamous Must resist constant wear and tear Thick with layers Outer layer of skin is strengthened and toughened with keratin (protein) Mouth, anus, esophagus, vagina- no keratin here

Pseudostratified Epithelium “appears” to be layered but is not Cilliated cells line respiratory tract, nasal, trachea, bronchi Contain goblet cells which secrete mucus and the ciliated cells move debris along the surface

Pseudostratified Tissue

Transitional Epithelium Ability to expand and regain its shape Urinary bladder, uterus, etc.

Glandular Epithelium Manufacture and secrete a substance “Gland” Singular- mucus goblet cell or Group cells Exocrine- secrete into ducts that open onto surfaces like the skin or digestive tract (Salivary, sweat) Endocrine- secrete directly into the bloodstream (Thyroid, pituitary)

Glands

Body Membranes Lines the internal sides of cavities and surrounds organs; line the tubes that open to the outside Contain other structures passing through it…blood vessels, nerves, etc. Divide areas of the body into compartments Anchor organs to other structures

Mucus Membranes Line the interior wall of organ and tubes that open to the outside Digestive, respiratory, urinary, reproductive Epithelium overlying connective tissue ET contains goblet cells that secrete mucus Mucus protects from bacteria and viruses Mucus in stomach protects from digestive enzymes

Serous Membranes Line the thoracic and abdominal cavities and their organs Simple squamous overlying connective tissue Secrete a clear watery fluid that provides lubrication Pleural membranes in thoracic cavity…pleurisy (infection of the pleural and parietal membranes around the lungs) Pericardium (surrounds the heart) Peritoneum –abdominal cavity….Peritonitis- infection of the peritoneum (appendix bursts) Mesentery- peritoneum doubles back to form support for internal organs (intestines) Parietal (body wall) … Visceral (organ lining)

Synovial Membranes Line the cavities of freely movable joints (knee, elbow, shoulder)does not contain epithelial tissue…connective tissue (cartilage) Secrete a clear watery liquid (synovial fluid) that lubricates the ends of the opposing bones….nourishes the cartilage at the ends of the bones Rheumatoid arthritis- membrane becomes inflamed and grows thicker…fibrous tissue invades the joint and makes the joint bony and stiff

Meninges Membranes that surround the brain and spinal cord All connective tissue Meningitis – infection of the meninges

Cutaneous Membrane Skin Thin outer layer of stratified squamous attached to a thicker layer of connective tissue