Bone vs. cartilage
- Bone undergoes extensive remodeling on a regular basis
- Bone can be repaired after damage
- Bone responds to changes in activity level & stress
- Appositional growth only
- Relatively high O2 demands
Membranes
Epithelia & connective tissue combine to form membranes
Mucous
- Line cavities that communicate with the exterior
- Epithelial surfaces kept moist at all times: lubricated by goblet cells or multicellular glands or by exposure to fluids (semen, urine)
- Loose connective tissue component of mucous membrane = lamina propria
Mucous Tissue
- Serous Membranes
- Line sealed, internal cavities
- Three: each consist of mesothelium supported by loose connective tissue
- Pleura lines pleural cavities (lungs)
- Peritoneum - peritoneal cavity
- Pericardium (heart)
- Thin membranes
- Firmly attached to body wall & to organ
- Relatively permeable
- Tissue fluids diffuse onto exposed surfaces (moist, slippery)
- Transudate - fluid formed on surface of serous membrane
- Volume small, enough to prevent friction
- Increases with disease or injury
- Cutaneous Membrane
- Covers surface of body
- Consists of stratified squamous epithelium & a layer of loose connective tissue
- Is thick, waterproof and dry
- Synovial Membranes
- Bones of skeleton contact one another at joints (articulations)
- Each joint surrounded by a fibrous capsule
- Inner surface of joint cavity lined by a synovial membrane
- Consists of extensive areas of loose connective tissue bounded by a superficial layer of squamous or cuboidal cells
- No basement membrane
- Cellular layer incomplete - gaps
Connective Tissue
Framework of the Body
- Functions
- Provide strength & stability
- Maintain the relative positions of internal organs
- Provide a route for the distribution of blood vessels, lymphatics & nerves
- Superficial fascia, deep fascia, subserous fascia
- Superficial fascia (subcutaneous layer)
- Hypodermis
- Layer of loose connective tissue separating skin from underlying tissues & organs
- Provides insulation, padding
- Allows the skin or underlying structures to move independently
- Deep fascia
- Dense connective tissue
- All fibers in a layer oriented in same direction - may change from layer to layer
- Tough capsules that surround most organs part of deep fascia
- Perichondrium (around cartilage), periosteum (around bones), associated ligaments, connective tissues (tendons & aponeuroses) part of deep fascia
- Subserous fascia
- Layer of loose connective tissue that lies between the deep fascia & the serous membranes that line body cavities
- Function is to prevent movement of muscles or muscular organs from distorting lining
- Muscle Tissue
- Specialized for contraction
- Muscle cells possess organelles & properties distinct from other cells
- Sarcoplasm = refers to cytoplasm of muscle fiber
- Sarcolemma = rather than cell membrane
- Skeletal Muscle Tissue
- Very large muscle fibers
- May be .3 m (1 ft) long!
- Long & slender = fibers
- Each cell multinucleated (100s)
- Nuclei just under surface of sarcolemma
- Skeletal muscle fibers incapable of dividing
- New produced thru division of satellite cells (mesenchymal)
