Flashcards in Quiz 3 Deck (12):
1. Exocrine--secrete out of body (sweat glands, oil glands, salivary glands)
2. Endocrine--secrete into blood stream--blood stream goes everywhere. Secretions are called hormones
Exocrine gland types
1. Eccrine (merocrine): form secretory vesicles in their cells that are released through exocytosis
2. Holocrine: form secretions intracellulalry and then rupture to release contents. rare--include sebacious glands in scalp.--mostly fund in skin
3. like merocrine, but vesicles are larger and more viscous. found in axilla, and peroneally--activated at puberty.
-cells may be surrounded by non-living material that they have synthesized
-ground substance--mostly glycoproteins and water. surround cells and make up most of ECM
-protein fibers--callagen is most common making up large parts of connective tissue such as bone and tendon. elastin supplies stretchability to tissues
-basement membranes--at interface between epithelium and connective tissue.
1. tight: literally sew cells together preventing diffusion btwn them. impermeable.
2. desmosomes and hemidesmosomes: less restrictive than tight junctions but still hold cell together, particularly epithelial lining.
3. Gap junctions: allow transfer of contents btwn two adjacent cells w/o having to pass through membrane.
connective tissue function
1. primarily supportive--tendons, bones, cartilage
2. nutrition and immunity--blood is a connective tissue
3. storage--the bones contain adipose and a reservoir of calcium
4. morphology--body's shape is pretty much defined by connective tissue. Many characteristics of old age are based on the failing of connective tissue (wrinkles, sore joints, osteoporosis etc)
loose connective tissue types
1. collagen fibers--scatters and far apart. tissue has some strength but can be easily stretched
2. fascia--attaches to skin down onto underlying muscle and bone. allows skin to move freely over bone
3. adipose--modified fascia that contains adipocytes that stores lipid
4. hemopoietic--red bone marrow located w/i marrow of certain bones. produce blood cells that break off from it and float freely in the blood.
dense connective tissue types
-tendon: collagen fibers are close-packed and all aligned in same direction. strongest tissue. connects muscle to bone
-dermis: dense irregular connective tissue can resist stretch from all directions. supports skin.
-ligament: dense fibrous elastic connective tissue containing elastin, attaches bone to bone or organ to bone. strong but stretches to absorb stress. also found in walls of arteries and veins.
1. hyaline--contains large amount of chondroitin. found in moving joints
2. elastic cartilage-- contains elastin and chondroitin and collagen. forms tip of nose and ear
3. fibrocartilage--contains chondroitin and collagen--stronger ands stiffer than hyaline, found in weight bearing joints like vertebral disks and knee menisci
osseous tissue types
-Spongy (cancellous) bone--found in heads of long bones, lots of open spaces filled with marrow.
-compact (haversian) bone--very dense tissue with large amounts of collagen and calcium hydroxyapatite. strong, resilient--supports the body. shafts of long bone
-laminar bone--forms dense flat plates of bone--found in skull and ribs
*as you age your osteocytes decrease; takes longer for your bones to repair
Membrane types and locations
1. cutaneous: the skin; covers and protects the outer surface of body. It contains several specialized structures
2. mucous membrane: the mucosa; covers and protects the inner surfaces of the body in the lungs and alimentary canal. Goblet cells in the lining produce thick viscous liquid call mucin. The membrane also carries out selective absorption for nutrition.
3. serous membrane: serosa; lines the inner surface of some of the body cavities such as the peritoneal cavity, pericardial cavity, and pleural cavity. it produces thin watery serous fluid which can fill the cavity formed by the serous membranes.
4. synovial membrance: line the cavities between freely moving joints. The lining cells produce a thin, slipper fluid called synovium, which acts as a lubricant.
membranes structure and function
-all composed of epithelial lining tissue and supportive connective tissue
-aside from protecting the lining surface, the epithelium can also be secretory, producing a thin watery fluid that can act to lubricate and clean the surface . ex. mucosa produces a mucopolysaccharide-rich mucous secretion that protects the digestive tract.
-tissues contain stem cells, which can undergo cell division and constantly replace parts of the membrane that are damaged or worn down . ex. we lose about 15 layers of cells of skin a day