Chapter 4- Tissues Flashcards
Superficial to deep; ectoderm (nerve tissue ), mesoderm (muscle and connective tissue ), and endoderm (Epithelial tissue). Epithelial tissues arise from all three germ layers.
Primary germ layers
Groups of cells similar in structure that perform common or related function
Tissues
Study of tissues
Histology
Sheets of cells that covers body surfaces and cavities.
Two main forms: covering and lining epithelia and glandular epithelia.
Main functions: protection, absorption, filtration, extraction, secretion, and sensory reception.
Epithelial tissue
Apical surface side is exposed to surface or cavity.
Basil surface, lower attach side, faces inwards towards body. Attaches to basil lamina.
Polarity ( characteristics of epithelial tissue)
-Needs to fit closely together.
-Many form continuous sheets.
-Lateral contact include: tight junctions, Desmosomes.
Specialized contacts (characteristics of epithelial tissue
Reticular lamina: consist of network of collagen fibers
Supported by connective tissues (characteristics of epithelial tissue)
Made up of basil and reticular lamina. Resists stretching and tearing
Basement membrane
No blood vessels are found in epithelial tissue. must be nourished by diffusion supplied by nerve fibers.
Avascular but not innervated (characteristics of epithelial tissue)
Epithelial cells have high regenerative capacities. Some cells are exposed to friction some to hostile substances resulting in damage.
Regeneration (characteristics of epithelial tissue)
A single layer thick
Simple epithelia
Two or more layers thick and involved in protection
Stratified epithelia
Flatten and scale like
Squamous
box like, cube
Cuboidal
Tall, Column like
Columnar
Function:Allows materials to pass by diffusion infiltration in sites where protection is not important. secrets lubricating substances in Serosae.
Location: kidney glomeruli; air sacs of lungs, lining of heart, blood vessels, and lymphatic vessels.
Simple squamous epithelium
Function: secretion and absorption
Location: kidney tubules, ducts and secretory portions of small glands. Ovary surface.
Simple cuboidal epithelium
Function: absorption; secretion of mucus, enzymes, and other substances. Ciliated type propels mucus by ciliary action.
Location: non-ciliated type line most of digestive tract, gallbladder, and excretory ducts of some glands.
Simple columnar epithelium
Function: secrete substances, particularly mucus; propulsion of mucus by ciliary action.
Location: Ciliated verity, lines, the trachea and most of the upper respiratory tract. ducts of large glands.
Pseudostratified columnar epithelium
Function: protects underlying tissues, and areas subjected to abrasion
Location: Nonkeratinized forms the moist linings of the esophagus, mouth, vagina
Stratified squamous epithelium
Quite rare, found in some sweat and mammary glands, typically only two cell layers thick.
Stratified cuboidal epithelium
Very limited distribution in body.
Small amounts found in pharynx,in male urethra and lining some glandular ducts. Only apical layer is columnar
Stratified columnar epithelium
Function: stretches readily
Location: lines the ureters, bladder and part of the urethra
Transitional epithelium
Most abundant and widely distributed of primary tissues.
Major functions: binding and support, protecting, insulating, storing reserve fuel, transporting substances (blood).
Connective tissue
-All arise from mesenchyme tissue.
-Have varying degree of vascularity.
-Cells are suspended/embedded in extracellular matrix (ECM) (protein, sugar mesh)
Characteristics of connective tissue
Ground substance + fiber=
Extracellular matrix
Gel like material that fill space between cells.
Components; Interstitial fluid, cell adhesion proteins , proteoglycans.
Ground substance
Three types of fibers provides support.
Collagen-strongest and most abundant type. Tough, provides high tensile strength.
Elastic fiber-network of long, thin, elastin fibers that allow for stretch and recoil.
Reticular-short fine highly branched collagenous fibers. Offer more “give’
Connective tissue fibers
Immature form of cell
“Blast cell”
Mature, less active form of blast cell that now becomes part of and helps maintain health of matrix
“Cyte” cells
Found in connective tissue proper
Fibroblasts
Found in cartilage
Chondroblasts
Found in bone
Osteoblasts
Store nutrients
Fat cell
Tissue respond to injury
White blood cells
Initiate local inflammatory response
Mast cells
Phagocytic cells that “eat” dead cells
Macrophages
Consist of all connective, tissues, except bone, cartilage, and blood
Connective tissue proper
Function: wraps and cushions organs
Location: widely distributed under epithelia of body
Areolar connective tissue
Function: food fuel, insulates against heat loss, supports and protect organs
Location: under skin, around kidney and eyeballs; within abdomen, and in breasts
Adipose connective tissue
Function: soft internal skeleton, supports other cell types
Location: lymphoid organs
Reticular connective tissue
Function: attaches muscles to bones, attaches bones to bones
Location: tendons, most ligaments
Dense regular connective tissue
Function: withstand tension exerted in many directions
Location: Organs and joints. Dermis of skin.
Dense irregular connective tissue
Function: allows to recoil after stretching
Location: walls of large arteries
Elastic connective tissue
Matrix secreted from chondroblast and chondrocytes. tough flexible material that lacks nerve fibers.
Avascular-receives nutrients from membrane surrounding it.
Cartilage
Function: resilient cushion, resists compressive stress
Location: coastal cartilage of the ribs
Hyalin cartilage
Function: maintains shape of a structure while allowing great flexibility
Location: ear
Elastic cartilage
Function: tensile strength allows it to absorb compressive shock
Location: intrevertebral discs
Fibrocartilage
-Support and protects.
-Stores fat and synthesizes blood cells in cavaties
-Has more collagen compared to cartilage.
-Has calcium salts
-Osteoblast
-Osteocytes-maintain the matrix
-Richly vascularized
Bone tissue
-Atypical connective tissue because it is fluid.
-red blood cell, white blood cell, platelets.
-blood clotting
-transport, nutrients, waste, gases
Blood
-highly vascularized
-responsible for most types of movement
Muscle tissue
Function: voluntary movement, locomotion
Location: attached to bones or occasionally to skin
Skeletal muscle
Function: involuntary control
Location: heart
Cardiac muscle
Function: involuntary control.
Location: mostly in the walls of hollow organs
Smooth muscle
Function: Neurons transmit electrical signals from sensory receptors and to effectors
Location: Brain, spinal cord and nerves
Nervous tissue
