the tissue Flashcards
Epithelial tissue
- covers exposed surfaces
- lines internal passageways and chambers (organs/cavities)
- produces glandular secretions
Connective tissue
- Fills internal spaces
- provides structural support
- stores energy
- supports, surrounds, connects other tissues
- defends body from invasin
- protects organs
- transport fluid and dissolved tissue
- Ex: bones, cartilage
Muscle tissue
- Contracts to produce movement
- includes skeletal muscle, cardiac muscle, and smooth muscle
Nervous tissue
- conductes electrical impulses
- carried info
Epithelia
- cells exhibit polarity (has top and bottom)
- apical specializations: microvilli, cilia, stereocilia
- “bottom” = basal surface
- attached to underlying basement membrane (floor on which cells will stand)
- cells connected to one another at lateral surface
One layer of epithelia
simple
Several layers of epithelia
Straified
Epithelia: Shape of cell at the top – flat
Squamous
Epithelia: shape of cell at the top – square/cube
- Cuboidal
Epithelia: shape of cells at the top – taller than they are wide
- columnar
Simple Squamous Epithelia
- one layer of flat cells
- locations: serous cavities, some blood vessels, alveoli of lungs
- fxns: reduces friction, allows permeability, allows absorption and secretion
Stratified Squamous Epithelia
- several layers of cells; top layer is flat
- locations: surface of skin, lining of oral cavity, throat, rectum, anus, vagina
- fxnx: protection
Simple cuboidal epithelia
- one layer of cells;appear cube-shaped
- locations: glands, ducts, kidney tubules
- fxn: limited protection, secrete, and absorb
Stratified cuboidal epithelia
- several layers of cells; top layers appears cube-shaped
- locations: some ducts (rare)
- fxn: protection, secretion, absorption
Simple columnar epithelia
- one layer of cells; taller than they are wide
- locations: lining of digestive system, uterine tubes, collecting ducts of kidneys
- fxn: protection, secretion, absoprtion
Stratified columnar epithelia
- Several layers of cells; top layer is columnar
- locations: relatively rare, small parts of pharynx, mammary glands, salivary gland ducts, urethea
- fxn: protection
Pseudostratified epithelium
- all cells rest on basement membrane, but nuclei are located at varying distances
- locations: respiratory tract, male reproductive tractv
- fxn: protection, secretion
Transitional epithelium
- transitional: stratified; can stretch
- locations: urinary tract
- fxn: permits expansion and recoil
what is glandular epithelium arranged as?
secretory sheets (look like sheets) or as glands
3 components of connective tissue
- cells
- protein fibers
- ground substance (basically stuff btw the cells)
3 types of connective tissue
- CT proper: loose and dense
- Fluid CT: blood and lymph
- Supporting CT: cartilage and bone
Fixed cells of connective tissue
- fibroblasts: produce CT fibers
- fixed macrophages: phagocytize pathogens and destroy damaged cells
- adipocytes: store lipids (fats)
- mesenchymal cells: “stem cells”
- melanocytes: synthesize melanin (makes our skin dark)
wandering cells of connective tissue
mostly immune cells -> arrive in CT mainly from immune system
1. free macrophages: mobile phagocytic cells (passing thru -> can be coming from the blood to go live in the lungs)
2. mast cells: stimulate local inflammation
3. lymphocytes: immune response (WBC’s get stimulated when you are sick)
4. leukocytes: mobilize during infection/injury
CT fibers - collagen
- most common and strongest
- protein subunits wound like a rope and flexibe
- contract and relax based on how its wound, but it’s not actually contractile
- just extend and recoil back