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
CT fibers - elastic
- contain elastin protein
- can branch
- have ability to stretch and recoil
- wound up in such a way that means that you can stretch it out and then it bounces back
CT fibers - reticular
- narrower than collagen
- form a meshwork (“reticulated”)
- “particular”
Loose CT Proper — Areolar CT
- all cell types present
- open framework -> think airy
- fxn: cushions organs, mobile support, immune protection
- location: found within/deep to the dermis, covered by epithelium of different tracts like respiratory tract, btw muscles, around blood vessels, nerves joint
Loose CT — adipose CT
- adipose = fat
- mostly adipocytes
- fxn: stores energy, insulates, provides padding
- deep to skin and around some organs
Loose CT — reticular CT
- reticular fibers, macrophages, fibroblasts
- fxn: provides supporting framework
- makes sense since we reticular fibers that provide a meshwork which is good for support in this type of CT
- location: liver, kidney, spleen, lymph nodes, bone marrow
- shown in a lot of organs: we need a goodframwork so our organs can fxn properly
dense CT — dense regular CT
- collagen fibers are parallel; aliigned in parallel to stress
- fxn: provides firm attachment, conducts pull of muscles
- tendons and ligaments
Dense CT — elastic CT
- include elastic fibers in addition to collagen
- stabilizes positions
- btw vertebrae (ligamentum flavum); suspensory ligament of penis and clitoris
Dense CT — dense irregular CT
- fibers form interwoven meshwork aligned in various directions
- provides resistance to forces in many directions
- dermis, organ capsules, periosteum
Supportive CT — hyaline cartilage
- closely packed collagen fibers; translucent matrix
- provides stiff, compresible support; reduces friction
- found: synovial joints, supporting respiratory tract, nasal septum
Supportive CT – elastic cartilage
- elastic fibers packed in matrix
- provides support but tolerates distortion
- found: pinna of ear, epiglottis, etc.
Supportive CT – fibrocartilage
- extremely dense collagen fibers, resembling dense regular CT
- resist compression
- found: menisci in knee, intervertebral discs, etc.
Supportive CT – bone
- osteocytes: bone cells
- lacunae: arranged around blood vessels
- periosteum: around bones
(look at slides for pics)
Mucous membrane
- line passageways
- moistened by mucous
- contain lamina propria (areola CT)
- digestive and respiratory tracts
Serous membrane
- line internal cavities
- delicate, moist, permeable
Synovial membrane
- located within cavity of synovial joints
- produce synovial fluid, which lubricates joints
Cutaneous membrane
- covers body surface
- thick, waterproof, usually dry
Skeletal muscle tissue
- “striated” - has stripes
- under voluntary control (you can move your own heart)
- cells (fibers) are long, cylindrical, and multinucleate
Cardiac muscle tissue
- striated
- under involuntary control (don’t tell your heart to pump)
- fibers are short, branched, connected by intercalated discs
Smooth muscle tissue
- not striated
- involuntary control (can’t tell ourselves to push our food down our gastrointestinal system faster)
- fibers are short, spindle-shaped, with one nucleus in the middle of cell
Neuroglia
- support cells (many different types that specialize in physical, nutritional, regulatory neuroglia)
Neurons
- structural and functional cells reacting to the physical and chemical changes in their environment
- help transmit the nerve impulse
