Flashcards in Tissues Deck (86):
Definition of tissue
(Tissu= woven) are small groups of cells that are similar in structure and preform a common or related function.
What are the 4 basic Tissue types?
1) nervous tissue
2) muscle tissue
3) epithelial tissue
4) connective tissue
What is nervous tissue responsible for?
What is muscle tissue responsible for?
Contracts to cause movement
What is epithelial tissue responsible for?
Forms boundaries between different environments, protects, secretes, absorbs , filters, excretion, sensory reception.
What is connective tissue responsible for?
Supports, protects, binds other tissues together.
Epithelial tissue definition
A sheet of cells that covers a body surface or lines a body cavity.
What are the 2 types of epithelial tissue ?
Covering/lining epithelium: forms outer layer of skin, forms barriers in open cavities.
Glandular epithelium: fashions the glands of the body
What are the 6 special characteristics of epithelium?
2. Specialized contacts
3. Supported by connective tissue
4. Avascular but innervated
Polarity of epithelium
Has Apical surface and basal lamina/basement membrane
Cellularity of epithelium
Epithelium is composed entirely of cells.
Specialized contacts of epithelium
1. Gap junctions
3. Tight junctions
Epithelium is avascular but innervated which means?
It has no blood vessels but it does have nerve endings.
What is special about the regeneration of epithelium cells?
They regenerate quickly
Epithelium always has ______ tissue.
Connective tissue (CT)
What is a gap junction
A communication junction between adjacent cells. Cells are connected by hollow cylinders called connexion a composed trans membrane proteins. Allows simple sugars, ions and small molecules pass through these water filled channels from one cell to another.
What is a tight junction?
A series of integral protein molecules in the plasma membranes of adjacent cells fuse together. To prevent molecules from passing through.
What is a desmosome?
(Binding bodies) Anchoring junctions- like Velcro or zipper hell together by thin linker protein filaments. They bind neighboring cells to make tissues stronger and resist tension and tearing (found in heart)
What are the classifications of epithelial tissue?
1. Simple Squamous (endothelium and mesothelium
2. Simple cuboidal epithelium
3. Simple columnar epithelim
4. Pseudostratified columnar epithelium
5. Stratified squamous epithelium
6. Stratified Cuboidal
7. Stratified columnar
8. Transitional epithelium
What is simple squamous ET? What does it do? Where is it found?
- A single layer of flat squamous cells
- Found where filtration or the exchange of substances by rapid diffusion is a priority.
- Found in kidneys, air sacs of lungs; lining of heart, blood vessels and lymphatic vessels. Lining of central body cavity (serosae)
What is simple columnar et? What does it do? Where is it found?
- a single layer of tall, closely packed cells, aligned like soldiers in a row.
- absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (reproductive cells) by ciliary action.
- Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus.
What is simple cuboidal et? What does it do? Where is it found?
- a single layer of cube like cells with large, spherical central nuclei.
- secretion and absorption
-ducts and secretory portions of small glands; ovary surface
What is Pseudostratified columnar epithelium? What does it do? Where is it found?
- single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia.
-secrete substances, particularly mucus; propulsion of mucus by ciliary action.
-Nonciliated type in males sperm carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of upper respiratory tract.
What is stratified squamous epithelium? What does it do? Where is it found?
-thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are squamous; in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers.
-protects underlying tissues
-non-keratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a membrane.
What is transitional et? What does it do? Where is it located?
-resembles both stratified squamos and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamos elite, depending on the degree of organ stretch.
-stretches readily, permits stored urine to distend urinary organ.
-lines the ureters, bladder, and part of the urethra.
What is a gland?
A gland consists of one or more cells that make and secrete a particular product, usually water based, can be steroid based.
Glands are classified by 2 sets of traits. What are they
1. Where they release their product endocrine and exocrine
2. Relative cell number
Unicellular or multicellular
Cancer causing genes
Benign forms of onconogenes in normal cells
Steps of tissue repair
3. Regeneration and fibrosis
Cells release inflammatory chems. Clot is formed.clot dries hardens and forms a scab
Restores blood supply. Granulation tissue forms under scab
When et is replaced with same tissue. Scar in dermis
Found inside body, ventral body cavity. Moist simple squamous et resting on areolar ct. Secretes serous fluid
Any membrane open to outside world. Wet membrane usually stratified squamous or simple columnar et
Thin sheet of loose ct under epithelial tissue of mucus membrane
Mucous membranes are often adapted for
Absorption and secretion
Not all mucous membranes secrete
Mucus, ex. Urinary bladder does not
Skin, keratinized stratified squamous et firmly connected to CT (dermis). Exposed to air and is a dry membrane
Branching cells of nervous tissue, contain axon, dendrites and cell body. Conducts nerve impulses is not replacible
Neurons receive stimuli through
Electrical impulses I've a great distance
Protect and insulate the neuron. Is not excitable
Found in walls of hollow organs. Not stripped. Involuntary muscle. Propels things through body
Found in walls of heart. Some stripes. Only one nucleus per cell, interdigitate at special junctions. Contracts and propels blood
Myofilaments cause striped look. Found in "muscle muscles" may have many nuclei. Voluntary movement. Locomotion. Attached to bones or skin
Red, white, and platelet cells in plasma matrix. Transports stuff. Found in blood vessels
Aka bone. Hard calcified matrix has a lot of collagen. Osteocytes lie in lacunae. Supports, protects, works with muscle to cause movement. Stores minerals makes blood cells in marrow
1. Hyaline cartilage
2. Elastic cartilage
3. Fibro cartilage
In ear( pinna) soft flexable. Looks like hyaline but has more elastic fibers
Contains collagen fibers which are undetectable. Looks like glass contains chondrocytes which lie in lacunae. Found in costal cartilages, nose, trachea, embryonic skeleton
Contains stripes of thick collagen fibers. Chondrocytes in lacunae. Can withstand school and tension. Found in intervertebral discs and pubic symphysis
Any CT with a dense matrix
Found in aorta, allows tissue to recoil after stretching. Has a lot of elastic fibers.
Dense irregular CT
Found in dermis of skin, joint and organ capsules, sub mucosa of digest. Tract. Collagen fibers placed irregularly. Withstands tension in many directions.
Dense regular CT
Found in tendons and most ligaments. Parallel collagen fibers. Has fibroblasts and a few elastic fibers. Attaches things and withstands stress in one direction
Cartilage has blood vessels?
Spongy, made if reticular fibers. Loose CT. Supports other cell types. Found in lymphoid organs, spleen, lymph nodes, bone marrow
Fatty, similar to areolar. Provides reserve body fuel, cushions and insulates. Under skin, behind eyeballs, in boobs, and tummy
Most abundant, packing peanuts of body. Contains all cell and fiber types in matrix which is gel like. Holds tissue fluid. Plays role in inflammatory response, cushions organs. Found in lamina propria and around capillaries
Contains Heprin and histamine
White blood cells
Nutrophils, respond to injury
Fibers found in matrix
2 classes connective tissue proper
Loose and dense
Connective tissue have what characteristics?
Degrees of vascularity
Non living extra cellular matrix
Types of multicellular exocrine glands
1. Simple tubular-
2. Simple branched tubular
3, compound tubular
4. Simple alveolar
5. Simple branched alveolar
6. Compound alveolar
7. Compound tubular alveolar
Simple tubular alveolar is found where?
Simple branched tubular ducts are found where?
Gastric (stomach) glands
Compound tubular is ducts are found where?
Simple alveolar ducts are found
Not in humans
Simple branched alveolar ducts are found
Sebaceous oil glands
Compound alveolar ducts are found in
Compound tubuliaveolar ducts are found where
Ex. Of a unicellular gland
Endocrine gland secrete
Inside the body
Exocrine gland secrete
Outside the body
Merely secrete a substandard through exocytosis
Accumulate products within until they rupture. Whole cell goes, Ex. Sebaceous oil glands
Only a part of cell is given up, debated in wether humans have this gland. Best possibility is in lactating mammary glands