Wk 4 Histology Flashcards
Histology
Study of normal structures of tissue
Tissue
( What is it?)
- A population of different cells related in structure and function.
- Has surrounding material extra cellular matrix. (ECM)
Types of tissue
(4 types)
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nervous tissue
Epithelia tissue
(5 things about it)
° Tightly packed sheets of cells with no visible ECM.
° Covers and lines all body surfaces and cavities.
° Glands that manufacture secretions (sweat and saliva) or chemical messengers (hormones).
° avascular (no blood vessels)
° BM (basement membrane)
Connective tissue
(3 things about it)
° Connect tissue to one another.
° ECM ( Extracellular matrix) is visible between cells
° Binds, supports, protects, and transportation of substances.
Muscle tissue
Contraction
Nervous tissue
(Consist of 2 cells)
°Neurons
Make, send, received messages.
°Neuroglia
Supports activities of neurons.
Extracellular matrix
( What is it?)
Compose of substances in a liquid, gel, or solid that’s suround cells.
Extracellular matrix
(Function)
° Provide tissue with strength to resist tensile (stretching) and compressive forces
° Directs cells to proper positions within tissue and holds those cells in place.
° Regulate development, mitotic activity, and survival of cells.
Extracellular matrix
( Made out of?)
Ground substances and protein fibers.
Ground substances
° Components: water, nutrients, ion, and macromolecules.
Macromolecules
°Glycosaminoglycans (GAGs)
°Protenoglycans
°Cell-adhesion molecules (CAMs)
Protein Fibers
(3 of them)
° Collagen fibers
°Elastic fibers
°Reticular fibers
Collagen fibers
°white
°fibrous
°resistant to tension
Elastic fibers
°Yellow
° Protein elastin surrounded by glycoproteins.
° Exhibits elasticity
Reticular fibers
°weblike
° Meshwork or scaffold that supports cells and ground substance of tissue.
Epithelial Tissue
(5 Functions)
- Protection
- Immune defense
- Secretion
- Transport into other tissues
- Sensation
Epithelial Tissue:
Protection
Shield underlying tissues from mechenical and thermal injury
Epithelial Tissue:
Immune defense
form physical barriers; contain cells of immune system
Epithelial Tissue:
Secretion
produce /push out hormones and
oils
Epithelial Tissue:
Transportation into other tissue.
form selectively permeable membranes ( Absorbs and takes it somewhere else)
Epithelial Tissue:
Sensation
detects changes in internal and external environments
Ex. Taste buds specialize sensory epithelial cells
4 types of simple epithelial tissue
°Simple Squamous
°Simple Cuboidal
°Simple Columnar
°Pseudostartified ciliated columnar
Simple Squamous
One layer of flat cells adapted for rapidly diffusion of substances
Found in lungs
Simple Cuboidal
One layer of cubed shaped cells that absorb and secreation
Found in kidneys
Simple Columnar
Single layer of rectangular shaped cells may have microvilli or cilia
Found in the villi of the small intestine
Pseudostartified ciliated columnar epithelial (PSCCE)
Appears layered but isn’t is one layer thick and ciliated
Found in trachea
Stratified Epithelial Tissue
(4 types)
- Stratified Squamous
- Stratified cubodial
- Stratified columnar
- Stratified transitional
Stratified Squamous
(2 types)
°Keratinized Stratified Squamous Epithelial
°Nonkeratinized Stratified Squamous Epithelial
Keratinized Stratified Squamous Epithelial
° Outer cellular layers are dead.
° lack nuclei
° Filled with protein keratin
° Outer layers of skin (epidermis)
Nonkeratinized Stratified Squamous Epithelial
° apical cellular layers retain nuclei; still alive
° Wet mucus membrane (digestive system)
Stratified Cuboidal Epithelial
° Rare in humans.
° Lines ducts of sweat glands
Stratified Columnar Epithelial
° Relatively rare in humans.
° Found in male urethra, cornea of eye, ducks of salivary glands.
Transitional Epithelial
° Only found in urinary system (uterus, urinary bladder, urethra)
° Can expand and flatten
Gland
(There are 2)
Specialize cells that produce secretions.
Endocrine and Exocrine
Endocrine glands
Secrete hormones directly into the bloodstream (ductless)
Single cells to multicellular glands with branching
Ex. Thyroid, pituitary, ovary
Exocrine glands
Have ducts
Secretions have only local effects on cells in the general vicinity.
Exocrine glands
Unicellular (goblet cells = mucus)
Digestive and respiratory tracks.
Protect underline epithelia.