Derm-Dr. Houston (exam 3) Flashcards
- What is tissue?
- What are the four primary tissues?
Tissue: A group of similar cells and cell products working together to perform a specific role in an organ.
The four primary tissues:
* Epithelial
* Connective
* Nervous
* Muscular
What is the purpose of nervous, muscle, epithelial and connective tissue?
The four primary tissues differ from each other in (3)
What is the matrix (extracellular material) composed of? (2)
The four primary tissues differ from each other in:
* Types and functions of their cells
* Characteristics of the matrix (a.k.a tissue fluid/gel, extracellular fluid/material, interstitial fluid)
* Relative amount of space occupied by cells versus matrix
Matrix (extracellular material) is composed of:
* Clear gel called ground substance
* Fibrous proteins
What are the three types of fibers and their characteristics?
Collagen
* Strongest and most abundant type
* Provides high tensile strength
Elastic
* Networks of long, thin, elastin fibers that allow for stretch
Reticular
* Short, fine, highly branched collagenous fibers
Epithelial tissue
* What are the main two types by location?
Covering and lining epithelia
* On external and internal surfaces
Glandular epithelia
* Secretory tissue in glands
Characteristics of Epithelial cells:
* What is the polarity?
* Composed of what?
* Supported by what?
* Vascular? Nerves?
* High rate of what?
What are the cutanous, serous and mucous membranes?
What is a gland? Usually composed of what?
A cell or organ that secretes substances for use elsewhere in the body or releases them for elimination from the body
* Usually composed of epithelial tissue in a connective tissue framework
What are exocrine glands? Surfaces can be what?
Exocrine glands — maintain their contact with surface of epithelium by way of a duct
* Surfaces can be external (examples: sweat, tear glands) or internal (examples: pancreas, salivary glands)
- What are endocrine glands? What are hormones?
- What are examples?
- Endocrine glands — secrete hormones directly into blood
- Hormones: chemical messengers that stimulate cells elsewhere in the body
- Examples: thyroid, adrenal, and pituitary glands
What is the most widespread epithelium in the body?
Stratified squamous
Stratified Epithelia:
Deepest layers undergo what? How?
Deepest layers undergo continuous mitosis:
* Daughter cells push toward the surface and become flatter as they migrate upward
* Finally die and flake off (exfoliation or desquamation)
What are the two kinds of stratified squamous epithelia?
- Keratinized — found on skin surface, abrasion resistant
- Nonkeratinized — lacks surface layer of dead cells
Keratinized Stratified Squamous Epithelium
* What are the characteristics?
* Resist and retards what/
* Where are the locations?
- Multiple cell layers; cells become flat and scaly toward surface
- Resists abrasion; retards water loss through skin; resists penetration by pathogenic organisms
- Locations: epidermis; palms and soles heavily keratinized
Cotton candy, lacey purple top layer
Non-keratinized Stratified Squamous Epithelium
* Similar to what?
* Resist what?
* What are the locations?
- Same as keratinized epithelium without surface layer of dead cells
- Resists abrasion and penetration of pathogens
- Locations: tongue, oral mucosa, esophagus, and vagina
What are the different types of loose CT? What are the different dense CT?
* What are the characteristics of both
- What are the different cartilages?
- What is the bone tissue?
- What is the liquid CT?
Cartilage?
What are the cells of cartilage? Dense what? Why is there very little repair?
- Cells = “chondrocytes”
- Dense network of collagen & elastic fibers embedded
- No blood vessels or nerves = very little repair
Areolar Tissue
* What are the characteritics?
* Possess all what?
* Why is it packing material?
- Loosely organized fibers, abundant blood vessels
- Possess all three fiber types and all six cell types
- “Packing Material”- underlies epithelia, in serous membranes, between muscles, passageways for nerves and blood vessels
Adipose Tissue
* What are the characterisitcs?
* What is the purpose
* What produces heat?
Empty-looking cells with thin margins; nucleus pressed against cell membrane
Energy storage, insulation, cushioning
* Subcutaneous fat and organ packing
* Brown fat of juveniles produces heat
Dense Irregular Connective Tissue
* What are the characteristics?
* Withstands what?
* Locations?
- Densely packed, randomly arranged, collagen fibers and few visible cells
- Withstands unpredictable stresses
- Locations: deeper layer of skin; capsules around organs