Chapter 4: tissues Flashcards
What are the 4 types of tissues?
Epithelial, Connective, nervous, and muscle
Nervous tissue
Internal communication (brain/spinal cord/nerves)
Muscle tissue
Contracts to cause movement
- Attached to bones (skeletal)
- Heart (cardiac)
- Walls of hollow organs (smooth)
Epithelial tissue
Forms boundaries between environments, covers, protects, secretes, absorbs, filters
- Lining of GI tract organs + hollow organs
- Skin surface (epidermis)
Connective tissue
Supports, protects, and binds other tissues together
- Bones
- Tendons
- Fat and other soft padding tissue
What are the two things that epithelial tissue consists of? Define them
Epithelia: covers exposed surfaces and line internal cavities + passageways, often contain secretory cells/gland cells, scattered among other cell types
Glands: derived from epithelia, but secretory cells predominant
What are the 2 types of glands?
Exocrine: secretes onto external surfaces or into internal passageways (ducts) that connect to the exterior
Endocrine: secrete hormones into interstitial fluid via distribution by bloodstream
What are the 5 characteristics of epithelia
- Polarity - apical/basal
- Specialized contacts - intercellular junctions
- Connective tissue support - basement membrane
- Avascular but innervated (no blood supply but receives nutrients from tissues via diffusion)
- Regeneration - rapid rate of division
How many layers in a simple and stratified epithelium?
1 for simple epithelium (absorption/secretion/filtration)
> 1 for stratified (protection in high abrasion areas)
What are the 3 simple epithelium cells?
- Squamous flat: kidney, flattened cells, diffusion and filtration, air sacs
- Cuboidal box: single layer cubelike, secretion/absorption, kidney tubules, ducts
- Columnar tall: tall cells, some with cilia, goblet cells, absorption/secretion of mucus, and the cilia types will propel mucus, abdomen
What are the 5 types of stratified tissues?
- Pseudostratified columnar: single layer of cells differing heights, secretion of mucus, upper respiratory + trachea for ciliated and nonciliated for male sperm ducts, propels via ciliary
- Stratified squamous: thick membrane and flattened, surface cell dead, basal cell active, protection, keratinized, esophagus + mouth + vagina
- Stratified cuboidal: rare, sweat and mammary glands, 2 cell layers thick
- Stratified columnar: limited, pharynx, male urethra, lining some mammary glands
- Transitional: both squamous + cuboidal, basal = cuboidal, surface = squamous, stretches and permits stretching of urinary organ, ureters + bladder
Glandular epithelia
gland is one/more cells that makes and secretes aqueous fluid
- Site of product release (endocrine/exocrine)
unicellular/multicellular
Unicellular exocrine glands
Only important unicellular gland is globet cell
- produce mucin –> mucus
- secreted via exocytosis
Multicellular exocrine glands
composed of a duct + secretory unit
- structure: duct (simple) or structure of secretory units
What are the 3 modes of secretion? define them
- Merocrine (merely secrete): products are secreted by exocytosis (pancreas/sweat/salivary)
- Holocrine: products are secreted by rupture of gland cells
- Apocrine: pinches off secretion + repairs, controversial if found in humans (mammary)
