2.1 Tissues Flashcards
What are the 4 types of tissues?
Connective
Nervous
Muscular
Epithelial
What are the locations, characteristics and functions of epithelial tissues?
Location:
Lines inner and outer body surfaces and body cavities
Forms glands
Characteristics:
dense cells, minimal extracellular matrix
free apical surface (top) to attached basal surface (bottom)
avascular – no blood vessels
sensory innervation
high regeneration
Function
protection, permeability, secretion, and sensation
What are the two surfaces of epithelial cells? What attached inferiorly?
Apical
Basal
Basement membrane
Describe simple squamous epithelium. What is the prime function?
single layer of flat cells Function: diffusion and secretion lines body cavities (mesothelium) lines alveoli in the lungs and capillarie DIFFUSION
Describe stratified squamous epithelium. What is the function?
many layers of flattened cells
cells at the apical surface are more flattened than basal surface
Function: protect underlying skin from abrasion
Location: skin, mouth, esophagus, rectum, vagina
Describe simple cuboidal epithelium.
single layer of cube-like cells, central round nucleus
Function: secretion and absorption
Location: ducts of glands, kidney tubules, and covers the ovaries
Secreting and absorbing
Often see microvilli, vesicles for section
Describe stratified cuboidal epithelium. Where is it found?
two layers of cuboidal cells
more rare
Function: secretion
Location: lines sweat glands
Where are simple columnar epithelium found? Function?
single layer of tall cells, oval nuclei
often includes goblet cells, which produce mucus
Function: absorption and secretion
Location: lines digestive tract, gallbladder, uterine tubes
Where is stratified columnar epithelium found? Function?
multiple layers of columns
apical cells are columnar, basal cells underneath vary in size and shape
Function: secretion
Location: large ducts of glands (i.e. salivary glands) RARE
Where is pseudo stratified columnar epithelium found? Function?
single layer but disorganized, so appears as stratified
some cells are shorter than others, jumbled nuclei
may contain goblet cells and cilia
Function: secretion and propel substances across cell surface
Location: upper respiratory tract, male urethra
Where is transitional epithelium found? Function?
multiple layers of cuboidal-like stretched to squamous-like
basal cells appear cuboidal, apical cells are dome or balloon shaped
Function: stretches to permit distension of urinary organs
Location: Lines ureters, bladder, and renal pelvis
What in an endocrine gland?
secrete INTO the tissue layers
release secretions directly into surrounding tissues substance then diffuses into bloodstream
Ductless
Secrete hormones
Examples: thyroid gland, pituitary gland, adrenal glands
What is an exocrine gland?
secrete OUT of the tissue layers
release secretions out to a body surface or lumen
Duct present
Secrete mucus, oils, other body fluids
examples: Sweat and oil glands, goblet cells
Where are connective tissues found?
fluid, loose, and dense types found between layers, binding and connecting structures and organs together - variable
What are the characteristics of connective tissue?
cells
extracellular matrix:
ground substance: gel or fluid
fibers: elastic, collagen, and/or reticular fibers
More matrix, more extracellular substance, and fewer cells (vs the sheets of epithelial cells)
Pay attention to cell types, and substances that surround the cells in connective TISSUE
Are fluid tissues, loose, and dense connective tissues
Extracellular matrix- stuff outside of the cell
Many types of CT have: fibroblasts, which makes cells that make the ECF
