Ch. 4- Tissues Part 2 Flashcards
What is a simple epithelium?
single layer of cells
functions:
- diffusion
- osmosis
- filtration
- secretion
- absorption
What is a stratified epithelium?
2 or more layers of cells
function:
- protection of underlying tissues
What are the 4 different cell shapes?
1) squamous
2) cuboidal
3) columnar
4) transitional
What are the 3 arrangements of cells in layers?
1) simple epithelium
2) stratified epithelium
3) pseudostratified epithelium
What is a pseudostratified epithelium?
cells have varying heights
all cells attached to basement membrane but not all reach apical surface
mucus- secreting unicellular gland cells among ciliated cells
Where is the pseudostratified epithelium located?
nasal cavity
trachea
bronchi
ductus deferens
part of male urethra
What are the functions of the pseudostratified epithelium?
protection
secretion
cilia-mediated transport of particles in mucus
What is the squamous shape of epithelium?
cell has a thin, flat and irregular shpae
allows for rapid passage of substances through them
What is the cuboidal shape of epithelium?
cell width and height similar
shaped like cubes
some microvilli
function in either absorption or secretion
What is the columnar shape of epithelium?
cell is taller than it is wide
may have cilia or microvilli
functions:
- protection
- absorption
- secretion
What is the transitional shape of epithelium?
cell shape changes from cuboidal to squamous
function:
- distensibility (expansion and recoil)
What is nonstratified squamous nonkeratinized epithelium?
lines wet surface
cells are constantly moistened by mucus from salivary and mucous glands
What is stratified squamous keratinized epithelium?
found in epidermis
provides protection from abrasions and penetrations of organisms, retards water loss
keratinocytes
What happens as apical layer cells die?
sloughed off and replaced by new cells that migrate upward from the basilar layer
What are endocrine glands?
ductless and tubeless
produce and secrete hormones
hormones go through basal lamina
multicellular (thyroid/ pituitary glands)
What are exocrine glands?
most have duct or tubule
secrete their products via ducts onto body surfaces or into body cavties
more numerous than endocrine
secretions include enzymes, sweat, tears
unicellular and multicellular glands
What can multicellular exocrine glands be further classified based on their?
1) duct structure
2) shape of their secretory units
3) mode of secretion
What is CT?
most abundant and variable tissue type
arise from mesenchyme cells
many vascularized and contain sensory receptors
consists of specialized cells and matrix
What are the 8 functions of CT?
1) bind together, support and strengthen other body tissues
2) compartmentalize structures
3) interconnects other types of structures
4) establish a structural framework fro the body
5) protect and insulate internal organs
6) transport fluids and dissolved material
7) defends the body from invading microorganisms
8) primary site of stored energy
What is lose CT?
more ground substance , less fibers
Types:
- Areolar CT
- Adipose Tissue
- Reticular Tissue
What is dense CT?
has more fiber, less ground substance
Types:
- dense regular CT (tendon/ ligament)
- dense irregular CT (deep dermis/ capsule around internal organs)
- elastic CT
What is fluid CT?
cells in a watery matrix
types:
- blood
- lymph
What are types of supporting CT?
- Cartilage (hyaline, elastic and fibrocartilage)
- bone
What are fibroblasts?
most common cells in CT
secrete collagen and elastin= fibers
certain components of ECM
What are adipocytes?
fat cells
store triglycerides
What are mesnchymal cells?
multipotent progenitor cells that give rise to CT
What are macrophages?
derived from monocytes
wander through CT phagocytizing foreign material and activating immune system
What are mast cells?
secrete:
- heparin that inhibits blood clotting
- histamine that dilates blood vessels
released as part of inflammatory response and tissue repair
What are lymphocytes?
migrate from blood into CT in response to tissue damage and infection
What are plasma cells?
differentiate from B lymphocytes
synthesize antibodies
What are microphages?
are neutrophils and eosinophils that are phagocytic blood cells
What are 3 types of CT fibers?
1) collagen
2) reticular
3) elastic
What are collagen fibers?
most common fibers in CT
each fiber consists of bundle of protein subunits
tough and resistant to stretch yet flexible
abundant in:
- bone
- cartilage
- tendons
- ligaments
- dermis
What are reticular fibers?
thin collagen type fibers with glycoprotein
resists forces applied from many directions
from framework which stabilizes the positions of functional cells
What are parenchyma of reticular fibers?
functional parts of an organ in the body
What are stroma of reticular fibers?
structural tissue of organ
What are elastic fibers?
thin branching fibers made of elastin
stretch and recoil
elastic ligaments (rare) abundant in elastic fibers
give skin, lungs, arteries ability to stretch and recoil
What is areolar CT?
consists of loose arrangment of collagenous and elastic fibers
underlying all epithelia
seprates skin from deeper structures
absorbs shock
What is adipose tissue?
nucleus pressed against cell membrane
functions:
- energy storage
- insulation
- cushioning
What are reticular tissue?
loose network of reticualr fibers and cells
forms supportive framework
found in:
- lymph nodes
- spleen
- liver
- thymus
- bone marrow
What is dense regular CT?
Consists of densely packed parallel collagen fibers, compressed fibroblasts nuclei, and open space
Forms:
- tendons
- ligaments
- aponeurosis
What is dense irregular CT?
densely packed collagen fibers running in random directions
scantly open space
few visible cells
withstands stress applied in different directions
What is elastic tissue?
consists of mainly dense irregular CT consisting mainly of elastic fibers
allows recoil of tissue after stretching
What is the matrix of cartilage made of?
Chondroitin Sulfates
