Tissue Organization Flashcards
List the 4 tissue types
epithelium, connective, muscular, nervous
where can epithelial tissue be found in the body?
what does epithelial tissue do
covering body surfaces
linings of body cavities
which tissue forms the majority of glands?
epithelial
Name and describe characteristics of epithelium
cellularity - made of tightly packed cells
polarity - has an apical surface and a basal surface
attached to a basement membrane
avascular- no blood vessels
extensive innervation
high regeneration capacity - apical surface exposed to enviornment= constant trauma/loss of cells; frequent mitosis in basal level
list functions of epithelial tissue
physical protection
selective permeability
secrets and excretes
sensation
How is epithelial tissue classified?
two-part name
layers - simple, stratified, pseudostratified
shape of cells (at apical surface) - squamous, cuboidal, columnar, transitional
describe the relationship between structure and function of simple vs stratified epithelium
simple - better for diffusion, absorption, and secretion because only one layer
stratified - more layers = better protection function
list some locations for the following simple squamous simple cuboidal simple columnar pseudostratified (+/- cilia) stratified squamous (+/- keratin) strat cuboidal strat columnar strat transitional
lung air sacs kidney tubules stomach trachea skin, esophagus rare- ducts of glands rare - pharynx, urethra bladder
how do exocrine glands differ from endocrine glands?
structure, function, secretions
give an example of each
what is a unicellular gland?
exocrine - lack ducts, secrete into blood or interstitial fluid; ex. thyroid
endocrine - connected to epithelial surface via duct; ex. sebaceous glands, mammary glands, salivary glands;
exocrine gland - close to epithelium surface; ex. goblet cell secrets mucus
list the types of connective tissue
proper (ligaments, tendons, body fat)
cartilage
bone
blood
what makes up the connective tissue matrix?
cells, protein fibers, and ground substance
what is the most important ground substance molecules? and why
Glycos-aminos-glycans (GAGs)
molecules are negatively charged and hydrophilic which attracts H2O; can hold H2O molecules = makes CT range from a fluid to a solid
what is a fibroblast? List the three sizes
resident cell in CT; most abundant in CiT proper; produces fibers and ground substance
collagen, elastic, and reticular
what is caused by Vitamin C deficiency with symptoms of weakness, gum ulceration, hemorrhages, and abnormal bone growth; how does collagen fit into this diagnosis
scurvy
collagen supports and strengths most tissues
vitamin C is needed to make healthy collagen fibers
What are the 2 kinds of cells that are present in CT?
resident cells = stationary cells specific to each CT type
wandering cells = WBCs
what are some wandering cells present in CT?
What are some of their functions?
mast cells - secrete heparin and histamine to dilate blood vessels
plasma cells - make antibodies
free macrophages - phagocytic cells
other leukocytes
describe collagen fibers
strong, flexible, resistant to stretching
can be found in tendons and ligaments
white in fresh tissue
describe elastic fibers
have wavy branching fibers = protein called elastin
easily stretch and recoil = help structures return to normal shape after stretching
found in skin, lungs, arteries
describe reticular fibers
thinner than collagen
form branching interwoven framework
what is ground substance?
this is where fibers and cells live
made by CT cells
can be viscous, semisolid or solid
what molecules make up ground substance
GAGs, proteoglycans, adherent glycoproteins
Name the resident cell of cartilage
chondrocyte
list the types of cartilage
hyaline, fibrocartilage, and elastic cartilage
Hyaline cartilage - list some characteristics and locations
most common and abundant
has no fibers
thick collagen
greatest strength and most flexible
tip of nose, trachea, intercostal of ribs
support and makes up most of fetal skeleton
fibrocartilage
parallel collagen fibers
resists compression and shock absorber
found in menisci of knee joints, intravertebral discs
elastic cartilage
maintains shape while allowing for lots of flexibility
lots of elastic fibers web like mesh
ear, epiglottis of larynx
what cell makes up bone
osteocytes
define periosteum
outer covering of bone, made up of dense irregular CT
what are the 2 types of bone
spongy - interior, non-weight bearing
compact/cortical - exterior, hard
List some functions of bone
support tissues protect vital organs provide levers for movement store minerals such as Ca house hemopoietic cells
what are some functions of spongy bone?
store fat, make RBCs/WBCs/platelets
list the types of muscle tissue
skeletal
cardiac
smooth
where can nervous tissue be found?
within brain, spinal cord, and nerves
define neurons and glial cells
neurons - receive transmit and process electrical signals
glial cells - do not transmit signals
what is the function of glial cells?
support protect and provide nutrients for neurons
define organs
structure made of 2 or more tissue types
work together to perform specific functions
usually has all 4 tissue types
define a body membrane
formed from epithelial tissue connected to underlying CT aka simple organ
only has 2 tissues
list the function of body membranes
line body cavities
cover viscera
cover body’s external surface
what are the 4 types of body membranes
mucous
serous
cutaneous
synovial
describe mucous membranes
line parts that are open to external environment
urinary, respiratory, digestive and reproductive tracts
usually covered in a layer of mucus
what do serous membranes line?
body cavities not open to external environment
define hypertrophy
increase in SIZE of existing cells
define hyperplasia
increase in NUMBER of cells of a tissue
deine atrophy
shrinkage of tissue by decrease in cell number OR size due to lack of use
define necrosis
tissue death due to irreversible tissue damage
