tissues: the living fabric Flashcards
what is histology
the study of tissues
what are the three steps to preparing tissue
1.) fix tissue in formaldehyde
2.) section the tissue into longitudinal/cross sections
3.) stain the tissue in different colors
what does formaldehyde do to tissues
denatures the proteins present in the tissue
what is used to help support the tissue when the tissue is sectioned
wax
what is the most common tissue stain
H (purple) and E (pink)
what are the four primary tissues
epithelial, muscle, connective, nervous
what does nervous tissue do
control, internal communication
what does epithelial tissue do
cover, form boundaries between different environments
what does connective tissue do
support, protect, and binds other tissues together
what does muscle tissue do
move, contracts to cause movement
what does epithelial tissue mean
on top - layer/membrane
what are the 4 characteristics of epithelial tissue
very cellular (little extracellular space), avascular (no blood vessels), very regenerative (mitosis occurs frequently), polar
what makes epithelial tissue polar
the basal and apical surfaces
what is a basal surface
tissue that is attached to connective tissues at the basal membrane
what is the apical surface
tissue that is exposed at the top/the free edge
what are the 2 types of epithelium
simple and stratified
how are tissues named
according to the shape of the cell on the apical layer
describe the shape of squamous cells
flat
describe the shape of cuboidal cells
cube
describe the shape of columnar cells
column
what is the function of simple squamous epithelium
filtration and exchange
where are simple squamous epithelium tissues found
lung air sacs, lining blood vessels, membranes in the ventral body cavity, kidney function
what is the function of simple cuboidal epithelium
absorption and secretion
where are simple cuboidal epithelium tissues found
kidney tubules, small glands/ducts, the ovary surface
what is the function of simple columnar epithelium
absorption and secretion
where are simple columnar epithelium found
gastrointestinal tract lining, glands, uterine lining
what are goblet cells
single cell glands that secrete mucus
what are goblet cells named for
their shape
what is pseudo-stratified columnar epithelium
tissue that looks stratified but is simple
what is the only epithelium that has cilia
pseudo-stratified columnar epithelium
where is pseudo-stratified columnar epithelium found
the respiratory tract
where are all pseudo-stratified columnar epithelium attached to
the basement membrane
what is the function of stratified squamous epithelium
a wear and tear barrier because of the thickness of the tissue
where is stratified squamous epithelium found
lining of the mouth, anus, esophagus, vagina, urethra (wherever tissue is exposed to the surface of the body)
what is functional epithelium
tissue that changes shape as the function of the tissue changes
where is functional epithelium found
ureters and bladder
when functional epithelium is stretched, what type of tissue does it appear as
stratified squamous epithelium
when functional tissue is relaxed, what type of tissue does it appear as
stratified cuboidal
where is stratified cuboidal tissue found
glands, ovarian follicles
where is stratified columnar tissue found
recto-anal and esophageal stomach junctions
what do glands do
secrete something
what is a unicellular gland
a 1 cell gland
are most glands unicellular or multicellular
multicellular
merocrine vs holocrine
vesicles vs whole cell rupture
simple vs compound
one duct vs more than one duct
tubular vs alveolar/acinar
tube like vs sac-like shape
what do endocrine glands do
secrete hormones through the basement membrane
what are the three types of epithelial membranes
cutaneous, mucous, serous
what is the cutaneous membrane
the skin, a dry membrane with two parts (dermis and epidermis)
what is the mucous membrane
a membrane that is moist, exposed to the surface, and has mucus
what is the serous membrane
a membrane that is watery, moist, and not exposed
what are the characteristics of muscle tissue (4)
packed with cells, excitable, contractile, and elastic
what does excitable mean
can be stimulated
what does contractile mean
can be shortened
what does elastic mean
can be stretched and bounce back (recoil)
what are the 3 types of muscle tissue
skeletal muscle, cardiac muscle, and smooth muscle
what does skeletal muscle look like (4)
large, cylindrical, striated, multinucleate cells
is skeletal muscle voluntary
yes, you can consciously control it
what is skeletal muscle attached to
bone (but some is attached to the skin)
what does cardiac muscle look like
mid-sized, branched, cylindrical, striated, 1-2 nucleated cells
what is the purpose of intercalated discs
intercalated discs is where cardiac muscle is attached to and is connected to gap junctions to allow muscles to contract as one unit
is cardiac muscle voluntary
no, you can’t consciously control it
what is smooth muscle defined by
not being striated
what does smooth muscle look like
small, spindle-shaped, non-striated, 1 nucleated cells
is smooth muscle voluntary
no, you can’t consciously control it
where is smooth muscle found
in the linings of internal hollow organs
what is the most abundant and diverse tissue
connective tissue
what is the most important characteristic of connective tissue
the predominate extracellular matrix
what is the extracellular matrix full of
fibers and group substances
what 3 fibers are present in the extra cellular matrix
collagen, elastic, reticular
what are fibers
protein strands
what does collagen do
gives tensile strength
what does elastic fiber do
gives muscle the ability to stretch and recoil
what is reticular fiber
a “mesh/network” of thin fibers (collagen-like)
what is in ground substance (3)
tissue fluid, cell adhesion molecules, proteoglycan molecules
what does tissue fluid contain
water and various solutes
what are CAMs
a type of protein molecule that help cells adhere
what is the core of proteoglycan molecules
proteins
where are glycosaminoglycans (GAGs)
the ground substance in an extracellular matrix
what do glycosaminoglycans (GAGs) do
hold onto water
what do “blasts” cells do
make connective tissue
what do fibroblasts do
make fibrous connective tissue
can fibroblasts ever become fibrocytes
no because fibroblasts are always active
what do osteoblasts do
make bone
what do chondroblasts do
make cartilage
what do hemocytoblasts do
make blood
where are “cytes” cells found
in mature connective tissue
what are “cytes” cells
“blasts” cells found in mature connective tissue
what are the 3 migrants that migrate into the CT from the blood
WBCs, macrophages, and mast cells
what are mast cells involved in
inflammation
what do mast cells secrete (3)
heparin, protease enzymes, histamines
what are the 3 kinds of loose connective tissue
areolar, adipose, reticular
what is areolar connective tissue
tissue with a few fibers and lots of ground substance
where is areolar connective tissue found
deep to the epithelium
what is adipose connective tissue
areolar tissue that is taken over by adipocytes
where is the little cytoplasm found
at the edge of adipose c.t. cells
why do we see empty space in adipose tissue
the inclusion of fat droplets
what happens to adipose tissue cells when weight is gained/lost
cells increase/decrease in size
what is white fat
tissue with 1 large droplet of fat in cells (the majority of adipose tissue)
what is brown fat
tissue that has many small fat droplets and many mitochondria in cells
what is brown adipose fat most important for
infants
what does reticular tissue form
mesh
what does reticular fibers do
support tissue for blood cells in the spleen, bone marrow, lymph nodes
what are the 3 types of dense connective tissue
dense regular, dense irregular, elastic
what is the difference between loose and dense connective tissue
dense tissue has more fibers
what is dense regular connective tissue described by
collagen fibers going in the same direction
where is dense regular connective tissue found
tendons, ligaments
what is dense irregular tissue described by
collagen fibers going in different directions
where is dense irregular tissue found
dermis, capsules of internal organs
what is elastic connective tissue made of
elastic fibers
where is elastic connective tissue found
large blood vessels, ligaments, vocal cords
what is cartilage
a type of connective tissue
what are the 4 characteristics of cartilage
there are fibers present, there is specialized ground substance, it is avascular, it is made of chondrocytes in lacunae
what are the 3 types of cartilage
hyaline, elastic, fibrocartilage
describe hyaline cartilage and where it is found
hazy, glassy appearance
found in: joints, ribs, nose, trachea, larynx
describe elastic cartilage and where it is found
cartilage with lots of elastic fibers
found in: ear, epiglottis
describe fibrocartilage and where it is found
lots of collagen fibers (makes extra strong)
found in: intervertebral discs, pubic joint, knee menisci
how does bone differ in composition from cartilage
has a calcified matrix
what does calcified matrix do to the bone
the calcium deposits make the bone firm
what are bone cells
osteocytes found in lacunae
what are the 2 types of bone
spongy and compact
what is compact bone
bone with layers (lamellae)
what does plasma have
extracellular matrix
when does blood have fibers
when it clots
when is blood without fibers
when blood is flowing
what are the 3 formed elements of blood
RBCs, WBCs, platelets
what are RBCs made of
erythrocytes (red)
what are WBCs made of
leukocytes (white)
what are platelets made of
thrombocytes
what are thrombocytes
cell fragments
what is the function of nervous tissue
communication
what are the 3 characteristics of nervous tissue
packed with cells (cellular), neurons receive and transmit messages, neurons and supporting cells are the overall makeup of nervous tissue
what is spongy bone
internal layer of skeletal bone, also called cancellous bone
what are glial cells
supporting cells that have a 10x greater presence than neurons
what are the parts of a neuron
cell body (soma), axon, dendrite
