Lab 6: Histology I (embryonic + connective tissue) Flashcards
histology
study of tissues
what is tissue
A group or layer of cells that work together to perform a specific function.
4 basic tissue types
epithelial, connective, muscle, nervous
Microtome
instrument that sections pieces of tissues
epithelial tissue
tissue that covers the body, lines body cavities, forms glands
connective tissue
binds + supports various organs
muscle tissue
movement
nervous tissue
sends + receives stimulus
3 primary layers in embryo
ectoderm, mesoderm, endoderm
what does ectoderm (outer) give rise to
skin cells of epidermis, neuron n.s, pigment cells
what does endoderm (inner)give rise to
mucous layers of:
Digestive (intestine+liver)
Respiratory (lung)
Urinary tracts
Digestive glands
what does mesoderm (middle) give rise to
Muscle
Blood vessels
Connective tissues
gelatinous tissue in mesoderm
mesenchyme
difference b/w apical and basal surface on epithelial tissue
apical = upper surface, may have villis
basal= lower surface attached to base
2 ways to classify epithelial tissue
of cell layers and shape of apical surface
how are cells arranged in epithelial tissue
in continuous sheets in multiple or single layers
function of epithelial tissue
covers surfaces, lines body cavities, form glands
how are epithelial held together
by specialized cell junctions (tight junctions and desmosomes)
function of apical surfaces and what does it face *3)
faces:
1. external body surface
2. body cavity
3. lumen
4. tubular duct
function: absorption and secretion
location of basal lamina
this is where basal surface sits if cell is found in single deepest layer
what does the basal lamina contain
Contains glycoproteins from epithelium + collagen fibers
where is reticular lamina
below basal lamina
what is reticular lamina
network of collagen fibers produced by cells in connective
what is basement membrane
basal lamina + reticular lamina
what is simple epithelium
single layer of cells
what is the epithelium that has several layers
stratified epithelium
type of epithelial cells that resemble little squares
cuboidal
type of epithelial cells that are flat and plate-like
squamous
type of epithelial cells that are tall and columnar shaped
columnar
what is the thinnest epithelium
simple squamous
location of simple squamous
Line the heart, blood vessels lymphatic vessels + form entire capillary walls
function of simple squamous
filtration and diffusion
in the kidney, simple squamous functions to__ and __
diffusion (loop of Henle) and filtration (Bowmans capsule)
in the lungs, alveoli are formed of simple squamous to allow for ___
diffusion of respiratory gases
location of simple cuboidal epithelium
Thyroid gland, kidney tubules, ducts of many glands
function of simple cuboidal
secretion and absoption
where is nucleus at simple cuboidal
center
where is nucleus at simple columnar
near base
location of simple columnar
Small / large intestines
Stomach
Various glands
function of simple columnar
secretion + absorption
Has goblet cells = produce mucus (lubricant / protective barrier)
what is the falsely stratified epithelium called
pseudostratified columnar epithelium
why is pseudostratified false
All cells contact basement membrane
what does pseudostratified contain that the others don’t have
cilia and goblet cells
cilia function
(beat dirt ball so it doesn’t go down lungs)
goblet cells function
(produce mucus to trap inhaled foreign particles)
location of pseudostratified columnar epithelium
Upper respiratory tract
-Lines nasal cavities, trachea, bronchi (respiratory passages)
function of pseudostratified columnar epithelium
secretion and protection
stratified squamous epithelia function
Thickness = protect body against mechanical stress and undergo mitosis for replacement cells
cells above basal cells in stratified squamous are __
polygonal shape
keratinized function
Protects epithelium + underlying tissues from heat, microbes, chemicals
non keratinized forms moist linings of
Mouth, pharynx, esophagus, vagina, anus
keratinized is __ skin
Dry skin nd dead
non keratinized appearance and function
lots of cell layers
Flat
Has nuclei
Protect from absorption
difference between keratinized and non keratinized
keratin filled cells + organelles die
transitional epithelium location
Linings of urinary bladder
Ureters
Upper portion of urethra
function of transitional epithelium
accommodate pressure changes, without rupturing organ
glandular epithelia location
beneath covering epithelia as single cells / clusters of cells
glandular epithelia function
secretion + produce substances into ducts that open onto surfaces (exocrine glands; cells move materials from within cells)
- Secret substances into fluids (endocrine glands)
what is exocrine gland
Single epithelial cell (unicellular gland)
May also be multicellular + diff structures
2 types of exocrine gland stuctures
Simple (unbranched) duct
Compound (branched) duct w/ secretory portion being tubular + acinar
what is merocrine (eccrine glands) and examples
glands that release fluid
products by exocytosis
Ex: salivary glands, sweat glands, pancreatic glands
no damaged to cells to get secretion out
glands that pinch off portion of cell as part of secretion
Top half is damaged
apocrine glands
example of apocrine glands
mammary glands
what is holocrine glands
when whole cells filled w/ secretion are released
E
x: sebaceous glands of the skin
The whole thing is damaged
process used when glands release fluid products
exocytosis
exocytosis and endocytosis differences
Endocytosis is the transport into the cell and exocytosis is the transport out of the cell.
3 types of exocrine glands
merocrine, apocrine, holocrine
3 structural features common to all connective tissue?
cells, protein fibers, ground substance
connective tissue function
mechanical binding + support
Circulation of body fluids
Insulation
Storage of food reserves
Process of inflammation
what is extracellular matrix made of
protein and ground
vascularized and avascularized meaning
vascularized - rich blood supply and avascularized is poor
what is vascularized in body
body
what is avascularized in connective tissue
cartilage and dense connective tissue
Ground Substance components:
GAG (glycosaminoglycans)
-Chondroitin sulfate + hyaluronic acid
-Proteoglycan
-Adhesive glycoproteins
3 fibers of connective tissue types
collagen, elastic, reticualr fibers
4 types of connective tissue proper
areolar, adipose, reticular, dense regular
2 types of supporting connective tissue
cartilage and bone
cell names ending in blasts are
immature cells, secrete matrix, actively mitosis
where is fibroblast found
connective tissue
where is chondroblast
in cartilage
where is osteoblasts found
bone
ending cytes meaning
mature cells, maintaining matrix, less active
areolar CT function
-Attach skin to underlying tissue
-Fill spaces b/w various organs + hold them in place
-Surround & support blood vessels
areolar CT location
under epidermis (outer layer of skin)
Collagen fibers
tough + provide strength to matrix (thick + light Color)
elastic fibers
elasticity + stretch + recoil (thin + stained darker)
3 cell types in areolar
- fibroblast
- mast cell
- macrophages
fibroblast
actively mitosis cell that secretes ground substance + fibers
- Produce and secrete matrix components
mast cell
has coarse, dark staining granules in cytoplasm
Secrete histamine + heparin
macrophage
large, arise from wbc
-Engulf + destroy bacteria or foreign particles
RETICULAR CT function
forms internal framework
reticular location
Spleen, liver, bone marrow, lymph nodes, blood vessels, nerves
cells present in Reticular CT
Fibroblast (reticular cells), wbc, macrophages
reticular fibers
short, thin, branched networks of collagen- like fibers
adipose CT (rock) function
1.Synthesis + lipid storage
2.Protection
3.shock absorber
4. Forms insulating layer for body temp regulation
adipose CT location
Under skin, around kidneys, heart, eyeballs. Within abdomen + breasts
what is adipose characterized by
large lipid droplet that swell the cell so the cytoplasm becomes thin + nucleus is displaced to the edge of cell
Dense Regular Connective Tissue location
Skin dermis
Kidney, muscles, bones, nerves
dense regular ct function
forms fibrous coverings
dense regular difference b/w areolar, reticular, adipose
fewer cells + less ground substance
2 ty[es of dense regular ct
regular (parallel pattern)
irregular (thicker + run several directions)
dense regular is composed of
tendons and ligaments
what is tendons attach to
muscle to bone
what is ligaments attached to
attached bone to bone
cartilage function
rigidity + flexibility
cartilage receive __ from __ in
nutrients, blood vessels, perichondrium
location of cartilage
where two bones meet and at the ends of all your bones that form joints (elbows, knees, ankles)
bone and cartilage difference
Bones are the hard, inelastic and tough organ that forms part of the vertebral skeleton.
Cartilage is a soft, elastic and flexible connective tissue that protects the bone from rubbing against each other.
3 types of cartilage
Hyaline
Elastic
Fibrocartilage
dense CT that surrounds cartilage
perichondrium
the outer layer of perichondrium consist of and arranged in
layer of collagen fibers
Arranged in irregular interwoven pattern
inner layer of perichondrium is where ___
where collagen fibers merge with ground substance
inner layer is where __ are formed
chondroblasts (produce matrix)
a cyte found in the inner layer of perichondrium
chondrocytes ( mature cartilage cells founds in lacunae)
lacuna
an unfilled space
what is matrix in hyaline cartilage
gel liek that has collagen fibers
hyaline cartilage location
Articular surfaces of bones
Ends of ribs
Nasal septum, larynx, trachea, bronchi
Long bones (reduce friction)
hyaline cartilage function
helps your bones move smoothly past each other in your joints.
elastic cartilage is characterized by
elastic fibers
elastic cartilage function
support and flexibility
elastic cartilage location
external ear (pinnacle)
epiglottis
wall of auditory (eustachian) tube
how does fibrocartilage differ from hyaline and elastic
less organized and lacks perichondrium
fibrocartilage location
B/w vertebrae + knee menisci b/w tibia + femur
fibrocartilage function
support + withstand heavy pressure
fibrocartilage forms what
(vertebral discs) + pubic symposia (joint b/w pubic bones of pelvis)
bone function
support and proctection
what does bone provide and store
Provide cavities for fat storage + blood cells synthesis
Storehouse for minerals, Ca, P
2 basic types of bone
spongy (cancellous) and compact
where is spongy bone found and consists of
-found internally
-Consists of framework of trabeculae (columns of bones)
where is compact found and composed of
found externally and composed of osteons / Haversian systems
what is osteons
solid sheet of bone tissue into structural units
what is osteocytes and where is it found
mature bone cells found in lacunae (spaces) b/w lamellae
osteocytes function
Contain nutrients + remove wastes via cytoplasmic extensions that occupy canaliculi
canaliculi
networks of small canals that radiate from each other lacunae
- Remove wastes
Periosteum
where blood vessels are located
Matrix bone
hard + rigid b/c of inorganic mineral salts ( Ca + P)
characteristic of bones in acid
removes inorganic component (Ca + P)- inorganic, mineral, salt
Loses hardness,
Keeps flexibility
characteristic of bone in organic
characteristic of bone when baked
denatures organic (collagen)
Brittle, parts flake off
Loses flexibility
