Basic tissues + Epithelium Flashcards
tissue definition:
group of similar cells/ cell products (extracellular matrix- liquid, semisolid, solid) which perform special function
basic tissues:
- epithelial
- nervous
- connective
- muscle
type of cells: epithelial
aggregated (mass), polyhedral shaped
type of cells: nervous
intertwining elongated processes
type of cells: muscle
elongated contractile
type of cells: connective
several types: fixed and wondering
amount of extracellular matrix: epithelial
small amount
amount of extracellular matrix: nervous
none
amount of extracellular matrix: muscle
moderate
amount of extracellular matrix: connective
abundant
main function: epithelial
lining, covering, protecting surfaces/ body cavities, glandular secretion
main function: nervous
transmit nervous impulse
main function: muscle
movement
main function: connective
support/ protection
eg. covering/lining/protecting surfaces and how?
skin, gut
cells in layers covering external surface or lining cavities
eg. secretion and how?
glands
specialised cells which produce secretions
eg. absorption
intestines
eg. sensation
neroepithelium
eg. contractility
myoepithelial cells
epithelial: structure
layer of tightly packed cells, eg pores are invaginations (infolding) of e. cell
epithelial: situated
polarised: always 1 exposed surface (apical/free)
one or several layers (basal layers)
alwaysconnected to connective tissue underneath (lamina propria)
epithelial: avascular?
no blood flow, receives nutrients from lamina propria
basement membrane:
membrane formed by secretion of epithelial/connective cells, separating epithelium from connective tissue
also selectively permeable filter between the tissues
two layers of basement membrane:
basal lamina:
- protein filaments (laminin, collagen, glycoprotein, proteoglycans) in amorphus (shapeless) matrix
- from epithelial cells
reticular lamina:
- reticular fibres embedded in ground substance
- from connective tissue
cell surface specialisations . eg:
microvilli, stereocillia, cilia
microvilli: and use, eg
small protrusions (brush border), made of microfilaments
increasing SA for absorption
small intestine, proximal renal tubules
stereocilia use and eg:
elongated microvilli
eg. inner ear, epididymis (back of testicle), vas deferens (ducts which carry sperm)
cilia use and eg:
large elongated motile structure, made of microtubules inside cell membrane
eg. respiratory epithelium
cell shapes:
squamous, cuboidal, columnar
cell layer arrangements:
simple, pseudostratified, stratified
types of simple cells:
si. squamous
si. cuboidal
si. columnar (non)/ ciliated
si. pseudostratified (non)/ ciliated
types of stratified cells:
st. squamous (non)/ keratinised
st. cuboidal
st. columnar
st. transitional
location and nucleus position: simple squamous epithelium
central flattened nucleus
pulmonary alveoli, kidneys, inner wall lining of blood/lymphatic vessels (endothelium), form serous membrane (lining body cavities and organs)- pericardium, pleura, peritoneum (mesothelium)
location and nucleus position: simple cuboidal epithelium
central round nucleus
glands, glandular organs, ducts (ovary surface, salivary gland ducts, pancreas), kidney tubule lining
location and nucleus position: simple columnar epithelium
nucleus close to basement mem.
lining of intestine, uterine tubes, bronchioles
location and nucleus position: pseudostratified epithelium
varied position of nucleus
trachea, bronchi, nasal cavity
features/ function: simple squamous epithelium
flat irregular shaped cell, mosaic pattern
function- diffusion, filtration
features/ function: simple cuboidal epithelium
tightly fitted cube-shape cells
function- secretion, filtration, absorption
features/ function: simple columnar epithelium
tall columnar cells, tightly fitted
function- protection, lubrication, secretion, absorption
non-ciliated: has microvilli (increase SA) for absorption
ciliated: support beating of secondary oocyte through uterine tube
features/ function: pseudostratified epithelium
different cell heights, appears to be stratified (eg. goblet cell)
function- non ciliated: protection, secretion,
(if ciliated) movement of particles
features/ function: stratified squamous epithelium
apical surface cells= squamous while deeper cells are cuboidal
function: areas of wear and tear, top layer of cells constantly replaced via mitosis of innermost cells
stratified squamous epithelium and location: dry
keratinised cells:
protein strengthens tissue, prevents water loss
eg. epidermis
stratified squamous epithelium and location: wet
non-keratinised: mucosa
for protection and secretion
eg. mouth, oesophagus, larynx, vagina, anal canal
features/ function/ location: stratified cuboidal
rare, only 2-3 layers of cuboidal
for protection, secretion
eg. sweat gland ducts, pancreas
features/ function/ location: stratified columnar
rare, basal layer (short irregular cells, apical cells= columnar)
for protection, secretion
eg. conjunctiva, large salivary gland ducts
features/ function/ location: transitional epithelium
cells with change form according to distension- flat (stretched), cuboidal (relaxed)
for protection, distensibility (ability to swell)
eg. urinary bladder lining, ureters, renal calyces
function/ eg: glandular epithelia cell
specialised cells for secretion, primarily export molecules:
protein (insulin), lipids (steroids), salts (sweat glands), carbs (salivary glands)
both uni/multicellular
features: exocrine glands
release secretions via system of ducts - open to surface of the body
in contact with external or internal surfaces (Eg. skin, GIT)
features: endocrine glands
release secretory products (hormones) into extracellular space -> bloodstream
features/ eg/ location: unicellular glands
simplest secretory cells found among non-secretory (eg. goblet cell)
goblet cell found in lining of intestines, respiratory tract, conjunctiva
produce carbohydrate-rich glycoprotein, mucin secreted as mucus
features/ classification: multicellular glands
invaginations of tissue surface, secretory portions (deepest part) and ducts
simple or compound (ducts)
shape (secretory portion):
tubular (tube)
acinar (flask-like)
tubuloacinar (tube with sac-like dilatation - dilated part)
list 8 types of multicellular glands:
- simple tubular
- simple branched tubular
- simple coiled tubular
- simple acinar
- simple branched acinar
- compound tubular
- compound acinar
- compound tubuloacinar
method of secretion and eg: merocrine
via exocytosis (most common) where vesicles open onto cell surface, secretory product discharged from cell
eg. pancreatic acinar cells
method of secretion and eg: apocrine
part of apical cytoplasm of cell is released WITH secretory product
eg. apocrine sweat glands, mammary and prostate glands
method of secretion and eg: holocrine
breakdown of entire secretory cell
eg. sebaceous skin glands
preparing a slide: fixation
to keep cells alive, formaldehyde, ethanol
preparing a slide: embedding
to make cells harder, paraffin wax, plastic resin
preparing a slide: sectioning
thinly slice sample, microtome
preparing a slide: staining
special dyes to see particular components:
haematoxylin (blue/purple stain) and eosin (pink/red)
