Lecture 3 - microscopy and tissue recognition Flashcards
how do you calculate magnification
eyepiece magnification x objective lens
magnification power
what is working distance
Distance between objective lens and slide
what is resolution
Ability to separate two small elements in the structure of an object that are very close together
what is numerical aperture
Estimate of the amount of light from sample collected by objective lens
what happens if numerical aperture is low
the amount of light refracted is low
how do you get clearer resolution
oil and water =
+ refraction index
+ working distance
+light
how does light go through the micrscope
- Light passes through COLLECTOR LENS which focuses it at a plane of CONDENSER DIAPHRAGM
- Condenser lens aligns these light rays into a straight line
what does the objective lens do
gathers light from specimen and magnifies the image
what does the tube lens do
manipulates light to make the image appear even clear
what does the eyepiece lens do
magnifies the image
is light white
no - made up of different colours
what is the sample prep
for transmission electron microscopy
- Very thin sections so electrons can pass through
- Samples embedded in hard resin to make them easier to cut
- Allows electrons to pass through sample
- Samples treated with heavy metals increasing image contrast
what is the sample prep for scanning electron microscope
- Samples not cut into sections as it visualises just the surface
- Coated with thin layer of metal
- Samples treated with heavy metals
- Metal coating makes them conductive
what are the three main tissue types:
epithelial tissue
connective tissue
muscular tissue
what are the four layers of epithelial structure
apical surface
lateral surface
basal surface
basement membrane
what does the epithelial tissue do
covers body surfaces, hollow organs, body cavities
And forms glands
what does the connective tissue do
protects, support and binds organs
stores energyas fat
provides immunity
what does muscular tissue do
physical force required to make body structures move
generates heat
what does the apicalsurface contain
cilia or microvilli
what does the lateral surface contain
junctions
what does the basal surface bind to
basement membrane
what layers does the basement membrane have
2 layers:
- basal lamina with laminin and collagen
- reticular lamina with fibroblasts that make collagen
whats the squamous shape like and what does it allow
flat and wide
allow the rapid passage of substances
what is the cuboidal shape like
tall as they are wide (cube shaped)
what is the columnar shape like
taller than they are wide
what is the transitional shape like
changes shape depending on tissue
what is the simple arrangement
only one layer
cells contact basment membrane
what does pseudostratified appear as
layers but cells go from apex to the base
what is the stratified layer
two or more layers
only basal layer in contact with basement membrane
where is simple squamous epithelium found
bodily sites - everywhere
what do simple squamous form
layer around mesothelium of serous membranes
where is simple cuboidal epithelium found
in tissues with absorption and secretion roles
key organs e.g. pancreas ovaries salivary thyroid
where is non-ciliated simple columnar epithelium found
where secretion and absorption is needed
GI tract
what are cilia replaced by in Non-ciliated simple columnar epithelium
microvilli
what are microvilli important for
absorption and increase overall surface area
what does ciliated simple columnar epithelium remove
removes trapped particles
where is Stratified columnar epithelium found (rare)
in ducts of sweat glands
plays protective role around tissues
what structure does transitional endothelium have
various
what are the functions of connective tissue
support
strength
protect and insulate organs
compartemnetalisation
what are the 5 types of connective tissue
loose
dense
cartilage
bone
liquid
what do fibroblasts cell look like
flat and have branches coming off them
what do fibroblasts secrete
protein fibres and form a groundwork substrate
what are the three main types of protein fibres
collagen
elastin
reticular
what is the function of chondrocytes
make cartilaginous connective tissue
what is the function of adipocytes
stores fat
what are the function of osteocytes
makes bone
what is an example of loose connective tissue
areolar
what does areolar act as
packing material holding skin and underlying tissue together
packing glands, muscles and nerves together
what distinguishes areolar or elastin
areolar is dark purple
what is areolar connective tissue
a mature loose connective tissue
widely distributed around the body
has all 3 cell types
what is adipose tissue
mature loose connective tissue
what does adipose tissue form
the subcutaneous layer under skin
what is the adipose tissue function
reduce heat loss
pads the tissues
stores fat as an energy store
what type of connective tissue is reticular
loose connective tissue
what does reticular connective tissue contain
reticular fibres and cells and forms an intertwined network
YOU GOT THIS
what is the cell and fibre type of dense irregular connective tissue
cell - fibroblasts
fibre - collagen
what are dense irregular connective tissue designed to do
provide strength in tissue when forces are acting in multiple directions
where is dense regular connective tissue found
in all areas where strength is needed in one direction
what are examples of dense regular connective tissue
tendons and ligaments
what is cardiac muscle tissue composed of
composed of intercalated discs and striations
what is smooth muscle composed of
smooth muscle fibres
give skeletal muscle features:
myoblast -> satellite cells on immature muscle fibre (then mature)
sarcomere - from actin and myosin
sarcoplasm and sarcolemma
what is unique about cardiac muscle
it has connexins that allow action potentials to spread from one cardiac cell to another
which muscle is voluntary and involuntary
smooth muscle - involuntary
cardiac muscle - involuntary
skeletal muscle - voluntary
where is each muscle usually found
smooth - arteries, organs, blood vessels
cardiac - only in heart
skeletal - attached to bones via ligaments
