Quiz 1 Flashcards
(111 cards)
level of ogranization
atoms, molecules, organelles, cells, tissues, organs, systems, organism
cells
smallest unit of living matter
200 diff types in the body
tissues
collection of similar cells = simple tissues
collection of different cell types = comound tissues
4 types of tissues
epithelial
connective
nerve
muscle
organs
anatomically distinct groups of tissues working to perform specific functions
systems
collection of organs working together for a similar or related roles
histology definition
study of cells and tissues
relationship between structure and function of tissue
tissues structure that are not seen by naked eye
basis for histopathology
pathology
study of diagnosis of disease
3 types of light microscopy
bright feild
phase contrast
differential interference contrast microscopy
bright field microscopy
can see natural colours or stained samples
specimens appear dark on a bright background
phase contrast microscopy
based on difference in refractive indexes
optic converts the differences in RI to differences in brightness therefore nucleus can be distinguished from the cytoplasm
differential interference contrast microscopy
makes specimen 3D based on differences in refractive index
difference is converted into detectable amplitude differences
may not actually represent the specimen in real life
staining in light microspcopy
basic dyes/cationic dyes - stain RNA/DNA because of their negative charge
e.g: hematoxylin
acidic dyes (negative charge) - stain basic residues such as protein e.g: eosin
H&E staining causes nuclues and ribosomes to stain blue and cytoplasm and collagen red or pink
magnification and resolution
magnification = how many times larger an image is
resolution is the ability to distinguish between two separate points
resolution on a light microscope vs electron microscope
light microscope:
dependent on wavelength of light - if the object is big enough to interfere with a wavelength in the spectrum then the image is able to be seen
electron microscope:
wavelengths are 10 000 times shorter and therefore EM has higher resolution
what limits resolution
+ know how to calculate
numerical aperture: the ability of the lens to collet thelight and the wavelength of light
lenses with NA values over one require oil
types of EM
Scanning EM (SEM)
- reflected off surface
- 3D image
Transmission EM (TEM)
- pass through
- 2D image
- best resolution
where is epithelial tissue located?
external and internal surfaces of the body - covering body surfaces, lining body cavities, forming glands
means that anything in/out must pass through the epithelial tissue
located on a basement membrane/ basal lamina
how does epithelial tissues get nutrition?
they are a vascular
dependent on loose connective tissue to supply nutrients and oxygen as well as remove by-products
major functions of epithelial tissue
coverings or linings = protection
absorption (intestine)
secretion (glands)
sensation and contraction
basal lamina
lies at interface between epithelial cells and connective tissue
two basal laminas can fuse in places when no intervening connective tissue is present
characteristics of epithelium
sheets of cells held together tightly by junctions
they can shed and renew
composed of polarized epithelial cells, specialized to perform a variety of functions such as regulation of passage
simple squamous epithelial cells
single layer of flattened cells - look like fried eggs
can do simple secretion and filtering
located in places where the passage of chemicals is rapid such as:
- making up endothelial lining of lymphatic vessels
- alveoli of lungs
- lining of capillaries
- some parts of the kidney glomerulus and tubules
simple cuboidal epithelial cells
allow passage of chemicals
thicker than squamous therefore have protective function
complex function in secretion compared to squamous
also have role in absorption
located in the secretory part of most glands and kidney collecting tubules