Lab Three Flashcards
what are the pink fibers in connective tissue proper?
collagen
what is the arrangement of collagen fibers in loose (areola) connective tissue proper?
thick bundles of fibers running in all directions
what are the black fibers in connective tissue proper?
elastin
what is the arrangement of elastin in loose (areola) connective tissue proper?
finer branching fibers
what is the shape of a fibroblast?
flattened cell
what is the function of fibroblasts?
secrete both the ground substance and the fibres of the extracellular matrix
what are the things that fibroblasts secrete?
collagen
elastin
reticular fibers
ground substance (cell adhesions proteins, proteoglycans)
what does ground substance contain?
cell adhesion proteins
proteoglycans
what is a prominent organelle in fibroblasts and why?
Rough endoplasmic reticulum. Fibroblasts manufature lots of proteins to secrete, which are synthesised by the RER
what are the types of connective tissue proper?
loose (areola)
dense (collagenous)
elastic
reticular
what is the arrangment of fibers in dense regular conective tissue?
collagen fibers run in thick parallel bundles and provide great tensile strength when a pulling force is applied in one direction
very few elastin fibres
where is dense regular connective tissue found in the body?
present in tendons, most ligamnets and aponeuroses
what is aponeruroses?
a fibrous or membranous sheet connecting a muscle and the part it moves
what does baking bone do to the structure?
baking denatures the protein, therefore the collagen is destroyed, removing the tensile strength and the bone becomes brittle
what does vinegar to do bone structure?
Calcium salts are dissolved in the vinigar thus making the matrix less rigid, and ‘bendy’
what are the features of Dense connective tissue extracellular matrix?
-densely packed parallel collagen fibers, and a few elastin fibers
therefore in withstands tensile stress when pulled in one direction
what are the features of Hyaline cartilage extra cellular matrix?
Collagen fibres present but form amorphous matrix, Chondroytes lie in lacunae
Therefore resists compressive stress, because it is firm but flexible
what is the feature of a bone extracellular matrix?
Hard calcified matrix
Osteocytes lie in lacunae within the matrix
Therefore the bone supports, protects and acts as a level
what are the features of adipose tissue extra cellular matrix?
Sparce matrix containing a lot of adipocytes filled with large lipid droplets
Therefore is a food reserve, supports and insulates
what are the three types of muscle?
Skeletal (straited) muscle
Smooth muscle
Cardiac muscle
where do bundles of connective filaments connect to the smooth muscle cells?
at the focal densities
what is a supporting tissue?
connective tissue that provides protection to muscle fibers
how many cells make up one muscle fiber?
One skeletal muscle cell = one muscle fiber
how many nuclei are found in each skeletal muscle cell?
Many nuclei, varies between cells
what are the features of a sarcomere?
the sarcomere is from one Z line to the next and contains overlapping thick filaments (A band) and the thin filaments (I band)
what are thin filaments of the sarcomere made from?
actin
what are the thick filaments in the sarcomere made from?
myosin
what happens when the sarcomere contracts?
the thin and thick filaments slide over each other. The A band stays constant, the I band narrows and the Z lines are pulled closer together.
what junctions form intercollated disks in cardiac muscle?
Fasia adherens- actin filaments insert into the z lines)
Desmosomes (anchoring points for intermediate filaments)
Gap junctions
where do actin filaments inside cardiac muscle cells insert into to transmit contractile force?
into the z lines at the fascia adherens
how does excitation spread within cardiac muscle cells?
through gap junctions
what is the role of swann cells?
Myelinate insulated nerves
what is the benefit to myelinated nerves?
Get less dissipation of excitation
Speeds up transmission of AP
what is the disadvangated to nerve myelination?
Myelination must be absent as dendrites for activation
what strictures in a CNS neruon reflect a high metabolic activity?
Mitochondria
Golgi Bodies
Ribosomes (RER)
Nucleolus
what is the hypodermins?
a layer of tissue immediately inferior to the dermins that is not part of the skin (has a supporting role)
Comprised of adipose tissue
what are the cells within the stratum corneum?
dead flattened keratinised cells
what are the cells of the epidermis?
Stratified squamous epithelium
what are the cells of the stratum lucidum?
cells have no nuclei or organelles
what are the cells of the stratum granulosum?
contain keratohyalin granules
what are the cells of the stratum spinosum?
Keratinocytes held together by desmosomes (prickle cells)
what are the cells of the stratum basale?
1 layer of cuboidal cells, many hemidesmosomes and desmosomes mitotic figures
