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hematoxylin and eosin staining
-most common stain
first step in preparation of a tissue or organ sample
-Formalin, 37% aqueous solution of formaldehyde usually used.
1.) Fixation-preserve structure
2.) Prep for sectioning-typically by paraffin
3.) staining-allows examination
Used for connective tissue
Cartilage will show up blue/green
-Muscle fibers show up red
Primarily used for connective tissue
-bone matrix-deep blue
Used for visualization of reticular fibers and nerve fibers
-Reticular and nerve fibers both show up as brown/black in color
Primarily used to stain blood cells
-Can differentiate between neutrophils, eosinophils, basophils, platelets)
-ex. plump macrophages that have characteristic appearance in the cytoplasm of crumpled tissue paper (Gaucher disease)
used for staining of basement membrane, and localizing carbohydrates
-glycogen and other carbohydrates stain as magenta
Hematoxylin-stains blue and is used for nucleic acids and rER
-Eosin- used for elastic and reticular fibers
grow from microtubule-organizing centers located near the nucleus toward the periphery.
_Railroad tracks that allow vesicular movement
_make up cilia and flagella
_Responsible for movement of chromosomes during mitosis and meiosis
-Play role in cell movement and shape
-Largest cytoskeletal component!
structures essential for protein synthesis and composed of ribosomal RNA and ribosomal proteins
-translate protein-coding sequences from mRNA
nucleus-storage and use of genome
nucleolus-synthesis of rRNA and partial assembly of ribosomal subunits involved in regulation of cell cycle
Technique to visualize membrane proteins
-Lipid bilayer split along hydrophobic plane to expose 2 interior faces of the membrane, an E-face, backed by extracellular space, and the P-face which is backed by cytoplasm
6.) structural proteins
transport certain ions, such as Na+ actively across membrane
also transport Amino acid, sugars and metabolic precursors of macromolecules.
allow passage of small ions, molecules, and water across the plasma membrane in either direction (passive diffusion)
or voltage-gated ion channels/ligand gated ion channels
anchor intracellular cytoskeleton to extracellular matrix.
Ex.) Integrins that link cytoplasmic actin to extracellular matrix proteins (fibronectin)
major mechanism by which large molecules enter, leave and move in the cell
_buddy from the plasma membrane of one compartment fuse with the plasma membrane of another compartment
AKA cell drinking
-nonspecific ingestion of fluid and smaller proteins molecules via small vesicles, usually smaller than 150 nm
-performed by virtually every cell
-continuous dynamic formation of small vesicles at cell surface
have a unique membrane that is resistant to hydrolytic digestion occurring in their lumen
-have nucleases, proteases, lipases, phopholipases and represent a major digestive compartment in the cell that degrades macromolecules derived from endocytotic pathways.
-Phagocytosis occurs whereas the endosome transforms into the lysosome
1.)apical plasma membrane
2.) basolateral plasma membrane
3.) endosomes or lysosomes
4.) apical cytoplasm
1.) sorting signals-represented by a linear array of amino acid or associated carbohydrate molecules. Signal recognized by sorting machinery, which directs protein to right vesicle
2.) Physical properties-groups of proteins first partitioned into separate lipid rafts that are later incorporated into transport vesicles destined for a targeted organelle
present in virtually all cell types
Require energy in form of ATP to work
-smallest cytoskeletal component
1.) anchorage and movement of membrane proteins
2.) formation of structural core microvilli on absporptive epithelial cells
3.) locomotion of cells-movement achieved by actin filaments by polymerization at their growing ends
ropelike filaments because diameter of 8-10 nm between those of actin and microtubules.
-essential for the integrity of cell-to-cell and cell-to-extracellular matrix junctions
contain products of metabolic activity of the cell and consist largely of pigment granules, lipid droplets and glycogen
_NON-LIVING/NON-MOVING components of cell
-Ex.) Hemosiderin, glycogen, Lipid inclusions (fat droplets) and crystalline inclusions
1.) heterochromatin- highly condensed chromatin (where most transcribed genes are located)-appear as Dark staining
2.) euchromatin- dispersed form of chromatin-(appear as light staining due to density)
Telomeres shorten with each cell division and is an important indicator of the lifespan of the cell.
-Often times in malignant cells, an enzyme called TELOMERASE, that adds repeated nucleotide sequences to the telomere end and can extend lifespan of cell.
Barr body can be used to identify the sex of a fetus.
-Initially discovered in female cats, where X-chromosome appears as well-stained round body adjacent to the nucleolus.
-CDK (cyclin dependent kinase)
_cyclin-Cdk complex acts at different phases of the cell cycle and targets different proteins to control cell cycle dependent functions
malfunction at any of the DNA damage checkpoints or the spindle assembly checkpoints in early mitosis
_failure to arrest the cell cycle before or at mitosis results in aberrant chromosome segregation causing apoptosis or aneuploidy
-malfunction at G1 restriction checkpoint may result in malignant transformation
-Cell lysis leads to intense inflammation caused by disintegration of cell
-Programmed cell death causes DNA fragmentation, membrane blebbing, and formation of apoptotic bodies
_phagocytosis clears up debris
1.)Provide basal bodies for cilia and flagella
2.) mitotic spindle formation
During mitosis, the position of centrioles determine the location of mitotic spindle poles.
-provide structural framework for various tissues and organs
-composed of TYPE 3 COLLAGEN
Most locations reticular fibers are formed by fibroblasts
-Can be produced by SCHWANN CELLS, that secrete reticular fibers
-in blood vessels/muscularis of alimentary canal, where SMOOTH MUSCLE secretes reticular fibers
AKA brittle bone disease
-Type 1 Collagen abnormality
-brittle bones, weak tendons, repeated fractures after minor trauma, hearing loss
Mutation of genes in collagen polypeptide chains
-Type 3 collagen abnormality
-causes: hyperflexibility of joints
hyperextensibility of skin and vascular and organ disruption
-Type IV collagen pathology
1.) hematuria-results from structural changes in glomerular basement membrane of kidneys
2.) progressive hearing loss
3.) ocular lesions
Allows stretch and distension
Found in elastic cartilage, elastic arteries, and elastic ligaments
1.) central core of elastin-hydrophobic properties allow for random coiling of fibers-allows sliding to occur
2.) network of fibrillin microfibrils
2.) vascular smooth muscle cells
Marfan's-causes chest deformity, arachnodacyly, and long arms big feet
Also produces nonfunctional elastic fibers which then decrease skin elasticity
-includes mesenchyme and mucous CT
2.) Connective tissue proper
-includes dense CT: regular vs. irregular and loose CT
-adipose tissue, blood bone, cartilage, hemopoietic tissue, lymphatic tissue
relatively uniform appearance
-3 dimensional cellular network
-CAPABLE of turning into other tissue types
Cells: fibroblasts and few mesenchymal cells
-less reticular fibers
loosely arranged collagen fibers and many different types of cells
_abundant ground substance
-primarily found under epithelium
-Lamina propria- LCT of mucous membranes
-may contain elastic fibers to allow flexibility
-less regularly arranged than those of tendons
-multiple collagen layers
-layers are arranged in regular arrays (orthogonal array)
-synthesize fibers and ground substances
contains actin and myosin
-located in the LCT
0regualtes the shape and emptying of glands
-wound contraction and closure
1.) mechanical and structural support
2.) biochemical barrier
3.) metabolic regulation
4.) anchors CT cells
5.) cell migration and wound healing
6.) regulates growth and maturity
3.) multiadhesive glycoproteins
1.) collagen fibers
2.) reticular fibers
3.) elastic fibers
1.) alpha chain
cartilage (both hyaline and elastic)
-resistant to intermittent pressure
if have long muscle fiber, one nucleus isn't enough to code for all proteins
-need to have a whole bunch of cells that work together that fuse to code for necessary amount of actin and myosin
0formed fusion of single cells-myoblasts
1.) myoblasts fuse to form skeletal fiber (myotube)
-myotube more like a rod than a tube!
2.) Satellite cells run outside of sarcolemma inside basal lamina and are necessary for growth, repair and regeneration
_Satellite cells divide and fuse to muscle fiber and become part of muscle fiber to make more contractile protein
c. 2% of muscle cell pop.
-Satellite cells divide and fuse to muscle fiber and become part of muscle fiber to make more contractile protein
-can't tell satellite cells from monucleus
-typical muscle fibers
-innervated by alpha-motor neurons and generate tension during contraction
3 main types of muscle fibers
1.) Type I (slow oxidative) (SO)
2.) Type II-b (fast glycolytic fibers- FG)
3.) Type II-a (fast oxidative fibers) (FOG)
Smallest and slowest to contract.
-specialized for contracting for longer time periods with improved mitochondrial performance and greater oxygen supply (oxidative)
larger and contract faster
-produce greater tension
-fatigue rapidly because of ATP use
-Myosin heavy chain
-different isoforms of MHC hydrolyze ATP at different rates, therefore have different velocities of contraction
1.) what is the velocity of contraction of the fiber (slow (I) or fast (II)
2.) how resistance is the fiber to fatigue? (oxidative or glycolytic metabolism)
3.) How much tension is generated by the fiber?
(proportional to cross-sectional area of fiber
Type IIb (FG)
-remember proportional to cross-sectional area of fiber
alpha motor neuron
1.) Muscle spindle
2.) Golgi tendon organ
-run parallel to muscle fibers
-stretch receptor important for reflexes, maintaining muscular tone, and smoothing muscle movements
Golgi tendon organs
-lie in series with muscle fiber
-prevents muscle from being torn from bone
-CNS tells motor neuron to stop being so active when tendon organs get activated it turns off muscle contraction to prevent injury
-small diameter, skeletal muscle fibers encased in proteoglycan/glycoprotein filled CT capsule
-termed nuclear bag or nuclear chain, are innervated by sensory neurons (group 1a and II) at their central regions and gamma motor neurons in their polar regions
in response to excessive tension on the tendon
-inhibits muscle from contracting strongly
Moderates muscle contraction before it tears a tendon or pulls it loose from the muscle or bone
Layers of muscle from biggest to smallest
contractile protein called actin plus tropomyosin and troponin, which act as a switch for contraction.
One troponin-tropomyosin complex for every 7 globular actin molecules
1.) Inhibitor (blocks binding site)
3.) T-binds troponin
two heavy chains and four light chains compose each molecule
-heads have binding site for actin and one for ATP
-Myosin is oriented tail-to-tail in thick filaments, such that the center of each thick filament is devoid of myosin heads
intermediate filament protein that surrounds myofibrils/ sarcomeres at the level of the Z-line.
-keeps myofibrils in line when contracting
-Desmin is unique to muscle cells, so any tumor cell that reacts with antibodies to desmin had their origin in muscle
voltage gated sensor
1.) ACH causes influx of Na+ which depolarizes sarcolemma
2.) depolarization is conducted deep into fiber by T tubules
3.) depolarization causes VG sensors to release Ca++ from the terminal cisternae of SR into the sarcoplasm of fibers
-Troponin C subunit
1.) attached phase
2.) release phase
3.) bending or cocked phase
4.) power stroke/force generation phase
1.) myosin head is bound to actin in the absence of ATP (attached phase)
2.) binding of ATP to myosin head reduces the affinity of myosin to actin (release phase)
3.) energy generated by hydrolysis of ATP into ADP and Pi recocks the myosin head (bending or cocked phase)
4.) Pi is released and myosin head tightly binds to actin. Myosin head returns to unbent position which is lower in energy conformation (power stroke)
protein that suppresses muscle growth
-KO for this gene in animals produces phenotype with muscle hypertrophy. Mutations do rarely occur in humans
Hormone produced and secreted by atrial myocytes. ANP increases excretion of sodium (water follows) from kidney, thereby reducing blood pressure
Ca++ binds calmodulin. complex bind to myosin light chain kinase, which phosphorylates myosin.
-Myosin is activated to form cross-bridges with actin and fiber contracts
-When Ca++ gets pumped out of cell, phosphatase cleaves phosphate from myosin inactivating it, and contraction ceases
Remember that the bronchi wall has 5 layers:
4.) cartilage layer
What is this tissue?
What are defining features?
-Dark Basal Bodies (BB)
-prominent basement membrane
What is this type of tissue?
Where is this tissue specifically located?
-located at the top of the Nasal Canal!
Bottom layer: olfactory epithelium
Top layer: respiratory epithelium
This is a cross section of what organ?
What tissue type is this and what function does it serve?
-Cross section of the Larynx
-Has stratified squamous epithelium due to air movement
-Notice Vocalis muscle which provides force to put tension and torque on the cords
What structure is this an electron micrograph of?
What is the space in the center called?
What happens in this space?
-Alveolar sacs, which is the space surrounded by clusters of alveoli
-This is the primary site for gas exchange
Made up of alveolar epithelium