Exam 1 (Lecture 1-9) Flashcards
Histology is the study of microscopic anatomy of cells and _____.
Tissues
List the 4 major types of tissues.
1) Epithelial 2) Connective 3) Muscle 4) Nervous
Where might simple columnar epithelial be found?
Ileum; Intestine
Where might simple cuboidal epithelial be found?
Kidney
Where might stratified squamous epithelial be found?
Skin
Where might transitional epithelial be found?
Ureter; Bladder
Who was considered the “father of modern histology” and introduced the notion that tissues are distinct entities and diseases attach tissues rather than whole organs or the body?
Marie Francois Xavier Bichat
Who pioneered the concept of pathological processes by applying the cell theory (all living things are made of cells and come from preexisting cells)?
Rudolph Carl Virchow
Schleiden was a botanist that recognized the ____ is the essential unit of the living organism. Also erroneously developed that cells arise by budding from the nucleus.
Cell
Schwann was a zoologist that compared animal cells to ____ cells and distinguished five classes of tissues.
Plant
Who are the scientists credited with discovering all living things are composed of cells?
Schleiden and Schwann
Kolliker applied Schwann’s theory of five tissues to _____ development of animals and wrote first book on histology.
Embryology
Janssens (uncles and nephew) produced the first what? With what level of magnification?
Microscope; 30x
Who described cork and other cells and introduced the term “cell”?
Robert Hooke
Anthony Leeuwenhoek made over 247 simple microscopes capable of what level magnification? Where did he send 26 of these microscopes?
100x; To the Royal Society
What is the bending of light from one medium to another?
Refraction of Light
Light waves transmitted through a vacuum travel at a (fixed/variable) velocity.
Fixed
Velocity of Light / Velocity of light inside transmitting medium
Refractive Index (R.I.)
The refractive index (R.I.) of air is…
1
The 2 factors that affect degree of light bending are:
1) Refractive Index (R.I) 2) Angle the light strikes the surface
Light striking a perpendicular surface will go (straight/angled).
Straight
The measurement for the refractive power a lens has are…
Diopters
1 diopter = 1 ____ / Focal length of a lens
Meter
Convex lens is shaped like a…
Football
The point through which all parallel rays of light will pass after passing through each part of the lens is called the…
Focal point
T/F – The distance from the center of the lens to the focal point is called the diopter length.
False – It’s called the focal length.
What image is formed when the object is placed outside the focal point? Name some characteristics of this image.
Real Image – Inverted; Can be projected onto a screen; Differs in size from the object (greatest magnification will be obtained from lenses having a very short focal length with the object as close as possible to the focal point)
What image is formed when the object is placed inside the focal point? Name some characteristics of this image.
Virtual Image – Not inverted; Cannot be projected onto a screen; Can be magnified; No points exist at any plane in space at which rays radiating from the object are brought to focus.
The ability of a microscope (or any optical instrument) to distinguish two small points as separate points is called…
Resolution
Resolution is achieved by reducing the diameter of _____ lines around the two points.
Diffraction
List the 5 components of a Compound Light Microscope.
1) Light source 2) Condenser 3) Stage 4) Objective lens 5) Ocular lens
Based on the pros and cons, what microscope am I talking about? Ability to magnify, ability to resolve structural detail, specimen must be thin, and little contrast in unstained specimen.
Compound Light Microscope
What microscope can be used to examine unstained cells and tissues, examine living cells, and allows to see transparent objects?
Phase Contrast Microscope
What microscope allows very thin optical images of specimen to be created, out-of-focus images to be subtracted from image by computer program, and let’s the computer make 3D reconstructions of the specimen by stacking images?
Confocal Scanning Microscope
What microscope uses a beam of electrons rather than light?
Transmission Electron Microscope
Name the steps to prepare tissues for observation under a microscope.
1) Fixing 2) Dehydration 3) Removal of alcohol 4) Embedding
______ prevents further deterioration of the tissue specimen and helps to harden the tissue prior to embedding and sectioning.
Fixing
One of the most widely used fixing agents is called…
Formalin
_____ fixatives fix chromatin, nucleoli, and spindle fibers but not mitochondria or nucleoplasm. Give examples.
Acid; Carnoy’s fluid, Zenker’s fluid, Bouin’s fluid
Type of acid fixative; Mixture of alcohol, chloroform, and glacial acetic acid. Useful for preserving glycogen in animal tissues.
Carnoy’s fluid
Type of acid fixative; Contains potassium dichromate, mercuric chloride, and glacial acetic acid. Useful for sharp histological details, but must be washed carefully to prevent black crystals.
Zenker’s fluid
Type acid fixative; Contains picric acid, formalin, and glacial acetic acid. Used generally and gives good cytological detail.
Bouin’s fluid
_____ fixatives can be used to fix tissues where mitochondrial staining is desired. In this procedure, chromatin is dissolved.
Basic
Type of basic fixative. Contains potassium dichromate, ammonium dichromate, copper sulfate, and distilled water. Requires a long fixing time (2 days) and washing under running water.
Zirkle-Erliki fixative
Because the tissue sample will eventually be embedded and infiltrated with a hydrophobic material (usually paraffin), all the water must be removed from the tissue in a process called…
Dehydration (use ethanol)
_____ consists of replacing the alcohol with an agent such as xylene or cedar oil. This makes tissues more transparent.
Clearing
In embedding, the tissue is moved through several melted ____ baths.
Paraffin (waxy substance)
What are the fixatives used for TEM?
Gluteraldehyde (preserves proteins by cross-linking them); Osmium tetroxide (Reacts with lipids and imparts electron density to cell and tissue structures)
What substance is used in TEM for embedding? How do the tissue samples differ in TEM due to this?
Monomeric resin (epoxy resin); Tissue samples are typically much smaller, less than 1 mm3
It is easier to lay tissue specimen in order with a (hand-held/rotary) microtome.
Hand-held
Because animal tissues are colorless, and to help them see better or tell us more about the tissue, scientists will ____ the tissue.
Stain
To prepare for staining a tissue, _____ is removed by using _____.
Paraffin; Xylene
Stains routinely used that display structural features are…
H and E (hematoxylin and eosin)
What stains are used specifically to reveal elastic material?
Orcein and resorcin fuchsin stains
What stain is useful to show reticular fibers and basement membranes?
Silver impregnation
Fat-soluble stains are used to demonstrate lipids. An example of this stain is…
Sudans
______ dyes for staining react with the anionic groups of tissue components such as phosphate groups, sulfate groups, and carboxyl groups. Give examples of these dyes. (High pH)
Basic; Methyl Green, Methylene Blue, Pyronine G, Toluidine Blue
_____ dyes for staining bind to tissue components by forming electrostatic linkages with cationic groups such as the amino groups of proteins. Give examples of these dyes. (Low pH)
Acidic; Acid fuchsin; Aniline blue, Eosin, Orange G
The phenomenon whereby a dye changes color after reacting with a tissue component is called…
Metachromasia
An example of a metachromatic stain is…
Toluidine blue; Appears blue but can stain red-purple
Histochemistry is the study of the _______ of cells and tissues.
Chemistry
_________ can be used to study the presence of specific tissue constituents (antigens) by using monoclonal antibodies.
Immunocytochemistry
Schiff reagent reactions are dependent on the formation of (aldehyde/ketone) groups following exposure to HCl or periodic acid. This is a type of histochemical staining technique.
Aldehyde
Name the 2 types of Schiff reagent reactions:
Fuelgen reaction and Period acid-Schiff reaction (PAS)
Mild hydrolysis with HCl exposes aldehyde groups on deoxyribose and the Schiff reagent reacts with the aldehyde groups to form a deep-pinkish color. What reaction is occurring?
Fuelgen reaction
Periodic acid is used to cleave bonds between adjacent carbons of carbohydrates and form aldehyde groups and Schiff reagent reacts with aldehyde groups to form a deep-pinkish color. What reaction is occurring?
Periodic acid-Schiff reaction (PAS)
The (apical/basolateral) domain are the surfaces of the cell in contact with a lumen or external environment. Contains surface modifications such as cilia or microvilli.
Apical
The (apical/basolateral) domain are the surfaces of cells that are locked together by special junctional complexes with neighboring cells as well as the surface opposite the (apical/basolateral) domain. In contact with basement membrane and surrounding cells.
Basolateral; Apical
T/F – Epithelial tissues are avascular and innervated.
True
The (endoderm/ectoderm/mesoderm) include the skin epidermis and glands.
Ectoderm
The (endoderm/ectoderm/mesoderm) include the lining of the gastrointestinal tract, including glands.
Endoderm
The (endoderm/ectoderm/mesoderm) include the lining of blood vessels, mesothelium, and Bowman’s capsule.
Mesoderm
Epithelial tissues sit on top of what membrane?
Basement
What are the 2 components of the basement membrane?
Basal lamina and reticular lamina
_______ and ______ are 2 special types of epithelial tissue.
Pseudostratified and Transitional
When the epithelium appears stratified, but all cells are in contact with the basal lamina, it’s called….
Pseudostratified
Epithelium from the skin is usually (heavily/lightly) keratinized.
Heavily
Epithelium from the vagina and esophagus is usually (heavily/lightly) keratinized.
Lightly
All cells in this epithelium are in contact with the basal lamina, but the dome-shaped surface cells and location of the nuclei make it appear stratified.
Transitional
What type of epithelial tissue is found in vessels, lining lumina of ducts, walls of alveoli, Bowman’s capsules, and inner surfaces of membranous labyrinth and tympanic membrane?
Simple squamous
What type of epithelial tissue is found on the surface of ovaries, pigmented epithelium of retina, kidney tubules (Microvilli - brush border), gland and ducts, terminal bronchioles, choroid plexus, and anterior capsule of lens of eye?
Simple cuboidal
What type of epithelial tissue is (ciliated/non-ciliated) and found in upper respiratory tract, uterine tubes, uterus, paranasal sinuses, and central canal of spinal cord?
Ciliated simple columnar
What type of epithelium tissue is (ciliated/non-ciliated) and found in digestive tract beginning with the cardia of the stomach, gall bladder, and in parts of the excretory ducts of glands?
Non-ciliated simple columnar
Intestinal cells have (cilia/microvilli) on the apical surface of their (simple/stratified) columnar epithelium.
Microvilli; Simple
This type of epithelial tissue is seldom found but may occur in small areas of anal mucosa, large excretory ducts of some glands, and part of the male urethra.
Stratified cuboidal
This type of epithelium is seldom found but may occur in the ducts of adult sweat glands, fornix of the conjunctiva of the eye, parts of the male reproductive/urinary tract, the pharynx, and the epiglottis.
Stratified columnar
What is the difference between microvilli and stereocilia?
They are similar, but stereocilia are longer and are often branched.
This type of epithelium is found in the trachea (ciliated), and in the epididymis (stereocilia).
Pseudostratified
This type of epithelium is found in the urinary system, also referred to as urothelium.
Transitional
Epithelium tissue either functions to _____ & line or to be _____.
Cover; Glandular
Epithelial tissue can have either ____ or ____ barriers to maintain concentration differences.
Tight; Leaky
Microvilli are finger-like projections of the apical membrane that are (motile/non-motile).
Non-motile
The main purpose of the brush border formed by microvilli is to…
increase surface area for absorption
Microvilli is made of an _____ filament core and extends into the ______ web (a network of cytoskeletal proteins under apical membrane of the cell).
Actin; Terminal
Cilium is (motile/non-motile).
Motile
Cilium has ___ peripheral doublets and a central pair of microtubules.
9
The peripheral doublets within cilium contain an ____ and ____ tubule.
Alpha; Beta
Alpha tubules in cilium contain ___ protofilaments, ____ spokes (extending to sheath around central pair of microtubules), and pairs of ____ arms projecting to Beta unit of next doublet.
13; radial; dynein
The central pair of microtubules in cilium are composed of ___ protofilaments each.
13
Beta tubules in cilium contain ___ protofilaments.
10-11
The cell membrane is made of a ______ bilayer.
Phospholipid
The phospholipid bilayer consists of (hydrophobic/hydrophilic) heads and (hydrophobic/hydrophilic) tails.
Hydrophilic; Hydrophobic
These are small patches of cholesterol and sphingolipids in the cell membrane that compartmentalize cellular processes by serving as organizing centers for assembly of signaling molecules, influencing membrane fluidity, membrane protein trafficking, and regulating neurotransmission and receptor trafficking.
Lipid rafts
_______ is not an integral part of the membrane. It protects the cell from ionic and mechanical stress, serves as a barrier against microorganisms, and is involved in cell-to-cell interactions.
Glycocalyx
These proteins can be removed more easily than integral proteins and are found on both the outer and inner leaflets of the cell membrane, facing either the extra or intracellular fluid.
Peripheral proteins
These proteins are embedded within the cell membrane and span the lipid bilayer one or more times or are anchored to the bilayer but do not fully pass through it.
Integral proteins
These are a type of integral protein that pass completely through both phospholipid layers of the membrane. Typically serve as channel and transporter proteins.
Transmembrane proteins
This is the movement of particles from high to low concentration with no ATP and no transport molecules.
Diffusion
This is a type of diffusion where a solvent (water) is diffused across a semipermeable membrane from high to low concentration with no ATP and no transport molecules.
Osmosis
A type of diffusion from high to low concentration that requires transport molecules but not ATP.
Facilitated diffusion
Movement against a concentration gradient that requires energy and transport molecules.
Active transport
A type of transport protein that carries a single molecule or ion unidirectionally.
Unitransporter
A type of transport protein that is a co-transporter and carries 2 molecules or ions simultaneously or sequentially in the same direction.
Symporter
A type of transport protein that is a co-transporter and carries 2 molecules or ions simultaneously or sequentially in opposite directions.
Anitporter
The basal lamina is produced by the ______.
Epithelium
The reticular lamina is produced by the ______.
Connective tissue
List the 5 components of the basal lamina:
1) Laminin 2) Fibronectin 3) Type IV collagen 4) Entactin (nidogen) 5) Proteoglycans
What type of collagen is associated with the basal lamina?
Type IV, produced by epithelial cells.
The major component of the basal lamina is the…
Laminin
Laminin has binding sites for all other components of the basal lamina and consists 3 chains called ____, ____ and ____.
Alpha, Beta, and Gamma
Fibronectin is a protein made up of 2 _______ chains cross-linked by disulfide bonds.
Polypeptide
The (cellular/plasma) form of fibronectin is produced by fibroblasts and part of the extracellular matrix
Cellular
The (cellular/plasma) form of fibronectin is secreted into the bloodstream by hepatocytes.
Plasma
Fibronectin has binding sites for….
1) Heparin (proteoglycan) 2) Integrins 3) Collagen 4) Fibrin
What does CAM stand for?
Cell Adhesion Molecule
Depending on their need, CAMs can be dependent or independent on…
Calcium
Calcium-dependent CAMs are…
Cadherins and Selectins
Calcium-independent CAMs are…
Integrins and Immunoglobulin superfamily molecules
Cadherins (calcium-dependent CAMs) can be _______ or _______.
Classical or Nonclassical
Classical cadherins are major components in calcium-mediated adherent junctions. Typically form cis- and trans- homophilic dimers. The 3 types are…
1) E-cadherins - found in epithelial tissues 2) N-cadherins - found in nerve cells 3) P-cadherins - found in the placenta
Nonclassical cadherins include ______ and _____. They are found in desmosomes (macula adherens).
Desmocollins and desmogleins
What are the most common type of cadherins? Where are they found?
E-cadherins; Found at tip of extracellular end of cadherin molecule
Loss of what type of CAM is associated with invasive behavior of tumor cells?
E-cadherins
These are small proteins that link the cytoplasmic end of a cadherin with cytoplasmic actin.
Catenins
E-cadherins form dimers via a HVA binding face. HVA stands for…
Histidine-Valine-Alanine sequence
______ are a major interface between the cadherins that hold adjacent cells together and the actin cytoskeleton of those cells.
Catenins
The alpha form of catenins bind directly to the ________.
Cytoplasmic actin
The beta form of catenins attach to the cytoplasmic end of a _______ , serve as a ______ cofactor, and is also attached to the _____ catenin.
Cadherin; transcription; alpha
A type of calcium-dependent CAM that binds to carbohydrates and are involved in the movement of leukocytes from blood to tissues (extravasation).
Selectins
At the extracellular end of selectins, there is a binding site for carbohydrates called the…
Carbohydrate-recognition domain (CRD)
_______ -binding sites are found near the CRD in selectins.
Calcium
There are 3 classes of selectins, these are…
1) P-selectins – associated with platelets 2) E-selectins – associated with activated endothelial cells 3) L-selectins – associated with leukocytes
These calcium-independent CAMs are glycoproteins that are mainly involved in cell-extracellular matrix interactions.
Integrins
Integrins consist of 2 subunits, ____ and ____.
Alpha and beta
Integrins bind to both the _________ and the ______.
Extracellular matrix; cytoskeleton
Extracellular domains of integrins bind to molecules in the extracellular matrix such as _______ and ______.
Fibronectin and laminin
Integrins interact with the ______ sequence in fibronectin and laminin.
RGD (Arg-Gly-Asp)
The 3 things laminin and fibronectin in the basement membrane interact with are…
1) Collagen (including type IV) 2) Heparan sulfate proteoglycans 3) Entactin (nidogen)
In hemidesmosomes, integrins link the basal domain of cells to the extracellular matrix via the intracellular ________.
Tonofilaments
Members of this family possess an extracellular segment with one or more folded domains characteristic of immunoglobulins.
Immunoglobulin Superfamily
Members of the Ig-Superfamily include…
N-CAM – neural adhesion molecules I-CAM 1 and I-CAM 2 – intercellular adhesion molecules
There are 3 categories of junctional complexes, these are…
1) Adherens 2) Occludens 3) Gap junctions
This junctional complex is found on the basolateral surfaces of epithelial cells. They anchor cells together and reinforce the physical integrity of tissues and cells that make up tissues.
Adherens
This junctional complex establishes an impermeable barrier between adjacent cells, especially epithelial cells. This prevents paracellular transport and maintains concentration differences between environments on either side of epithelial sheets.
Occludens
This junctional complex is composed of molecular pores that enable cells to rapidly exchange ions and small molecules that help coordinate activities among the cells that make up the tissue.
Gap junctions
This junction can be either adherens or occludens variety. They travel all the way around the circumference of the cell and link all neighboring cells to the central cell. Sometimes referred to as belt-like complexes.
Zonula
This is a “spot” or snap-like junction. They are of adherens variety and often referred to as desmosomes or hemidesmosomes.
Macula
Desmosomes are associated with the (lateral/basal) domain of epithelial cells.
Lateral
Hemidesmosomes are associated with the (lateral/basal) domain of epithelial cells.
Basal
These anchoring junctions are characterized by intercellular spaces which are filled with cadherin proteins.
Adherens
The cadherin proteins filling the intercellular spaces of adherens are called…
Desmogleins and desmocollins
Desmoglein 1 and 2 are found in the ______.
Epidermis
Autoantibodies to desmoglein 1 cause a loss of adhesion of keratinocytes in the superficial layers of the epidermis and cause…
Pemphigus foliaceus (a blistering disease)
The cadherin proteins associated with adherens are anchored to cytoplasmic plaques containing…
Desmoplakin and plakoglobin
Zonula adherens are associated with _____ microfilaments.
Actin
Macula adherens are associated with _______ filaments (tonofilaments).
Intermediate
The associations of zonula adherens with actin microfilaments and macula adherens with intermediate filaments are mediated by interactions with ______ and _____ which are cadherins.
Desmocollins and desmogleins
A ____ ____ (tight junction) is a belt-like occluding junction.
Zonula occludens
Occluding junctions provide a barrier against the paracellular transport pathway whereby _____ and ____ are transported from one side of an epithelial barrier to the opposite side by passing between the cells.
Solutes and fluids
These are communicating junctions that allow cells to directly communicate.
Gap junctions
Gap junctions are composed of ________.
Connexons
Each connexon of a gap junction consist of ___ connexins, forming a _______ structure with a hollow center.
6; hexagonal
Connexons are often clustered into _____ and facilitate movement of molecules up to ____ in diameter.
Patches; 1.2 nm
When calcium concentrations are high, gap junctions will (close/open).
Close
Gap junctions are responsible for _____ and _____ coupling.
Chemical and electrical
Junctional complexes are associated with which cellular domains? A. Apical B. Basolateral C. Basal Only D. Lateral Only
B. Basolateral
Transitional epithelium is associated with which of the following systems? A. Respiratory B. Lymphatic C. Cardiovascular D. Urinary
D. Urinary
Although not common, stratified cuboidal epithelium may be found in which of the following areas? A. Vaginal epithelium B. Part of the male urethra C. Urinary Bladder D. Kidney tubules
B. Part of the male urethra
Lightly keratinized stratified squamous epithelium is characteristic of which of the following locations? A. Vaginal epithelium B. Part of male urethra C. Urinary Bladder D. Kidney tubules
A. Vaginal epithelium
The basal lamina is associated with which type of collagen? A. Type I B. Type II C. Type IV D. Type VII
Type IV
Which of the following types of cell adhesion molecules is associated with zonula occludens and desmosomes. A. Cadherins B. Integrins C. Selectins D. Immunoglobulin superfamily
A. Cadherins
Which of the following are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and the cells that make up the tissues? A. Zonula adherens B. Zonula occludens C. Hemidesmosomes D. Connexons
A. Zonula adherens
The extracellular domains of which of the following bind to molecules in the extracellular matrix such as fibronectin and laminin? A. Cadherins B. Integrins C. Selectins D. Immunoglobulin superfamily
B. Integrins
Which of the following are molecular complexes that anchor cells together and reinforce the physical integrity of tissues and the cells that make up the tissues? A. Zonula adherens B. Zonula occludens C. Hemidesmosomes D. Connexons
A. Zonula adherens
Which of the following are molecular complexes that primarily serve to prevent paracellular transport? A. Zonula adherens B. Zonula occludens C. Hemidesmosomes D. Connexons
B. Zonula occludens
Which of the following are only associated with the basal domain? A. Zonula adherens B. Zonula occludens C. Hemidesmosomes D. Desmosomes
C. Hemidesmosomes
The cytoskeleton is made up of three specific kinds of protein structures called…
1) Microfilaments (actin)
2) Intermediate filaments
3) Microtubules
These are part of the cytoskeleton, are 7 nm thick, organized into bundles and 3D networks, and bind to specific transmembrane proteins either directly or indirectly.
Actin microfilaments
Actin microfilaments exist as monomers (__-actin) and long chains (__-actin).
G-actin; F-actin
What are the 3 major varieties of actin microfilaments and are they found in muscle tissue or not?
1) alpha-actin (found in muscle tissue)
2) beta-actin (non-muscle actin)
3) gamma-actin (non-muscle actin)
Each actin monomer (G-actin) has a binding site for ____, which binds tightly to G-actin. Each of these monomers can bind tightly with two other actin monomers to form filamentou actin (F-actin). All of these actin monomer are oriented in the same direction, therefore the actin filaments display _____.
ATP; Polarity
The first step in actin polymerization is nucleation. A trimer is formed then additional actin monomers can be added to either end. ____-actin associates with the growing (plus or barbed) ends.
ATP
This drug affects actin polymerization by binding to barbed ends and blocking elongation. It can inhibit movements such as cell division.
Cytochalasins
This drug affects actin polymerization by binding to actin filaments and preventing dissociation. It can be labeled with fluorescent dyes to allow visualization of actin filaments.
Phalloidin
T/F. Actin structure is very similar in all cells, therefore making the diversity of its functions based on actin-binding proteins rather than the actin itself.
True
This actin-binding protein is found in the RBCs and binds cortical cytoskeleton to the plasma membrane.
Spectrin
This actin-binding protein solely binds cortical cytoskeleton to the plasma membrane.
Dystrophin
These actin-binding proteins act as cross-links in microvilli.
Villin and Fimbrin
This actin-binding protein cross-links stress fibers and connects actin to protein-plasma membrane complex complexes.
alpha-Actinin
This actin-binding protein cross-links actin at wide angles to form screen-like gels.
Filamin
This actin-binding molecule controls treadmilling by triggering depolymerization of ADP-bound actin ate the minus end.
Cofilin
This actin-binding molecule controls treadmilling by initiating growth of F-actin from sides of existing filament, which causes branching.
Arp2/3
This actin-binding molecule controls treadmilling by preventing depolymerization by binding to actin filaments.
Phalloidin
This actin-binding molecule controls treadmilling by binding to G-actin and inducing F-actin depolymerization.
Latrunculins
This actin-binding molecule controls treadmilling by capturing actin monomers and prevents monomers from being polymerized.
Thymosin
This actin-binding molecule controls treadmilling by binding to actin monomers and preventing them from being polymerized. It facilitates the exchange of bound ADP for ATP, which favors polymerization. (*Only ATP-actin monomers can be assembled into F-actin)
Profilin
This actin-binding molecule controls treadmilling by desabilizing F-actin and caps actin filaments, preventing loss and addition of G-actin. In presence of Calcium ion, it fragments actin filament and remains bound to the plus end.
Gelsolin
This part of the cytoskeleton is 8-10 nm thick, abundant in cells subject to mechanical stress, and provide tensile strength in cells such as neurons and muscles. They also strengthen epithelial cells as desmosomes and hemidesmosomes.
Intermediate filaments
All intermediate filaments have a common monomer consisting of a central alpha-helical rod flanked by ____ and ____ domains which determine the specific functions of the filament.
Head; Tail
__________ filaments form a cytoplasmic network in most cells and associate with other cytoskeletal elements to form a scaffolding that organizes the internal structure of the cell.
Intermediate
This part of the cytoskeleton is 25 nm thick, and is composed of tubulin dimers.
Microtubules
In microtubules, the tubulin dimers are made of an _____ unit and a _____ unit. Their protofilaments are longitudinal rows of these tubulin dimers.
Alpha; Beta
Microtubles consist of ___ protofilaments arranged parallel to form a cylinder with a hollow core. The protofilaments have fast-growing ___ end and slow-growing ___ end.
13; Plus; Minus
Tubulin dimers with ____ bound to the __-tubulin associate with the growing end. The plus end grows more rapidly than the minus end in the presence of low calcium ion concentration.
GTP; Beta
After polymerization of the tubulin dimer, GTP is hydrolyzed to ___ and the tubulin is less stable. Dimers at the minus end dissociate.
GDP
In microtubles, at high concentrations of tubulin-GTP the dimers are added (faster/slower) than GTP is hydrolyzed, making the microtubule (grow/dissociate).
Faster; Grow
In microtubules, at low concentrations of GTP, the GTP at the plus end is _________ and dimers are lost.
Hydrolyzed
This structure functions in cell movement, support and strength for the cell, phagocytosis, mitotic spindle formation, cytokinesis, cell-to-cell and cell-to-extracellular matrix adherence, and changes in cell shape.
Cytoskeleton
This type of gland includes salivary, mammary, sweat, sebaceous, liver, and pancreas. It secretes its product via a duct derived from the original connection to the epithelial layer.
Exocrine gland
This type of gland includes pituitary, thyroid, pineal, parathyroids, adrenals, gonads, liver, and pancreas. It secretes its product (a hormone) into surrounding blood vessels (no duct).
Endocrine gland
A gland is said to be ______ if the secretion affects neighboring cells (i.e., growth factors).
Paracrine
A gland is said to be _____ if the secretion affects the cell that released the secretory product.
Autocrine
Some examples (multicellular/unicellular) glands are goblet cells of intestine and trachea (exocrine), mucous cells of stomach (exocrine), and enteroendocrine cells (endocrine).
Unicellular
(Simple/Compound) multicellular glands exhibit ductal branching.
Compound
This type of secretion is considered watery, and enzyme-filled. An example is the parotid salivary gland.
Serous
This type of secretion is thick and mucin-containing.
Mucous
This type of secretion is a mix of ______ and ______. An example is the submandibular and sublingual glands.
Serous; Mucous
In this mechanism for secretion, the secretory product is typically stored in membrane-bound vesicles and the cytoplasm/cell membrane is retrieved in an exocytosis/endocytosis cycle (this includes most glands).
Merocrine (eccrine)
In this mechanism of secretion, the apical cytoplasm is released along with the secretory product. An example is the axillary sweat glands.
Apocrine
In this mechanism of secretion, the entire cell is released as part of the secretory product. An example is the sebaceous glands.
Holocrine
A compound gland is a multicellular gland divided into subunits called ______. Each of these is equivalent to a simple branched gland.
Lobules
The components of the gland derived from epithelium (secretory units and ducts) comprise the ________.
Parenchyma
The septa, which divides the gland into lobules and lobes, as well as the capsule that surrounds the entire gland is collectively called the…
Stroma
A (lobe/lobule) is a subdivision of a (lobe/lobule).
Lobule; Lobe
_____ are the secretory components of a lobule. They can be serous, mucous, or sero-mucous (mixed). The basement membrane covers the outer surface of this and myoepithelial cells are found between the basment membrane and secretory cells.
Acini (Acinus)
_________ ducts are ducts that lie within a lobule. There are 2 types of this duct, which are:
Intralobular; Intercalated ducts; Striated duct
This type of duct is a form of intralobular duct. It drains the secretory acini and is lined by simple squamous epithelium transitioning to low cuboidal epithelium. It’s involved in bicarbonate/chloride ion exchange.
Intercalated ducts
This type of duct is a form of intralobular duct. It’s lined by cuboidal epithelium transitioning to columnar epithelium with basal striations (for active transport). It actively reabsorbs sodium ions; passively reabsorbs chloride ions; and aactively secretes potassium ions.
Striated duct
This type of duct is formed by the confluence of two or more striated ducts and are found in the septae between adjacent lobules. These ducts are line with pseudostratified columnar epithelium.
Interlobular ducts
This type of duct is formed by the confluence of two or more intralobular ducts. They are lined with stratified columnar epithelium.
Lobar ducts
List the minor salivary glands:
1) Von Ebner’s glands
2) Labial glands
3) Palatal glands
4) Buccal glands
**These keep surface of oral cavity moist
List the major salivary glands:
1) Parotid glands
2) Submandibular glands
3) Sublingual glands
The parotid glands (salivary) are composed of only ______ acini.
Serous
The submandibular glands (salivary) are mixed glands with both ______ and ______ acini, but the ______ acini are predominant. These form a crescent-shaped configuration around the mucous acini; and are called serous _______.
Mucous; Serous; Serous; Demilunes
The sublingual glands (salivary) are mixed glands, containing both _______ and ______ acini, but the _______ acini are predominant.
Serous; Mucous; Mucous
In _______ connective tissue, both collagen and elastic fibers are present and arranged in a very loose, random fashion.
Loose
In ________ connective tissue, collagen fibers predominate. Can be regular or irregular.
Dense
This type of connective tissue is made predominately of reticular fibers.
Reticular
This type of connective tissue is made predominately from elastic fibers.
Elastic
If fibers are arranged tightly and parallel, then it is…
Dense regular
If fibers are arranged tightly and randomly, then it is…
Dense irregular
Embryonic connective tissue is also known as…
Mesenchyme
The connective tissue found within the umbilical cord is called…
Wharton’s Jelly
This type of connective tissue is found in tendons and ligaments.
Dense regular
This type of connective tissue is found in fascia, submucosa of GI tract, and in dermis of integument.
Dense irregular
This type of connective tissue is found primarily with lymphatic tissue.
Reticular
This type of connective tissue is associated with walls of blood vessels.
Elastic
What are the “special” classes of connective tissue? (4)
1) Adipose
2) Cartilage
3) Blood
4) Bone
This type of connective tissue is type of adipocyte and is unilocular.
White fat
This type of connective tissue is an adipocyte and contains numerous smaller lipid droplets. Multilocular, has slightly more cytoplasm, and abundant in mitochondria which gives them their color.
Brown fat
The connective tissue matrix is composed of ______ fibers (most abundant), _____ fibers, ______ fibers, and _______ _______ which is composed of glycosaminoglycans and glycoproteins.
Collagen; Reticular; Elastic; Ground substance
Type I collagen is synthesized as a ___________. This sequence is cleaved after translocation of the polypeptide into the endoplasmic reticulum (ER) lumen of the fibroblast. Once here, it is called a ________ and is secreted by the fibroblast into the extracellular matrix.
Prepropeptide; Propeptide (Procollagen)
The procollagen molecule has terminal (helical/non-helical) ends that prevent polymerization. These ends are cleaved by ________ in order to allow polymerization to occur. Once these ends are cleaved, the molecule is now referred to as _________.
Non-helical; Peptidases; Tropocollagen
Tropocollagen monomers spontaneously assemble into staggered array to form _______ fibers, with the characteristic banded pattern. The assembled polymer is called _______.
Collagen; Collagen
In what cells can Type I collagen be synthesized?
Fibroblasts, Chondroblasts, Osteoblasts, and Odontoblasts
In what cells can elastic fibers be synthesized?
Fibroblasts or smooth muscle cells
Elastin is synthesized as a _________ and is secreted from the fibroblast as a _________. After this, it’s converted to _________ by extracellular enzymes, also secreted by the fibroblast.
Prepropeptide; Propeptide; Tropoelastin
In the synthesis of elastic fibers, _______ monomers are assembled into amorphous fibers or sheets with the aid of several types of _______. The finished product are the elastic fibers.
Tropoelastin; Fibrillins
________________ (GAGs) are large, negatively charged linear polymers (polydisaccharides) consisting of repeated disaccharide units.
Glycosaminoglycans
Along with glycoproteins, GAGs form most of the __________ substances of connective tissue.
Amorphous
This type of GAG is the largest, lacks a sulfate group, and is present in nearly all connective tissues. Serves as a lubricant in synovial fluids.
Hyaluronic acid
Types of glycoproteins, which work primarily as “connecting” type molecules, are…
Fibronectin; Chondronectin; Laminin
These are the principal cell types found in connective tissue. They are also the most numerous found in connective tissue. They work to secret and maintain CT.
Fibroblasts and Fibrocytes
Some other cell residents of fibrous CT includes: (3)
Macrophages; Mast cells; Plasma cells
This type of cell within fibrous CT can be irregular in shape with blunt processes. It’s capable of amoeboid movement and is part of mononuclear phagocytic system. Can fuse with others of its kind to form large multinucleated phagocytic foreign body giant cells.
Macrophages
This type of cell within fibrous CT is irregularly oval in outline. It’s a small spherical/ovoid nuclei often masked by membrane-bound granules, which are metachromatic when stained with Toluidine blue. (Looks grainy)
Mast cells
This type of cell within fibrous CT (although rare) is activated by B lymphocytes. They resemble lymphocytes but are larger and have a large pale nuclei with “clock-face” distribution of heterochromatin.
Plasma cells