Term
| How many cells are in the human body? |
|
Definition
|
|
Term
| 25 trillion cells are this type |
|
Definition
|
|
Term
| What does each cell contain? |
|
Definition
Organelles
Inclusions
Cytoplasmic matric |
|
|
Term
|
Definition
Little Organs
Structural elements that confer functional attributes to the cell and may be membranous or non-membranous. |
|
|
Term
| Cell mitochondrial levels |
|
Definition
| May be 35% of a cardiac muscle cell but is totally absent in erythrocytes. |
|
|
Term
| Cytoplasm v Cytoplasmic matrix |
|
Definition
Cytoplasm - Part of cell external to the nucleus that suspends organelles and inclusions
Cytoplasmic matrix (cytosol) - The portion of the cytoplasm devoid of organelles and inclusions. Contains numerous molecules and electrolytes. |
|
|
Term
|
Definition
| Found in the cytosol of various cell types where it functions to transport fuel in cells exhibiting high energy requirements (cardiac and skeletal muscle cells and nerve cells). In response to insult, damaged cells release CK into the blood where it can then be assayed as a diagnostic marker, for example, of myocardial infarction, muscular dystrophy, and muscle inflammation. |
|
|
Term
|
Definition
Discrete accumulations of end products of metabolic activity and are considered nonliving.
Stored foods, Pigments, and crytalline in composition. |
|
|
Term
|
Definition
|
|
Term
|
Definition
In cytoplasm as clusters or discrete electron-dense particles in electron micrographs.
Abundant in hepatocytes and striated muscle cells.
Depot of energy reserve that can be deployed to meet energy shortage. |
|
|
Term
| Glycogen: Light microscopic level |
|
Definition
| Demonstrated by presence of magenta granulations in the cytoplasm as a result of employing the PAS reaction. |
|
|
Term
| Glycogen Storage diseases |
|
Definition
| Result in accumulation polysaccharides in the cytoplasmic matrix. |
|
|
Term
| Glycogen synthase deficiency (type 0) |
|
Definition
| Storage disorder that decreases cellular glycogen stores. |
|
|
Term
|
Definition
| Non-membrane buond and found in relative abundance in adipocytes, hepatocytes, muscle and steroid-secreting cells. Function as depots of energy and precursor molecules for synthesis of steroid hormones. |
|
|
Term
| Type 1a (Von Gierke Disease) |
|
Definition
Enzyme Defect: Glucose-6-phosphatase
Structural Changes: Liver enlargement, glycogen accumulation in cytoplasm and nucleus, kidney enlargement, glycogen accumulation in epithelial tubular cells
Clinical Features: Stunted growth, failure to thrive, hypoglycemia (may lead to convulsions), metabolic acidosis due to increased lactate, hyperlipidemia, elevated uric acid leading to gout in many patients, liver neoplasms, renal disfunction. |
|
|
Term
|
Definition
Enzyme Defect: Lysosomal alpha-1,4-glucosidase
Structural Changes: Liver and heart enlargement, Liver lysosomes expand with glycogen; in heart glycogen accumulates in sarcoplasm and lysosomes; skeletal muscle changes similar to that observed in heart
Clinical Features: Muscle weakness and decreased tone; cardiac failure; skeletal muscle atrophy; respiratory muscle weakness |
|
|
Term
| Type V (McArdle Syndrome) |
|
Definition
Enzyme Defect: Muscle phosphorylae
Structural Changes: Specific to skeletal muscle, subsarcolemmal accumulations of glycogen
Clinical Features: Cramping with strenuous exercise; exercise intolerance; myoglobin elevated with strenuous exercise; CK elevated; venous lactate does not increase with exercise. |
|
|
Term
| Lipid accumulation derangements |
|
Definition
| Fatty liver change as a result of alcohol abuse or nonalcoholic fatty liver disease |
|
|
Term
|
Definition
| Colored chemical substances that are found in the cytosol. Except melanin, not bound by a membrane. Non-membrane pigments include hemosiderin and lipofuscin. |
|
|
Term
|
Definition
Yellow-brown pigment that serves to store iron.
Normally found in small amounts in the macrophages of the spleen, liver, and red bone marrow as these professional phagocytic cells degrade erythrocytes. This degradation releases iron from Hb and binds to apoferritin (protein) in cytosol. Iron-apoferritin complex then forms ferritin micells that aggregate into hemosiderin granules. |
|
|
Term
|
Definition
| Iron load elevation that causes increased deposition of hemosiderin in tissues and organs. Seen with increased absorption of iron in diet, impaired use of iron by the body, hemolytic anemias, and repeated transfusions of blood. |
|
|
Term
|
Definition
| Disorder characterzed by a more severe accretion of iron due to a genetic defect causing excessive iron absorption or transfusion reaction |
|
|
Term
| Heart failure Cells (Damming of blood in pulmonary circulation) |
|
Definition
| Results in extravasation of blood into the alveoli where alveolar macrophages degrade the erythrocytes and accumulate iron as hemosiderin. Fluid accumulation in lungs and patient coughs sputum laden with macrophages well endowed with hemosiderin. When Prussin blue is applied to sputum sample, the iron is well demonstrated by appearing blue. Pathological observation is consistent with heart failure diagnosis. |
|
|
Term
| Three types of pigment melanin found in humans. |
|
Definition
Eumelanin
Phaeomelanin
Neuromelanin |
|
|
Term
|
Definition
| Brown-black pigment found in membrane-limited granules in the epidermiis and eye as the pigment layer of retina and pigmented epithelium of the ciliary body and iris. In skin, eumelanin occupies a supranuclear position (think of nuclear hat of eumelanin) in keratinocytes (principle cell type of epithilium). Protects genetic apparatus from potentially mutagenic effects of ultra-violet radiation. |
|
|
Term
|
Definition
Elevated in response to UV radiation.
Increased in Addison' disease in response to elevated adrenocorticotropin hormone.
Absent in albinos due to lack of tyrosinase, necessary enzyme for eumalanin and phaeomelanin production. |
|
|
Term
|
Definition
Yellow to red pigment. Found in skin and hair.
Responsible for tinting a pinkish red color, specifically responsible for red hair.
Not protective against ultraviolet radiation and may even become carcinogenesis in response to UV light. |
|
|
Term
|
Definition
Brown-black in color, limited by a membrane, and found in igmented, catecholaminergic neurons of four deep nuclei of brain.
Found in substantia nigra (black substance), locus coeruleus, dorsal motor nucleus of the vagus nerve, and the median raphe of the pons.
Substantia nigra and locus coeruleus are most pigmented.
Function may be neuroprotective against toxic metals and reactive oxygen species. |
|
|
Term
|
Definition
| Loss of neuromelanin-containing catecholaminergic neurons from the substantia nigra leads to depigmention of this deep brain structure. |
|
|
Term
| Lipofuscin (lipochrome or wear-and-tear pigment) |
|
Definition
| Brownish-yellow pigment that is an amalgam of lipids, metals, and organic molecules. Accumulates in long-lived cells, such as neurons and cardiac muscle cells, and hepatocytes. |
|
|
Term
|
Definition
Measure of cellular stress (free radical injury and lipid peroxidation)
Increased cellular deposition is seen in severe malnutrition and cachexic states associated with cancer. |
|
|
Term
|
Definition
| Discernible with light microscopy in specific cell types, such as Sertoli cells and interstitial cells (of Leydig) found in the testis). Inclusions not specifically confined to the cytoplasm as electron microscopy has revealed their presence in organelles. |
|
|
Term
| Cause of crystalline inclusions in organelles. |
|
Definition
| May be due to viral infections and mitochondrial myopathy. |
|
|
Term
|
Definition
| Structural elements that confer functional attributes to the cell and may be membranous and non-membranous. |
|
|
Term
|
Definition
Plasma membrane
Only visible as a trilaminar structure with electron microscopy.
Contains ampiphilic phospholipids, cholesterol, Lipid rafts, and proteins. |
|
|
Term
|
Definition
| Microdomains in membrane where sphingolipids and cholesterol and chiefly concentrated. Raft region is thick and unique causing certain proteins to aggregate. Raft microdomain is signalling platform. |
|
|
Term
| Lipid rafts: Clinical Relevance |
|
Definition
Cancer cell types exhibit greater concentrations of cholesterol which correlates with more lipid rafts.
Simvastatin has been shown to induce apoptosis of cancer cells by reducing raft formation. Down regulates cell survival signaling molecule, Akt. |
|
|
Term
|
Definition
Pheripheral: Attached ionically to extra-or cyto-side of plasmalemma. Can be removed with salt (ionic) solutions.
Integral: Partially embedded in membrane or extend across entire thickness. |
|
|
Term
|
Definition
| Occurs when normal prion protein (PrP) located on outer surface of plasmalemma of neurons is converted to abnormal variant. Cross-linked filaments resistant to proteolysis. Accelerates conversion of normal PrP to same form. Normal prion proteins have antioxidant function and may serve to establish long-term memory. |
|
|
Term
| Beta-amyloid precursor protein. |
|
Definition
| Transmembrane protein altered in Alzheimer's disease. Forms protein aggregate resistant to proteolysis. Important in neuronal migration during development, synaptic formation and repair,cell signaling, long-term potentiation of memory, and cell adhesion. |
|
|
Term
| Six Categories of integral proteins |
|
Definition
Receptors
Transporters
Pores or channels
Enzymes
Linkers
Junctional Proteins |
|
|
Term
|
Definition
| Allow a cell to respond to external signal. |
|
|
Term
|
Definition
Administered to dilate the pupil to aid in examining the fundus and retina.
Blocks acetylcholine from binding to its muscarinic cholinergic receptor on the sphincter muscle of the pupil causing it to dilate. |
|
|
Term
|
Definition
| Beta1-adrenergic antagonist. Dampens sympathetic drive to heart. Lowers arterial pressure by decreasing heart rate and contractility of the cardiac muscle. |
|
|
Term
|
Definition
Uniporters, symporters, or antiporters.
Passive or active |
|
|
Term
|
Definition
| K/Na pump is unable to maintain gradient across the cell membrane. increase in intracellular ionic concentrain pulls water into the cell by the process of osmosis resulting in cytoplasmic and organellar swelling. |
|
|
Term
| Multidrug resistance protein (type 1 and 2) |
|
Definition
| Found in various cell types (intestinal epithelial cell, hepatocytes, renal proximal convoluted tubule cells, and endothelial constituting blood-brain and blood-testis barrier) Transports substrates across the plasmalemma. |
|
|
Term
| Multidrug-resistance protein (MDR-1) and Clinical Correlations |
|
Definition
MDR-1 causes some cancer cells to be resistant to cytotoxic drugs. Overexpression of of MDR-1 transport proteins that pump cytotoxic agents out.
Drug avaiability. Overexpression in intestinal epihelial cells diminishes the absorption of pharmacological agents that are substrates for the transporter. Bioavailability may not reach therapeutic level.
Underexpresion enhances absorption of pharmacological agents that are substrates. Supratherapeutic plasma level of the drug may also be toxic.
Possible therapy in gene silencing through RNA interference and inhibitors of the protein. |
|
|
Term
| MDR-2 Protein: Clinical Correlations |
|
Definition
| Transports conjugated bilirubin into passageways called canaliculi. Protein defective in Dubin-Johnson syndrome. Affected have mildly elevated levels of direct bilirubin in blood. Microscopy reveals coarse pigment granules of epinephrine metabolites in the lysosomes of hepatocytes. Disease has a benign course and no treatment required. |
|
|
Term
|
Definition
| Allow passage of chemical substances across plasmalemma. |
|
|
Term
|
Definition
Protein channels for water and 12 isoforms exist. Aquaporin-2 expresed by renal collecting tubule cells for water reabsorption.
Vasopressin causes translocation of aquaorin protein channels into plsma membrane of tubule cell increasing movement of water across apical domain of tubule cells and into blood vascular system (reabsorption).
Nephrogenic Diabetes insipidus results when both aquaporin-2 genes are inactivated by mutations causing water to not be reabsorbed and eliminated excessively in urin. |
|
|
Term
|
Definition
| Autosomal recessive disease from mutation in CFTR. Channel for Cl- and other ion channels disrupted. Affected epithilial tissues in the airways, gi tract, and sweat gland have organ specific abnormal ion transport. Sweat glands secrete elevated Na+ and Cl- ions, Excess transport in lungs results in movement of water from mucus into cell creating thicker mucus that is harder to clear. |
|
|
Term
| Enzymes in plasmalemma of small intestine |
|
Definition
| Hydrolyze oligopeptides to amino acids and oligosaccharides into monosaccharides |
|
|
Term
|
Definition
| Unable to adequately digest lactose and may suffer from diarrhea, cramping, and gas when they ingest dairy products. |
|
|
Term
| GGTP or GGT (gamma-glutamyl transpeptidase) |
|
Definition
Released into blood from plasmalemmae of epithelial cells lining the bile duct in response to cellular injury caused by cholestasis (obstruction to bile flow)
GGTP found in other tissues so additional tests needed to confirm diagnosis |
|
|
Term
| Linker proteins of plasmalemma |
|
Definition
Adds structural support and allows response
Integrins, sarcoglycans, dystroglycans. |
|
|
Term
|
Definition
Links protein complex of sarcoglycans and dystroglycans to the actin cytoskeleton in muscle cells.
Mutated in DMD leading to degeration and loss of myocytes. |
|
|
Term
|
Definition
| Implicated in four different forms of limb-girdle muscular dystrophies. Mutations similary disrupt the interface leading to a severe course of Duchenne-like features. |
|
|
Term
|
Definition
Form connections between one cell and other cells.
Occludins, claudins, E-cadherin, desmocollin, desmoglein |
|
|
Term
| Carbohydrates of plasmalemma |
|
Definition
In the form of oligosaccharides and attached to membrane lipids and proteins forming glycolipids (only in cyto monolayer) and glycoproteins.
React with regulatory molecules, repel other negatively charged substances, and protection as some carbohydrate components participate in immune reactions. |
|
|
Term
|
Definition
| Glycolipid that serves as a cell receptor for the cholera toxin. Receptor concentrated on lipid rafts, Toxin bind to ganglioside GM1 and then ramps of cAMP synthesis leading to efflux of sodium and water into intestine. Diarrhea |
|
|
Term
| What to five distinct pathways of endocytosis require? |
|
Definition
Expenditure or energy
Ca 2+ |
|
|
Term
| Five distinct pathways of endocytosis |
|
Definition
Macropinocytosis
Clathrin-mediate endocytosis
Caveolae-mediated endocytosis
Nonclathrin/noncaveolin endocytosis
Phagocytosis |
|
|
Term
|
Definition
GTP fueled process that allows many cell types to uptake large volumes of extracellular fluid and solid cargo in large endocytotic vesicles called macropinosomes.
Created due to actin assembly causing protrusions of plasmalemma enriched with lipid rafts. Protrusions bend around extracellular fluid to form macropinosomes. General nutrient uptake.
Thyroid gland -> ingest thyroglobulin from colloid, internalize, and ingest in lysosome to release thyroid hormones.
Dendritic cells: immune surveillance
Pathogenic Bacteria: Stimulate macropinocytosis through release of toxins to escape targeting by phagocytic cells. |
|
|
Term
| Clathrin-mediated endocytosis |
|
Definition
Specific sites called coated pits. Pits coated with clathrin and associated proteins. Most stimulated by ligand-receptor interaction.
Also referred to as receptor-mediated endocytosis. |
|
|
Term
| Clathrin-mediated endocytosis: Purpose |
|
Definition
Ingest specific nutrients and regulate receptor density on the plasmalemma.
LDL: LDL's bind to LDL-receptors that aggregate in coated pit, cytoplasmic portion possesses a coated-pit binding site which anchors intermediary protein called daptin Ligand-receptor complex is formed, clathrin promotes invagination of plasmalemma and vesicle is pinched off by dynamin, a GTP-ase Results in formation of cytoplasmic clathrin-coated vesicle that sheds its clathrin coat and then fuses with other vesicles or is delivered to the endosomal compartment o fthe cell while disassembled clathrin is recyled to cytoplasmic side of the plasmalemma. |
|
|
Term
| Dominant intermediate Charcot-Tooth-Marie Neuropathy type B |
|
Definition
| Dynamin 2 Mutations leads to defects in clathrin-mediated endocytosis. Myelination of axons is dependent on dynamin 2 and clathrinmediated endocytosis perturbations impairs myelination. Disease is characterized by muscular atrophy, loss ot touch sensation predominately in the distal lower limbs, and foot drop. |
|
|
Term
|
Definition
AD disorder of absent or defective LDL receptors.
Complete Absence of LDL receptors
Defective transport between ER and Golgi apparatus. Transport may be completely or partially locked
Defective binding of LDL to recepto
Deficiency of LDL receptors ni coated pits.
Defective uncoupling of LDL from its receptor following internalization so recycling is abated.
Total cholesterol levels will range from 30 mg/dl to greater than 500 mg/dl.
Elevated levels accelerate development of atherosclerosis, subjecting patients to revascularization procedures. |
|
|
Term
| Clathrin-mediated endocytosis: Independent of ligand-receptor interaction |
|
Definition
| Synaptic transmission. Synaptic vesicles dock with plasmalemma and release neurotransmitter via exocytosis. Adds membrane to presynaptic terminal. Synaptic vesical discharges it contents and membrane is recycled to prevent accretion. Clathrin molecules will then cat the membrane to be retrieved through endocytosis. Once vesicle is internalized, it will be recharged with neurotransmitter. |
|
|
Term
| Caveolae-mediated endocytosis |
|
Definition
| In microdomains of plasmalemma. Enriched with cholesterol along with caveolin, a protein. caveolin binds to cholesterol and forms and stabilizes regions of plasmalemma. Cavelae gets flask-shaped invaginations and are numerous in endothelial cells (lining vascular structures) where they shuttle proteins and nutrients from blood to tissues. Endocytosis of caveolae requires actin microfilaments and the GTPase dynamin. Once internalized, the vesicles, termed caveosomes retain their caveolin coat unlike clathrin coated vesicles which become uncoated. |
|
|
Term
|
Definition
| Enters cells through endocytosis mediated by caveolae. SV 40 found in monkey species and used in polio vaccines. Exposed to US individuals and some tumor cells contain virus |
|
|
Term
| Nonclathrin/noncaveolin endocytosis |
|
Definition
| Occurs on lipid rafts May function to direct the secretory pathway. Sphingolipids are added to the lipid bilayer of secretory vesicle formed y Golgi.Sphingolipids then direct secretory vesicle to plasmalemma for exocytosis. Spingolipid-enriched bilayer of vesicle is incorporated into the plasmalemma. New lipid raft microdomains are determinant sites for nonclathrin/noncaveolin endocytosis as a means to recycle sphingolipids back to Golgi. |
|
|
Term
| Toxins that enter cells through the nonclathrin/noncaveolin pathway |
|
Definition
Chorea and Shiga
Toxins are also internalized by clathrin-mediated endocytosis. Only have ill effect through nonclathrin noncaveolin endocytosis |
|
|
Term
|
Definition
Internalization of large particles, pathogenic invaders, foregin objects, mediated by receptors. Activation of receptors -> rearrangement of cytoskeleton causing protrusions of plasmalemma to extend and engulf the offending agent.
Membrane-limited structure has been internalized, referred to as phagosome. Fated to lysosomal compartment of cell. |
|
|
