Exam 1 Flashcards
(115 cards)
1
Q
Importance of animal cadaver and dissection
A
To help students understand the 3D relationship of different anatomical structures and appreciate anatomical variations
2
Q
Historical aspects of animal and human cadaver dissection in science and medicine
A
Was expensive to obtain bodies for cadaver dissection, people would dig up graves or commit murder in order to sell bodies to medical schools, animals were often used if humans were not attainable
Anatomy Act of 1832 made this illegal, gave medical schools access to unclaimed corpses
3
Q
Applications of anatomy in biomedical sciences
A
Dissections, pro-sections, plastinated specimens, surgery, radiology, physical examination
4
Q
Topographic anatomy
A
Anatomic study based on regions, parts, or divisions of the body; emphasize relationships of various systemic structures
5
Q
Anatomical body planes
A
Dorsal/ventral, medial/lateral, cranial/caudal, rostral/caudal, proximal/distal, palmar/plantar, transverse/sagittal
6
Q
Relevance of enzymes in the body, organs, and as diagnostic tools
A
Biological catalysts that are normally proteins, primary amino acid sequence gives enzyme a tertiary structure and function
7
Q
Nomenclature of enzymes
A
EC number or add -ase
1. Oxidoreductases
2. Transferases
3. Hydrolases
4. Lyases
5. Isomerases
6. Ligases
8
Q
Nomenclature of enzymes
A
EC number or add -ase
1. Oxidoreductases
2. Transferases
3. Hydrolases
4. Lysases
5. Isomerases
6. Ligases
9
Q
Substrate specificity
A
Specificity is controlled by structure - the unique fit of substrate with enzyme controls the selectivity for substrate and product yield
Enzymes selectively recognize proper substrates over other molecules
Ex: Lock-and-key model and induced-fit model
10
Q
Cofactors and coenzymes
A
Metal ions - electrostatic bonds
Prosthetic groups - small organic molecules, permanently associated, covalent
Coenzymes - small organic molecules, water-soluble vitamins, non-covalent association/loosely bound
11
Q
Interactions of substrates or analogs with enzymes
A
Lower the activation energy
Act in very small quantities
Rate constants change but Keq remains the same
Smaller Km = tight binding
High Km = weak binding
Vmax = theoretical maximum rate, never actually reached
12
Q
Mechanisms for the control of enzyme-catalyzed reactions
A
Competitive inhibition: Vmax constant, Km increases
Non-competitive inhibition: Vmax decreases, Km constant
Allosteric regulation: enzymes situated at key steps in metabolic pathways are modulated by allosteric effectors that are usually produced elsewhere in the pathway; may be feed-forward activators or feedback inhibitors; usually SIGMOID
13
Q
Enzymes lower activation energy by…
A
Forming a highly-ordered substrate in their active site and decreasing translational motion
14
Q
Km =
A
[E][S] / [ES] = Kd
15
Q
Kcat =
A
Vmax / Et
16
Q
Phosphorylation of enzymes causes…
A
Activation/inactivation and covalent modification of the enzyme
17
Q
Principles of acids and bases
A
Acid: any base that can donate a proton
Base: any substance that can accept a proton
Most acids important to us physiologically are weak acids
18
Q
Weak acids commonly observed in animals
A
Volatile acid - metabolism; CO2
Non-volatile acid - fixed; H2SO4, phosphoric acid, HCl, lactic acid
19
Q
Henderson-Hasselbach equation
A
Calculates relationship between an acid’s pKa and the [A-] and [HA] at a given pH
Buffers can only be used reliably within a pH unit of their pKa
pH = pKa + log ([A-]/[HA])
20
Q
Sources of weak acids and bases in animals
A
Blood - carbonic acid and bicarbonate, plasma protein buffering
Lungs - CO2 and H2O to carbonic acid to H+ and bicarbonate
Weak acids - aspartic acid, glutamic acid
Weak bases - arginine, histidine, lysine
21
Q
Major tissue types
A
Connective
Epithelial
Muscle
Nervous
22
Q
Basic cell types
A
Germ
Muscle
Fat
Bone
Blood
Nerve
Epithelial
Immune
23
Q
Hollow organs
A
Organs with cavities for liquids and other materials to move through
Smooth muscle, vasculature, more surface area, nerves, and secretory epithelia
(Ex: stomach, intestines, bladder, etc.)
24
Q
Solid/planar organs
A
Dense with firm tissue texture and do not have cavities
Nerves, epithelium, muscle, adipocytes, blood supply, connective tissue
(Ex: kidney, liver, pancreas, breast, lung, etc.)
25
Relate cellular and molecular events to the manifestation of diseases
Mitosis: non-heritable mutations
Meiosis: heritable mutations
Changes in DNA sequence can alter proteins
Mutation types: missense, nonsense, frameshift, insertion/deletion of AA, deletion/insertion of large piece of DNA, repeated segments, single-nucleotide polymorphism (SNP)
Retrogenes: DNA copy of mRNA inserted somewhere new
26
Different patterns of inheritance
Autosomal dominant
Semi-dominant/co-dominant/additive
Autosomal recessive
X-linked
X-inactivation
Complex mode of inheritance
Loss or gain of function mutations
Epistasis
27
When is genetic testing appropriate?
To manage inherited diseases
Want to know how much more likely the animal is to get the disease if they carry the risk allele
28
Uses and limitations of PCR based testing
Used to determine specific genotype of animals, can be used to detect DNA of pathogens in samples from potentially infected animals
Extremely specific, do not test for all possible mutations in a gene or other genes
29
Uses and limitations of DNA testing
Breed-specific, only test for specific mutation that has been identified, NOT all possible mutations that could cause a similar disease
Mutation tests are ideal, checks for presence of mutated copy of gene
Marker tests have greater error rate, tests for a marker that is found to be inherited along with the disease phenotype
30
Steps involved in working through a clinical case
Signalment - name, age, sex, neuter status, breed
Presenting complaint(s)
History - recent and past pertinent
Physical examination
Problem list
Differential diagnoses
Plan
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DAMNITV scheme
Degenerative
Anomalous (congenital)
Metabolic
Neoplastic, nutritional
Inflammatory, infectious, immune-mediated, iatrogenic, idiopathic, inherited
Trauma, toxins
Vascular
32
Purpose of cell cycle and regulation
Accurate duplication of DNA and segregation of copies into 2 daughter cells, duration in each part of the cycle varies by cell type
S phase (synthesis), G2 (gap), M phase (mitosis), G1, G0 (quiescent)
Controlled by cyclin dependent kinases (Cdk) that phosphorylate proteins/prevent major cell cycle events and are regulated by cyclin
33
Structural and functional relationships within the nucleus
Nuclear envelope: lipid bilayer, separate cytoplasm from nucleus
Chromatin: euchromatin (uncoiled, relaxed) and heterochromatin (bound, dense)
Rough ER: captures select proteins from cytosol, covered in ribosomes (further processing, post-translational modifications)
34
Components and functions of the nucleolus
Not membrane bound, site of rRNA transcription, processing and ribosomal assembly
-Dense tubular component: nascent RNA (transcription)
-Granular component: site of assembly of pre-ribosomal subunits
-Fibrillar center: rRNA genes, RNA polymerase, signal recognition particle (SRP)
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G1-Cdk complex
Cyclin D
Cdk4, Cdk6
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G1/S-Cdk complex
cyclin E
Cdk2
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S-Cdk complex
cyclin A
Cdk2
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M-Cdk complex
cyclin B
Cdk1
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Transport of proteins into the nucleus depends on
a. protein size
b. nucleoporins
c. nuclear export signal, importin a/b, Ran-GTP
d. nuclear export signal
a. protein size
40
In the nucleolus, the fibril center contains
a. RNA polymerase, newly made rRNA
b. rRNA genes, RNA polymerase, pre-ribosomal subunits
c. newly made rRNA
a. RNA polymerase, newly made rRNA
41
The cell cycle is controlled by
a. internal and external factors
b. internal and external cues altering cyclin dependent kinase activity
c. time only
d. tumor suppressor genes
b. internal and external cues altering cyclin dependent kinase activity
42
Phosphorylation of Rb occurs by ___ and allows for ___.
a. Cdk4-cyclin D complex, transition into M phase
b. Cdk4-cyclin D complex, progression through checkpoint 1
c. Cyclin D, transition into S phase
d. Cdk2, transition into S phase
b. Cdk4-cyclin D complex, progression through checkpoint 1
43
Pelger-Huet anomaly resulting in hypomorphic nuclei in granulocytes is due to
a. mutations in p53
b. mutations in various tumor suppressor genes
c. Rb inactivation
d. mutations in lamins
d. mutations in lamins
44
Relationship between plasma membrane and membrane bound intracellular organelles
Membrane systems form enclosed compartments separate from the cytosolic compartment
Creates functionally specialized aqueous spaces within the cell that allow for biochemical reactions requiring very different conditions to occur
Membrane contains proteins to import/export specific metabolites
45
How proteins move through the rough endoplasmic reticulum and Golgi
SRP binds to ribosome to stop growth of protein, ribosome attaches to ER
Traffic from ER to the Golgi is regulated by vesicle coating with COP II, transit through the Golgi is regulated by COP I
46
Organization and function of the rough endoplasmic reticulum
Consists of stacks of flattened cisternae interconnected by portions of tubular rough ER surrounded by cytosol
Ribosomes present in linear array attached to membranes
Lumen or cisterna contains glycosylated polypeptides
47
Organization and function of the Golgi apparatus
Series of stacked and flattened cisternae and associated vesicles
Cis face: cisterna closest to ER, entry site of products derived from ER
Medial face: formed by stacked saccules where most glycosylation takes place
Trans face: closest to the apical domain, distribution or sorting site of products for transport to lysosomes or secretion (exocytosis)
48
Organization and function of lysosomes
Primary degradative compartments of the cell, involved in multiple physiological processes (cholesterol homeostasis, plasma membrane repair, bone/tissue remodeling, pathogen defense, cell death, cell signaling)
Contain large numbers of acid hydrolases, operate in a highly acidic environment
pH gradient maintained by ATP-dependent H+ pump
Mannose 6 phosphate receptors on endosomes to fuse with lysosomes
49
Organization and function of peroxisomes
Cellular detoxification
Proteins are targeted to the interior by targeting AA signals
Catalase decomposes H2O2 to H2O
Abundant in the liver (hepatocytes)
50
Lysosomal pH is maintained by
a. diffusion
b. ATP dependent H+ pump
c. mannose 6 phosphate
d. fusion with endoscope to become secondary lysosomes
b. ATP dependent H+ pump
51
The luminal compartment of a secretory vesicle becomes outer plasma membrane
a. true
b. false
a. true
52
Production of glycoproteins in the ER requires
a. signal peptide that is removed after binding the ribosome
b. transfer of sugar chains to specific residues on the protein
c. release of the protein
d. all of the above
d. all of the above
53
Proteins are transported from the ER to the
a. cis, medial, trans
b. trans, medial, cis
c. membrane directly
d. in COP I coated vesicles
a. cis, medial, trans
54
Deficiency in M6PR results in
a. exocytosis of lysosomal hydrolyses, but not betaGC
b. exocytosis of lysosomal hydrolyses and betaGC
c. lack of receptor recycling
d. reduced exocytosis
a. exocytosis of lysosomal hydrolyses, but not betaGC
55
Lipid and protein components of plasma membrane
Cholesterol
Outer leaflet: phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, glycolipids
Inner leaflet: phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine
56
Contribution of cholesterol to stiffness and/or fluidity of plasma membrane
Cholesterol increases fluidity of the tails of lipid molecules and stiffens regions near the polar head
57
Integral membrane proteins
Inserted into the lipid bilayer
Extracellular portion generally glycosylated
Intracellular portion bound to cytoskeletal components
58
Peripheral membrane proteins
Linked directly to the plasma membrane by protein-protein interactions
Extracellular portion generally glycosylated
Intracellular portion bound to cytoskeletal components
59
Simple diffusion
Non polar and lipid-soluble substances
Diffuse directly through lipid bilayer or through channel proteins
Faster if larger membrane surface, thinner membrane (shorter distance), greater concentration gradient, greater molecular permeability, smaller molecules
Permeability depends on lipid solubility, molecule's size, lipid composition of membrane
60
Facilitated diffusion
Transported substances bind carrier proteins or pass through protein channels
Channels can be selective and regulated
No ATP energy consumption
(Ex: glucose, amino acids, ions)
61
Carrier proteins
Integral transmembrane proteins
Show specificity for certain polar molecules including sugars and amino acids
Saturate with ligands/substrates
Never form an open channel between the two sides of the membrane
62
Channel proteins
Open or gated (usually closed)
Often highly selective (size, charge)
Chemical (intracellular messengers)
Temperature, mechanical/tension, electric (voltage) signals
Consist of subunits
Ion channels (K+, Na+, Ca2+) and leak channels (open all the time, allow water/ion movement)
Create water-filled pore
63
Active transport
Transport against a concentration gradient
Requires energy input (usually ATP)
Primary and secondary
64
Primary active transport
Energy from ATP used to move Na+ and K+ against gradients, creating potential energy stored in the ion concentration gradients
65
Secondary active transport
Uses energy stored from Na+ gradient to move other molecules against their own gradients
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Uniporter
Transports one substance across the cell membrane
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Symporter
Cotransporter that carries two molecules simultaneously or sequentially in the same direction
68
Antiporter
Cotransporter that carries two molecules simultaneously or sequentially in the opposite direction
69
Lipid bilayers that comprise the cell membrane are
a. impermeable to ions
b. permeable to ions
c. impermeable to small non-charged polar molecules
d. permeable to small non-charged polar molecules
e. both a & c
f. both a & d
f. both a & d
70
In general, Fick's law of diffusion holds that
a. rate of diffusion is reduced with increased surface area
b. rate of diffusion is increased with increased surface
c. is influenced by the thickness of the membrane
d. b & c
e. a & c
d. b & c
71
Secondary active transport
a. uses a concentration gradient for one molecule to drive transport of another molecule
b. uses ATP
c. is found only in epithelial cells
d. both a & b
e. none of the above
d. both a & b
72
Osmolarity
Measures number of particles per liter in Osmols/L
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Osmolality
Expresses osmotic pressure of solution in relation to the mass of the solution
Total number of osmoles (solute) in a volume of water
Osmols/kg
74
Membrane structure and permeability - osmosis
When concentration of solvent is different on opposite sides of semipermeable membrane, water moves to equilibrate solute, direction depends on number of particles in a given volume on each side of the membrane
75
Ion concentrations in intracellular fluid (ICF)
Sum of what is inside the cell
High K+
Low Na+ and Cl-
76
Ion concentrations in extracellular fluid (ECF)
Plasma and interstitial fluid
Low K+
High Na+ and Cl-
77
Hydrostatic pressure
Exceeds oncotic pressure, mainly driven by albumin
Pushes water and low molecular weight substances into the ECF
78
Oncotic pressure
Ability for albumin to draw water back into the veinous blood
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Tonicity
Only counts the effective osmoles (those that can't pass the membrane and are confined to the ECF)
Osmolality of a solution relative to plasma
Affects RBC size (hypotonic, isotonic, hypertonic)
80
Why can osmolality and oncotic pressure cause 'nephrotic edema' in chronic kidney disease?
Albumin leaks to urine, causing proteinuria/albuminuria
Blood plasma becomes albuminemic reducing oncotic pressure
Blood loses water/fluid into nearby tissues resulting in edema
81
Why can exocrine pancreatic insufficiency result in 'osmotic diarrhea'?
Decreased production of digestive enzymes in the pancreas --> undigested fats, proteins, and carbs remain in lumen
Increased solutes draw increased water, dehydrating the body and cause watery, smelly, undigested stools
82
Water-soluble (hydrophilic) cell communication
Likely to have an extracellular receptor
83
Lipid-soluble (hydrophobic) cell communication
Likely to have an intracellular receptor
84
Juxtacrine signaling
Direct contact between cells
85
Paracrine signaling
Short distances, short lived (sec-min)
Affects nearby cells
86
Autocrine signaling
Cell signals itself
87
Synaptic signaling
Long distances, extremely fast (msec)
Cell to cell specificity
88
Endocrine signaling
Widely disseminated signal
Typically bound to a transport protein
Slow on, slow off (sec-days)
89
G protein coupled receptors (GPCR) function
Stimulatory vs. inhibitory
Mediate signal transduction that either stimulates or inhibits production of a second messenger
90
Four most biologically important intracellular second messengers
1. Cyclic AMP (cAMP)
2. Inositol 1,4,5 triphosphate (IP3/Ca2+)
3. Diacylglycerol (DAG)
4. Cyclic guanosine monophosphate (cGMP)
91
How intracellular signals are produced by receptor tyrosine kinases (RTKs)
Enzyme-linked receptors
Often mediate actions of other growth factors
Catalyze autophosphorylation of intracellular tyrosine(s) to promote dimerization
92
Cytoplasmic and nuclear receptors
Hormone receptors bind to their lipophilic ligand in the cytoplasm or nucleus
93
Structure and function of ligand-gated ion channels
3-5 subunits that cross the membrane 4 times, typically 2 extracellular ligand binding sites, one or more activation gate(s), a selectivity filter, one or more desensitization mechanisms, may involve accessory proteins
Sites for post-translational modification
94
Structure and function of voltage-gated ion channels
Sense changes in membrane potential (voltage sensor), one or more activation gate(s), a selectivity filter, inactivation gate
Accessory proteins bind sites that modulate function and/or target ion channel to the membrane
Sites for post-translational modification
Conformational changes occur over "long" molecular distances
95
Stimulatory ion channels
Nicotinic cholinergic and ionotropic glutamate receptors
Muscarinic can be stimulatory/inhibitory
96
Inhibitory ion channels
GABAa and glycine receptors
Muscarinic can be inhibitory/stimulatory
97
How ions are altered in an action potential
1. Resting state - K+ current high
2. Excitatory ligand gated channel activated - nAChR --> Na+/Ca2+ influx, depolarization
3. Peak of AP - high Na+ current, K+ current increases
4. Repolarization - Na+ current inactivates, K+ current very high
5. Hyperpolarization - Na+ current ~0, K+ decreases to rest
98
Difference of action potential at neuronal axons and cardiac T-tubule
Influx of Ca2+ channels electrically balanced by K+ efflux
Ca2+ channels close but delayed rectifier K+ channels remain open and return membrane potential to -90mV
Allows sufficient time for ventricles to empty and refill prior to next contraction
99
Examples of channelopathies
Congenital or acquired myasthenia gravis
Hyperkalemia periodic paralysis
Myotonia congenita
100
Mechanisms leading to canine myasthenia gravis
Congenital - heritable mutations in genes encoding proteins expressed at the neuromuscular junctions
Acquired - autoimmune disorder, blocking autoantibodies that bind to nAChR
101
Mechanisms leading to equine HYPP
Several single point mutations within TMS of NaV1.4
Delayed inactivation of Na current, repetitive discharges, loss of excitability
Genetic defects cause this sodium channel to become leaky with higher levels of K+ ions in blood
102
Developmental stage where three germ layers are formed
What happens if something goes wrong at this stage?
Gastrulation
Occurs during second week of embryogenesis in most domestic animals, after implantation into uterine wall
Termination, congenital defects, nothing may present
103
Ectoderm
Outer layer; forms skin and neuroectoderm
Epidermis, mouth, cloacal opening, optic lobes, cerebellum, spinal cord, etc.
104
Mesoderm
Middle layer; forms tissues such as muscle, bone, blood vessels
Dermis, kidney and urogenital ducts, limbs, gonads, heart, vessels, etc.
105
Endoderm
Inner layer; forms lining of digestive tract and most organs
Esophagus, tracheal tube, stomach, liver, pancreas, intestines, urinary bladder, cloaca, etc.
106
Actin filaments
Smallest, form basis for apical structure (brush border), extensive network in contractile cells
107
Intermediate filaments
Very stable, located throughout cytoplasm and hold condensed chromatin in the nucleus, provide cytoskeletal backbone for many cell types, classes based on cellular associations
108
Microtubules
Thickest, provide structure and shape to eukaryotic cells, have broad distribution throughout the cell, provide basis of cilia and serve as railroad for transport
109
Dynamic filaments
Actin filaments, microtubules
110
Non-dynamic filaments
Intermediate filaments
111
Tight junctions (zonula occludens)
Control passage of ions and solutes on apical portion of the cell membrane
Prevents paracellular exchange of intrinsic proteins and lipids between apical and basolateral membrane
Composed of claudins and occludins
Actin microfilaments
112
Adherens junctions (zonula adherens)
Link to cytoskeletons of adjacent cells to form strong cohesive epithelium
Associated with actin filaments
113
Desmosomes (macula adherens)
Structural support via keratin interactions (very strong)
Link cytoskeletons of adjacent cells to form strong cohesive epithelium
Associated with intermediate filaments
114
Gap junctions
Permit passage of ions and small molecules between cells
Intercellular signaling
No cytoskeletal (filament) associations
115
Hemidesmosomes
Specialized junctional complexes located at the basal aspect of cells
Important for adherence of epithelial sheets to matrix
Associated with intermediate filaments
