Mini 1 - week 1+2 Flashcards
1
Q
What is cystic fibrosis?
A
A defect in the CFTR protein (12 transmembrane domains) that pumps chloride in and out of the cell that causes chloride to not be pumped out and so water to build up.
2
Q
What is the path of the vertebral artery? What happens when blood flow is restricted (e.g. atherosclerosis).
A
It is a branch of the subclavian artery, it travels through the C6-C1 transverse foramina, goes medially along the C1 posterior branch and then passes superiorly through the foramen magnum to the brain. In the event of reduced blood flow, prolonged turning of the head can reduce blood flow to the brain.
3
Q
What is OLDCARTSP?
A
Questions you ask a patient - onset, location, duration, character, associated/alleviating/aggravating factors/symptoms, radiation, timing, severity, and prior episodes.
4
Q
How do membranes do cell-cell communication?
A
With the carbs attached to their lipids and proteins (glycolipids, glycoproteins).
5
Q
What is special about aromatic amino acids?
A
They’re somewhat hydrophobic, often found in active sites, participate in stacking interactions with substrates.
6
Q
Describe primary transcripts.
A
A leader sequence of 1kb or longer (this is recognized by binding proteins that participate in assembly of it into a ribonucleoprotein), long tail sequences that are common in eukaryotes, a capped mRNA, tRNA and rRNA transcripts that are cut into pieces to form individual RNAs.
7
Q
What is the action of the rhomboid major + minor?
A
Retract and inferiorly rotate the scapula. Fix scapulae to thoracic wall.
8
Q
What is the role of myosin in a cell?
A
It can move along F-actin or slide one actin fiber past another with the use of ATP. Actin/myosin fibers in not muscle are called stress fibers. Motility by crawling ‘lamellipodium’. - microtubules also involved
9
Q
What does the superficial layer of the extrinsic back muscles do?
A
It controls the upper limb. It also connects the axial skeleton with the superior appendicular skeleton.
10
Q
What is whiplash?
A
Severe hyperextension (like the hangman’s) which stretches/tears the anterior longitudinal ligament. There may also be a rebound hyperflexion injury.
11
Q
How do tetracyclines work?
A
They bind the 30S subunit and block tRNA binding so no protein is synthesized.
12
Q
What is maltose?
A
alpha1->4 glucose+glucose.
13
Q
What are the effects of uncompetitive inhibitors? What are some examples?
A
They bind the E-S complex at not an active site, it lowers Km and Vmax. Lithium for inositol monophosphate.
14
Q
What is the origin and insertion of the infraspinatus?
A
O: Infraspinous fossa I: greater tubercle
15
Q
What is the blood supply of the latissimus dorsi?
A
The thoracodorsal artery.
16
Q
What is an oil?
A
A hydrophobic liquid. It can be a hydrocarbon, triglyceride, or fatty acid.
17
Q
How are tRNAs processed?
A
They are spliced (though differently than mRNA), RNAse P trims the 5’ end until it is left with one phosphate. tRNAse Z trims the 3’ end and then nucleotidyl transferase adds a (nonencoded) CCA.
18
Q
What is the path of the spinal accessory nerve / CN XI?
A
It goes from the cranium down the neck and back deep to the trapezius. It is relatively superficial and can be easily injured with a blunt or penetrating injury.
19
Q
What are the stages of change in the transtheoretical model?
A
Pre-contemplation (no intention of changing behaviour), contemplation (aware there’s a problem - no commitment to action), preparation (intent of taking action), action, maintenance, relapse.
20
Q
What is a lipid raft and what does it have to do with signalling?
A
Aggregations of sphingomyelin, glycolipids, and cholesterol that make sections of the membrane less fluid. Signal transduction in these is more rapid. They also limit signalling by physically sequestering signalling components - block nonspecific interactions and suppress intrinsic activity of signalling proteins. They may also contain incomplete signalling pathways that are activated when a require molecule is recruited into the cell. Integrins are often activated in lipid rafts.
21
Q
Where is the oxygen removed from ribose to ake deoxyribose?
A
At the 2’ carbon.
22
Q
What is a back strain?
A
Stretching and/or microscopic tearing of muscle fibers caused by overly strong contraction. Often the erector spinae are involved and spasms may be in response to inflammation. This is a common sports injury.
23
Q
Describe receptor-ligand kinetics.
A
Similar to enzyme kinetics but with a Bmax and a KD (binding dissociation constant) where 1/KD is the equilibrium constant. RL = Ro [L]/ [L]+KD
24
Q
What is the Henderson-Hasselbach equation?
A
pH=pKa + log[A-}/{HA]
25
What does the intrinsic layer of back muscles do?
It acts on the axial skeleton only. It acts on the vertebral column to control movements and maintain posture.
26
What are the BMI ranges?
\<18.5 (underweight), 18.5-25 (normal), 25-30 (overweight), \>30 (obese).
27
What is a dermatome?
A unilateral area of skin innervated by the GSA fibers of a single spinal nerve.
28
What kind of targeting sequence and proteins are needed for import into nucleus vs export from the nucleus?
A positively charged one and a hydrophobic one. NLS/NES. these can be on the cargo itself or on an associated protein. Importins are the receptors for NLS and Exportins for NES. A small GTPase called RAN regulates the binding and release of cargo.
29
What is a wax?
A long chain, hydrophobic branched hydrocarbon. It can be solid, semisolid, or liquid.
30
What do kinetochore proteins do?
Link the mitotic spindle to centromeres.
31
What is the insertion of the latissimus dorsi?
The intertubercular sulcus of the humerus.
32
What are hydrolases?
Use H2O addition to break bonds.
33
What are the spinal cord meninges and spaces?
The epidural space is filled with fat and is between the dura mater and vertebral column. The subdural space is only a potential (pathological) space and is between the dura mater and the arachnoid mater. The subarachnoid space is filled with CSF and is between the arachnoid mater and the pia mater.
34
Describe the unusual structure of collagen.
A high glycine and proline %. A triple helix quaternary structure.
35
What provides sensory innervation to the back?
The cutaneous branches of the posterior rami.
36
What is the insertion od the deltoid?
The deltoid tuberosity of the humerus.
37
What is ankylosing spondylitis?
It is an inflammatory form of spinal arthritis where \>1 vertebral and/or sacroiliac joints fuse. It causes a hunched forward appearance and is more common in males than females.
38
What can alternatively spliced H2A do and what are some examples?
It can replace H2B. H2A.Z is associated with promoter/nucleosome free regions. H2A.X is associated with regions undergoing DNA repair and T cell differentiation. Macro H2A is associated with Barr bodies.
39
What are the levels of health prevention?
Primordial, primary, secondary (disease), tertiary (disease+illness), quaternary (illness).
40
Describe class II nuclear hormone receptors.
They exist prebound to DNA. Ligand binding causes the release of co-repressors and the recruitment of co-activator proteins. They are generally heterodimers.
41
How do aminoglycosides work?
They bind the 30S subunit and impair proofreading so there are faulty proteins.
42
What is a detergent?
A natural or synthetic amphipathic compound that acts as a surfactant (forms micelles in water) as a result of its head being bigger than its hydrophobic tail.
43
Name the three bodily planes that depend on standard anatomical position.
Transverse/axial/transaxial - divides body into superior/cephalic/cranial and inferior/caudal. Coronal - divides body into anterior/ventral and posterior/dorsal. Sagittal - divides body into right and left.
44
What are cytoplasmic inclusions?
Transitory, nonmotile, not membrane bound aggregations in the cytosol. They can be common fat droplets, lipofuscin granules, and glycogen rosettes.
45
What are the effects of suicide inhibitors? What are some examples?
They bind outside the active site and reduce Vmax. They do this permanently because it is covalent. Aspirin for COX (makes prostaglandins), Nerve gases for AchE, PPIs (decrease acid secretion in the stomach), Penicillin type antibiotics for enzymes that make cell walls. They resemble serine proteases and are very slow cleavable substrates.
46
What does glycolysis make?
Pyruvate from glucose.
47
What are the IOM's Aims for Improvement?
Safe, Timely, Efficient, Effective, Equitable, Patient-centered.
48
How is DNA packaged?
146bps wrap 1.67 times around a nucleosome octamer, which tightens by H4 deacetylation into a 30nm Toroid.
49
What happens when light goes into your eye?
Cis-retinal absorbs light and isomerizes to trans-retinal. This causes a conformational change in rhodopsin. Gt (transducin) is activated, the alpha subunit bound to GTP activates phosphodiesterase. PDE converts cGMP to GMP. This causes the closure of CNG channels (that cGMP usually keeps open) which results in membrane polarization.
50
What are the purines and what are the pyrimidines and which are two rings?
Purines are two rings and they are A and G. Pyrimidines are C, T, and U.
51
What is the general structure of a glycerol phospholipid?
2 fatty acids plus a head (can be attached to a phosphate). The middle fatty acid is usually unsaturated. Common heads are ethanolamiine, choline, serine, inositol.
52
What's an oxyanion hole for?
It has a backbone/sidechains that interacts with the carbonyl of the peptide bond and helps stabilize the tetrahedral intermediate.
53
What are the types of repetitive DNA? And how much of the genome is repetitive DNA?
Transposons (generally defunct retroviruses) - have inverted repeats, LINEs and SINEs (derived from retroviral integration or transposable elements), and other repetitive DNA found in telomeres, centromeres, micro and mini satellites. About 52% of the genome.
54
What is a lipid?
A natural, nonpolar (or amphipathic) molecule that stores energy, makes up membranes, vitamins, and does signalling. Includes waxes, oils, fat, detergents.
55
What is the facet/zygophasial joint?
Joint between two one vertebra's superior articular facet (on articular process) and another's inferior one.
56
What is the action of teres minor?
Lateral rotation
57
What are ribosomes made of?
40S SSU (1rRNA + 33 proteins), and 60S SSU (3rRNA + 40 proteins).
58
Describe the costal facets of the thoracic vertebrae.
The superior and inferior ones articulate with the head of the rib, and the transverse ones (on the edge of the transverse processes) articulate with the costal tubercle.
59
Where is glycogen stored? Where does gluconeogenesis take place?
Liver and muscle. Liver and a little bit kidney.
60
When does mRNA bind an NES?
Only when it's finally processed.
61
What is a crush/compression fracture?
A fraction of the body due to a sudden forceful flexion. It can be accompanied with the dislocation/fracture of the articular facets between two vertebrae and/or the rupture of interspinous ligaments.
62
How are microtubules and actin involved in mitosis?
Actin/myosin make up the contractile ring. The + ends of microtubules plug into centrosome kinetochores (mitotic spindle).
63
What is the action of the infraspinatus?
Lateral rotation of the arm and to stabilize the glenohumeral joint.
64
What is the origin and insertion of the supraspinatus?
O: supraspinous fossa I: greater tubercle
65
Describe pre-initiation of translation.
In the nucleus, elongation factors bind pre-mRNA shortly after its binding site is synthesized, and additional elongation factors and the small subunit of the ribosome are recruited. The met-tRNA binds, and this all exits once the mRNA is fully matured.
66
What is the innervation of the supraspinatus?
the suprascapular nerve (C5).
67
What does colchicine treat and how?
Gout is uric acid crystals depositing in joints and swelling, attracting leukocytes, and swelling more. Colchicine prevents white blood cells from migrating there by counteracting microtubule action in crawling.
68
List the extrinsic superficial back muscles and their innervations.
Trapezius (descending, middle, ascending head) - CN XI. Latissimus dorsi - thoracodorsal nerve (C6-8). Levator scapulae, rhomboid major, rhomboid minor - dorsal scapular nerve (C5). Rhomboids separate branch than levator.
69
How do enhancers and repressors work?
Both can rearrange the nucleosome to expose or cover the promoter region. Enhancers usually bind the DNA and then additional proteins which recruit TFs and RNA polymerase. Repressors can themselves block the DNA binding site.
70
How many vertebral bodies are there?
33. 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), and 4 coccygeal (fused after age 30).
71
What and where is the cauda equina?
The bottom of the spinal cord where nerves begin to taper out and travel to the intervertebral canal exit. It is surrounded by a dural sac.
72
What is the action of the erector spinae group?
They extend the vertebral column, give some rotation tot he vertebral column, and act on the vertebral column to control movements and maintain posture.
73
What is Hutchinson-Gilford progeria caused by?
Lamin A.
74
What are the secondary spinal curves?
The newborn spine is kyphotic. Lordosis forms in the cervical and lumbar vertebrae with the child starts holding her head up and standing respectively.
75
What is the insertion of teres major?
The medial lip of the intertubercular sulcus.
76
Describe intermediate filaments.
Toughest one, rope structure, can survive cell death. They're less dynamic.
77
What's a way to treat lumbar stenosis?
Decompressive laminectomy.
78
What are oxidoreductases?
They facilitate redox chemistry, often need FAD or NAD as a cofactor. If they need NAD they are dehydrogenases.
79
Describe the blood flow to the scapular/upper arm region.
The subclavian artery branches into the dorsal scapular, axillary, and thyrocervical trunk (transverse cervical and suprascapular artery). The axillary continues down and branches into the subscapular and circumflex arteries, and the subscapular branches into the thoracodorsal. The thoracodorsal, circumflex, and subscapular all connect to the dorsal scapular from the other direction. Also there are posterior intercostal arteries coming into the dorsal scapular.
80
What is a hangman's fracture?
Abrupt hyperextension of the neck breaks the pedicles of C2 posterior to the superior articular facets.
81
What is a fat?
A hydrophobic solid. Usually a triglyceride.
82
What is the difference between cilia and flagella?
Flagella are (~60um), cilia (2-5um). You can have multiple cilia but only one flagellum. Cilia are in the respiratory tract, fallopian tubes, and move around the cerebrospinal fluid in the brain.
83
What is the insertion of the trapezius?
The acromion and spine of the scapula.
84
What's the size of a nucleus?
Aout 8 um.
85
Where are many actin-binding proteins located?
Right under the plasma membrane (and so, so is most F-actin).
86
If a particular disc is herniated, which nerve will be affected?
The nerve going through that foramen except in the case of lumbar where it is the one above that foramen.
87
What happens in the case of a posterolateral disc herniation?
It may spare the nerve at the level of injury but affect the one inferior.
88
Describe the arterial blood supply of the spinal cord.
- 1 anterior spinal artery that branches from the vertebral artery - 2 posterior spinal arteries that arise directly or indirectly from vertebral arteries These are reinforced by radicular arteries, branches of segmental arteries, ascending cervical arteries, deep cervical arteries, posterior intercostal arteries, lumbar arteries, and sacral arteries.
89
Does the nucleolus have a membrane?
No.
90
How can a GPCR signal be terminated?
Ligand unbinding. Self-GTP hydrolysis. Endocytosis (sequestered and eventually returned or degraded in the lysosome). When the ligand dissociates, GRK phosphorylates the protein and arrestin binds and block further signalling.
91
What is special about OH-containing amino acids?
They are structural, engage in H-bonding, often found in active sites. The OH can be phosphorylated or glycosylated.
92
What is the rotator cuff made of?
The supraspinatus, infraspinatus, teres minor, and subscapularis.
93
How are axons organized?
Into fascicles, which make up peripheral nerves. In the CNS, groups of axons are called tracts.
94
Describe the unusual quaternary structure of Cu, Zn superoxide dismutase.
It has a dimer (16,000Da monomer). Each of its subunits have 8 antiparallel beta sheets in a barrel.
95
What is the action of the deltoid?
Abducts the arm \>15 degrees.
96
What are the four most abundant phospholipids?
Phosphotidylcholine, sphilgomyelin (also a choline head but a sphingosine backbone not glyerol), phosphotidylserine (the only negatively charged phospholipid), and phosphotidylethanolamine.
97
Which joint is for nodding your head and which is for shaking?
Atlanto-occipital and atlanto-axial.
98
How does glucagon affect glycogen?
Glucagon binds a G protein receptor, and it releases GDP and binds GTP, and then the alpha subunit bound to GTP comes off. This activates adenylate cyclase which makes cAMP. cAMP binds PKA which is activated and phosphorylates glycogen phosphorylase kinase which phosphorylates glycogen phosphorylates which degrades glycogen to G1P.
99
What is the innervation of the deltoid?
The axillary nerve (C5-6).
100
What forces are present in protein tertiary structure?
H-bonds, ionic bonds, van der waals forces, disulfide bridges (the only covalent interaction - will not be hurt by denaturing agents but can be broken by reducing agents like glutathione) or oxidizing agents.
101
What is the innervation of the serratus anterior?
The long thoracic nerve (C5-7).
102
What are the kinds of membrane proteins?
Integral (which a detergent is needed to remove) and peripheral (which can be removed by a high salt rinse).
103
What is the insertion of the levator scapulae?
The medial border of the scapula - superior to the root of the scapular spine.
104
What are ligases?
They catalyze formation of various bonds.
105
What are the mechanisms catalysts use?
Substrate (or group) specificity, bind/stabilize transition state, provide covalent chemistry by orienting substrate and enzyme, providing acid/base chemistry.
106
How do chloramphenicol, macrolides, and lincosamides work?
They bind the 50S subunit to prevent peptide bond formation so there is no protein synthesis.
107
What muscles make up the suboccipital triangle? What margins do they make up?
Rectus capitis posterior major - superomedial. Obliquus capitis inferior - inferolateral. Obliquus capitis superior - superolateral. The greater occipital nerve (C2) is inside the triangle.
108
What is the structure of a telomere?
TTAGGG with shelterin protecting the ends. The last 300bps form a D-loop The loss of telomeres creates sticky ends tahat are hotspots for DNA repair and recombination.
109
What are the mechanisms of bringing things into the cell?
Phagocytosis, pinocytosis, and receptor mediated endocytosis (usually by clathrin-coated pits).
110
What are the sources and fates of Acetyl CoA?
Sources: pyruvate, fatty acids (beta-ox), ketone bodies Fates: TCA, fatty acid synthesis, ketone body production
111
What is the blood supply of rhomboid major and minor?
The dorsal scapular artery.
112
What is special about acidic amino acids?
They are often sites for protein modifications.
113
Describe the venous drainage of the spinal cord.
3 anterior and 3 posterior spinal veins that communicate with each other and drain into the anterior and posterior medullary veins. They join the internal vertebral/epidural plexus (valveless) and communicate with the dural sinuses and then the vertebral veins. They also communicate with the external vertebral plexii on the external aspect of the vertebrae.
114
What muscles does the suboccipital nerve (C1) innervate?
rectus capitis posterior major/minor and obliquus capitis superior/inferior.
115
What are the effects of competitive inhibitors? What are some examples?
Binds the active site and increases Km. Statins (e.g. pravastatin competes with HMG-CoA for HMG-CoA reductase). Methanol for alcohol dehydrogenase (converts to formic acid and formaldehyde).
116
What is the blood supply of the levator scapulae?
The dorsal scapular artery.
117
Where do the R groups project in beta sheets? What are examples of beta sheet containing proteins?
They alternate up and down. Often to avoid the 'edge effect' they form barrels. Porin and IgG.
118
List the intrinsic back muscles.
The paraspinous muscles and the erector spinae group.
119
What and where is the lumbar cistern?
An enlargement of subarachnoid space between the conus medullaris and the end of the dural sac around S2. Around L4 through this is where you do spinal anaesthesia or a lumbar puncture.
120
What is the Michaelis-menten equation?
Vo=Vmax
121
What do the different RNA polymerases transcribe?
RNA Pol I: rRNA (in the nucleolus) RNA Pol II: mRNA RNA Pol 3: tRNA
122
What is Karteneger syndrome?
Primary cilia dyskinesia. An autosomal recessive disease, lack of axonemal dynein in motile cilia. causes reduced/absent mucus clearance from the lungs and male infertility.
123
Describe starch, glycogen, and cellulose.
glucose polysaccharides. Starch is amylose (linear alpha1-\>4) and amylopectin (also has alpha1-\>6 branches). Glycogen is the same as amylopectin but has more branches. Cellulose is beta1-\>4 and we cannot break this down.
124
What does the intermediate layer of the extrinsic back muscles do?
It controls only the axial skeleton. It helps with respiratory and proprioceptive movements (and the serratus posterior muscles)?
125
What are the fates of pyruvate?
Acetyl CoA, oxaloacetate, alanine (for nitrogen transport). Also lactate in anaerobic fermentation and ethanol in some microorganisms.
126
Describe the venous drainage to the vertebal column.
The spinal veins form internal and external venous plexii. Both the external and internal plexii have anterior and posterior components, and the internal plexii is valveless (a potential path for metastasis). There are also basivertebral veins within the vertebral bodies. They all end up draining into the vertebral veins.
127
Where do the R groups project in alpha helices? What are examples of alpha-helix containing proteins?
They project out. Hemoglobin and rhodopsin (7 TM alpha helices, one kinked with a proline)
128
What are the ACGME (Accreditation Council on Graduate Medical Education)'s general competencies?
Systems-based practice, professionalism, interpersomal & communication skills, patient care, practice-based learning and improvement, medical knowledge.
129
Describe somatic sensory nerve signaling.
A sensory/GSA type axon travels in the spinal nerve and reaches the dorsal root. Then it becomes a tract in the spinal cord and reaches the brain.
130
What are transferases?
They move a functional group from one molecule to another.
131
How fast does DNA replication occur?
2000nt/sec.
132
Describe class I nuclear hormone receptors.
They exist in the cytoosol bound to HSP90. When the ligand binds, the alpha helix flips, releases HSP90, the receptor dimeries into a homodimer and translocates to the nucleus.
133
Briefly go over fatty acid synthesis in the liver. Where does it get its ATP?
AcCoA -\> FAs which combine with glycerol phosphate to make triglycerides which are then packaged into VLDLs. It gets its ATP from the pentose phosphate pathway / hexose monophosphate shunt.
134
Where is spina bifida occulta seen?
In L5 and/or S1.
135
What are the differences between arteries and veins?
Arteries go from the heart to capillary beds, and veins go the other way. Arteries carry oxygen rich blood, veins carry deoxygenated blood. Arteries are thick walled and have a lumen and veins are thin walled and lumenless.
136
What are glycoproteins involved in?
Regulation of folding/structure.
137
What are groups of neuronal cell bodies called?
In the CNS, nuclei. In the PNS, gangia.
138
What does insulin do?
It upregulates glucose use by all tissues, upregulates GLUT4 release in adipose tissue and skeletal muscle, activates LPL in adipose tissue, promotes anabolism.
139
How do you recognize the atlas?
It has no body and a transverse ligament.
140
How do cells attach to their surroundings?
With integrins. Integrins are made up of alpha and beta subunits - one cell can have multiple integrins on its surface. Once an integrin is activated, it sends signals about the status of the ECM which can control tissue specific gene expression or release it if its in the wrong place - which can trigger apptosis. Integrin activation often occurs in lipid rafts.
141
What is the blood supply of the trapezius?
The transverse cervical artery.
142
What is the difference between trimeric G proteins and small G proteins?
Small ones are monomeric and do not have intrinsic hydrolysis activity. They need a GTPase accelerating protein (GAP) specific for it to hydrolyze GTP.
143
What is coccydynia?
Coccyx pain from injury, childbirth, straining.
144
How does taxol work?
It is an anti microtubule drug, and because it's needed to form the mitotic spindle the cell arrests and hopefully apoptoses.
145
What is the action of the trapezius?
Descending head - elevation of the scapula. Ascending head - depression of the scapula. D+A=superior rotation of the scapula. Middle head - retraction of scapula.
146
What is the origin and insertion of the subscapularis?
O: subscapular fossa I: lesser tubercle
147
What can alternatively spliced H3 do and what are some examples?
It can alter packing. H3.3 is found in euchromatin and H3 CENPA anchors the nucleosome to the centromere.
148
What is a back sprain?
Only ligamentous tissue is involved; no dislocation or fracture. It comes from strong contractions related to movement of the vertebral column.
149
Describe the somatic motor pathway.
It is a 2 neuron system. First, a UMN in the primary motor cortex sends a signal down a GSE axon axon to a LMN in the ventral horn. Then the LMN sends a signal down the ventral root to a peripheral spinal nerve, which eventually innervates a muscle.
150
What is the difference between a dermatome and cutaneous nerve areas?
The cutaneous nerve supplies an area of sin related to a peripheral nerve and can contain fibers from several individual spinal nerves. Its areas overlap with dermatomes and are generally broader and wider than a single dermatome.
151
Decribe the structure of cilia and flagella.
Microtubules in a 9+2 array of tubulin dimers, nucleated by a basal body. They contain axonemal dynein.
152
What is the general structure of a phospholipid? Where are the major classes synthesized?
Glycerol backbone, phosphate head, two fatty acid tails, one saturated and one unsaturated. The major classes are synthesized in the SER.
153
What are the effects of noncompetitive inhibitors? What are some examples?
They bind outside the active site and reduce Vmax. G6P for hexokinase. NNRTIs for reverse transcriptase.
154
What and where is the filum terminale?
It continues down from the conus medullaris and tethers the spinal cord to the coccyx.
155
What are lymphatics?
They drain surplus tissue fluid/leaked plasma proteins/remove debris. They regulate the interstitial fluid. They follow vein pathways.
156
What is the structure of NAD/FAD?
a base + a ribose/ribitol + a phosphate in a dinucleotide structure. The nicotinamide/flavine bases are made from niacin (B3) and riboflavin (B2). NAD is usually soluble and has more redox potential than FAD, which is typically bound as a substrate?
157
What is a denticulate ligament?
It anchors the spinal cord to the dura mater at the midpoint between two spinal nerves.
158
When is a buffer strongest/weakest?
strongest: pH=pKa weakest: pH=pI
159
What is the action of the supraspinatus?
It abducts the arm 0-15 degrees. It also stabilizes the glenohumeral joint.
160
What is special about branched chain amino acids?
Amino group is sent to pyruvate to make alanine, and the carbons are sent to TCA.
161
What is the action of the subscapularis?
Medial rotation of the arm.
162
How many dermatomes are there?
30. 7 cervical (C1 doesn't have one, it's just motor), 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal.
163
What is the RNA template for telomerase and what is the telomere sequence?
CCCUAA TTAGGG
164
What is the innervation of the subscapularis?
The upper and lower subscapular nerve (C5-6).
165
Describe the average transmembrane protein domain.
20 amino acids in an alpha helix.
166
Describe actin fibers.
From the greek "ray", or "beam". Present in all cells, usually 50% as free subunits (G-actin) and 50% as filaments (F-actin). F-actin is a 2 stranded helix with a + and - end. It's added onto the + end bound to ATP and added onto the - end bound to ADP.
167
What is important about chondroitin-sulfate repeats?
They provide a lot of negative charge to sugar chains that keeps them hydrated and apart and provides connective tissue elasticity.
168
What is the innervation of teres major?
The lower subscapular nerve (C6).
169
What does TCA make?
CO2 from Acetyl CoA (which is made from pyruvate by PDH).
170
When is initiation of transcription complete?
When RNA is over ten bases long or (if it is destined to become mRNA) the RNA is capped.
171
What do nuclear lamins do?
They provide an attachment site for chromatin to the nuclear envelope and control nuclear envelops disassembly.
172
What is a chance fracture?
It is an anterior crush fracture and also fractures along the transverse processes of the vertebra.
173
What is the path of the dorsal scapular nerve?
It goes down the neck and along the medial border of the scapula then emerges between the anterior and middle scalene muscles/
174
What is the resolution in light microscopy and electron microscopy?
LM: 0.2um EM: 0.2nm
175
What is the path of the spinal nerves?
They emerge laterally from the intervertebral foramina and divides into anterior and posterior branches.
176
What does carbonic anhydrase do?
Facilitates the dissolution of carbon dioxide in water (CO2 needs to be hydrated to move more easily in blood). It is a metalloenzyme (Zn cofactor).
177
What are lyases?
They catalyze damage of C-C, C-O, C-N, C-S, C-halide, P-O bonds.
178
Go over the three kinds of amino acid in terms of metabolism.
Ketogenic - feed directly into Acetyl CoA. Glucogenic - feed into pyruvate/replenish TCA, be gluconeogenesis precursors Urea cycle - amino group is converted with CO2 into urea
179
What are glycolipids involved in?
Immune recognition and physical barriers.
180
What is the thickness of a membrane?
7.5-10nm.
181
What's the general formula for carbohydrates?
CxH2xOx
182
Describe synaptic signalling.
A chemical signal released from a synaptic terminal that travels short distances to affect electrical signalling in adjacent cells.
183
What's a ganglioside?
A ceramide(lipid)+branched sugars
184
What pH optima do stomach, lysosomal, and cytosolic enzymes have (vaguely)?
Low, higher but below neutral, usually near 7.
185
What and where is the conus medullaris?
The ending point of the spinal cord around L1/L2. In neonates, it is L3/L4.
186
What is sucrose?
alpha1-\>2 glucose+fructose
187
Describe nuclear hormone receptors.
They modify gene transcription by recruiting TFs in response to a variety of hydrophobic hormones (e.g. cortisol, thyroxine, testosterone, estradiol, Vitamin A (retinoic acid), Vitamin D3 (calcitriol).
188
How any pairs of spinal nerves are there and where do they course.
31. 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, one coccygeal. The cervical ones course superior to their vertebra (C8 above T1 vertebra), and the others course inferiorly.
189
What is the IQR?
The interquartile range between 25% and 75% values.
190
What is an uncinate process?
A bony lip around the rim of vertebrae C3-T1. If it grows osteophytes, it can compress the nerves and arteries with a 'mini stroke'.
191
Describe cholesterol, and where is it made. Where is it in the membrane? Do plants have it?
Small polar head group, one fatty acid tail. When it is warm, it stiffens the membrane - makes it less deformable and decreases permeability to small polar molecules. When it is cold (which doesn't happen physiologically), it prevents tight packing and maintains membrane fluidity. It is a precursor for most steroid hormones. It is made on the SER. It is distributed equallly among the membrane. Bacteria and plants do not have it - plants have similar phytosterols that the human gut cannot absorb.
192
How does CREB work?
PKA caused by a Gs activate CREB which causes CBP to bind CREB. This complex binds CRE (cAMP response element) which results in transcription.
193
What are the spaces of the scapulary/arm muscles?
Triangular - circumflex scapular artery. Quadrangular - axillary nerve and posterior circumflex humeral artery. Triangular interval - radial nerve and deep artery of the arm.
194
What is a burst/Jefferson fracture?
4 breaks in C1 in the anterior and posterior arches. It comes from strong compression on the top of the head which drives the occipital condyles into the lateral masses of C1.
195
Which vertebra has a vertebra prominens?
C7.
196
What are the start and stop codons?
start:AUG stop: UAA/UGA/UAG
197
What are the surfaces of the hands and feet called?
Hands and feet have their own bodily planes. The top of the feet and back of the hands are called dorsal. The palm surface is called palmar and the sole surface is called plantar.
198
List the extrinsic intermediate back muscles.
The serratus posterior superior and inferior.
199
How do hydrophilic and hydrophobic signals get into the cell?
Through membrane receptors and by diffusing through the membrane respectively.
200
What are the books the IOM wrote?
To Err is Human (1999) and Quality Chasm (2001)
201
What are flexion and extension?
They decrease the angle and increase the angle between bodily parts respectively.
202
What is the action of serratus anterior?
Abduction of the arm and protraction of the scapular.
203
What are the types of intermediate filaments?
Keratins (epithelial cells), neurofilaments (nerve cells), vimentin (CT, muscle, glia), nuclear lamins (all cells). The type can tell you where a cancer cell originated from.
204
Where is heterochromatin?
It lies against the nuclear envelope in patches but is broken at the site of NPCs.
205
Where do you do an epidural?
Around L4 in the lumbar cistern or in the sacral hiatus. You do it in the epidural space.
206
What is a disc herniation? Where does it most frequently happen?
The nucleus pulposus slipping out and compressing the spine. It happens mostly posterolaterally, the risk increases with age, and most commonly it is at L4/L5 and L5/S1.
207
What goes through NPCs?
Nuclear poree complexes. Cell ions, small metabolites, proteins under 40kDa.
208
What does creatine kinase do?
Store energy in creatine phosphate.
209
What is lactose?
beta1-\>4 glucose+glactose.
210
What is the innervation of teres minor?
The axillary nerve (C5-6) terminal branch.
211
Name the ligaments of the vertebral column.
Anterior&posterior longitudinal ligaments - surround the vertebral bodies, A is broader than P, prevent hyperextenson/flexion. Ligamentum flavum - connects the laminae, is yellow and elastic and limits flexion. Nuchal ligament - thick and broad from the external occipital protuberance to the C7 spinous process. It lets the back muscles attach. Intertraverse, interspinous, and supraspinous ligaments. Supraspinous takes over for nuchal from C7 downwards.
212
What are the components of the replisome?
RNA Pol alpha/Primase, RNA Pol delta (replicates the lagging strand, binds polalpha, FEN1, ligase), RNA Pol epsilon, RNA Pol beta/PCNA/Sliding clamp (trimeric, brings pols delta and epsilon), FEN1 (removes RNA primers), and SSB/Replication Protein A (RPA).
213
What is the structure of microtubules? What do they do?
Dimers of alpha and beta tubulin that form a hollow microtubule. They grow and shrink at the + end, add on by GTP-bound, fall off as GDP-bound. Often assisted by MAPs. They determine the position of organelles and provide tracks for cellular transport.
214
What is a caveola?
Caveolae are when lipid rafts are coated with caveolin and form an organelle that is capable of transcytosis. It is abundant in all cells lining blood vessels.
215
What is the action of the levator scapulae?
Elevates the scapula. Inferior rotation of the glenoid cavity.
216
What is the action of the paraspinous muscles?
They act on the vertebral column to control movements and maintain posture.
217
What is the axial skeleton?
The cranium, vertebral column, manubrium, sternum, and ribs. Everything else is the appendicular skeleton.
218
Where are rRNAs made? And how?
In the nucleolus. Nuclear imported ribosomal proteins assemble around the rRNAs in the nucleolus. The subunits are exported to the cytoplasm.
219
What are the innervations of the extrinsic and intrinsic muscles of the back (broadly)?
Extrinsic - anterior rami of spinal nerves and CN XI. Intrinsic - posterior rami of spinal nerves.
220
What muscles do ipsilateral head rotation?
Obliquus capitis inferior Rectus capitis posterior (major and minor) Longissimus capitis Splenis capitis
221
How many proteins are not translated in ribosomes?
13. They're translated in the mitochondria.
222
How do things move along the microtubules?
With motors - kkynesin toward the + end and dynein toward the - end.
223
How can you identify a cervical vertebra?
It has transverse foramina.
224
What is the action of the serratus posterior superior and inferior?
They control respiratory and proprioceptive movements.
225
What are the general mechanisms of the serine proteases?
Chymotrypsin: cleaves peptide after aromatic residues, small side chain that lets large hydrophobic residues bind. Trypsin: cleaves after Lys and Arg, has a negative side chain that binds with a positive side chain of the substrate. Elastase: cleaves Gly, Val, Ala, has small hydrophobic side chains that interact with also phobic residues in the substrate.
226
How long are telomeres?
3-20kb, once its under 1kb the cell goes into senescence (permanen G0).
227
What are deep posterior neck muscles responsible for?
Extension and lateral flexion.
228
What is the innervation of the infraspinatus?
The suprascapular nerve (C5).
229
What muscles do contralateral head rotation?
Sternocleidomastoid Semispinalis capitis
230
What is the insertion of the serratus anterior?
The anterior surface of the medial border of the scapula.
231
What are the palpable structures on the back?
Vertebra prominens (C7) Scapular spine (T4) Medial border of scapula Inferior angle (T7/T8) Iliac crest (L4) Posterior superior iliac spine Acromion Greater tuberosity Ribs 6-12 Anterior superior iliac spine Sacrum Greater trochanter Ischial tuberosity
232
How do cells attach to each other?
With Cadherin (calcium dependent). Cells of the same type express the same cadherin. cadherins form desmosomes which link to intermediate filaments and hold cells.tissue layers together.
233
What is the Michaelis-menten equation?
Vo=Vmax [S] / Km + [S]
234
What are the intrinsic shoulder muscles? Also kind of serratus anterior.
The supraspinatus, infraspinatus, deltoid, teres major and minor, and the subscapularis.
235
What is the inertion of teres minor?
The greater tuberce.
236
What is the action of the latissimus dorsi?
Extends, adducts, medially rotates the humerus. Lifts the body when climbing.
237
What is the action of teres major?
Adduction and medial rotation.
238
What increases membrane fluidity?
Increased temperature and unsaturation.
239
What is a MTOC?
AKA a centrosome, it is where microtubules grow out of. It is on one side of the nucleus under the golgi. It is made of two centrioles at right angles to each other, surrounded by a cloud of proteins (periocentriolar material). It caps the microtubule - ends near the nucleus in interphase cells and at the spindle poles in mitotic cells. The gamma-Turc in the pericentriolar material nucleates/provides the start for the tubules to grow.
240
Which polymerases bind PCNA?
Trick question, they all do - but pol beta is always found with it.
241
What if eEF2 does not have GTP?
Translation cannot proceed.
242
How does the replication complex assemble?
CDK and DDK are phosphorylated, which phosphorylates cdc6. It leaves and cdc45 joins - forming the initiation complex. The GINS complex then comes in and binds the ORIs and maintains the replication fork. RPC leads PCNA onto DNA at the origin and for each okazaki fragment.
243
What is the sequence of an intron?
A 5'GU then later an A upstream from several pyrimidines, then AG 3'.
244
What kind of drugs are the first line of defense for bacterial infections?
Anti-cell wall drugs.
245
What is Acyclovir?
A ddGTP that treats short-term viruses like HSV and VSV. It treats HIV along with AZT (zidovuzine) that blocks reverse transcriptase.
246
Where are enhancers? Can you have more than one enhancer per gene?
Upstream of the RNA-Pol binding site (up to 10kb upstream). Yes.
247
What is the typical effect of hormonal regulation?
Typically, to upregulate genes.
248
What part of RNA Pol II is important for transcript maturation?
The C-terminus.
249
How does vitamin D3 work?
It and its receptor complex upregulates the calbidin expression to elicit increased uptake of calcium by the intestines.
250
How does polio work?
It is a (+)ssRNA virus. The 5' end of its RNA has IRES structure which recruits the host 40S SSU preferentially to its own.
251
How does ricin work?
It is lecithin from castor beans (lethal at 1mg/kg) that breaks the glycosidic bond of A4324 in the 28S RNA.
252
What is A4324
Part of the 28S RNA in the large subunit that is required for elongation factor binding.
253
How does the diptheria toxin work?
The C-term of the A subunit (processed in the endosome and released in the cytosol) ADP-ribosylates eEF2 and so it cannot catalyze GTP.
254
What is the structure of the diptheria toxin?
A dimer if from Corynebacterium diptherium or a monomer from Pseudomonas aeruginosa.
255
What arises from the brachiocephalic trunk?
The subclavian artery from which emergent he vertebral artery (moves superiorly), and the internal thoracic artery (which goes inferiorly), and the rest of the branches of the subclavian.
256
Where is the angle of Louis?
Around the 2nd rib - at T4/T5.
257
What are the fascia of the breast/pectoral region?
Deltoid, Axillary, Pectoral, Clavipectoral.
258
What is the action of pec major?
The clavicular head flexes the humerus, the sternocostal head extends it from the flexed position. Both heads adduct and medially rotate.
259
What is the innervation of pec major?
The lateral + medial pectoral nerve (C5-7).
260
What is the action of pec minor?
It stabilizes the scapula against the thoracic wall.
261
What is the insertion of pec minor?
The coracoid process?
262
What is the innervation of the pec minor?
The medial pectoral nerve (C8-T1).
263
What is the action of the subclavius?
It anchors and depresses the clavicle.
264
What is the innervation of the subclavius?
Nerve to subclavius (C5-6).
265
What is the orientation of the fascia of the breast/pectoral region?
The pectoral becomes the axillary laterally. The clavipectoral is continuous with the axillary. The deltoid is continuous with the pectoral anteriorly.
266
Where is a clavicular fracture most common?
At the junction of the middle and lateral 1/3 of the clavicle. The subclavian vein is just deep to the clavicle, can be affected.
267
Describe the drainage into the subclavian vein.
The basilic and brachial veins join into the cephalic vein, which joins with the axillary vein and goes into the subclavian.
268
Where does the nervous innervation to the breast come from?
The anterior and lateral cutaneous branches of the 4-6th intercostal nerves.
269
What is the dermatome of the nipple?
T4.
270
What is polythelia?
Extra nipples.
271
What's the retromammary space?
The space between breast and pectoral fascia.
272
What are the parenchyma?
At puberty, the lactiferous ducts form 15-20 lobules of mammary glands, which constitute the parenchyma.
273
What's inside the breast?
Secretory ligaments, fat, and suspensory ligaments holding it up.
274
What is the blood supply of the medial mammary?
The internal thoracic artery.
275
What is the blood supply of the lateral mammary?
The lateral thoracic artery. Also posterior intercostal arteries give lateral mammary branches from the lateral cutaneous branches.
276
Where do breast carcinomas usually come from?
Adenocarcinomas arising from the epithelial cells of the lactiferous ducts in the lobules.
277
What are some general symptoms of breast cancer?
Lymphedema, swelling, peau d'orange, can feel palpable nodes.
278
What are the symptoms of breast cancer that has invaded glandular tissue?
Large dimples caused by shortening / traction of the suspensory ligament.
279
What are the symptoms of breast cancer that has invaded retromammary space, pectoral fascia, or interpectoral lymph nodes.
Pectoral fascia - rock-hard, fixed nodule. The breast elevates when the pec contracts.
280
What are the symptoms of breast cancer that has invaded the subareolar space?
Retraction and deviation of nipples caused by shortening of ducts.
281
What are the types of mastectomies?
Simple/total - breast tissue. Modified radical - breast tissue + lymph nodes. Radical - breast tissue + lymph nodes + muscle.
282
Where does breast lymph go?
To the subareolar lymphatic plexus.
283
Where do the lateral quadrants of the breast drain their lymph to?
The axillary lymph nodes (they get 75% from these areas).
284
Where do the medial quadrants of the breast drain their lymph to?
The parasternal lymph nodes (they can also travel to the contralateral breast).
285
Where do the inferior quadrants of the breast drain their lymph to?
The subdiaphragmatic lymph nodes.
286
Where do the axillary lymph nodes drain to?
The humeral, subscapular, pectoral LNs -\> the central LNs -\> the apical LNs. Mostly the pectoral LNs first though.
287
What is the most common sense of breast cancer metastasis?
The axillary lymph nodes.
288
What is a sentinel lymph node?
The first node to drain an affected area. Radioactive particles injected at least 3-4 hours prior to surgery. If tumour is in the medial breast, the SLN may be in the sternal/internal mammary chain.
289
Where does the subclavian artery turn into the axillary artery?
At the lateral border of the first rib.
290
Where does the axillary artery become the brachial artery?
At the inferior border of teres minor.
291
What are the branches of the axillary artery?
The superior thoracic, the thoracoacromial (clavicular, acromial, deltoir, pectoral), the lateral thoracic, the subscapular (thoracodorsal, circumflex scapular, etc), the posterior circumflex humeral, the anterior circumflex humeral.
292
What percent of the genome is used for transcription?
27%.
293
What is haploinsufficiency?
A loss of function mutation where being a heterozygote you do not make enough of the functional protein.
294
What is dominant negative?
Where a mutated defective allele actually inactivates the functional other allele to the point that it would be better to just only have one copy of the allele. This is common in proteins that make homodimers/multimers.
295
What are some examples of tautomeric shifts that result in mutations?
T going keto-\>enol A going amino-\>imino
296
What are some examples of deamination resulting in mutations?
A-\>I C-\>U G-\>Xanthine 5'methylC-\>T
297
What are intercalating agents and what are some examples?
Planar, aromatic agents that insert between base pairs and push them apart. Proflavin, EtBr.
298
Name a base analog.
5'Bromouracil in keto is a T analog and in enol is a C analog.
299
How do bacterial protect their own DNA from restriction enzymes?
Through the methylation patterns.
300
What are Alu sequences?
The most common of repetitive DNA sequence. A type of SINE (300bp) that is very active in transposition and often causes disease. It encodes a 7S L RNA that makes SRP.
301
What is SRP?
Signal recognition peptide. a ribozyme that recognizes amino terminals of newly translated proteins. It brings the ribosome into the ER and forms the RER. All SRP bound proteins will be put into the ER.
302
What are the components of a plasmid?
RE sites, ampicillin resistance (Ampr), an ORI, LacZ.
303
What is a probe?
An ssRNA or ssDNA that is labeled wit an enzyme, a fluorescent tag, or a radioactive tag. They can be made to bind with high or low stringency.
304
How big are ASOs?
15-20nt.
305
What genetic risks come with advanced maternal or paternal age?
Maternal - abnormal chromosome number Paternal - point mutations
306
What does base excision repair correct? What if it doesn't do the repair?
Single nucleotide mistakes. Either a mutation or a break in DNA will occur - the latter causes apoptosis.
307
How does base excision repair work?
A glycosylase removes the base, then an AP EN comes in. In short patch repair, a 5'dRP lyase is followed by a polymerase (nondispacing synthesis) and then a ligase. In long patch repair, a polymerase comes in (displacing synthesis) followed by a flap EN and then a ligase.
308
What is Lynch syndrome?
AKA Hereditary non polyposis colon cancer. An autosomal dominant defect in mismatch repair. It causes a \>50% risk of colon cancer and an increased risk of endometrial and other cancers.
309
What does nucleotide excision repair correct? What if it doesn't repair?
UV damage. If it doesn't work, mutations accumulate and eventually the cell results in senescence.
310
What is TC-NER? What illnesses can be caused by mutations to the mechanism?
RNA Pol itself identifies the lesion by halting, and recruits repair enzymes. Mutations can cause trichothiodystrophy (rough scaling skin, brittle hair, impaired mental function) or cockayne syndrome. Both of these have photosensitivity.
311
What is G-NER? What illnesses can be caused by mutations to the mechanism?
XPC-RAD23B or DDB1-DDB2 scan the whole genome. They uncoil a ~40nt loop, and remove 25-30nt. RPC loads polymerase delta/epsilon/ki onto the 3' end and ligase seals the nick.
312
What if double strand break repair fails to repair?
Senescence and then apoptosis.
313
What are the types of double strand break repair?
NHEJ, Homologous recombination (needs to be done in metaphase, requires a sister chromatid), MMEJ (microhomology mediated end joining). MMEJ first degrades the 3' ends to reveal small regions of homology and then copies the homologous region to repair the break.
314
What is ataxia-telangiectasia?
A homozygous mutation in ATM related protein kinase (a signalling protein required for dsDNA break repair). Cerebellar ataxia starting in early childhood, thymus hypoplasia, immunodeficiency, lymphoreticular malignancies, dilation of small blood vessels (telangiectasia), extreme sensitivity to ionizing radiation.
315
What happens if singe strand breaks aren't repaired? How are there repaired?
DNA replication will halt followed by homologous recombination. It's repaired using DNA ligase in all cells if detected prior to replication.
316
What can RFLP detect?
Paternity, large insertions/deletions.
317
How is Sickle-cell anemia caused?
It is a mutation in the beta chain of hemoglobin that eliminates an MstII cut site.
318
How is Huntington's Chorea caused?
\>35 CAG repeats.
319
What is PCR most useful for?
For when there are small amounts of DNA, e.g. preimplantation testing, identifying pathogenic DNA, sequencing fossil DNA.
320
How long are the probes in microarrays?
30-100nts.
321
How does whole genome sequencing work?
Microarrays that find polymorphisms statisticlaly associated with a trait (linked). Follow up with sequencing.
322
How does next-gen sequencing work?
It uses ddNTPs like in Sanger but they are labeled with coloured dyes and a machine reads the order of colours going through it to determine the sequence.
323
What are BRCA1 and BRCA2?
22 exons, \>5500bp and 26 exons, \>11,000bp respectively. Mutations in these dominantly account for 2-4% of breast and ovarian cancers, especially early onset ones.
324
How do you detect CNVs?
Make a CGH array - probes for monomorphic DNA sequences scattered all over the genome. Reference DNA labeled green, patient labeled red, mix in 1:1 ratio, compare the red:green ratio.
325
How do ZFNs work?
A FokI endonucleare targeted with a sequence of covalently fused Zn fingers.
326
What is the relationship between ALS and the SOD-1 mutation.
The G93A in SOD-1 is mutated. A knockout of the SOD-1 gene does not mimic ALS in mice, but a knockin of the mutation does.
327
What's the use of whole-genome sequencing?
To discover single-gene (Mendelian) disorders, rare variants, figure out location of a mutation, predictive testing for disease susceptibilities, determining risk to offspring, cancer genomics, comprehensive embryo screening.
328
What is Bartter syndrome?
A membrane transport defect that causes renal salt wasting, hypokalemia, hypotension, metabolic alkalosis.
329
What is Fick's law?
Applicable only in simple diffusion. J=A/T x S x (C1-C2) A being surface area, T being thickness, S being lipid solubility, and the concentration gradient being electrical or chemical depending on whether or not they are electrolytes or not.
330
What kind of things need help crossing the membrane?
Hydrophilic things.
331
How are Jmax and Km found?
By plotting J against concentration gradient.
332
Describe a pore.
Not selective, not regulated, lots of incorrect things can get through.
333
Describe an ion channel.
Water filled pore, selective and gated. An alpha subunit and regulatory subunits. Has a pore forming region, selectivity region, and a gate (maybe an inactivation gate).
334
What is the function of the Na+ channel?
Voltage gated generates action potentials. Non voltage gated results in Na+ transport in epithelia.
335
What is the function of the K+ channel?
Maintain membrane potential, terminate signal in excitable cells, excite muscle and nerve cells. Homeostasis of K+ (e.g. GI tract, kidney).
336
What is the function of the Ca++ channel?
Calcium entry to cells, signalling mechanisms, excitability in some cells.
337
What is the function of the Cl- channel?
Excitability in CNS neurons and transport of Cl- out of cells (e.g. in epithelia).
338
What is the exchange rate of the Na+/K+ "sodium pump" ATPase? What cells is it in?
3 Na+ out, 2 K+ in. It's in virtually every cell.
339
What is the function of the Ca++/H+ ATPase? What cells is it in?
Also called PMCA - it is in most cells and helps them maintain low intracellular calcium.
340
What is the function of the H+/K+ ATPase? What cells it it in?
It exchanges 2 of each. It is in the plasma membranes of parietal cells in the stomach and intercalated cells in the kidney (into gastric/collecting duct lumen).
341
What is the function of the H+ ATPase? What cells it it in?
It pumps H+ out of the cytosol into various organelles. A form is expressed in the plasma membrane of some kidney nephron cells.
342
Name some antiporters?
H+/Na+. HCO3-/Cl-. out/in
343
Name some cotransporters/symporters
Na+/Cl- Na+/Cl-/K+ Na+/glucose Na+/amino acids all go in.
344
What is a uniporter? What are examples?
A channel selective for a single solute - the solute binds at one side of the membane, undergoes a conformational change, releases the solute on the other side, returns to its nonbound conformation. The GLUT1-4 transporters that move glucose into cells are an example.
345
What's the difference between GLUT1 and GLUT2?
GLUT1 is in most cells, and a deficiency causes epileptic disorder. GLUT2 is in the pancreas, liver, kidney, and a deficiency causes Fanconi-Becel syndrome.
346
What are the relative speeds of a pore, channel, and carrier?
Pore\>channel\>carrier
347
Describe the Na+/K+ pump-leak coupling.
Na+ enters the cell, coupled to Ca+ exiting. The entered Na+ exits via the Na+/K+ leak pump. The K+ then exits via leak channels, generating the negative membrane potential.
348
What are the percentages of total body water in men, women, newborns?
60%, 50%, 75%
349
In a man, what are the approximate percentages of different water compartments?
40% ICF, 20% EFC ( roughly 13% interstitial and lymph, 3% plasma, 1% transcellular fluid)
350
What is formula used to find volume of a container with an indicator?
V=M/C or if indicator is not ideal in a significant enough way, V=M-Mexcreted/C
351
What are the qualities of an ideal indicator?
Nontoxic, rapidly and evenly distribute, restricted to compartment, not metabolized, has an easy to measure concentration, does not change body fluid distribution.
352
What indicator(s) are typically used in the ECF?
Radiosulphate, inulin, mannitol, thiosulfate
353
What indicator(s) are typically used in the plasma?
123I-albumin, Evan's blue
354
What indicator(s) are typically used in the interstitial fluid?
ECF plasma
355
What indicator(s) are typically used in the intracellular fluid?
TBW-ECF
356
What is osmosis?
Diffusion of fluid from low osmolality to high osmolality compartments.
357
What is net flux of water?
The sum of the unidirectional fluxes - when osmolality is increased, unidirectional flux decreases from that compartment.
358
How can you measure osmotic pressure?
By applying a hydrostatic pressure that prevents the net influx of water.
359
What is the van't Hoff equation for osmotic pressure?
pi= n C R T (n=number of particles, C=mol/L) This predicts the osmotic pressure for very dilute solutions, depending on the solute and concentration a different correction factor needs to be subtracted from this value to make it more accurate.
360
What are osmolarity and osmolality measured in?
Osmolarity: mosm/L Osmolality: mosm/KgH2O
361
What is the normal osmolality for ICF and ECF?
275-290 mosm/KgH2O.
362
How do you measure osmolality in a lab setting?
Freezing point depression.
363
What is a reflection coefficient?
Sigma. From 0-1. 1 means it is completely reflective/non permeant. An effective osmolyte.
364
What's the formula for effective/physiological osmotic pressure?
pi = sigma n C
365
What are the major effective osmolytes? How can you use them to estimate plasma osmolarity?
Na+, Cl-, glucose, BUN (blood urea nitrogen). 2[Na+] + [glucose]/18 + [BUN]/2.8.
366
What is tonicity?
Determined by effective osmolytes.
367
What are RVD and RVI?
Regulatory volume decrease and increase. RVD - common strategies are efflux of K+ as well as efflux of organic solutes like amino acids. RVI - common strategy is Na+ influx.
368
Describe the trunks of the brachial plexus.
Superior (C5 and C6) Middle (C7) and Inferior (C8 and T1)
369
Describe the cords of the brachial plexus.
The posterior cord is all the posterior divisions of the trunks. The lateral cord is the anterior divisions of the superior and middle trunk. The medial cord is the anterior division of the inferior trunk.
370
Describe the terminal branches of the brachial plexus.
Axillary - posterior cord (C5,C6) Radial - posterior cord (C5-T1) Musculocutaneous - lateral cord (C5-C7) Ulnar - medial cord (C8-T1) Median - lateral and medial cord (C6-T1)
371
Name the supraclavicular branches of the brachial plexus.
Long thoracic (C5-C7) Dorsal scapular (C5) Nerve to subclavius and suprascapular nerve (from the superior trunk - C5,C6)
372
What is the non terminal branch that comes out of the lateral cord of the brachial plexus?
The lateral pectoral nerve (C5-C7)
373
What are the non terminal branches that come out of the posterior cord of the brachial plexus?
Upper subscapular (C5), lower subscapular (C6), Thoracodorsal (C6-C8)
374
What are the non terminal branches that come out of the medial cord of the brachial plexus?
Medial brachial cutaneous, medial antebrachial cutaneous, medial pectoral - all C8,T1
375
What are the muscles of the anterior compartment of the arm? What are they innervated by? What is their blood supply?
Biceps brachii, coracobrachialis, brachialis. Musculocutaneous nerve Brachial artery
376
What are the muscles of the posterior compartment of the arm? What are they innervated by? What is their blood supply?
Triceps brachii, anconeus The radial nerve and deep artery of the arm (triangular interval)
377
What is the origin of the biceps brachii?
Long head - supraglenoid tubercle, short head - coracoid process.
378
What is the insertion of the biceps brachii?
Radial tuberosity and forearm fascia via biccipital aponeurosis.
379
What is the action of the biceps brachii?
Supinates, flexes supine forearm, helps hold humeral head in glenoid fossa.
380
What is the action of the coracobrachialis?
Adduct humerus, flex arm.
381
What is the action of the brachialis?
Flexes the forearm in all positions.
382
What is the insertion of the triceps brachii?
The olecranon process.
383
What is the action of the triceps brachii?
Long head - extends forearm, adducts and extends arm, resists inferior dislocation of humerus in adduction
384
What is the action of the anconeus?
Assists in forearm extension, stabilizes the elbow.
385
Where are the capitulum and trochlea relative to each other?
Capitulum is lateral, trochlea is medial.
386
Where are the coronoid and olecranon fossa relative to each other?
The olecranon fossa is posterior, and the coronoid fossa is anteriorly above the trochlea.
387
What can a surgical neck fracture result in?
Injury to the quadrangular space (the axillary nerve and posterior humeral artery). Damage to the axillary nerve results in loss of innervation to the deltoid, sensory loss of skin over the deltoid. You can feel a palpable depression under the acromion.
388
What can a humeral shaft fracture result in?
Tranverse - deltoid pulls proximal fracture laterally. Spiral - may cause shortening. Damage to the triangular interval (radial nerve and deep artery of the arm).
389
What can a distal humerus fracture result in?
Can be inter or supracondylar. Can result in damage to the medial nerve and brachial artery.
390
What are the components of the elbow joint?
Humeroulnar (hinge), humeroradial (glide), and proximal radioulnar (pivot) joints.
391
What are important portions of the radius?
Radial head + tuberosity.
392
What are the important portions of the ulna?
Olecranon process, coronoid process, trochlear notch.
393
How does supination of the arm occur?
The head of the radius swivels inside the annular ligament, against the capitulum and radial notch of ulna.
394
Describe elbow dislocation.
The most common is posterior dislocation, where the person falls on an extended, abducted arm. It hyperextends and the radius and the ulna are dislocated posteriorly relative to the humerus.
395
What is the terrible triad?
Elbow dislocation + radial head fracture + coronoid process fracture.
396
What is nursemaid's elbow?
Common in the left arm of kids 1-4. The radius comes off (subluxation and dislocation) and pinches the annular ligament against the capitulum.
397
Describe the rupture of the tendon of the long head of the biceps brachii.
Common in men over 60 as a result of tear over the intertubercular sulcus. An audible snap/pop followed by a "popeye" deformity and pain/tenderness at the shoulder.
398
What are the deep tendon reflexes?
Biceps brachii (to test musculocutaneous), triceps brachii (to test radial nerve). Diminished means lesion at the LMNs in the peripheral nerves. Brisk means lesion at the UMNs in the CNS.
399
Describe the route of the musculocutaneous nerve.
It pierces the coracobrachialis, travels distally between the biceps and brachialis, then emerges lateral to the biceps as the lateral cutaneous nerve of the forearm.
400
Describe the route of the radial nerve.
Enters the arm posterior to the brachial artery medial to the humerus, anterior to the long head of the triceps. Descends inferolaterally \*with the deep artery\* in the radial groove, between the lateral and medial heads of the triceps. When lateral to the humerus it pierces lateral intermuscular septum as it moves to the forearm anterior to the lateral epicondyle, between the brachialis and brachioradialis.
401
What does injury to the radial nerve do?
Superior to the origin of triceps = paralysis of all muscles controlled by it, sensory loss. In the radial group = paralysis of the medial head of the triceps and all posterior muscles of the forearm distal to the affected site, sensory loss. Characteristic wrist drop.
402
What does a blood pressure cuff do?
Compress the brachial artery against the humeral shaft.
403
What is a Volkmann's contracture?
Sudden occlusion or laceration of the brachial artery resulting in a permanent contraction/flexion.
404
What connects the cephalic and basilic veins?
The medial cubital veins.
405
What does the cephalic vein travel with?
The lateral antebrachial cutaneous nerve.
406
What does the basilic vein travel with?
The medial antebrachial cutaneous nerve.
407
What makes up the superficial cubital fossa?
The medial and lateral epicondyles on the top, the brachioradialis laterally, pronator teres medially.
408
What makes up the deep cubital fossa?
From medial to lateral, the biceps brachii tendon, brachial artery, and medial nerve.
409
Describe upper trunk (brachial plexus) injuries.
Caused by excessive angle increase between the neck and shoulder. Muscle paralysis depends on the location of injury. Loss of sensation on the lateral arm/forearm.
410
What is a prefixed and a postfixed brachial plexus?
C4-C8 and C6-T2 respectively.
411
What is Erb-Duchenne palsy and how is it caused?
"Waiter's tip" deformity, shoulder medially rotated and extended and adducted, forearm pronated. Deltoid, brachialis, biceps brachii paralyzed. Caused by a separation of head and shoulder (labor dystocia) during birth. An upper brachial plexus (C5 and C6) injury.
412
What is Klumpke Palsy and how is it caused?
Claw hand from ulnar nerve involvement, ape hand ith median nerve involvement. Can be associated with Horner syndrome (myosis). Caused by upper limb trauma during birth. A lower brachial plexus injury (C8 and T1).
413
What is claw hand and how is it caused?
It is weak finger abduction and adduction, medial hand numbness, clawing of digits 4-5. It is caused by medial elbow and wrist trauma - specifically trauma to the ulnar nerve.
414
What is radial nerve palsy and how it caused?
Wrist drop, inability to extend wrist, loss of sensation from dorsum of thumb. Caused by trauma to the lateral albow or fracture to the midhumerus at the radial groove.
415
What is Carpal Tunnel Syndrome and how is it caused?
Ape hand, sometimes loss of sensation on the lateral 3 1/2 digits. Wrist flexion hurts, wrist extension relieves pain. Symptoms worse at night. Caused by repetitive wrist motion (swelling within the flexor retinaculum compresses the median nerve).
416
What is winged scapula and how is it caused?
Serratus anterior paralysis, medial scapula protrudes if patient pushes against a wall. Caused by a lesion to the thoracic nerve - often by a surgery (mastectomy) and trauma to the lateral chest.
417
What is the cutaneous innervation of the radial nerve?
Basically the entire posterior compartment of the arm and the forearm.
418
What is the cutaneous innervation of the axillary nerve?
The skin over the deltoid.
419
What is the cutaneous innervation of the median nerve?
The lateral 3 1/2 fingers on the palmar side and their tips on the dorsal side.
420
What is the cutaneous innervation of the ulnar nerve?
The medial 1 1/2 fingers and the skin below them on the palm and back.
421
What indicators are used to measure TBW volume?
3H2O, 2D2O, antipyrine.
422
What does the musculocutaneous nerve pierce?
The coracobrachialis.
423
What does the medial pectoral nerve pierce?
Pectoralis minor.
424
What does the cephalic vein run with?
The lateral antebrachial cutaneous nerve (what the musculocutaneous nerve becomes)
425
What does the basilic vein run with?
The medial antebrachial cutaneous nerve.
426
What does the lateral thoracic artery run with?
The long thoracic nerve.
427
What does the brachial artery run with?
The median nerve.
