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Aristotle, Galileo, Galen, and William Harvey details
- Aristotle – all problems solved by thinking, no experiments.
- Galileo – first true scientist, performed ball experiment.
- Galen – developed physiology based on 4 humors (black bile, yellow bile, phlegm, and blood).
- William Harvey – discovered blood circulation
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Steps in the scientific method
Problem, hypothesis, experiment, data, conclusion, report
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How does a negative feedback loop work?
Sensor detects deviation from set point, sends information to an integrating center which controls effectors that correct the deviation
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How does a positive feedback loop work?
Response of effectors moves the variable farther away from the set point
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Relationship of variables to diffusion: concentration gradient, temperature, mass, surface area, distance, medium
- Concentration gradient - direct
- temperature - direct
- mass - inverse
- surface area - direct
- distance – inverse
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Carbohydrates: basic formula? Polarity? Types w/ examples?
- CnH2nOn. Polar.
- Monosaccharide (glucose, galactose, fructose)
- Disaccharide (sucrose [glucose + fructose], maltose [glucose + glucose])
- Polysaccharide (glycogen, starch)
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Lipids: polarity? Types w/ example?
- Nonpolar.
- Triglycerides (fats and oils)
- Phospholipids (phospholipids bilayer)
- Steroids (cholesterol [precursor for steroid hormones], corticosteroids [produced by adrenal glands], sex steroids [produced by gonads])
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Proteins: polarity? Levels of structure, held by? Functions?
- Mostly polar but can contain nonpolar sections.
- Primary – sequence of amino acids (peptide bonds)
- Secondary – alpha-helix or beta-pleated sheet shape (H+ bonds, electrostatic interactions)
- Tertiary – twisting/folding of a peptide chain (chem. Interactions involving R groups)
- Quaternary – interaction of multiple peptide chains (chem. Interactions involving R groups).
- Structural functions, hormones, enzymes, receptors
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Amino Acid structure?
Central C connected to Amino group (NH2), H atom, Carboxyl group (COOH), and R-group
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Transcription vs. translation?
- Transcription – DNA -> RNA
- Translation – RNA -> protein
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Mitochondria structure
Double membrane. Inner membrane (cristae) surrounds matrix.
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Rough ER function
Synthesizes proteins for cell membranes, lysosomes, and export from cell
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Smooth ER function
Lipid synthesis, Ca2+ storage, metabolize various molecules
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Golgi body function
Posttranslational modifications, sort/direct finished products to destination
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Nucleolus function
RNA synthesis
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How is apoptosis completed?
Caspaces (enzymes) fragment DNA and disassemble organelles
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Aerobic Respiration steps and ATP released
- Glycolysis – glucose breakdown (2 ATP)
- Krebs Cycle (2 ATP)
- Oxidative phosphorylation (26-28 ATP)
- 30-32 ATP total per glucose molecule
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Anaerobic Respiration alternate name? Used by? ATP released?
- Lactic acid fermentation.
- Used by quick skeletal muscle fibers and RBCs.
- 2 ATP per glucose.
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What does brain use to get energy?
Aerobic respiration of blood glucose ONLY
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Types of tissue w/ function?
- Muscle (movement, heat production)
- nerve (communication)
- epithelial (barriers, secretion/absorption)
- connective (structure/support)
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Muscle tissue types. Striation? Shape? Voluntary? Location?
- Skeletal – striated, very long, multinucleated, involuntary.
- Smooth – small, fusiform, not striated, involuntary.
- Cardiac – heart only, striated, involuntary
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Epithelial tissue types. Function? Classification?
- Covering – thin sheets that cover all body surfaces, linked via basement membrane. Classified by cell depth (Simple [1 cell thick], stratified [2+ cells thick]) and cell shape (squamous- flat, cuboidal- cube, columnar- rectangular).
- Glands – clusters of epithelial cells that secrete materials. Classified by Exocrine (w/ ducts, outside of body), endocrine (no ducts, hormones into blood)
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Connective tissue classification? Examples?
- Classified by extracellular matrix (ground substance + fibers) and cells.
- Tendons, dermis, adipose, cartilage, bone, blood
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Bulk transport: description? Examples? Active?
- Large # of molecules can be exchanged w/ extracellular fluid simultaneously.
- Phagocytosis, endocytosis, exocytosis. Active transport
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Vesicle vs. vacuole
Vesicle – small, vacuole – large
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Phagocytosis: description? What uses phagocytosis?
- Cell extends pseudopods around particle which merge to form a vacuole.
- Neutrophils, monocytes (macrophages)
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Endocytosis: description? Examples
- Invagination of plasma membrane to import materials ALSO removes material from plasma membrane.
- Pinocytosis (cell invaginates and fuses over interstitial fluid)
- Receptor-mediated endocytosis – binding to receptor proteins induces membrane invaginations and substances on receptors are pulled into the vesicle
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Exocytosis: description
Fusion of vesicle with plasma membrane, contents released into extracellular fluid ALSO adds material to plasma membrane
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Simple diffusion vs. facilitated diffusion and who uses what?
- Simple diffusion – across membrane without carrier protein (directly across membrane – nonpolar molecules [O2, CO2, steroid hormones], through channel proteins – polar molecules [water, Na+, K+]).
- Facilitated diffusion – across membrane with carrier protein (glucose)
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Blood plasma osmotic pressure? NaCl isotonic value? Glucose isotonic value?
- 300 mOsm or .3 Osm.
- 9g/L (.9% m/v) NaCl.
- 50g/L (5% m/v) glucose
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Aquaporins produced/inserted by? Function?
Produced in ER, inserted by Golgi (via exocytosis). Change membrane’s H2O permeability.
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Carrier mediated transport description? Active vs. passive?
- Both – bind to substance on one side, change shape to release substance on other side, have a maximum rate of transport (can become saturated), highly specific.
- Passive (facilitated diffusion) effected by diffusion variables.
- Active (pumps) act against concentration gradient
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Active transport examples, details?
- Ca2+ pumps – Ca2+ binds to carrier protein in cytosol, carrier protein is phosphorylated by ATP -> ADP + Pi, carrier protein changes shape moving Ca2+ out of cell (where concentration is greater).
- Na+/K+ ATPase – pumps 3 Na+ out of cell and 2 K+ into cell simultaneously to generate gradients for electrical impulses in nerves and muscles AND drive co-transport of other substances across the membrane (glucose)
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Tracts vs. nuclei vs. nerves vs. ganglia
- Tracts (axons, CNS).
- Nuclei (cell bodies, CNS).
- Nerves (axons, PNS).
- Ganglia (cell bodies, PNS)
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Axon hillock vs. axon terminal
- Axon hillock – where action potential originates, base of axon near cell body.
- Axon terminal – where neurotransmitters are released (presynaptic terminal).
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Types of neurons (functional)? Cell body/axon location? (_polar)? Afferent/Efferent? Function?
- Sensory – afferent, cell body in PNS, axon in CNS, relays stimuli from tissue to CNS, dendrites/sensory receptors, unipolar.
- Motor – efferent, cell body in CNS, axon in PNS, carries signals from CNS to effector (muscle/gland), multipolar. Somatic motor – skeletal muscles. Autonomic motor – smooth and cardiac muscle, glands. Autonomic divided into sympathetic (fight or flight) and parasympathetic (rest and digest).
- Association – interneurons, cell body and axon in CNS, receive from/send to other neurons, analyze/modulate/modify/integrate signals, responsible for cognition/memory, 99% of neurons, multipolar
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Types of neurons (structural)? Location? Shape?
- Multipolar – many dendrites with a single axon, most common (motor/association).
- Pseudounipolar – single short process that branches like a T (sensory).
- Bipolar – two processes, one dendrite one axon, rare (sensory in eyes, ears, nose)
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PNS neuroglial cells w/ function?
- Schwann’s cells – forms myelin sheath (single axon), helps regenerate damaged axons.
- Satellite cells – surrounds cell bodies in ganglia
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CNS neuroglial cells w/ function?
- Oligodendrocytes – forms myelin sheath (multiple axons).
- Astrocytes – controls permeability of blood-brain barrier, supports neuron activity.
- Microglia – act as macrophages.
- Ependymal cells – lines brain/spinal cord cavities creating CSF
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Major insulator in myelin sheath?
Multiple plasma membranes
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What is standard resting membrane potential? What 3 channels contribute to maintains this potential?
- -70 mV.
- K+ leak channels, Na+ voltage gated channels, and Na+/K+ ATPase
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Depolarization vs. hyperpolarization
- Depolarization – stimulation, more positive than RMP.
- Hyperpolarization – inhibition, more negative than RMP
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Major channel types in neurons w/ description? Location?
- Ligand-gated – binding of a chemical signal (neurotransmitter) causes channel to open, found on dendrites and cell body and synapses.
- Voltage-gated – depolarization causes channel to open (must reach threshold potential), found on axons (Ca2+, K+, Na+)
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What are the possible states for a voltage-gated Na+ channel w/ description?
- Closed – RMP, can be triggered by depolarization.
- Open – threshold (-55mV), Na+ flows into cell.
- Inactive – (+30mV), activation gate closes and is not able to be triggered
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Action potential description/information
- Begin at axon hillock,
- travel length of axon,
- rapid change driven by opening of voltage-gated Na+ and K+ channels,
- self propagating,
- all or none response [threshold potential (-55mV) must be met]
- cannot summate, must run toward axon terminal
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Events during an action potential – depolarization?
- event causes membrane to depolarize,
- if threshold potential is met voltage gated Na+ channels open causing Na+ to rapidly flow into the cell causing depolarization,
- when membrane potential reaches +30mV Na+ channels are inactivated which stops Na+ movement into the cell,
- at this time K+ channels are fully opened
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Events during an action potential – repolarization?
- K+ flows out of the cell, bringing potential back to RMP,
- when the potential is hyperpolarized beyond RMP both K+ and Na+ channels close (Na+ no longer inactive).
- Na+ and K+ gradients are restored by Na+/K+ ATPase
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What effect does a stronger stimulus have on a signal?
Signal strength remains identical (all or none) but frequency is increased
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Types of refractory period w/ description and timing
- Absolute refractory period – cannot respond to a 2nd stimulus, Na+ channels are either open or inactive.
- Relative refractory period – AP may be produced but stronger stimulus is required, Na+ channels closed but K+ still flowing out of the cell at a high rate
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Compound APs vs. individual APs?
Compound APs can vary in amplitude and threshold because many or few axons can be stimulated in a nerve (bundle of axons)
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How are neurotransmitters propagated to leave the axon terminal? Where do they go? What effect does a stronger stimulus have on this process?
- Voltage-gated Ca2+ channels on axon terminal open in response to AP, Ca2+ rushes into cell and induces exocytosis of neurotransmitter.
- Neurotransmitter diffuses across synaptic cleft and binds to receptors on the post-synaptic membrane.
- More frequent APs result in more neurotransmitters being released
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Ionotropic receptors vs. metabotropic receptors
- Ionotropic receptors – ligand-gated ion channels bind to a neurotransmitter which causes the channel to open.
- Metabotropic receptors – G-protein linked receptors generate second messengers (cAMP, IP3, DAG) which can have a variety of postsynaptic changes
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Types of synaptic potential w/ description?
- EPSP – excitatory, Na+ diffuses in, cell depolarizes, if EPSP is reaches axon hillock at threshold then AP is formed.
- IPSP – inhibitory, Cl- diffuses in, cell hyperpolarizes, makes threshold more difficult to reach
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Synaptic potential characteristics
Decrease in amplitude with distance, graded responses, no refractory period, can summate
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Spatial summation vs. temporal summation
- Spatial summation - summation due to multiple presynaptic neurons.
- Temporal summation – summation due to a single presynaptic neuron
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Nicotinic ACh receptors: ionotropic/metabotropic? Excitatory/inhibitory? Location? Function? How is neurotransmitter removed?
- Ionotropic.
- Excitatory.
- Found in specific regions of brain, skeletal muscle cells, cell bodies of autonomic motor neurons in ganglia.
- Na+ in and K+ out simultaneously.
- ACh quickly broken down by acetyl cholinesterase which is embedded in the post-synaptic cell membrane
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Muscarinic ACh receptors: ionotropic/metabotropic? Excitatory/inhibitory? Location? Function? How is neurotransmitter removed?
- Metabotropic.
- Excitatory in GI tract, inhibitory in the heart.
- Found in CNS neurons, smooth muscle, glands, and cardiac muscle.
- G-Protein dissociates into separate subunits that activate enzymes/ion channels.
- ACh quickly broken down by acetyl cholinesterase which is embedded in the post-synaptic cell membrane
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GABA receptors: ionotropic/metabotropic? Excitatory/inhibitory? Location? Function?
- Ionotropic.
- Inhibitory.
- Found in CNS neurons.
- Cl- in
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Monoamine receptors: ionotropic/metabotropic? Excitatory/inhibitory? Function? How is neurotransmitter removed?
- Metabotropic.
- Can be inhibitory or excitatory depending on postsynaptic cell.
- G-Protein dissociates into separate subunits that activate enzymes and produce second messengers that activate addition enzymes which induce metabolic changes or change in membrane potential.
- Monoamines generally taken back up by presynaptic cell then broken down by an enzyme inside the pre-synaptic axon terminal
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Examples of monoamines
- Seratonin,
- Catecholamines (dopamine, epinephrine, norepinephrine).
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autophagy
lysosome “eats” other organelles
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Chromatin
long/stringy functional unit of DNA (+protein)
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chromosome
short/condensed DNA packaged for movement
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cisternae
flattened sacks of the Golgi Body
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gene
sequence of DNA containing info. for amino acid sequence to make a protein
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glycogenolysis
breakdown of glycogen to create glucose
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osmolarity
M taking into account ALL permeable solutes
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dextrose
Isotonic glucose solution in hospitals
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membrane potential
difference in charge from inside of cell to outside of cell (typically negative)
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node of Ranvier
segment between myelenation on an axon
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saltatory conduction
APs jump from one node of Ranvier to the next increasing conduction speed (in a myelenated axon)
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