| Question | Answer |
|---|---|
| What is Vesicular transport? | the means by which large particles, macromolecules, and fluids are transported across the plasma membrane, or within the cell |
| Exocytosis? | move substances from inside the cell to the extracellular environment |
| Endocytosis? | move substances from OUTSIDE the cell to the intracellular environment |
| Phagocytosis? | type of endocytosis where an entire CELL is engulfed |
| What are the 2 vesicular transport processes that move molecules using protein-coated vesicles? | Transcytosis and vesicular traffiking |
| Where is Na+ more concentrated? | OUTSIDE the cell |
| Where does Na+ want to move? | Inside the cell |
| Where is K+ more concentrated? | INSIDE the cell |
| Where does K+ want to move? | to the outside of the cell |
| The Na+K+ pump is what kind of pump? | it is a counter transport |
| What are the 2 main types of secondary active transport? | The cotransport and the counter transport |
| CoTransport = ? | substance is transported in the SAME direction as the driver |
| Counter transport = ? | Substance is transported in the OPPOSITE direction as the driver |
| The Carrier Protein is located where? | on the plasma membrane of all cells |
| What plays an important role in regulating osmotic balance by maintaining Na+ and K+ balance? | Carrier Proteins |
| Inhibition by ouabain causes what? | Cells to swell and burst |
| The Na+-K+ pump exports what? | 3 Na+ |
| The Na+-K+ pump inports what? | 2 K+ |
| How much energy does the Na+-K+ ATPase pump use? | 2/3rds of cells energy! |
| What are the 3 primary active tranporters? | Na+-K+ ATPase pump, Ca2+ ATPase (Serca pump), and H+ ATPase |
| Which pump is present on the cell membrane and the Sarcoplasmic reticulum? | The CA2+ ATPase (active transport) |
| Which pump is found in parietal cells of gastric glands and intercalated cells of renal tubules? | The H+ ATPase |
| What is a secondary Active Transporter? | The energy is derived secondarily from energy that has been stored in the form of ionic concentration differences of secondary molecular or ionic substances between the two sides of a cells membrane (1st from primary active transport) |
| What is a primary active transporter? | the energy is derived directly from breakdown of ATP or some other high energy phosphate compound. Molecules are pumped against gradient. DIRECT use of energy |
| Voltage gated = ? | responds to the electrical potential across the cell membrane |
| Chemical (ligand) gating = ? | some protein channel gates are opened by the binding of a chemical substance (ligand), which causes a condormational/chemical bonding change in the protein molecule that opens/closes the gate (Ach) |
| Characteristics of Ion channels? | Ungated (size, shape, distribution of charge, etc) and Gated (voltage and chemically) |
| Nicotinic ACh receptor Channels are an example of what kind of channel? | A chemically gated ion channel |
| What are the 3 things that ion channels 'gate' in response to? | (1) Changes in membrane potential (2) occupation of receptors (3) mechanical forces |
| Changes in membrane potential: | (usually depolarization) Voltage gated channels. Action Potential propagation relies on voltage gated channels |
| Occupation of receptor: | Ligand-gated or receptor operated channels |
| Mechanical forces: | Mechanosensitive channels – important for proprioception |
| What are the structures in the Ion Channels? | Protiens that span the membrane, gave water filled channel that runs through protein |
| What are the properties of Ion Channels? | Have Conducting and Non-conducting states. Transition between states = "gating" |
| What is the permeability of axon membrane to ions determined by? | The number of OPEN channels |
| Which of the following can go into non-selective cation channels? Na+, Cl-, K+ |
Na+ and K+ |
| Which can go into Anion Channels? Na+, Cl-, K+ |
Cl- |
| Most voltage-gated channels open in response to what? | depolarization |
| Activation = ? | opening of channel when membrane is depolarized |
| Deactivation = ? | Closure of channel when membrane repolarizes |
| What 3 molecules diffuse through the cell membrane? | O2 (non polar), CO2 (polar and small), H2O (also polar and small) |
| What kind of molecules pass through the protein channels? | Glucose, Amino acids, and Na+ |
| Glucose, Amino acids, and Na+ pass through channels via what kind of diffusion? | Facilitated Diffusion (it is still PASSIVE, but they have a protein channel) |
| Passive Channels? | Non gated, Open at all times |
| Voltage gated channels? | contain voltage sensitive string of amino acids that cause the channel pore to ope or close in response to changes in membrane voltage |
| Channel pump? | Are Energy-driven ion exporters and/or importers designed to maintain steady-state ion concentrations. |
| What is vital to maintenance of the RMP? | the Na+K+ pump and leak channels |
| Transmitted gated channels? | abound in post-synaptic membranes. some are activated by transmitter molecules, others inderectly |
| Transductoin channels? | Are activated by peripheral sensory stimulation. sensory nerve endings exhibit different stimulus specificities in different locations, (eg mechanical in mm) |
| What molecules can diffuse through the cell membrane? | O2 (non polar), CO2 (polar, but small), H2O (polar, but small) |
| what molecules pass through protein channels/facilitated diffusion? | Na+, Glucose, and amino acids |
| (simple) Diffusion = ? | is a process in which substances move directly through the plasma membrane from an area of higher concentration to an area of lower concentration |
| Facillitated Diffusion = ? | Substances are moved through the plasma membrane by binding to protein carriers in the membrane or by moving through the channels membrane proteins |
| What are the 2 passive processes? | diffusion (no protein) and facilitated diffusion (protein needed to get larger molecules through) |
| Lipid-soluble molecules move how? | readily across the membrane |
| Water-soluble molecules cross how? | via channels or pores |
| K+ always wants to go which way? | from inside to OUTSIDE the cell |
| Na+ always wants to go which way? | from outside to INSIDE the cell |
| conformation change means what? | a gate opens |
| What are the 3 factors affecting the rate of diffusion? | Concentration difference, Permeability, and electrical potential |
| Concentration difference = ? | basically, the steepness of the concentration gradient. The bigger the difference between the 2 sides, the quicker the rate of diffusion |
| Permeability = ? | It is decreased by molecular weight of molecule. It is increased in membrane thickness. It is Controlled by the type of molecule or ion diffusing. |
| Which kind of transports require energy? | Active transports |
| Which kind of transports don't require energy? | Passive transports/facilitated diffusion |
| Passive process encompasses which kinds of transportation? | diffusion, osmosis, and facilitated diffusion |
| Active process encompasses which kinds of transportation? | Active transport, Exocytosis and Endocytosis |
| O2/H2O diffusing into the cell and CO2 diffusing out is what kind of transport? | Simple diffusion |
| A nerve electrical impulse results from opening protein channels for ions that move how? | via facilitated diffusion |
| pumping Na+ out and K+ in the cell is what kind of transportation? | Active transportation |
| How many Na+ move in the Na+K+ pump? | 3 Na+ out |
| How many K+ move in the Na+K+ pump? | 2K+ in |
| What are the functions of the plasma membrane? | maintain high concentration of materials inside the cell, keep bad stuff out, control movements in/out of cell, and let the cell sense its environment |
| what are cations? | Positively charged ions (Na+ and K+). They migrate to the cathode |
| what are anions? | Negative charged ions (Cl-). Migrate to the anode. |
| Which molecule can move most freely in/out of the cell and why? | Cl- —- because its equilibrium potential is closest to the inside of the cell (~ -71mV) |
| what (molecules) don't move through the cell on their own? | Ions, Hydrophilic molecules larger than water, and large molecules such as proteins |
| To regenerate, neurons must: | Be myelinated, have intact cell body, have functional schwann cells, axonal sprout growth rate is 1-4mm/day, and has to be close together |
| tract = | a collection of axons traveling together (CNS) |
| nucleus = | a cluster of cell bodies (CNS) |
| Lemniscus = | a tract in the brainstem (CNS) |
| Funiculus = | "small cord" region of white matter in the spinal cord (CNS) |
| Fasciculus = | "small bundle" of nerve fibers in the CNS (smaller than funiculus) |
| Decussation = | the region where a tract crosses to the opposite side (CNS) |
| Glial cells = | support cells in the CNS |
| Nerve = | a collection of axons traveling together (PNS) |
| Ganglion = | a cluster of cell bodies (PNS) |
| Schwann Cells = | Cells providing myelination (PNS) |
| Glial cells = | Support cells in the PNS |
| Multiple sclerosis occurs in the PNS or CNS? | The CNS – immune attack on Oligodendrocytes |
| What is the onset like for MS? | Rapid or slow onset |
| Guillain Barre occurs in the PNS or CNS? | PNS – immune mediated attack on nerve roots (schwann cells) |
| what is the onset like for Guillain Barre? | RAPID onset |
| Why can't the CNS regenerate? | no basement membrane, aconds in the CNS don't form neurilemmas, damaged neurons rapidly convert to scar tissues, and oligodendracytes bear growth-inhibiting proteins that prevent CNS fiber regeneration |
| Mature neurons are what? | Amitotic |
| Macrophages do what? | remove debris |
| Schwann cells =? | form regeeration tube and secrete growth factors |
| axons do what for the regeneration of nerve fibers in the PNS? | they regenerate damaged part |
| The Sodium-potassium pump moves ions across the cell membrane in which of the following configuration? | 3 sodium out, 2 K+ in |
| The parasympathetic system does what? | slows heart rate/ speeds peristalsis/ slows the breathing range/ constricts the pupil |
| What are some major components of the PNS? | Spinal nerves INSIDE the vertebral column/ DNRG/ spinal nerves outside the spinal cord/ peripheral nerves |
| What are the major components of the CNS? | the spinal cord and brain |
| Where do axon collaterals emerge on a myelinated neuron? | From the nodes of ranvier |
| Both MS and Guillain Barre: | Are disorders of the immune system |
| What is a main factor associated with inscreased conduction velocity in the axon? | large diameter (aka lots of mylenation) |
| Which type of neurons is found in the olfactory epithelium? | Bipolar |
| Which type of neurons is found in the DNRG (somatosensory)? | Pseudounipolar |
| Which type of neuron is found in CN 8? | Bipolar |
| Which type of neuron is found in the retina? | Bipolar |
| Which type of neuron is found in the purkinje cells (cerebellum)? | Multipolar – Golgi Type I |
| Which type of neuron is found in pyramidal cells (cerebral cortex)? | Multipolar – Golgi Type I |
| Which type of neuron is found in the Ant Horn cells of the spinal cord? | Multipolar – Golgi Type I |
| Which type of neuron is found in the stellate and Granule cells (cerebellar cortex)? | Multipolar – Golgi Type II |
| Which type of neuron is found in the Renshaw cells of the spinal cord? | Multipolar – Golgi Type II |
| Which kind of neuron has 1 LONG axon and 2+ dendrites? | Multipolar – Golgi Type 1 |
| Which kind of neuron has 1 SHORT axon and 2+ dendrites? | Multipolar – Golgi Type 2 |
| Which neurons are in the CNS ONLY? | Multipolar – Golgi Type 2 (Interneurons) |
| What are 2 other names for Interneurons? | Association and internuncial neurons |
| Which type of neurons transmit info from external environment to the CNS? | Sensory neurons (pseudounipolar and bipolar) |
| Which type of neurons transmit info from the CNS to the external environment? | Motor Neurons (Multipolar – Golgi type I) |
| Materials can be moved from low to high concentration via what transport? | Active transport |
| Which of the ion channels in the neuron are always open? | Leakage channels |
| Which of the following transport mechanisms can move Na+ across the cell membrane? (yes or no) Primary active transport/Secondary active transport/ Facilitated diffusion? | Primary: Yes/ Secondary: Yes/ Facilitated: Yes |
| In the resting state the neuron has: | Higher concentration of K+ and lower concentrations of Na+ and Cl- |
| If the Na+ equalibrium potential is 60+mV and the membrane potential moves from its resting potential to 0mV, in what direction will Na+ now move through any open Na+ channels? | Na+ will tend to move into the cell |
| if the K+ equilibrium potential is -90mV and the membrane potential is -70mV, in what direction will K+ move through open K+ channels? | K+ will tend to move OUT of the cell |
| In order for sodium to pass through a voltage-gated channel: | Both gates must be open |
| What is the Equilibrium potential for K+? | Ek = -90 |
| What drives K+ in and out? | Electrostatic forces drive K+ in//Concentration gradient drives K+ out |
| The resting membrane potential of a neuron is determined by: | The permiability of the membrane to particular ions. "the resting membrane potential is closest to the equilibrium potential for the ion with the highest permeability" |
| Gated channels exhibit which kind of properties? | They can be either voltage or chemically gated// They are activated in response to depolarization// they are deactivated in response to repolarization |
| What is important in determining the membrane potential when multiple ions are permeable to the membrane? | The concentration gradient of the individual ionic species// The permeability of the membrane to the individual ionic species |
| What is mostly responsible for the negative charge? | The protein anions primarily on the ICF side |
| In the resting state, the neuron membrane is: | impermeable to protein anions, slightly impermeable to Na+, 75X more permeable to K+, freely permeable to Cl- |
| What are the 3 important factors? | concentration gradient, electro chemical gradient, and permeability |
| what is the mV for K+? | -90 |
| what is the mV for Na+? | +60 |
| What is the mV for Cl-? | -71-ish |
| A membrane potential = ? | is a voltage across the cell membrane that occurs due to a separation of oppositely charged particles (aka charge difference across the membrane) |
| The resting membrane potential = ? | is a condition in which the inside of the cell membrane is negatively charged compared to the outside |
| K+ concentration = | K+ goes OUT of the cell (based on how many other K+'s are hanging out in the cell — goes from High to low concentration) |
| K+ electrochemical gradient = ? | K+ goes IN (based on cell charge) |
| Axodendritic synapses usually have what effect on the target neurons? | MOSTLY Excititory effect |
| Axosomatic synapses have what effect on the target neurons? | MOSTLY Inhibitory effect |
| Axoaxonic synapses have which effect on the target neurons? | almost always inhibitory |
| Neurofilaments = ? | provide skeletal stability by attachment to proteins beneath the axolemmal membrane |
| Tetanus toxin prevents the release of what? | Glycine (= motor neurons go out of control – especially those to the face, jaws, and spine) |
