What is the function of the action potential in neurons? 10. Describe the role of sodium ions and sodium channels in the action potential. 11. What would happen to a neuron if it were exposed to tetrodotoxin?
3. The role of the sarcoplasmic reticulum releases calcium ions that will cause the troponin/ tropomyosin complex to move. This will expose the binding sites on actin so that the cross-bridges of myosin can bind to it. *High calcium concentrations = concentration occurs (bind to troponin – moves tropomyosin out of the way to reveal the hidden receptor site) *Low calcium concentrations = concentration does not occur (troponin goes back – move the tropomyosin back in the way of the myosin = blocks). (Calcium ions) are stored in the Sarcoplasmic reticulum.
Angiotension II causes vasoconstriction, which raises the blood pressure. Angiotension II also stimulates aldosterone release from the adrenal gland. This leads to increased sodium reabsorption by the kidneys, which causes water to follow it, which then increases intravascular volume. The increased vasoconstriction and increased blood volume raise the blood pressure. Additionally, the perceived hypovolumic status causes the release of antidiuretic hormone (ADH) from the posterior pituitary.
Graded potentials are electrical signals that have variable amplitude, are localized, and travel short distances along the membrane. In contrast, an action potential has a fixed amplitude, and can travel greater distances along the membrane. 3. a. Describe how there can be an electrical change on either side of a membrane thereby generating a membrane potential. The membrane potential is due to the presence of an ionic concentration difference and electrical gradient between both sides of the membrane.movement of charged molecules across the cellular membrane leads to the creation of electrical signals.
The salts will be dissolved in distilled water by small quantities until the reaction reaches When ionic compounds dissolve in water, they either absorb energy from or release energy to the surroundings. If a chemical reaction absorbs heat from the surroundings, it is an endothermic reaction. If a solution releases heat to its surroundings, it is an exothermic reaction. The enthalpy of dissolution is the enthalpy change associated with the dissolution of a substance in a solvent at a constant pressure. The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies.
3. Liberated neurotransmitter molecules trigger nerve impulses in the first-order sensory neurons that synapse with gustatory receptor cells. 4. (From here on out it is different for each tastant) (Salty) __________ ions enter gustatory receptor cells via Sodium channels in the plasma membrane. 5.
Explain. Use the idea of what happens when these two different types of compounds dissolve in water in your answer. 6. Which compound types (ionic or covalent) produce more particles when dissolved in water and why? 7.
1. Does the body adjust its pH by glomerular filtration, tubular reabsorption or tubular secretion? Explain how it does so. Body adjust its pH by tubular secretion, because hydrogen ions generated by the dissociation分离 of the carbonic acid碳酸 are secreted by sodium-linked counter transport in exchange for Na+ in the tubular fluid and then into the bloodstream, where they help prevent changes in plasma pH. 酸离子是由于碳酸分离而生成的，碳酸是由于sodium-linked counter 跟钠交换得来的。 2.
terest 11, How neurons communicate with other cells 1 to attract other electrical charges 2 leakage channels, voltage gated channel, ligand gated channel 3 only works for the ions LiceIC+ 4 action potential, graded potential 5 it will stop exchanging 6 it will decrease 7 they are sustained 8 cell membrane 9 voltages 12. All or none principle An action potential takes place in 2 phases: Depolarization: inside the membrane becomes + Repolarization : inside becomes more – Na+ and k+ are ions that move through the membrane via ion channels and change the electrical charge of the neuron - when NA+ channels open, NA+ moves inside= depolarization - When K+ channels open, K+ moves out + repolarization - When depolarization
• By combining models of cerebral emotional asymmetry and unilateral hemispheric activation, research has that positive emotions are associated with greater left frontal brain activity and that withdrawal-related negative emotions are associated with greater right frontal brain activity. • Optimism Stabilizes Cortisol Levels and Lowers Stress-cortisol tends to be more stable in people with a positive perspective. • Cortisol- We need cortisol to stimulate our sympathetic nervous system and kickstart our bodies into action. Cortisol levels typically peak just after we wake up and tend to decline through the day in people with a healthy adaptation to stress. The optimistic