A&P Unit 3 Exam: Chapter 11 (part 2)

Depolarizing graded potential can combine (summate) to cause an _____ _______.

Action potential

Cells produce electrical signals called _____ ______ It is the transfer of ______ from one part of the body to another Electrical properties result from _____ concentration differences across plasma membrane and ________ of membrane

Action potentials Information Ionic Permeability

What principles correlate with action potential's? No matter how strong the stimulus, as long as it is greater than threshold, then action potential's will occur

All or none principal

For depolarization and/or hyperpolarization, it has to do with the _______ in membrane potential. There is no action potential. You can change it from the typical resting membrane potential

Changes

Changing the concentration of Na+ inside or outside the cell has little effect since the gates remain _____ (since there are few leak channels for Na+) But, voltage gated channels open (like when ACh attaches to receptors), and Na+ diffuses in, ______ the membrane.

Closed depolarizing

Braided potential's are conducted in a _______ fashion (they will go away as they go along the plasma membrane of the cell body), meaning that their magnitude decreases as they spread over the plasma membrane. Greater potential cannot be measured a few millimeters from the point of stimulation.

Decremental

Changing the resting membrane potential: 1. If extracellular concentration of K+ increases: less gradient between inside and outside. ________ occurs 2. If extracellular ion concentration decreases: steeper gradient between inside and outside. ________ occurs

Depolarization Hyperpolarization

________: movement of resting membrane potential (RMP) towards zero. More positive inside because K+ is not leaving and Na+ is greater outside; closer to zero _______: movement of resting membrane potential (RMP) further away from zero; more K+ leaves to cell

Depolarization Hyperpolarization

Action potentials are caused by a _____ phase followed by a _______ phase

Depolarization Repolarization

_______: more positive (gets to positive threshold) _______: more negative (make it after potential [slight hyperpolarization])

Depolarization Repolarization

Proteins (negatively charged) are synthesized _____ the cell (nucleus is the instruction manual for it): large, don't dissolve in phospholipids of membrane.

Inside

Establishing the resting potential: 1. At equilibrium there is very little movement of _____ or other ions across the plasma membrane (movement of K+ out through leakage channels equals movement of ions is due to attraction to trapped _____: leakage channels working both directions. Movement of ions depends upon concentration gradient).

K+ proteins

The resting membrane potential is establish when the movement of ______ out of the cell is equal to the movement of _____ into the cell

K+ (potassium) 2x

______ ion channels: many more of these for potassium and chloride than for sodium. So, at rest, more potassium and chloride are moving than sodium. Protein repels chloride, they move out. Potassium are higher concentration on the inside than outside, so they move out. Always open and responsible for ______ when membrane is at rest. Specific for one type of ion although not absolute

Leak Permeability

Leak ion channels: In the resting cell, only the leak channels are ______; the gated channels are ______. Because of ion concentration differences across the membrane, K+ diffuses ____ of the cell down it's concentration gradient and Na+ diffuses ____ the cell down it's concentration gradient. The tendency for K+ to diffuse out of the cell is opposed by the tendency of the positively charged K+ to be attracted back into the cell by the negatively charged proteins

Leak: open Gated: closed K+: out Na+: in

Changing the resting membrane potential: K+ membrane permeability changes. In resting membrane, K+ in and out is equal throughout the ______ channels. But there are also ______ K+ channels in the membrane. If they open, more K+ diffuses out but this is _______ by the negative charge that starts to develop as the K+ diffuse out.

Leakage gated opposed

____ Na+ channels are opening for depolarization to occur. ____ (ion) goes into the cell and causes hyperpolarization

Ligand Cl-

_____-______: Open or close in response to a molecule that binds to receptors: proteins or glycoprotein. Such as acetylcholine bonding to its receptor proteins. Receptor proteins are usually glycoproteins. (For example, ACh binds to acetylcholine receptor on a sodium channel. Channel opens, and sodium enters the cell)

Ligand-gated

Number of charge molecules and ions inside and outside the cell is nearly equal (_____ equal). Concentration of ____ is higher inside than outside the cell, ______ is higher outside than inside the cell

NOT K+ Na+

What ion is responsible for action potential's because it causes depolarization?

Na+

Leak channels are attracted back to negative charge of chloride (potassium (K+) goes out and is attracted back in). The sodium and potassium pump keeps sodium at a high concentration _____ the cell

Outside

At equilibrium, very little movement of K+ or other ions takes place across the _____ ______

Plasma Membrane

There are more Leak Ion channels for ____ than for ____

Potassium than for Sodium

______ difference: unequal distribution of charge exist between the immediate inside and immediate outside of the plasma membrane: -70 to -90 mV

Potential

Chlorine ions are repelled by ______ and exit through always open non-Gated chlorine _____. Gated ion channels open and close because of some sort of _____. When they open, they change the _______ of the cell membrane. For these channels, there's an _____ gradient and _______ gradient

Proteins Channels stimulus permeability Electrical gradient and chemical gradient

Chlorine is high on the outside because it is repelled by negative _____ proteins can't cross the membrane because they are negatively charged (don't go anywhere) they are _______ so they can't pass through the membrane

Proteins hydrophilic

Graded potentials result from: 1. Ligands binding to _______ 2. changes in _____ across Membrane 3. mechanical stimulation 4. ______ changes 5. spontaneous change in ______

Receptors charge temperature permeability

Potassium going out maintains the ______ membrane potential and keeps that equilibrium at about -70 and there are fewer leak channels for _____ which is why there is higher concentration outside of the cell

Resting sodium

Voltage gated Na+ channels are _______ to changes in extracellular Ca2+ concentrations. If extracellular calcium concentration decreases, sodium gate _____ and membrane ______ if extracellular concentration of calcium increases, gates ____ and membrane _______ or becomes __________ (action potential's are less _____ to happen since it's more negative)

Sensitive Open and membrane depolarizes Closes and membrane repolarizes or becomes hyperpolarized likely

The ____ of the graded potential is proportional to the _____ of the stimulus. More depolarization will get you to that needed threshold for an _____ _____ to occur. Graded potential's can also summate. Thus, a graded potential produced in response to several stimuli as _____ than one produced in response to a single stimulus

Size strength action potential larger

Graded potentials can _____ or add onto each other. Spread (are conducted) over the plasma membrane in a decremental fashion: rapidly decreasing in magnitude as they spread over the surface of the _____ _____. Can cause generation of action potentials.

Summate plasma membrane

The ion concentration's present in a cell are the result of two processes: 1. ______ pump 2. ______ _________ Not that high concentration of sodium and chloride ions are located _______ the cell and high concentration of potassium and proteins are located ______ the cell. Note the steep concentration gradients of sodium and potassium, but in opposite directions

1. Sodium/potassium pump 2. membrane permeability sodium and chlorine high outside Potassium and proteins high inside

+____ mV is needed for action potential to propagate

+55

Graded potential's occur at the ____ cell body

Axon

The difference in charge is the ______ signal needed for action potential

Electrical

3. If leakage channels alone were responsible for resting membrane potential, in time sodium and potassium ion concentrations would eventually ______ 4. but they are maintained by the sodium potassium pump. For each ATP that is consumed (driven by ATP hydrolysis), ____(#) Na+ are moved ____ and ___(#) K+ are moved ___. It is slightly _____ outside the plasma membrane

Equalize three sodium move out two potassium move in positive

2. Na+, Cl-, and Ca2+ do you not have a great affect on resting potential since there are very ____ leakage channels for these ions (voltage gated sodium channels are sensitive to changes in ______).

Few calcium

_____ ion channels: these channels open and close because of some sort of stimulus. When they open, they change the permeability of the cell membrane

Gated

______: magnitude varies from small to large depending on stimulus strength or frequency

Graded

______Potential: this happens at the cell body where information is integrated (processed). At the cell body, it is _______ and not "all or none." Depolarization can go away (you need multiple depolarizations for an action potential to occur)

Graded (2X)

Series of permeability changes when a graded potential causes depolarization of a membrane. A large enough greater potential may cause the membrane to reach ______. Then get action potential.

Threshold

_____ receptors: respond to mechanical stimulation of the skin _____ receptors: respond to temperature change on/in the skin

Touch Temp

_______ zone: if enough depolarization happens (enough action potential), it will depolarize and summate this zone. This zone depolarizes and the action potential goes down (propagates) the _____ to the axon _____

Trigger axon terminal

_____-_______ ion channels: Open or close in response to small voltage changes across the cell membrane. At rest, membrane is negative on the inside relative to the outside. Once cell is stimulated, that relative charge changes and this channel either opens or closes. Most common are ____ or _____. In cardiac and smooth muscle, _____ is important

Voltage-Gated common: Na+ and K+ Ca2+