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Absolute refractory period
绝对不应期
The time interval during which a cell is incapable of initiating a second action potential.
Action potential
动作电位
An action potential is a rapid change in the membrane potential. Each action potential begins with a sudden change from the normal resting negative potential to a positive membrane potential (depolarization)
and then ends with an almost equally rapid change back to the negative potential (repolarization).
Active transport
主动转运
The movement of substances across the membrane occurs against the electrochemical gradient with the necessity of consumption of metabolic energy
afterload
后负荷
Afterload is the load that is given to the muscle after the beginning of the contraction.
All or none
全或无
The action potential fails to occur if the stimulus is subthreshold in magniture ,and it occurs with a constant amplitude and form regardless of the strength of the stimulus if the stimulus is at or above
threshold intensity, the action potential is therefore all or none in charater.
Cell membrane
细胞膜
The cell membrane, which envelops the cell is a thin ,pliable, elastic structure only 7.5 to 10 nanometers thick. It is composed almost entirely of proteins and lipids.
Channel
通道
Channels are membrane proteins that contain small, highly selective aqueous pores. Channels usually allow specific ion, eg ,Naせ,Kせ,Caぜ or Clそ to move down their electrochemical gradients across the membrane.
Complete tetanus
完全强直收缩
When the frequency of stimulation reaches a critical level, the successive contractions are so rapid that they literally fused together, and the contraction appears to be completely smooth and continuous. This is called completely tetanus.
Curare
箭毒
A substance that competes with acetylcholine for postsynaptic receptors at the neuromuscular junction and thereby blocks neuromuscular transmission.
Depolarization
去极化
The change in membrane potential away from the resting potential and toward the sodium equilibrium.
Diffusion
扩散
Diffusion means simply movement through the membrane caused by random motion of the molecules of the substances, moving either through cell membrane pores or through the lipid matrix of the membrane.
Electrochemical equilibrium
电化学平衡
Electrochemical equilibrium is a steady state, as in the resting membrane potential of a cell ,in which an electrical potential and chemical potential gradient are in balance and no net movement of charged particles occurs.
Endocytosis
入胞
Very large particles enter the cell by a specialized function of the cell membrane called endocytosis. The principle forms of endocytosis are pinocytosis and phagocytosis.
Excitation-contraction coupling
兴奋－收缩耦联
The process by which depolarization of the muscle fiber initiates contraction. The action potential is transmitted to all the fibrils in the muscle fiber via the T system. It triggers the release of calcium ions from
the terminal cisterns. The Caぜ initiates contraction.
Exocytosis
出胞
A stimulus to secrete causes the intracellular vesicles to fuse with the plasma membrane and to release the vesicles contents is called exocytosis.
Facilitated diffusion
易化扩散
In facilitated diffusion, transport proteins (carrier and channel proteins) hasten the movement of certain substances across a membrane down their concentration gradients.
Force-velocity curve
强度－速度曲线
A diagram expressing the inverse relationship between the shortening velocity and the force of contraction in muscle.
G protein
G 蛋白
A cell membrane protein that binds guanosine nucleotides and couples a hormonal signal from a receptor to an amplifier enzyme or ion channel.
Gene
基因
Each gene, which is a nucleic acid called deoxyribonucleic acid (DNA), automatically controls the formation of another nucleic acid, ribonucleic acid (RNA), this RNA then spreads throughout the cell to
control the formation of a specific protein.
Ionic channel
离子通道
Some proteins making ensembles across the membrane for ion penetration. According to whether opening the gate of channel is electrical-dependent, there are two types of channels. e.g., The ionic
channels connected to the ACh receptors at the endplate are non-electrically excited, whereas the sodium and potassium channels of axons are electrically excited.
Isometric contraction
等长收缩
Tension increases but the length of the muscle does not change when a muscle contracts.
Isotonic contraction
等张收缩
Tension remains constant but the muscle shortens when a muscle contracts.
Length-tension curve
长度－强力曲线
A graphic respresentation of the force capability of a muscle at various lengths.
Motor unit
运动单位
A motor axon, together with all of the skeletal muscle fibers it innervates.
Neuromuscular junction
神经肌肉接头
The complex structure responsible for signal transmission from nerve to skeletal muscle.
Preload
前负荷
Preload is the load that is given to the muscle prior to its contraction.
Receptor
受体
A protein molecule in the cell membrane or within cells that selectively binds to a specific chemical (hormone, growth factor, nourotransmitter, drug) and produces a specific physiologic effect.
Relative refractory period
相对不应期
A period follows the end of the absolute refractory period, during which it is possible to elicit a second action potential, but the threshold stimulus intensity is higher than usual.
Repolarization
复极化
Shortly after depolarization, the sodium channels begin to close and the potassium channels open more than they normally do. Then, rapid diffusion of potassium ions to the exterior re-establishes the
normal resting potential. This is called repolarization of the membrane.
Resting potential
静息电位
The difference in electrical potential across the membrane of an undisturbed cell, having a positive sign on the outside surface and a negative sign in the interior.
Resting stage
静息期
Resting stage is the resting membrane potential before the action potential begins. The membrane is said to be "polarized" during this stage.
Salutatory conduction
跳跃传导
Conduction of a nerve impulse down a myelinated nerve fiber by skipping from node to node.
Sarcoplasmic reticulum
肌浆网
Sarcoplasmic reticulum is a network of fine tubules and vesicles found in muscle cell and is involved in the transmission of excitation from the surface of the cell to the contractile proteins.
Second messenger
第二信使
A small, diffusible molecule produced when a hormone combines with a cell membrane receptor and which carries the message to the inside of the cell.
Sodium-potassium pump
钠－钾泵
The sodium-potassium pump is responsible for the coupled active transport of Naせ out of cells and Kせ into cells. Sodium-potassium pump is also an adenosine triphosphatase, an enzyme that catalyzes the
hydrolysis of ATP to adenosine diphosphate (ADP).
Tetanus
强直收缩
A sustained contraction resulting from the rapid restimulation of a skeletal muscle.
Tonus
紧张、张力
A sustained contraction of smooth muscle that may occur without continuous nerve stimulation.
Twitch
单收缩
The single mechanical response of a skeletal muscle to a single action potential.
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