용액 속에 수소이온이 많을수록 작은 값의 pH를 갖고, 수소이온이 적을수록 큰 pH값을 갖는다.

순수한 물의 pH인 7을 기준으로 pH 값이 7보다 작은 용액은 산성용액,

7보다 큰 용액을 염기성용액이라 한다.

슬슬 운동을 곁들이면서 일하는게 좋을 것 같다. 음 유산소 운동은 어떻게 하지;

Excitation-contraction (EC) coupling is a term coined in 1952 to describe the physiological process of converting an electrical stimulus to a mechanical response [1]. This process is fundamental to muscle physiology, whereby the electrical stimulus is usually an action potential and the mechanical response is contraction. EC coupling can be dysregulated in many disease conditions.

Smooth muscle

It is important to note that contraction of smooth muscle need not require neural input--that is, it can function without an action potential. It does so by integrating a huge number of other stimuli such as humoral/paracrine (e.g. Epinephrine, Angiotensin II, AVP, Endothelin), metabolic (e.g. oxygen, carbon dioxide, adenosine, potassium ions, hydrogen ions), or physical stimuli (e.g. stretch receptors, shear stress). This integrative character of smooth muscle allows it to function in the tissues in which it exists, such as being the controller of local blood flow to tissues undergoing metabolic changes. In these excitation-free contractions, then, there of course is no excitation-contraction coupling.

Some stimuli for smooth muscle contraction, however, are neural. All neural input is autonomic (involuntary). In these the mechanism of excitation-contraction coupling is as follows: parasympathetic input uses the neurotransmitter acetylcholine. Acetylcholine receptors on smooth muscle are of the muscarinic receptor type; as such they are metabotropic, or G-protein / second messenger coupled. Sympathetic input uses different neurotransmitters; the primary one is norepinephrine. All adrenergic receptors are also metabotropic. The exact effects on the smooth muscle depend on the specific characteristics of the receptor activated--both parasympathetic input and sympathetic input can be either excitatory (contractile) or inhibitory (relaxing). The main mechanism for actual coupling involves varying the calcium-sensitivity of specific cellular machinery. However it occurs, increased intracellular calcium binds calmodulin, which activates myosin light chain kinase (MLCK). MLCK phosphorylates the regulatory light chains of the myosin heads. Phosphorylated myosin heads are able to cross bridge-cycle. Thus, the degree to and velocity of which a whole smooth muscle contracts depends on the level of phosphorylation of myosin heads. Myosin light chain phosphatase removes the phosphate groups from the myosin heads, thus ending cycling (and leaving the muscle in latch-state).

미리 행동한다.

그런건 당연한 일이다.