生理学笔记book note 1.docx

Chapter 1
Levels anization in the human body
1. 12 systems of the human body
Nervous, Muscular, Skeletal, Endocrine, Cardiovascular, Immune, Lymphatic, Integumentary, Respiratory, Urinary, Digestive, Reproductive
Homeostasis [Dynamic: vary in a range]
1. maintenance of body fluid volume position is essential to homoestasis.
ICF=intracellular fluid
[2/3]
Interstitial fluid(4/5)
ECF[1/3]
Plasma(1/5)
ECF[1/3]
ECF=the internal environment
2. homeostasis is regulated via feedback systems & feedforward control
Involved system:
nervous system[send action potentials]
endocrine system[secrete messenger molecules: hormones]
Feedback system:
receptor-control center-effector
Feedforward control: events occur in anticipation of a change in a controlled variable.
Chapter 5
selective permeability of the plasma membrane
The lipid bilayer portion of the plasma membrane is highly permeable to nonpolar molecules(CO2), moderately permeable to small, uncharged polar molecules (water, urea, small alcohol), impermeable to ions/large, uncharged polar molecules.
gradients across the plasma membrane
Concentration gradient
Electrical gradient → membrane potential
Electrochemical gradient: net driving force that acts on an ion (decided by the magnitude & direction of both concentration & electrical gradient )
Passive transport
1. diffusion relies on the ic energy that is intrinsic to all particles.
2. simple diffusion occurs when a solute moves down it gradient without any help
Rate of simple diffusion is always proportional to the concentration gradient: steeper=higher rate
3. facilitated diffusion uses a protein to move a solute down its gradient
Channel-mediated facilitated diffusion:
gated channel / leak channel(pass slower but continuously)
Carrier-mediated facilitated diffusion
Specificity
Affinity: affinity of binding site for the solute is the same regardless of which side of the membrane. So direction of transport is deter