surface protein

integrin

Relevant to transport of substances across membranes

related to information transfer

related to energy transport

Immune Function

enzyme function

Object→lipid-soluble small molecules The rate of diffusion along concentration depends on the permeability of the membrane to the substance

O2, CO2, NO, NH3, N2, urea

Object→molecules that are insoluble in lipids or have low solubility in lipids Requires the assistance of special proteins in the cell membrane

Glucose and amino acids in the extracellular fluid enter the human cell Transmembrane transport of Na, K, Ca2 and other ions

carrier-mediated facilitated diffusion

Channel-Mediated Facilitated Diffusion

Directly utilizes the energy generated by ATP Mainly ions

sodium pump

Use the potential energy generated by the sodium-potassium pump to indirectly utilize ATP energy Key: Based on primary active transport

cotransport reverse transport

Absorption of glucose and amino acids in the small intestinal mucosal epithelium Renal tubular epithelial cells are reabsorbed

phagocytosis, particulate matter

swallow, liquid

Molecular structure of myofilaments

The area between two adjacent Z lines on myofibrils

Cross tube

vertical tube

Triple tube: Each transverse tube and the terminal pools on both sides form It is the key structure for the occurrence of excitation-contraction coupling activity.

The ion that couples excitation and contraction is Ca2 Thin muscle filaments slide toward the M line Ca2 binds to troponin Sarcomere shortening

Blocking agent:tubocurarine

Features time delay One way delivery one-to-one relationship Susceptible to environmental and drug effects

The initiating factor for muscle contraction is the binding of Ca2 to myogenin C of troponin. When a muscle contracts, the thin filaments slide toward the thick filaments. The length of the thick filaments themselves remains unchanged and the sarcomeres shorten.

Determine the length of the muscle before contraction, that is, the initial length

Afterload is the object of work done by a muscle or the resistance to contraction

Concept → Resting potential refers to the potential difference that exists on both sides of the cell membrane in a cell at rest. The outside of the membrane is higher than the inside of the membrane, and the potential is negative. Positive outside and negative inside

Principle of production→Ions are unevenly distributed on both sides of the cell membrane And the membrane has different permeability to various ions under different physiological conditions.

K outflow, the membrane is highly permeable to K Prerequisite → High sodium outside the membrane and high potassium inside the membrane

Polarization, the state in which the cell membrane potential is internally negative and externally positive when the resting potential exists Superization, membrane potential increases depolarization, decrease in membrane potential Repolarization, the process by which membrane potential returns to its resting potential after depolarization. Reverse polarization or superemission, the membrane potential further becomes positive after depolarization to zero potential.

Negative outside, positive inside The ascending branch, also known as the depolarization phase, includes depolarization and reverse polarization of membrane potential.

Peak potential, the ascending and descending branches of the action potential form a spike-like waveform Descending branch, repolarization process of membrane potential

feature

Three stages of experience Standby, activation, deactivation

Formation mechanism

conduction

Features

ultimate potential

excitement meaning

Three parameters of stimulation

Changes in excitability after cell excitation