Concept; performing surgery on experimental animals while they are awake or under anesthesia, exposing organs, and applying various factors for observation

Advantages: The experimental conditions are easy to control and the observation and analysis are objective.

Example: Dissect the vagus nerve and heart of animals, electrically stimulate the vagus nerve, and observe changes in heart function.

Concept: The organs and cells of animals are removed surgically and placed in a suitable artificial environment for observation.

Advantages: It can eliminate the influence of irrelevant factors and simply observe the impact of a certain factor on organ tissue cells.

Example: Frog heart ex vivo experiment

anabolic

Catabolism

Changes in the living environment that can be felt by the body, tissues, and cells

Changes in the body's internal metabolism and external activities caused by stimulation

objective signs of excitement

muscle cell contraction

glandular cell secretion

Nerve cells produce nerve impulses

Easily excited to generate action potentials

40%

Internal environment---the living environment in which cells and tissues are in direct contact

20% tissue fluid (15%), plasma (5%), lymph, cerebrospinal fluid.

The reflex arc is the basis of reflex activity

Central Nervous System Involvement

Need to be continuously strengthened

acquired

Superiority, predictability, flexibility

Example: Looking at plum blossoms to quench thirst

congenital, genetically acquired

No involvement of cerebral cortex is required

The reflex arc is relatively fixed

Example: sucking reflex, swallowing reflex, flexor reflex

Regulation of self or neighboring cell functions