A flexor reflex, which is also called a withdrawal reflex, is a multisynaptic reflex. It is a type of protective reflex where a painful stimulus triggers the contraction of flexor muscles. These reflexes have a slower onset and a longer response than the stretch (extensor) reflexes. A flexor reflex requires the contraction of a flexor muscle and relaxation of the extensor muscle in that limb. A good example of a flexor reflex is when you touch your forearm to the side of a hot oven.
Causes of Hypoxia. A severe asthma attack, or flare, can cause hypoxia in adults and kids. During an attack, your airways narrow, making it hard to get air into your lungs. Coughing to clear your lungs uses even more oxygen and can make symptoms worse. Other things can cause hypoxia, too: 1  Lung diseases such as chronic obstructive pulmonary disease (COPD), emphysema, bronchitis, and pulmonary edema (fluid in the lungs). 2  Strong pain medicines and other drugs that hold back breathing.
Damage from hypoxia is often seen in the hippocampus, the area of the brain that creates memories. Some toxic chemicals can attach onto the body's oxygen and cause brain damage from lack of oxygen, depending on the duration of the exposure and the level of chemical one is exposed to.