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.
Hypoxia differs from hypoxemia in that hypoxia refers to a state in which oxygen supply is insufficient, whereas hypoxemia refers specifically to states that have low arterial oxygen supply. Hypoxia in which there is complete deprivation of oxygen supply is referred to as anoxia.actic acid build up (in tissues and blood) is a sign of inadequate mitochondrial oxygenation, which may be due to hypoxemia, poor blood flow (e.g., shock) or a combination of both. If severe or prolonged it could lead to cell death. In humans, hypoxia is detected by chemoreceptors in the carotid body.