Class 11 NEET Biology Chemical Coordination and Integration

Adrenal medulla secretes two hormones called adrenaline or epinephrine and noradrenaline or norepinephrine (also called emergency hormones).
Both the hormones -
- Cause pupillary dilation (not constriction)
- Stimulate breakdown of glycogen resulting in increased concentration of glucose in blood i.e., cause hyperglycemia.
- Cause piloerection (raising of hair).
- Increase strength of heart contraction i.e. heartbeat.