ENDOCRINE SYSTEM – ROLES IN HUMAN BEINGS
WHAT IS ENDOCRINE?
Endocrine system consists of glands that secrete hormones. The glands have no ducts and are known as endocrine glands. Other glands are known as exocrine glands because they have ducts. The pancreas has an outer exocrine portion and an inner endocrine portion. Hormones are chemical substances, protein in nature which are secreted at one part of the body and have effects on other parts not necessarily near the point of secretion. They are secreted directly into blood and transported by blood. Each hormone either has a generalized co-coordinating effect on the body or brings about a specific response in a particular target organ.
Hormones produced in humans and the effects on the body.
- Enhance activity of sympathetic nervous system.
- Increased heartbeat
- High blood pressure
- Thin toneless muscles.
- Low blood pressure
- Inability to withstand stress
- Muscular weakness
Over secretion is termed hyperthyroidism this causes:
- Increased Basal Metabolic Rate (BMR) hence increased temperature.
- Person becomes very angry, nervous and hands may shake.
- Increased heart beat which lead to cardiac failure.
Under secretion is termed hypothyroidism:
- Poor growth and mental retardation (cretinism).
- Reduced metabolic rate hence decreased temperature.
- Person becomes inactive and slothful.
- Eyes and face become puffy as fluid gets stored under skin.
- In extreme cases the tongue is swollen and skin becomes rough.
- Enlarged thyroid gland.
Comparison between endocrine and nervous system
- Both endocrine and nervous system are involved in the coordination of body functions.
- Both have target organs.
- Both are controlled via a negative feedback mechanism, i.e too high production results in a reduced production.