Human Endocrine System
, Introduction
● In order to survive, this is accomplished by maintaining a constant internal
equilibrium in the body, known as homeostasis
● Despite the changes in the internal and external environment, the nervous system
and hormones enable animals to respond to external changes and control
conditions inside their bodies
● The endocrine system consists of endocrine glands, that secrete organic
compounds, or chemical messengers, known as hormones
● Di erent endocrine glands do not function in isolation, but interact by means of
hormone secretion
● This contributes to the maintenance of homeostasis that is controlled and
coordinated by the endocrine system
● Endocrine glands, or ductless glands that release the secretion of hormones
directly into the bloodstream
- The blood transports, the hormones to the target organ where they
perform their function
● Exocrine glands release their secretions via docs to the body cavity, or to the
outside of the body
- For example, saliva glands that secrete saliva into the ducts that open
in the mouth cavity
● The type of control and coordination brought about by hormones in the blood is
known as chemical coordination
Hormones
● Organic chemical messengers
● Most or proteins while some are steroids
● They are secreted in small quantities directly into the bloodstream by the endocrine
glands
● They are transported to a target organ by the bloodstream
● A target organ is an organ that is a ected by specific hormone, thus the organ has
receptors for the specific hormone, enabling it to respond to it
● Hormones have a regulatory function that can be stimulating or inhibiting
● Hormones may be regular by negative or positive feedback mechanisms
, Introduction
● In order to survive, this is accomplished by maintaining a constant internal
equilibrium in the body, known as homeostasis
● Despite the changes in the internal and external environment, the nervous system
and hormones enable animals to respond to external changes and control
conditions inside their bodies
● The endocrine system consists of endocrine glands, that secrete organic
compounds, or chemical messengers, known as hormones
● Di erent endocrine glands do not function in isolation, but interact by means of
hormone secretion
● This contributes to the maintenance of homeostasis that is controlled and
coordinated by the endocrine system
● Endocrine glands, or ductless glands that release the secretion of hormones
directly into the bloodstream
- The blood transports, the hormones to the target organ where they
perform their function
● Exocrine glands release their secretions via docs to the body cavity, or to the
outside of the body
- For example, saliva glands that secrete saliva into the ducts that open
in the mouth cavity
● The type of control and coordination brought about by hormones in the blood is
known as chemical coordination
Hormones
● Organic chemical messengers
● Most or proteins while some are steroids
● They are secreted in small quantities directly into the bloodstream by the endocrine
glands
● They are transported to a target organ by the bloodstream
● A target organ is an organ that is a ected by specific hormone, thus the organ has
receptors for the specific hormone, enabling it to respond to it
● Hormones have a regulatory function that can be stimulating or inhibiting
● Hormones may be regular by negative or positive feedback mechanisms
