Biology 102 Chapter 25 - Endocrine & Immune Systems
Homeostasis
Many of the physiological conditions of our bodies need monitoring and regulation.
The nervous system plays a significant role in this process.
The other organ system involved in this is the endocrine system.
Endocrine System
Composed of specialized cells (often forming
glands) found throughout the body.
Endocrine cells are secretory, they produce
and secrete special molecules called
hormones.
Hormones function to relay information from
one part of the body to another.
Hormones circulate with the blood throughout
the entire body, but only affect their specific
target cells.
Hormones
● Target cells have specific receptor Stimulus response
molecules that the hormones bind to. Hormone release is induced by a specific
● Non-target cells do not have them. stimulus.
● Since the target is so specific, hormones are When a hormone reaches its intended target
only needed in small quantities. tissue, there is a response.
1
Homeostasis
Many of the physiological conditions of our bodies need monitoring and regulation.
The nervous system plays a significant role in this process.
The other organ system involved in this is the endocrine system.
Endocrine System
Composed of specialized cells (often forming
glands) found throughout the body.
Endocrine cells are secretory, they produce
and secrete special molecules called
hormones.
Hormones function to relay information from
one part of the body to another.
Hormones circulate with the blood throughout
the entire body, but only affect their specific
target cells.
Hormones
● Target cells have specific receptor Stimulus response
molecules that the hormones bind to. Hormone release is induced by a specific
● Non-target cells do not have them. stimulus.
● Since the target is so specific, hormones are When a hormone reaches its intended target
only needed in small quantities. tissue, there is a response.
1
