The function of the endocrine system Flashcards
Glands and hormones
What is the endocrine system?
A network of glands throughout the body that manufacture and secrete hormones (chemical messengers).
What does the endocrine system work with?
The system works closely with the nervous system to regulate the physiological processes in the body.
How does it transmit messages?
The endocrine system transmits messages by using blood vessels to carry hormones to their target sites.
What are glands?
Special groups of cells within the endocrine system whose function is to produce and secrete hormones.
Glands and producing hormones
Each gland produces different hormones which regulate the activity of organs and tissues in the body.
What is the Pituitary gland?
The “master” gland whose primary function is to influence the release of hormones from other glands.
What is the adrenal gland?
Each adrenal gland is made of two distinct parts:
- Cortex (coating/outside) which produces cortisol
- Medulla (middle) which produces adrenaline
What is a hormone?
Hormones are the body’s chemical messengers. They are secreted by the glands. They travel through the bloodstream stream until they reach their target cells. A hormone binds to the target cell. When enough receptor sites in the target cell are stimulated a physiological reaction is created.
How glands work together in a system (cascade), with adrelanine.
- The hypothalamus sends a message (CRH the releasing hormone) to the pituitary gland.
- The pituitary gland sends a message (ACTH the stimulating hormone) to the adrenal gland.
- The adrenal cortex (target gland) secretes cortisol (its hormone).
- Cortisol binds to the target cell and helps the body respond to stress by releasing glycogen (creates a physiological change in the body).
How glands work together in a cascade simplified version.
HYPOTHALAMUS
# (releasing hormone)
PITUITARY GLAND
# (stimulatory hormone)
TARGET GLAND
# (hormone)
TARGET ORGAN
#
PARATHYROID RESPONSE
Why does the endocrine system have a negative feedback loop?
In order to avoid excess hormones in the blood stream the endocrine system has its own negative feedback loop.
When does negative feedback occur?
After the secretion of the different hormones in to the blood stream the hypothalamus detest this change in hormone levels in the blood.
What does the hypothalamus do once it has detected a change in hormone levels?
The hypothalamus “shuts down” the releasing hormone production from the hypothalamus and the stimulating hormone production from the pituitary gland. This slows down the secretion of the target gland hormone, resulting in a stable concentration of hormones in the blood stream.
