Endocrine System Flashcards
(13 cards)
Main features of control systems
Communication, control centre, receptor, effector and feedback
What is paracrine control?
Hormone is released locally and will act locally
What is autocrine control?
Agents are released from cells and have an effect on the cell releasing it
2main communication pathways
Nervous + endocrine
2branches of peripheral nervous system
Afferent and efferent
Name 2 important control centres
Hypothalamus and medulla oblongata
What does negative feedback do?
The output inhibits the function of the control centre and opposes the stimulus. It gives stability to control systems and allows the set point to be controlled within fine limits
What is positive feedback?
Stimulus produces a response which increases it’s effect. System can therefore go out of control
Define the term hormone
Chemical messengers involved in communication that travel via the blood stream
List the classes of chemical substances that can act as hormones
Glycoprotein hormones, polypeptide hormones, amino acid derivatives and steroids
Where do hormones bind to target cells?
Hormones that are able to cross membranes bind to receptors within the cell, those that can’t cross the membrane bind to receptors on the cell surface
What happens when receptors bind to cell surface receptors?
They often activate a second messenger is often released within the cell
Explain the ways hormone secretion may be controlled
Negative feedback
One hormone controlling another
Releasing or inhibiting hormones
Inactivation of hormones
