Homeostatic control systems Flashcards
Control systems are grouped into two classes:
1- Intrinsic controls:
2- Extrinsic controls:
Local controls that are inherent in an organ.
Intrinsic controls:
Extrinsic controls: Regulatory mechanisms initiated outside an organ. Accomplished by …… and
…….. systems.
nervous, endocrine
Refers to responses made after change has been detected.
Feedback
Types of feedback systems:
- Negative
- Positive
Primary type of homeostatic control (most common).
Negative feedback system
It opposes the initial change.
Negative feedback system
Monitors magnitude of a controlled variable.
sensor
Compares sensor s input with a set point.
Control center
Makes a response to produce a desired effect.
Effector
1, 2 , 3 , 4
stimulus, sensor, control, effector
childbirth
positive feedback
………. pushes head to stretch cervix muscle, this will send ……… to the brain (…….. gland) to secrete the …….. hormone which will stimulate the uterine contraction,
this will push the baby more against the ……..more signals to the brain more oxytocin and contactions. This action is repeated until the baby is born.
Uterine contraction, nerve impulses, posterior pituitary, oxytocin, cervix
contractions caused even more contractions
positive feedback
1
brain stimulates pititiuary gland to secrete oxytocin
