B10 Homeostasis Flashcards
What is homeostasis?
Homeostasis is maintaining optimum internal conditions in response to internal or external changes in the environment
What are some of the conditions that Homeostasis controls?
Blood gucose concentration
Temperature
Water content of the body
What are receptor cells?
Receptor cells are cells that detect changes in the internal or external environment. These changes are known as Stimuli. Receptors may be part of the nervous or hormonal system.
Homeostasis involves two systems; list them
Nervous system
Endocrine (hormone) system
What are co-ordination centres?
Co-ordination centres are cells that receive and process the stimuli sent from the receptors. They then co-ordinate a response from the body. The brain acts as a co-ordination centre for the nervous system and parts of the hormonal system, as well as the spinal cord and pancreas.
What are effectors?
Effectors are muscles or glands that bring about a responses to the stimuli that are received. These responses restore the body to optimum conditions
Describe the pathway through the nervous system
Receptors turn information into electrical impulses that are passed along to the co-ordination centres through sensory neurones. The co-ordination centres then organise a response and pass along an electrical impulse through motor neurones to the effector, which carries out the response
What do receptors turn stimuli into?
Electrical impulses that are transmitted through the nervous system
What are reflex actions?
Reflex actions are responses that are rapid and automatic that do not involve the conscious part of the brain. They are mainly protective.
What is the difference between reflex actions and the normal pathway to maintain homeostasis?
Instead of the co-ordination centre receiving the electrical impulse and making a decision, the impulse is sent to a relay neurone in the spinal cord which rapidly makes a sub conscious response and transmits an impulse to the motor neurone.
