Homeostasis and response Flashcards
(28 cards)
What is homeostasis?
The regulation of he internal conditions of a cell or organism to maintain the optimum conditions for function
What is controlled by homeostasis in the human body?
Blood glucose levels, body temperature and water levels
What two forms of responses are included in homeostasis?
Nervous responses (electrical signals) or chemical responses (hormones)
What is included in all control systems?
Receptor cells, coordination centres and effectors
What is the role of a receptor cell?
To detect changes in the enviroment, known as stimuli
What are some examples of coordination centres?
The brain, spinal cord and pancreas
What is the role of the coordination centre?
They recieve and process information from the receptors
What is the role of the effectors?
They bring about responses to restore the optimum levels, often using muscles or glands
What does the nervous system allow humans to do?
React to their surroundings and coordinate their behaviour
What route is taken by information in the nervous system?
Stimulus > receptor > coordinator > effector > response
What is the central nervous system?
The brain and the spinal cord
What does the CNS do?
It coordinated the response of effectors which may be muscles contracting or glands secreting hormones
What does the sensory neurone do?
Sensory neurons receive information via their receptors, which are part of the peripheral nervous system, and convert this information into electrical impulses
What is a synapse?
The junction between two neurones
What does a relay neurone do?
They carry nerve impulses within the central nervous system
What does a motor neurone do?
They carry nerve impulses away from the central nervous system
What are reflex actions?
Automatic and rapid responses to stimuli that do not involve the concious part of the brain
What is the endocrine system composed of?
Glands which secrete chemicals called hormones directly into the bloodstream
Where is the pituitary gland found?
In the brain
What organ manages the blood glucose levels?
The pancreas
What hormone is produced when blood glucose is too high?
Insulin, causing glucose to move from the blood into the cells
What hormone is produced when blood glucose is too low?
Glucagon
What is type 1 diabetes?
A disorder where the pancreas fails to produce insulin; it is treated with insulin injections
What is type 2 diabetes?
A state where the body cells no longer respond to insulin produced by the pancreas; treated by a healthier diet and more exercise
