Homeostasis Flashcards
Define homeostasis
Homeostasis is the regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes
What does homeostasis maintain optimum conditions for
Homeostasis maintains optimal conditions for enzyme action and all cell functions.
What is homeostasis used to do in the human body/puropse of homeostasis in human body
Used to keep /control of
- blood glucose concentration
- body temperature
- water levels.
Constant
What does homeostasis consist of
Homeostasis consists of automatic control systems making sure them at the internal conditions of the body stay as constant as possible
What can the automatic control systems in the human body involve
The automatic control systems in the human body can involve the nervous responses (nervous system ) or chemical responses (hormones)
what do all control systems include:
general features of automatic control system
All control systems include:
Cells called receptors
Coordination centres
Effectors
(they also have stimulus + response)
What is the purpose of the receptors
receptors detect stimuli (changes in the environment)
Environment could mean the body’s internal conditions e.g. concentration of glucose in the blood or also the body’s external conditions e.g. temperature of the skin
Examples of coordination centres
Brain
Spinal cord
Pancreas
Purpose of coordination centre
Coordination centres receive and process information from receptors (receptor cells)
Examples of effectors
Muscles or glands are example of effectors
What is the purpose of the effectors
Effectors bring about responses which restore optimum levels.
Describe the stages of the automatic control system
Cells called receptors, detect stimuli (changes in the
environment)
The receptor cells now pass information to a co-ordination centre e.g. the brain, the spinal cord or the pancreas
coordination centres (such as the brain, spinal cord and pancreas)
receive and process information from receptors
The coordination centre now sends instructions to the effector
Effectors are muscles or glands, which bring about responses which
restore optimum levels
State the two parts which the nervous system consists of
which make up the nervous system
The nervous system consists of two parts:
Central Nervous System (CNS) - the brain and the spinal cord
Other nerves running to and from the central nervous system
Describe the actions that take place, when a stimulus is detected
Receptors detect a stimulus and send electrical impulses along
sensory neurones to the central nervous system
The central nervous system is the coordination centre - The CNS makes a decision
The CNS coordinates the response of effectors
This now sends information as electrical impulses down motor neurones to effectors and the effectors bring about a response
Effectors are usually a muscle which contracts or a gland which secretes a hormone
Information from receptors passes along cells (neurones) as electrical
impulses to the central nervous system (CNS). The CNS is the brain and
spinal cord. The CNS coordinates the response of effectors which may
be muscles contracting or glands secreting hormones (or sweat).
Role of the nervous system
The nervous system enables humans to react to their surroundings and
to coordinate their behaviour.
